Production and Biochemical, Phytochemical, Sensory, and Microbiological Characterization of “Bili-Bili” and “Cochette,” Two Traditional Beers Produced from Sorghum ( Sorghum bicolor ) and Rice ( Oryza sativa )

“Bili-bili” and “cochette” are two traditional beers made from sorghum and rice, respectively. Despite the socioeconomical interest of these drinks, limited studies have been conducted to elucidate their quality and safety. To fll these gaps, the quality features and the safety status of both beers were assessed. After a reasoned feld survey, the samples from various locations in Maroua were collected and analysed using referenced methods. Te feld survey revealed that both beers were produced under unsanitary conditions using rudimentary procedures. Mean values of pH (2.99 and 3.58), TTA (1.1 and 0.9%), alcohol (3.8 and 2.5%), DM (6.4 and 11.1%), TSS (6.94 and 6.18 ° Brix), proteins (0.54 and 0.71g/100 mL), amino acids (0.30 and 0.38g/100mL), and ash (1.52 and 0.51%) were recorded in “bili-bili” and “cochette,” respectively. Similarly, the TPC, TFC, and carotenoid content of 325.5 and 352.4 mgGAE/100mL, 314.4 and 278.9mgQE/100mL, and 95.4 and 89.4mg/100mL were noted in both beers, respectively. “Bili-bili” and “cochette” exhibited free radical scavenging activity of 42.4 and 36.7% and reducing power of 87.3 and 119.5mgTE/ 100 mL, respectively. Overall acceptability ratings ranged from 5.6 to 7.5 and from 6.7 to 6.9 for “bili-bili” and “cochette,” respectively. No pathogen was detected, but the presence of total aerobic bacteria, fungi, coliforms, and aerobic spore-forming bacteria fora above the recommended limits made both beers unsafe and potentially harmful for consumers. Given all above, improving of the production scheme and microbiological quality of the two traditional beers are required to ensure the safety of consumers.


Introduction
Fermentation is one of the oldest and most widely used methods for processing and preserving agricultural products, extending shelf life, improving taste, and increasing both functional and nutritional properties of fermented foods and beverages [1].Fermented foods and beverages are now defned as food products made by controlled microbial development through enzyme conversion of food components.Traditional fermented foods and beverages have a vital role in many communities' cultures and customs, as well as in human nutrition.Tis group accounts for roughly one-third of human food and represents 20%-40% of the world food supply [2].
Beer is the oldest alcoholic fermented beverage and the third most consumed drink in the world, after water and tea [3].Due to the scarcity of barley in many African countries, traditional beers are typically made from sorghum, millet, maize, or rice, with sorghum serving as the predominant cereal [4].Sorghum is a staple food for more than 500 million people living in dry and semiarid areas [5] and provides essential nutrients and nutraceuticals such as phenolics and dietary fbers [6].Sorghum beers are by far the most prized traditional cereal-based beers in Africa.Tey are referred to as "dolo" in Burkina Faso and Mali [7], "tchapalo" in Côte d'Ivoire [8], "tchoukoutou" in Benin [9], and "pito" and "burukutu" in Ghana and Nigeria [10].In northern Cameroon, fermented sorghum beers are known as "bili-bili."In the same region, fermented cereal beer is referred to as "cochette" when sorghum is partly or fully replaced with rice.
"Bili-bili" is the most vended traditional beer in Maroua.Tis opaque alcoholic drink is brewed both by young and adult women using a set of operations orally transmitted by ascendants to transform sorghum grain to beer."Bili-bili" can be sweet, acidic, highly bitter, or bitter depending on the fermenting time.Te latter is the more prevalent version of "bili-bili.""Cochette" is a traditional local beer brewed by combining unmalted cooked-rice four with malted rice or malted sorghum.Tis fermented rice beer is mostly produced in Cameroon by Chadian women."Cochette" is a lowalcohol rice beer since spontaneous fermentation happens without the addition of yeasts, as opposed to other highalcohol yeast-fermented rice beers around the world such as "jou" and "zutho" from India, "sake" from Japan, "laochao" from China, "takju" from Korea, and "khaomak" from Tailand [11].Both traditional beers, like many African beers, have a remarkable socioeconomic character because they are a signifcant source of income for brewers, grain producers, and sellers.In addition, they are widely consumed by underpaid, unemployed, or rural people due to their low cost [12].
Te availability of low-cost foods and drinks produced with local knowledge and resources may aid in increasing dietary diversity, particularly among low-income households.As a result, recording of scientifc information on the quality and safety of locally produced goods is advantageous.Several research studies in Cameroon have been undertaken in this area to describe traditional processing and to characterise the quality attributes of various types of fermented beverages [13][14][15].However, there is no current scientifc record on both traditional beers.Tere is little information regarding their quality features, and no data on the bioactive properties and microbial communities associated with both indigenous cereal beers are available.Terefore, the aim of this study was to document the traditional preparation and to determine the physicochemical profle, proximate composition, bioactive compounds, and antioxidant properties, as well as microbial quality and safety of "bili-bili" and "cochette" collected in various locations throughout Maroua, the headquarter of the far north Cameroon.Te fndings generated in this study can be used to guide consumer buying choices concerning traditional beers.

Presentation of the Study Zone.
Te study was conducted in Maroua, the headquarter of the Far-North region of Cameroon.Te city of Maroua is divided into three districts, with a cumulated population of nearly 300,000 people working mostly in agriculture, cattle, and trade sectors.Commercial and craft center, Maroua is considered among the top ten cities of Cameroon.Te climate is tropical, dry, and hot, with yearly average temperature and rainfall of 28.3 °C and 794 mm, respectively.Te area is mostly populated by the Guizga, Mofu, and Fulani living peacefully among other communities such as Mandara, Massa, Toupouri, Mousgoum, and Kotoko.Te main food crops cultivated in the zone are cereals such as sorghum, millet, maize, and rice, as well as market gardening including onion, tomato, pepper, okro, and leafy vegetables.Te zone was chosen for its cosmopolitan character, high frequency of production, and diversity of traditional cereal-based beers.

Survey on the Production of "Bili-Bili" and "Cochette".
Te survey on the production of both traditional beers was conducted between February and March 2021 in fve locations as shown in Figure 1.Tey included Pont-vert (10 °35′47.579″Nand 14 °20′19.727″E),Domayo (10 °35′26.628″Nand 14 °18′41.712″E),Pitoaré (10 °35′40.080″Nand 14 °15′00.582″E),Palar (10 °36′07.284″Nand 14 °17′23.759″E),and Ouro-tchédé (10 °35′02.549″Nand 14 °16′51.498″E).Te places were chosen because they were the key production zones for both beers.Te survey was oriented using a structured questionnaire that addressed sociocultural aspects of production, raw material used, main production stages, conditions and factors infuencing the production, and adverse efects after consumption of the beverages.Te survey was carried out in two levels.Production sites and cabarets were investigated at the primary level, while individual and groups of respondents were interviewed with producers and consumers at the secondary level.Te exact number of production sites and cabarets present in 2 Journal of Food Quality Maroua was determined after a preliminary survey, while the number of people to be interviewed was estimated based on the total population of the study zone, from which we deducted 65% of Muslims and 42% of those under 16 who do not consume alcoholic drinks.To the remaining population, we applied a 95% confdence level and 5% margin of error to calculate the size of population to be interviewed.At the end of the day, 12 sites of production and 50 cabarets were visited and 22 producers and 120 consumers were interviewed.

Collection of Samples.
Te sampling was carried out between May and June 2021, during the dry season.It was oriented from the main producers and retailers, which were located at various areas of the study zone depending on the type of traditional beer.Each site was sampled on a daily basis, and each sample was tasted before collection to confrm its freshness.So, the samples, with a volume of 350 mL each, were collected fresh on the day of handling, placed into sterile plastic bottles, sealed, labelled, and stored in icebox containers midflled with lump ice.Four batches of 10 "bili-bili" samples each were collected from Palar, Domayo, Ouro-tchédé, and Pont-vert.Furthermore, 16 "cochette" samples were collected from Pitoaré and 2 lots of 12 samples each from Palar 1 and Palar 2. Te Palar area was divided into two subsites because "cochette" beer was produced with either malted rice (Palar 1) or malted sorghum (Palar 2).Finally, 40 "bili-bili" and 40 "cochette" samples were collected and transported aseptically under cold regime to the laboratory for physicochemical, phytochemical, sensory, and microbiological analyses.

Physicochemical Analyses.
Te pH value was directly measured with a calibrated portable pH meter (Eco Testr, Singapore) [16].Te total titratable acidity and volatile acidity were determined by using the titrating method as previously described by Kitessa et al. [17] and Basumatary et al. [18], respectively.Twenty-fve millilitres of the beer sample were pipetted and poured into a beaker, 3 drops of 5% phenolphthalein were added, and the sample was titrated with 0.1 N sodium hydroxide solution (NaOH) until the persistence of pink color.Te total titratable acidity value expressed in % of lactic acid and the volatile acidity reported as % of acetic acid were calculated using the following equations: , (1) ( Te electrical conductivity (EC), total dissolved solids (TDSs), and temperature were recorded immediately after sampling by using a digital multifunctional portable conductivity meter (e-1 TDS and EC, Shenzen, China).Te mean values of triplicate measurements were expressed in µS/cm, ppm, and °C, respectively.Te total soluble solids (TSSs) were measured with a portable ATC refractometer (RHB 90, Shenzhen, China) that was regularly calibrated with distilled water.Te recorded values were expressed in °Brix.Te specifc gravity was determined using the AOAC [19] method by dividing the ratio weight/volume of the beer sample by the same ratio for distilled water according to the following formula: Specific gravity(SG) � (Weight of sample/Volume of sample) (Weight of water/Volume of water) . ( Te alcohol content of the beer samples was estimated with the calculation method using the following formula that incorporates both TSS and SG measurements as previously reported by Bayoï and Etoa [20]: Te dry matter content was determined by drying the samples in a forced-air oven (Memmert, Germany) at 105 °C to a constant weight [12].Te dry matter value, expressed in percent mass by mass (%, m/m), was calculated using the following formula: Weight no dried sample+beaker (g) − Weight empty beaker (g) 2.6.Proximate Analysis of Traditional Beers.Te soluble protein content of "bili-bili" and "cochette" was determined using the Bradford colorimetric method based on the principle of protein-dye binding [21].Te free amino acid content was quantifed by ninhydrin reaction with alanine as reference [22].Te soluble protein content was expressed in g of BSA equivalent per 100 mL (g BSAE/100 mL) using the BSA standard curve (R 2 � 0.9809).Te free amino acid content was expressed in g of alanine equivalent per 100 mL of beer (g AE/100 mL) from the alanine calibration curve (R 2 � 0.9951).Total sugars of the samples were determined using the phenol-sulfuric method as described by Nielsen [23], while reducing sugars were quantifed using the 3,5-dinitrosalicylic acid (DNSA) method as reported by Jain et al. [24] with slight modifcations.Te glucose standard curve (R 2 � 0.9806) was used to determine the total sugar content expressed in g of glucose equivalent per 100 mL of beer (g GlcE/100 mL), while the galactose calibration curve (R 2 � 0.9972) was considered to quantify the reducing sugar content expressed in g of galactose equivalent per 100 mL of beer (g GalE/100 mL).
Te ash content was evaluated using Pigozzi et al.'s [25] method with minor modifcations by incinerating the samples in a mufe furnace (Nabertherm, Germany) at 550 °C to reach the constant weight.Te ash value was calculated in percentage mass by mass (%, m/m).

α-Carotene, β-Carotene, Lycopene, and Lutein
Contents.Te content of each carotenoid was determined as described by Sumanta et al. [26] with slight modifcations.Each beer sample (0.1 mL) was placed in a glass tube and 2.5 mL of hexane containing 1% of ascorbic acid (5%) was added.After vortexing, 1.5 mL of acetone was added and the mixture was still homogenized for 15 minutes.Subsequently, 2.5 mL of methanol was added and the reacting tube was incubated in darkness at room temperature for 3 h.Ten, the organic phase was collected and the aqueous phase was extracted once again with 2.5 mL of hexane.At the end of the day, both organic phases were combined and fltered through Whatman flter paper no. 4, and the absorbances were read at 445, 446, 450, and 472 nm with a UV-Vis spectrophotometer (Jenway 7305, Bibby Scientifc, Staffordshire, UK).α-carotene, β-carotene, lutein, and lycopene contents were calculated according to the following formula: α−carotene, β−carotene, lutein, and lycopene mg 100mL where OD is the optical density; V is the total volume of the extract (mL); d is the dilution factor; Ws is the weight of the sample (mg); and E 1% is the absorption coefcient of α-carotene (2725 cm −1 ), β-carotene (2592 cm −1 ), lutein (2550 cm −1 ), and lycopene (3450 cm −1 ).

Total Phenolic Content (TPC).
Te total phenolic content of the samples was determined using the Folin-Ciocalteu method as previously described by Fu et al. [27] with minor modifcations.Te diluted sample (0.2 mL) was added to 1 mL of Folin-Ciocalteu reagent and 1 mL of 20% sodium carbonate.Te mixtures were incubated at room temperature in darkness for 30 min before being measured for absorbance against blank at 765 nm using a UV-Vis spectrophotometer.A calibration curve (y � 0.0031x + 0.0013, R 2 � 0.9883) was established using gallic acid at various concentrations (0-250 µg/mL), and the TPC was expressed as mg of gallic acid equivalent per 100 mL of beer (mg GAE/100 mL).

Total Flavonoid Content (TFC).
Te total favonoid content (TFC) of the samples was determined using the aluminium chloride method as described by Lakenbrink et al. [28] with slight modifcations.Precisely, 1 mL of the sample was mixed with 0.2 mL of distilled water and 0.5 mL of 10% aluminium chloride.After 1 min, 2 drops of 1% acetic acid were added to the mixture and the absorbance against blank was determined at 430 nm with a UV-Vis spectrophotometer.Quercetin solutions at 0 to 250 µg/mL were used to establish the standard curve (y � 0.0022x -0.0117 and R 2 � 0.9964), and the results were expressed as mg of quercetin equivalent per 100 mL of beer (mg QE/100 mL).

Total Condensed Tannin Content (TTC).
Te content of condensed tannin (TTC) of the samples was measured using the vanillin method as described by Shewakena et al. [29].Each sample (0.5 mL) was added to 1.5 mL of acidifed vanillin solution (1 g of vanillin in 100 mL of concentrated HCl).After 2 min of homogenising, the mixture was kept in the dark at room temperature for 5 min to develop the redcolored complex.Te absorbance against blank was measured at 500 nm with a UV-Vis spectrophotometer.Te TTC was reported as mg of catechin equivalent per 100 mL of beer (mg CE/100 mL) from a catechin standard curve (y � 0.0027x and R 2 � 0.9871).
2.8.Antioxidant Properties of "Bili-Bili" and "Cochette" Te radical scavenging activity of "bili-bili" and "cochette" samples was determined using the DPPH assay according to the modifed protocol described by Floegel et al. [30].Each sample 10-fold diluted (0.5 mL) was added to 1.5 mL of the DPPH reagent in absolute ethanol in the ratio 1 : 10, and the mixture was left in the dark at room temperature for 15 min.Te absorbance was read at 517 nm, and the DPPH scavenging activity expressed in percentage of inhibition was calculated using the following formula: DPPH scavenging activity (%) � 1 − Abs of sample Abs of DPPH     × 100.
Abs of the sample is the absorbance of the beer sample mixed with the DPPH solution, and Abs of the DPPH is the absorbance of DPPH solution at 517 nm.
Te absorbance values were also used to determine the total antioxidant capacity expressed as mg of Trolox equivalent per 100 mL of beer (mg TE/100 mL) using a calibration curve (y � 0.0043x + 0.0259 and R 2 � 0.9617) of Trolox at various concentrations (0-120 µg/mL).

Ferric Reducing Antioxidant Power (FRAP) Assay.
Te ferric reducing antioxidant power was evaluated according to the method described by Taipong et al. [31] with minor modifcations.Prior to the analysis, the samples were 20-fold diluted and 0.5 mL of each sample was mixed with 1.5 mL of the FRAP reagent containing TPTZ (10 mM), acetate bufer (300 mM, pH 3.6), and FeCl 3 , 6 H 2 O (20 mM) in the ratio 10 : 1 : 1.After 5 min of incubation at room temperature in the dark, the absorbance against the blank was measured at 593 nm with a UV-Vis spectrophotometer.Te results were expressed as mg of Trolox equivalent per 100 mL (mg TE/100 mL) using a standard curve (y � 0.0075x -0.0139 and R 2 � 0.9979) of Trolox at the concentrations ranging from 0 to 120 μg/mL.

Phenolic Antioxidant Coefcient and the Relative
Antioxidant Capacity Index.Both parameters were used to achieve more comprehensive comparison of the antioxidant activity among the various samples analysed.
(1) Phenolic Antioxidant Coefcient (PAC).Te phenolic antioxidant coefcient (PAC) of each beer sample was determined using the results of DPPH, FRAP, and TPC assays as previously described by Petrović et al. [32].Te PAC was calculated as the ratio between the particular antioxidant activity (AOA) and TPC according to the following formulas: (2) Relative Antioxidant Capacity Index (RACI).Te relative antioxidant capacity index (RACI) is a comprehensive method for ranking the antioxidant activity of diferent food samples.Te RACI was determined by giving equal weight to both antioxidant assays, including the TPC considered as the reducing assay as described by Sun and Tanumihardjo [33].Tis unitless index was calculated in two steps.To begin, the antioxidant activity values in each dataset are transformed into dimensionless values known as standard scores calculated using the following formula: where x is the raw data, µ is the mean value, and σ is the standard deviation.Ten, the RACI was calculated by averaging the standard scores of a given sample.

Microbiological Analyses and Determination of the Safety
Status of "Bili-Bili" and "Cochette".Te microbial counts of "bili-bili" and "cochette" samples were performed in accordance with the microbiological guidelines.According to the standard ISO 6887-1: 2017 [34], the samples were serially diluted with sterile saline water (0.85% NaCl).Fifty millilitres of each sample were added separately to 450 mL of thiogluconate broth, and the suspensions were mixed for 10 minutes before incubating at 30 °C for 16 hours.Following the revivifcation, serial 10-fold dilutions from 10 −1 to 10 −8 were aseptically done using 1 mL of the preincubated sample and 9 ml of sterile saline water (0.85% NaCl).Ten, 0.1 mL of the appropriate dilution was spread plated in triplicate on the specifc sterile agar culture media and the inverted inoculated plates were incubated under the conditions specifed in Table 1.
Te safety status of traditional beer samples was assessed using the microbial scores endorsed on the microbial counts recorded during the microbiological analysis as previously described by Cuq [44] and Bayoï and Etoa [45].Using a microbiological quality scale, the microbial counts were compared to referenced intermediate values (3 m, 10 m, and 1000 m), all endorsed on the standard count (m).Ten, a microbial score ranging from 0 to 46 was assigned to each microbial count.Te safety score was computed by summing up all the microbial scores recorded from the various microbial counts that resulted from the examination of samples gathered in the same location.Based on the safety score, the beer was rated as excellent when it had a score of 0 and as unsafe when it had a score of 45 or above.

Sensory Analysis.
Te sensory evaluation of traditional beer samples from several Maroua locations was carried out using an acceptance hedonic test, as previously described by Bayoï et al. [46].An experienced panel of ten male judges (aged 18-27 years) was recruited.Before being informed about the purpose of the study and the experimental protocols, each panellist was requested to sign a consent form.Te testing started at 08 am, with suitable lighting (25 w lamps), humidity (60-65%), and room temperature (25-30 °).A sufcient distance was maintained to preclude communication between the panellists.Each fasting panellist received 30 mL of traditional beer in a cup labelled with random three-digit code, as well as another cup containing mineral water (30 mL) used to rinse their mouth before moving to the next sample.Te panellist rated the dislike or like degree of each sample by scoring six sensory attributes (bitterness, alcoholic taste, texture/viscosity, odor, color, and overall acceptability) using a 9-point hedonic scale (1 � dislike extremely and 9 � like extremely).

Statistical Analysis.
All measurements were carried out in triplicate and the results were presented as the mean-± standard deviation.Primary data collected using a structured questionnaire were analysed by descriptive statistics.To determine the diference between the various beer samples, the one-way analysis of variance (ANOVA) plus post hoc Tukey honest signifcant diference (HSD) were used and the diferences were considered signifcant at p < 0.05.Te correlations between the measured parameters of the beer samples were determined using the Pearson correlation coefcient (r), and the recorded coefcients were used to design heat map correlation matrices using the ChiPlot online database available at https://www.chiplot.online (accessed on 16 October 2023).Principal component analysis (PCA) was used to determine the relationship between the measured variables and the beer samples from various places.

Results and Discussion
3.1.Sociodemographic Characteristics of "Bili-Bili" and "Cochette" Producers.Table 2 summarises the results of surveys on "bili-bili" and "cochette" producers and some key information about the traditional processing of both beers.Te fndings revealed that all the producers of both traditional beers are female (100%).Tis was not surprising given that cooking is traditionally a woman matter in Africa.Tis observation was previously reported by Madilo et al. [47], Adinsi et al. [48], and Sacca et al. [49] that worked on the traditional production of "aliha" (a Ghanaian fermented maize-based beverage), "gowe" (an indigenous fermented cereal-based drink from Benin), and "akpan" (a West Africa traditional yoghurt-like cereal product), respectively.Most "Bili-bili" and "cochette" producers come from Cameroon (69.2%) and Chad (100%), respectively.Te principal Cameroonian tribes involved in "bili-bili" production are identifed as Tupuri (leading tribe), Giziga, Moundang, and Mofu, while Ngambaye and Sara are the leading Chadian ethnic groups concerned with "cochette" production.Tis indigenous beer is mainly produced by Chadian because it was imported from Chad, bordering to Cameroon in the northern side.Indeed, both countries share 1,116 km of border, with the famous Lake Chad as the natural boundary.

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Journal of Food Quality Small and dark [43] Journal of Food Quality whereas all "cochette" producers had less than 3 years of expertise (100%).Tis suggests that the production of traditional beers in Maroua is a highly sustainable venture because all the processors were under 40 years old (young) and have less than 10 years of experience [47,49].According to the survey results, both indigenous beers represent a source of income for the producers.Te majority of "bilibili" (69.2%) and "cochette" (83.3%) producers said this activity provided 50% of their income.

Characterization of the Traditional Processing of "Bili-Bili"
and "Cochette".Figure 2 depicts a consensus fowchart (A and B) and pictorial (C and D) of the traditional production of "bili-bili" and "cochette."As shown in Table 2, sorghum and rice were identifed by producers as the primary cereals required for the processing of "bili-bili" and "cochette," respectively.When the "bili-bili" is processed with a single cereal, the producers primarily used either yellow sorghum (45%), red sorghum (30%), or white sorghum (20%).Maize (5%), considered as minor cereal, is not appreciated as the base ingredient by "bili-bili" producers because they reported that customers complain about headaches after the ingestion of maize-based beers."Bili-bili" producers prefer to use the mixture of yellow (80%) and red (20%) sorghum because both varieties are available on the market all over the year (Table 2) and yields a beer appealed by the custumers.Te use of sorghum mixture contradicts the fndings of a survey conducted by Charles et al. [51] on the "bili-bili" processing.According to these authors, most "bili-bili" brewers in northern Cameroon employed red "djigari" sorghum as the base cereal.Tis could be explained by diferences in the number of producers surveyed and the study zone.Te survey of the current work was conducted in a limited sample of producers in Maroua, while the previous work was carried out in a large sample of producers from Maroua, Garoua, and Ngaoundéré, the main cities of the northern part of Cameroon.
All "bili-bili" producers soak the grains for 6-7 h at room temperature, before allowing them to germinate for 1-3 days.Te grains are watered twice a day, morning and night.According to the producers, the germination time varies between cereals.Red sorghum requires 2 days to germinate, yellow and red sorghum 3 days, and red sorghum and maize 3-4 days.In general, the germination time should be long enough to allow a large proportion of grains to germinate [52].Te germination time required during the processing of "bili-bili" was alike to that requisite for the production of "dolo" (sorghum-based beer from Benin), "tchakpalo" (cereal-based beer from Benin and Togo), "tchapalo" (sorghum-based beer from Côte d'Ivoire), "red kapsiki" (red sorghum-based beer from far north Cameroon), "pito" (Ghanaian and Nigerian cereal-based beer), and "dora-bonga" (sorghum-based beer from Central Africa Republic) [1].Te sprouted grains (as depicted in Figure 2(c)  d) are sun-dried for 2-3 hours before 12 hours of maturation.Te germinated kernels are sun-dried for periods ranging from 7 to 48 hours, depending on the climatic conditions such as sunshine intensity and wind speed.Sun drying (as illustrated in Figure 2(c) e) terminates the traditional malting stage and reduces the amylase activity in sprouted kernels [53].As shown in Table 2, the malting process was identifed as a critical stage in the production of "bili-bili" by the producers interviewed.Taylor and Dewar [54] stated that when the malting stage is not properly controlled, the malt is very poor and the beer quality sufers.Te germinated and dried grains are milled into malted four and mixed with water (6 L/kg of sorghum) before being allowed to settle for 3-4 hours.Te supernatant is recovered after decantation, and the foury bottom is precooked for 3-4 hours until the red color appears.Te previous supernatant is added to the precooked deposit, and the wort is allowed to cool at room temperature for 11 hours.Te wort was cooked either for further 5-6 hours or until the foam has completely disappeared (Figure 2(c) g).In addition to malting, cooking was identifed as another critical stage during "bili-bili" processing by many producers.Tis is consistent with the previous results reported by Bayoï and Etoa [55] who pointed out malting, cooking, and fermentation as the major critical stages during the production of "té" and "mpedli," two traditional sorghum beers from northern Cameroon.As shown in  10 Journal of Food Quality production.After cooking, the obtained sweet wort is decanted, allowed to cool for 5-6 h, and fltered before fermentation.Te starter culture also called "chai" is added to the cooled wort and fermented for 9-10 h to produce the fnal product known as bitter "bili-bili" (Figure 2(c) i).Tis bitter variant is the most appealed and regarded as the standard "bili-bili."Te unique diference between acidic and bitter "bili-bili" processing is the cooling stage, which lasts 13 hours instead of 11 hours.Te customers dislike the acidic variant because it is low alcohol and leads to diarrhoea.Te production of sweet and too bitter "bili-bili" difers from bitter "bili-bili" processing at the fermentation stage which was identifed by producers as another critical production stage (Table 2).Te sweet "bili-bili" is made without the use of "chai" during the fermentation stage.Tis sweet variant which smells diferently causes dysentery and stomach ache when it is consumed.Te very bitter "bili-bili" is produced by adding wild "chai" starter during fermentation which lasts 12-14 hours instead of 9-10 hours as during the fermentation of bitter "bili-bili."Te consumers dislike the too bitter variant due to headaches caused after its ingestion.Te majority of the producers (92.3%) stated that they spend 6-7 days for one run of "bili-bili" production (Table 2).Considering the main production stages, the traditional processing of "bili-bili" is comparable to that of most aforementioned indigenous sorghum-based beers [13,[56][57][58].
Te traditional production of "cochette" is depicted in Figures 2(b) and 2(d).Te base cereal used in the production of "cochette" is rice (Table 2).When it is unavailable, white sorghum is used as a substitute (Table 2 Journal of Food Quality the producers polled, most rice grains (5/6) used to make "cochette" is soaked, dried, and milled.Te four is mixed with boiled water (in a ratio of 3 kg for 5 L) and cooked until the couscous (known as "mourou cochette" in Ngambaye) is obtained (pictorial of Figure 2(d) B-D).After 8 hours of cooling, "mourou cochette" is added to the remaining onesixth of rice grains malted and milled into four and the mixture is hand kneaded until full homogenization.If malted rice four is unavailable, malted sorghum four can be used.Te starter culture known as "chai" is added (sometimes replaced by bitter bili-bili), and the mixture is fermented for 8-9 hours before fltration.Te fltrate (called "gouille" in Sara, a Chadian ethnic group) is mixed with about 2 litres of water to produce "cochette."According to Table 2, the majority of the brewers (93.3%) said the production of "cochette" takes 5 days.Te production of "cochette" is very similar to that of "zutho," an Indian rice beer [59].However, the fermentation time diferentiates both traditional beers; "zutho" ferments for 2-7 days, whereas "cochette" fermentation takes 8-9 hours.Furthermore, "haria," another rice beer from India, difers from "cochette" in that all rice grains are used unmalted and the mixture is fermented for 3-4 days after the addition of "bakhar" starter culture to the cooked and dried rice [60].

). According to what
Even though the traditional processing of "cochette" and "mpedli" (a sorghum-based beverage from north Cameroon) is similar, they difer in terms of raw material, starter culture, and fermentation time.In contrast to "cochette," the production of "mpedli" beer utilizes sorghum as the base cereal and its fermentation lasts 2 days without the addition of a starter culture [16].
3.3.Quality Attributes of "Bili-Bili" and "Cochette".Te physicochemical profle, proximate composition, and bioactive and antioxidant properties of "bili-bili" and "cochette" marketed in various locations in Maroua are presented in Tables 3 and 4, respectively.Te pH values of both traditional beers vary from one locality to another.However, the variations of pH were not statistically diferent (p � 0.794) in "bili-bili" samples but were highly signifcant (p ≤ 0.001) in "cochette" samples.Te lack of major fuctuations in pH values of "bili-bili" could be attributed to the maturity and mastery of good practices of "bili-bili" producers, who appeared to be more experienced than "cochette" producers.
Te mean temperature values of "bili-bili" samples varied between 37.3 ± 0.2 °C (Palar) and 40.1 ± 0.5 °C (Ourotchédé).About "cochette," the lowest average temperature (38.0 ± 0.6 °C) was noted for the samples collected from Palar 2 and the highest mean value (39.1 ± 1.2 °C) was recorded for the Pitoaré samples.Tere were signifcant diferences (p � 0.044) in temperatures between the diferent "bili-bili" samples, but no signifcant variation (p � 0.39) was found across the various samples of "cochette."Temperature afects the growth rate of microorganisms.Temperatures lower than ambient (25-30 °C) are benefcial for the microbiological quality of food products.Terefore, high temperatures measured in this study could contribute to an increase in bacterial communities in both traditional beers.
Te variation in the alcohol content between the two indigenous beers could be attributed to the manufacturing technique.All cereal grains are malted during the "bili-bili" procedure (Table 2), and two cooking stages are observed at   2), resulting in an increase in sugars available for alcohol conversion during fermentation.In contrast, just a small portion of the cereal used in "cochette" production is malted, and there is a single cooking stage.Both opaque beers had a lower alcohol content than "dora-bonga" (3.94-4.66%),"tchapalo" (5.08-5.22%),"haria" (3.4-11%), and "jou" (5.30-22.05%)[18,57,60,62].Terefore, due to its low alcohol content compared to "bili-bili" and the previously studied African beers, "cochette" can be consumed in adequate quantities as a refreshing drink to compensate the body water loss during the hot summer season in northern Cameroon.
Te mean EC and TDS values of "bili-bili" (1880-2179 µS/cm and 939.0-1091.3ppm, respectively) were greater (p ≤ 0.001) than those of "cochette" (915-1697 µS/cm and 457-848 ppm, respectively).Te diference in EC and TDS between "bili-bili" and "cochette" could be attributed to the mineral salts, organic acids, and proteins content of the raw materials used in the production.Te EC is a parameter used to determine the ionisation degree of a sample by measuring the concentration of mineral ions and ionizable compounds.Given that the EC values of both traditional beers are higher than 1000 µS/cm, they can be considered highly mineralized.
Changes in the dry matter were statistically signifcant in "bili-bili" (p � 0.026) and not signifcant in "cochette" (p � 0.348) among the various sampling sites.Te highest mean dry matter (DM) for "bili-bili" and "cochette" was recorded in the samples collected from Ouro-tchédé (9.51 ± 1.15%) and Palar 1 (12.03 ± 1.26%), respectively, while the lowest means were recorded in samples from Pont-vert (3.41 ± 1.23%) and Pitoaré (10.12 ± 0.19%), respectively.Te dry matter of both cereal-based beers measured in this investigation was within the 5-13% range as previously reported for various African beers [63].However, the DM contents of "bili-bili" and "cochette" were lower than the values of 15.4-20.2%found in "tchoukoutou/chakpalo" [64].Tese variations might be associated with the volume of water added, the cereal used, and time required to ferment the wort.
Total soluble protein and amino acid changed signifcantly (p ≤ 0.001) in "bili-bili" and "cochette" samples.Te average soluble protein and amino acid levels (g/100 mL) of the "bili-bili" samples varied between 0.489 and 0.615 and 0.170 and 0.420, respectively.Both parameters for "cochette" samples ranged from 0.681 to 0.752 and from 0.252 to 0.491, respectively.Te protein levels recorded in this study were higher than 0.14-0.39g/100 mL reported in "pito" [61] and 1.1-6.5 mg/100 mL reported in "dolo" [65], but lower than those reported in Central African Republic for "bili-bili" (2.79-2.90%)and "dora-bonga" (3.80-3.82%)[57].Because of their relatively high protein content, "bili-bili" and "cochette" could be viewed as additional meals used to supplement the protein-demand gap for the consumers and families who cannot aford more expensive animal-based proteins.Te amino acid levels of both beers were similar to 0.283-0.381g/100 mL as previously reported for "kounou," a fermented cereal beverage [15].Terefore, "bili-bili" and "cochette" intake may also be a rich source of essential amino acids important for the human diet.
Changes in total carbohydrates were signifcant (p ≤ 0.001) in "bili-bili" and "cochette."However, changes in reducing sugars were only signifcant (p � 0.001) in "bili-bili" samples.Te highest total sugar and reducing sugar levels were found in the "bili-bili" samples from Palar (0.614 g/ 100 mL) and Pont-vert (0.328 g/100 mL), respectively, as well as the "cochette" samples from Palar 1 (0.554 and 0.253 g/100 mL, respectively).Tese results were higher than those obtained in "dolo" (1.1-8.4 mg/100 mL and 4.21-19.94μg/mL, respectively).On the contrary, total sugar contents were lower than those recorded in "dora-bonga" (0.65-0.67%), "pito" (0.86-2.35 g/100 mL), "red kapsiki" beer (41.8-72.9g/L), and "tchapalo" (8.84 g/100 mL).Tese variations could be explained by the sugar content of the wort and its fermentation degree.It is well-known that the more the beer ferments, the less the sugar remains.Sugars are a good source of energy for the body; so, drinking both the cereal-based beers ("bili-bili" and "cochette") will assist customers to achieve their energy needs.Tis is why "bili-bili" and "cochette" are widely referred to as "manger-boire" drinks as many African fermented beverages because they are regarded both as a meal to satisfy hunger and a drink to relieve thirst.
In the current investigation, signifcant diferences (p ≤ 0.001) in phenolic, favonoids, and tannin contents were found in "bili-bili" and "cochette" samples collected from diferent locations.Te mean total phenolic content (mgGAE/100 mL) of "bili-bili" ranged from 230.7 ± 3.1 (Domayo samples) to 410.7 ± 1.3 (Palar samples).Te TPC of "bili-bili" in the current study is more than 38.48-71.062mg GAE/100 mL found by Charles et al. [51] for "bili-bili" and the 84.3-115 mg/100 mL reported by Ronald and Roger [13] for red kapsiki beer, both processed in far north Cameroon.Te highest mean TPC of "cochette" was found in Palar 2 samples (462.3 ± 3.1), while the lowest was found in Palar 1 (252.3± 2.7 mg GAE/100 mL).Te average TPC of "cochette" was higher than the 12.8-63.13mg GAE/100 mL reported by Handique et al. [69] for traditional Indian rice beers.Tese diferences in the TPC could be due to variances in processing procedures as well as the protein and sugar levels of the beverage.Te TPC is determined using the Folin-Ciocalteu reagent known to react with the phenolic groups and with sugars, proteins, and organic acids which may interfere with the fnal result.Given that the TPC of both traditional beers exceeds 100 mg GAE/ 100 mL [70], they may be considered as an important source of phenolic compounds, which are known as human healthpromoting molecules.
Te lowest and highest condensed tannin levels (mg CE/ 100 mL) of "bili-bili" were recorded in samples from Pontvert (245 ± 4.55) and Palar (273.3 ± 2.6), respectively."Cochette" recorded average condensed tannin contents ranging from 100.0 ± 1.5 to 266.2 ± 3.1 mg CE/100 for the samples from Palar 2 and Pitoaré, respectively.Tannins, bitter and astringent compounds, are antinutrients that can reduce protein digestibility and mineral absorption and impede digestive enzymes.It has been observed that tannin contents ranging from 108.3 to 120 mg/kg are high enough to pose a health risk [71].Given that the tannin levels recorded in the current study are signifcantly higher than the stated values, additional eforts to minimise tannins in both traditional beers are required to prevent the related health concerns.Terefore, the moderate intake of both opaque beers may contribute to promote human health due to the presence of carotenoids, polyphenols, favonoids, and tannins, known as antioxidant molecules.
Te phenolic antioxidant capacity (PAC) enables the comparison of the efectiveness of phenolic compounds present in the tested samples and provides specifc insight into the applied assay.Globally, the PAC of the various local beer samples was lower than 1.Tis suggests that phenolic compounds played a minor role in the scavenging activity and reducing power of both traditional beverages.Te highest PAC values were recorded in "bili-bili" collected from Ouro-tchédé (PAC DPPH � 0.17 ± 0.00) and "cochette" from Palar 1 (PAC FRAP � 0.55 ± 0.01).
Given the limitations of each approach for measuring the antioxidant activity, the relative antioxidant capacity index (RACI) method provides an alternate method which integrates several antioxidant chemical analyses.In this study, Journal of Food Quality from DPPH, FRAP, and TPC assays were used to generate the RACI value, which is a unitless scientifc value used to rank the antioxidant activity of foods.Tere was no signifcant change (p � 0.814) in the RACI values between the various "bili-bili" samples.Palar samples had the highest mean RACI value (0.96) followed by Pont-vert (0.04), Ourotchédé (−0.03), and Domayo (−0.97).Te RACI values of "cochette" samples varied nonsignifcantly (p � 0.61) between −0.48 ± 0.81 and 0.90 ± 0.34.Palar 2 samples had the highest RACI value (0.90) followed by those from Pitoaré and Palar 1 which had RACI values of −0.42 and −0.48, respectively.Given the scarcity of research using the RACI to evaluate the antioxidant activity of food products, the current work is one of the rare studies using the RACI to compare the food antioxidant activity, so the values recorded in this study cannot be compared to those in the literature.However, the RACI values of "bili-bili" were found to be higher than those of "cochette."So, the antioxidant activity of "bili-bili" appears to be greater than that of "cochette."Based on this, "bili-bili" consumption may be more appropriate for mitigating oxidative stress-related disorders.

Microbiological Quality of "Bili-Bili" and "Cochette".
Te mean counts of microbial groups enumerated in "bilibili" and "cochette" samples from various localities in Maroua city are presented in Table 5.Total aerobic mesophilic bacteria (TAMB), total coliforms (TCs), fecal coliforms (FCs), total aerobic and mesophilic spore-forming bacteria (TAMSFB), and sulphite-reducing Clostridia (SRC) were counted in all the samples of both traditional beers, except the "bili-bili" samples from Palar and Domayo in which no fecal coliform was detected.Te enumeration of all the microbial groups detected in "bili-bili" varied signifcantly (p < 0.05) among the samples from the various locations.In contrast, most microbial groups enumerated in the "cochette" samples varied nonsignifcantly (p > 0.05) from one sampling site to another.However, sole FC and SRC groups changed signifcantly (p < 0.01) in the "cochette" samples.All enumerated microbial groups were found above the limits applied to each group.Te minimum and maximum TAMB counts in "bili-bili" were recorded in the samples from Palar (1.5 × 10 11 cfu/mL) and Domayo (2 × 10 11 cfu/mL), respectively.TAMB counts of "cochette" ranged from (1.10 ± 0.42)10 10 to (1.50 ± 0.70)10 10 cfu/mL in samples collected from Palar 2 and Palar 1, respectively.TAMB counts of both traditional beers were higher than 3.18-4.58log and 5.98 ± 0.44 log reported, respectively, in "shameta" and "borde," two Ethiopian maize-based fermented beverages [17,72].Known as the quality indicator, the high count in TAMB may be related to the poor hygiene of the production site and sale point, as well as the utensils used during the processing and serving.Furthermore, this could be linked to the temperature of beer samples ranged from 30 to 40 °C required for the optimal growth of bacteria and other mesophilic microorganisms.
Te lowest TC and TF counts (cfu/mL) were found in "bili-bili" samples from Ouro-tchédé (1.1 × 10 6 ) and Pontvert (2 × 10 8 ), respectively.Meanwhile, the highest counts were recorded in the samples from Domayo (9.75 × 10 6 and 1.50 × 10 10 , respectively).Te highest FC counts were found in "bili-bili" samples from Ouro-tchédé (6.5 × 10 2 ) and Pontvert (1.5 × 10 3 ).Te maximum values (cfu/mL) of the three microbial groups were recorded in the samples of "cochette" from Palar 2 (1.8 × 10 7 , 7.5 × 10 7 , and 8.4 × 10 3 , respectively).TC, FC, and TF counts found in the current study were in a higher range than those reported with "kounou" [15].Te presence of coliforms in beers may be due to unsanitary practices during handling, transport, and sale.Fecal coliforms in both the fermented beverages could be explained by a postfermentation exogenous fecal contamination from environment, utensils, water, and handling, whereas the presence of fungi may be related to the very acidic pH (less than 4) and high-water content of both cereal-fermented beverages.Te presence of fungi in both beers is a call for concern given that they are cereal-based beverages.Indeed, cereals are frequently contaminated by a variety of fungi (Aspergillus, Fusarium, Penicillium, etc.) known to produce mycotoxins causing numerous foodborne diseases in consumers [73].Mycotoxins such as afatoxins, fumonisins, ochratoxin A, deoxynivalenol, and zearalenone are the majorly identifed in locally fermented cereal-based beverages.It has been reported that drinking of traditional beer increased exposure to some of the aforementioned mycotoxins by at least 6-fold above the recommended levels [74].
TAMSFB and SRC counts (cfu/mL) in "bili-bili" samples were lowest in Domayo (1.6 × 10 6 and 1.4 × 10 2 , respectively) and highest in Pont-vert (3.1 × 10 6 and 4.7 × 10 2 , respectively).Te "cochette" samples from Palar 1 and Pitoaré had the lowest counts of both microbial groups (1.1 × 10 6 and 2.2 × 10 2 , respectively), whereas the samples from Palar 2 had the greatest counts (2.2 × 10 7 and 8.5 × 10 2 , respectively).TAMSFB and SRC counts of both beers were greater in the current study than those reported in "shameta" [17] and "kounou" [75], respectively.Te presence of aerobic and mesophilic spore-forming bacteria in both beers could be used as an indicator of Bacillus spp., which is one of the troublesome food contaminants due to their ability to produce toxins and endospores [76].Te source of this microbial fora could be the raw materials and utensils employed during the production.Furthermore, aerobic spore-forming bacteria are amylolytic bacteria which can produce amylases and proteases that stimulate the growth of other microbial groups and product deterioration [17].Because sulphite-reducing bacteria (SRC) are an indication of soil contamination, their presence in both the traditional beers may suggest the use of either raw materials or utensils contaminated, either the contact of the product or one of its intermediates with the soil.Furthermore, the presence of SRC presumes that of Clostridium perfringens, frequently implicated in food poisoning cases.
No fecal Streptococci, Salmonella/Shigella, or Staphylococci spp. was found in any of the "bili-bili" and "cochette" samples.Both traditional beers were pathogen free due to their extremely acidic pH and the presence of endogenous antimicrobial compounds such as alcohol, phenolic compounds, and carotenoids.Te absence of fecal Streptococci and Staphylococci spp.adds to our understanding of the 16 Journal of Food Quality Journal of Food Quality fecal contamination.Indeed, fecal Streptococci and sulphite-reducing bacteria (SRC) provide temporal information about the contamination, whereas Staphylococci spp.indicates that the contamination was caused by humans.Given the presence of SRC and the absence of Staphylococci in the samples, the apparent fecal contamination described in this study could be old but not of human origin.However, considering that the fecal coliforms/total coliforms ratio is less than 1, this could point to an animal origin for the suspected fecal contamination.

Sensory Properties.
Sensory profles of "bili-bili" and "cochette" from various areas in Maroua are summarized in Table 6.Except for "bili-bili" which had a substantial bitterness, there was no signifcant diference (p > 0.05) in most sensory attributes of these traditional beers.Tese fndings were consistent with those previously reported by Bayoï et al. [14,15].As with other local beverages, Bayoï et al. [14] observed that color was the unique attribute that fuctuated considerably during the sensory examination of "téa lémi," a traditional pummelo wine from the far north of Cameroon.On the contrary, Bayoï et al. [15] showed that the provenance of samples had no efect on the sensory characteristics of "kounou."Te homogeneity of "cochette" sensory attributes suggests the mastery of the production scheme and the best refex which should be operated by the producers to ensure a regular sensory quality.Another reason could be the origin of "cochette" producers.Indeed, "cochette" is traditional rice beer brewed solely by Chadian women, while "bili-bili" is produced by women from Cameroon, Tchad, and the Central African Republic (Table 2).
3.6.Safety Status of "Bili-Bili" and "Cochette".Te safety scores of "bili-bili" and "cochette" marketed in various Maroua areas are presented in Table 7. Assessment of the safety status of "bili-bili" and "cochette" was carried out using the safety scores calculated by integrating the microbial scores assigned according to the microbial counts of each sample.Te safety level of the sample was defned as follows: the lower the safety score (0-45-point scale), the better the safety status of sample.Terefore, based on the safety scores of "bili-bili" samples, the safety status can be classifed as follows: Palar and Domayo (139.5)> Ourotchédé (139.9)> Pont-vert (141).Te safety status of the "cochette" samples ranged as follows: Palar 1 and Pitoaré (96.5) are superior to Palar 2 (141).As indicated in Table 7, the safety scores of all the collected samples were greater than 45, suggesting they were potentially dangerous for the consumer's health.Based on the overall safety scores received by the two traditional cereal-based beers, "bili-bili" (559.5) may be considered more dangerous than "cochette" (334).It is crucial to note, however, that the number of localities chosen (4) for assessing the safety status of "bilibili" was higher than that considered (3) for analysing the safety status of "cochette."Terefore, this may illegitimate comparing of the safety status of the two types of traditional beers marketed in the city of Maroua.

Correlation Analysis.
Heat maps Pearson correlation matrices of the physicochemical, proximate, sensory, microbiological properties, phenolic compounds, and antioxidant activities of "bili-bili" and "cochette" are plotted in Figure 3. Alcohol and TSS were positively correlated in "bilibili" (r � 0.995) and "cochette" (r � 1.000).Tis indicates that alcohol as the water-soluble molecule might be accounted for the soluble solids content of both opaque beers.Furthermore, negative and signifcant correlations were found between pH and titratable acidity (r � −0.673 and r � −0.742, respectively), suggesting that the acidic pH values express high organic acids content in "bili-bili" and "cochette." With regards to "bili-bili," the protein content was negatively correlated to the electrical conductivity (r � −0.994) and TPC (r � −0.988).Tis suggests that the proteins in "bili-bili" were less electrically charged and more neutral.Given the acidic pH of this traditional beer, this may imply that the proteins in "bili-bili" are rich in amino acids, normally nonionised and neutral at very low pH.Furthermore, the negative correlation between proteins and the TPC insinuates the low level of "bili-bili" proteins in hydroxylated amino acids, especially tyrosine (known as phenolic amino acid).
Te TFC and DPPH were inversely associated to the titratable acidity (r � −0.997 and r � −0.990, respectively), implying that "bili-bili" with low acidity levels had the best bioactive properties.Tis correlation is highly interesting because the negative health efect of strong acidity (gastric ulcers and bone and teeth erosion) could be countered by favonoids, which act as a guardian against infammation and oxidative damage.Tis was verifed by a high positive correlation between DPPH values and the TFC (r � 0.996), as well as DPPH values and the TPC (r � 0.866), indicating that the phenolic compounds and mainly favonoids may be major contributors to the free radical-scavenging function of "bili-bili" beer.
An inverse relationship was found between total bacteria and the alcohol content (r � −0.967), confrming the antibacterial efect of the alcohol [77].Te total fungi count was 18 Journal of Food Quality positively correlated to the titratable acidity � 0.992).Tis could be explained by their acido-tolerant character.Indeed, acidic environments typically stimulate fungi development.However, the TFC was negatively correlated to the fungi count (r � −0.995).Tis shows that favonoids in "bili-bili" exert an antifungal activity [78].Tere was a positive and signifcant connection between sulphite-reducing bacteria (SRC) and fecal coliforms (r � 0.963).Tis is not surprising given that both bacteria groups are typically associated with fecal contamination.Te overall acceptability and total coliforms were shown to be negatively related (r � −0.968), implying that the most accepted "bili-bili" samples were the least contaminated with coliforms and thus the safest.Tis is highly interesting and could explain why "bili-bili" consumption is rarely associated with most cases of food-borne diseases.Figure 4: PCA biplot of factor loadings and scores of "bili-bili" (a) and "cochette" (b) samples.AA: amino acid; α-car: α-carotene; AC: antioxidant capacity; Accep: acceptability; DM: dry matter; EC: electrical conductivity; Fcol: fecal coliforms; Fla: favonoids; FRAP: ferric reducing antioxidant power; Lut: lutein; Lyc: lycopene; RS: reducing sugar; SRC: sulphite-reducing Clostridia; SSs: soluble solids; TA: total titratable acidity; TAMB: total aerobic mesophilic bacteria; Tan: tannins; TC: total carbohydrate; Tcol: total coliforms; β-caro: β-carotene; Pol: polyphenols.
Te acceptability is positively correlated to pH (r � 0.976) and texture (r � 0.973).Bayoï et al. [14] found a comparable association between the overall acceptability of "téa lémi" and its pH (r � 0.990), and Bayoï et al. [15] reported a positive correlation between the overall acceptability of "kounou" and its texture (r � 0.736).
With regards to "cochette," a negative correlation was recorded between tannins and pH (r � −0.998).Tis correlation has a relevant nutritional interest because it indicates that the "cochette" samples with acidic pH levels had the highest tannin contents, and ingestion of such beverages should be avoided because of their limited nutritive value (presence of tannins) and health problems (stomach disorders and bone and teeth erosion) associated.
Te FRAP value and lutein carotenoid equivalent were perfectly and positively correlated (r � 1.000) in "cochette," suggesting that lutein could potentially contribute to the ability to reduce Fe 3+ .Te TPC and α-carotene (r � 1.000), fecal coliforms and the TPC (r � 1.000), and fecal coliforms and α-carotene (r � 1.000) had the same connection.Furthermore, total coliforms and α-carotene were positively correlated (r � 0.998), as well as aerobic spore-forming bacteria and lycopene (r � 0.999).Both prior correlations show that the "cochette" samples with the poorest microbiological quality had the highest levels of polyphenols and carotenoids, both known as antimicrobials [79].Tis could be explained by the fact that both groups of bioactive compounds had insufcient concentrations to provide an efective antimicrobial action.
Te overall acceptability was negatively correlated to the proximate composition, including sugar (r � −1.000), proteins (r � −0.998), and free amino acids (r � −0.998).Tis means that the more the "cochette" was nutritive, the fewer the "cochette" was accepted.Tis is not surprising given that this beer, as most traditional beverages, is ingested with little knowledge of its intrinsic qualities (microbial, physicochemical, nutritional, etc.).In general, the consumer's choice and purchase decision are solely based on the sensory characteristics of the product [80].
According to PCA (Figure 4(a)), the "bili-bili" samples from Pont-vert related to the positive side of F2 were characterized by the bitterness, the largest ash and lutein levels, and the lowest safety level.Tis safety status appears to be explained by the highest microbial indicators such as Fcol, SFB, and SRC counts.Mainly connected to the lefthand side of F1, the samples from Domayo were essentially characterized by the highest TA, protein and amino acid contents, and TF count.Te "bili-bili" samples from Palar, which are found in the space formed by the right hand of F1 and the side down of F2, were mainly associated with the highest levels of DM, alcohol, soluble solids (SSs), tannins, and α-car and β-carotene carotenoid equivalents.Te samples from Ouro-tchédé were discovered in the same location as those from Palar, but they were too close to the origin and hence poorly represented.Indeed, Ouro-tchédé samples are associated with the third factor (F3) (data not shown), which was not taken into account for the biplot conception.
About PCA of "cochette" (Figure 4(b)), F1 and F2 accounted for 52.47% and 47.53% of the total variance, respectively.F1 was associated with pH, TA, EC, TFC, TTC, lyc equivalent, DPPH, texture, SFB, SRC, and safety, whereas F2 was related to alcohol, SS, proteins, amino acid (AA), total sugar (TC), reducing sugar (RS), ash, β-car equivalent, TAMB count, and overall acceptability.Te samples from Palar 1 location, associated with the side up of F2, were defned by TAMB, RS, proteins, TC, AA, β-car and lyc equivalents, FRAP, and DM."Cochette" sampled from the Palar 2 site was placed in the area formed by the F1 left-hand side and F2 side down.Tey were characterized by the pH, SRC, SFB, Fcol, and Tcol counts and the poorest safety status.Te samples from Pitoaré found in the space defned by the positive side of F1 and the negative part of F2 were mainly characterized by the sensory attributes scores and the ash content.

Conclusion
To valorise "bili-bili" and "cochette," two fermented cerealbased beverages, the samples collected from various areas of Maroua were investigated.So, this study emphasized on their preparation procedure, as well as physicochemical features, quality attributes, and safety status of both local beers.Traditional "bili-bili" and "cochette" are made from sorghum and rice, respectively.Signifcant changes (p < 0.05) in physicochemical and microbial properties were observed, while most sensory aspects of both beverages showed no signifcant variation (p > 0.05).Both opaque beers were nutritionally rich, a good source of natural phenolic and carotenoid compounds with potential health benefts according to the scavenging activity and reducing power highlighted in vitro.However, these beers were highly contaminated with several microbial groups, suggesting poor handling practices and postproduction contamination given the acidic character of beverages.Tis calls for 22 Journal of Food Quality awareness among the regular consumers order to prevent food poisoning and stomach ulcer which may occur after repeated intake of these traditional acidic beers.Data generated in the current study provide crucial inputs to beer producers, vendors, and consumers.Furthermore, they could help regulatory authorities and policymakers in developing holistic preventive measures to protect against the consumption of unsafe beer.Terefore, there is a need to standardise these traditional beers by adhering to sanitary procedures and conducting routine quality control at every stage of the production, including raw materials, processing intermediates, and ready-to-serve drink.

Figure 1 :
Figure 1: Mapping of the survey and sampling sites.

Table 1 :
Standards, culture media, incubation conditions, and colonies features used for microbial analysis of "bili-bili" and "cochette" samples collected in various localities of Maroua.

Table 3 :
Physicochemical profle, proximate composition, bioactive and antioxidant properties of "bili-bili" samples sold in major production sites of the city of Maroua.� 10) Domayo (n � 10) Ouro-tchédée (n � 10) Pont-vert (n � 10) p values * Two or more mean values with the same lower case superscript letters are not signifcantly diferent (p > 0.05) in the same row.PAC DPPH and PAC FRAP : phenolic antioxidant capacity based on DPPH and FRAP assays; RACI: relative antioxidant capacity index.
* p values lower than 0.05 indicate signifcant diferences in mean values of samples from the diferent locations.

Table 4 :
Physicochemical profle, proximate composition, and bioactive and antioxidant properties of "cochette" samples collected in diferent marketing places of Maroua city.

Table 4 :
Continued.lower than 0.05 indicate signifcant diferences in mean values of samples among the diferent locations.Two or more mean values with the same lower case superscript letters are not signifcantly diferent (>0.05) in the same row.PAC DPPH and PAC FRAP : phenolic antioxidant capacity based on DPPH and FRAP assays; RACI: relative antioxidant capacity index.
p values *

Table 5 :
Mean microbial loads of microbial groups in "bili-bili" and "cochette" samples from various selling places of Maroua city.Two or more mean microbial values with the same lower case superscript letters are not signifcantly diferent (p > 0.05) in the same row.p values *

Table 6 :
Mean scores of sensory attributes of "bili-bili" and "cochette."Twoor more mean sensory scores with the same lower case superscript letters are not signifcantly diferent (p > 0.05) in the same row.p values * lower than 0.05 indicate signifcant diferences in mean values of samples among the diferent locations.

Table 7 :
Safety scores of "bili-bili" and "cochette" samples sold in various sites of the city of Maroua.