The objective of the research was to evaluate changes of dietetic functional mixed cerrado fruit jam (marolo, sweet passion fruit, and soursop) processed in a vacuum pot and stored for 180 days in BODs at 25°C and 35°C. The parameters evaluated were pH, soluble solids (SS), titratable acidity (TA), total sugars (TS), total carotenoids (TC), total phenolics (TP), vitamin C, antioxidant activity (DPPH), and microbiological analysis. There was a significant effect of storage time on pH, SS, TA, TC, TS, and TP. Vitamin C and DPPH showed an effect for the temperature x storage time interaction. Statistical models are not adjusted for pH and SS, presenting an average of 4.15 and 61%, respectively. Carotenoids decreased up to105 days; total sugars increased up to 105 days. The TP, vitamin C, and DPPH, at the temperatures evaluated, showed a decrease up to 105 days. Yeasts and filamentous fungi were not detected.
There is considerable demand for fresh fruit and their products. It is known that most fruits are seasonal and their useful life is very limited life, often requiring the application of heat treatments, via processing, in order to maintain and preserve quality and provide various products such as pulp, jam, jellies, and juices throughout the year, especially in the off-season. The flora of the cerrado has various fruit species with high potential for agricultural use, which are traditionally used by local people. The fruits are usually consumed raw or in the form of juices, liquors, ice cream, jams/jellies, and various sweet formulations [
However, they are perishable and the production of jam by using various additives (sugar, acid, sweetener, pectin, among others) and thermal processing is intended to prevent loss of postharvest fruit and offer a differentiated product to the consumer. According Worobo and Splittstoesser [
The useful life of a product is characterized in the period in which it is in good microbiological and sensory condition for consumption without jeopardize taste and health. These conditions are directly dependent on the physical, chemical, and microbiological transformations during storage, which are also related to the nature of the product (kind and amount of ingredients), packaging, and storage conditions (humidity, temperature, and storage time) [
The effect of temperature is very complex and may be due to various causes. Initially, with increasing temperature molecular activity increases as well as the formation of enzyme complexes [
Processing and storage of jams must be conducted in order to maintain their color, nutritional value, and radical scavenging activity [
According to Rababahet al. [
The objective of this study was to evaluate the physicochemical and microbiological alterations that occurred in the dietetic functional mixed cerrado fruit jam (marolo, sweet passion fruit and soursop), processed in a vacuum pot and packaged in polypropylene jars and stored in a temperature controlled chamber (BOD) at 25 and 35°C for 180 days.
The marolo (
The marolo and sweet passion fruit were washed in running water and immersed in 150 mg L−1 sodium hypochlorite solution for 15 minutes. After sanitizing, the fruits were processed at the Pilot Plant Laboratory-DCA Federal University of Lavras/UFLA. The marolo pulp was extracted manually with the aid of a knife to remove the seed from the pulp. The sweet passion fruit pulp was pulped manually, with the seeds removed with a spoon. Later, pulps (marolo and sweet passion fruit) were pulsed and mixed in a blender and were then packed in polyethylene bags and stored in a freezer at -18°C for use in the preparation of the mixed jam and for further analysis.
The preparation of mixed jam followed the formulation methodology developed according to previous results described by Souza et al. [
Formulation used in the production of dietetic functional mixed cerrado fruit jam.
| |
---|---|
Mixture of pulp | 60.00 |
Fructooligosaccharide (P95 - oarfit®) | 13.18 |
Polydextrose(commercial grade Nutramax®) | 23.16 |
Citric Acid (commercial grade Nuclear®) | 0.20 |
Potassium sorbate (commercial grade VETEC®) | 0.20 |
Low-methoxylated Pectin – LMP(commercial grade Danisco®) | 2.00 |
Locust bean gum | 0.61 |
Carrageenan gum (commercial grade Danisco®) | 0.61 |
Acesulfame-k (commercial grade Nutramax®) | 0.01 |
Sucralose (commercial grade Nutramax®) | 0.03 |
Total | 100.00 |
To process the mixed jam, a mixture of fruit pulp was made [marolo/sweet passion fruit/soursop (1:1:1)] and polydextrose was added. When the soluble solids reached 20°Bx, the low methoxil pectin (LMP) pectin and gum (carrageenan and locust) previously dissolved in water at 80°C were added to the first ingredients. For each 4 grams of pectin 50mL of hot water was used, when the soluble solids reached 25°Brix the fructooligosaccharides (FOS) were dissolved in water and added in a 1:1 ratio. At the end of the cooking process citric acid, potassium sorbate and sweeteners (sucralose and acesulfame-K) were added and then baking was stopped.
After processing, the jam was packaged in sterilized polypropylene jars. The filling was carried out hot (approximately 70-75°C). The containers were then closed, inverted (top down), cooled to room temperature, and then were kept under refrigeration for later analysis.
To evaluate the effect of time x temperature of the mixed jam that was stored in a climatic chamber, BODs (ELETROLAB, Brazil), an experiment was conducted in a factorial 2 x 5, with two temperatures (25 and 35°C) and 5 storage times (0, 70, 105, 140, and 180 days) in triplicate. The analysis follows the model described below [ i is 25°C and 35°C and is considered fixed;
The analyses were carried out in triplicate in dietetic functional mixed cerrado fruit jam. pH, soluble solids, and total sugars were determined using the AOAC [
Microbiological analyses were performed to detect mold and yeast colony-forming units (CFU), according to the law [
It was found that only the storage time has a significant effect on pH, titratable acidity (TA), soluble solids (SS), total sugar (TS), and total carotenoids (TC). Table
Regression equations adjusted for variables that do not present significant interaction between temperature and storage time (0, 70, 105, 140, and 180 days) and for variables that have a significant effect of the interaction between the mixed jam storage times (0, 70, 105, 140, and 180) and temperature (25°c and 35°C).
| | | | |
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pH | Y = 4.11 + 0.0006 | 0.49 | 1.84 | 3.97 |
TA | Y = 0.41 = 0.011 | 0.89 | 2.75 | 3.97 |
SS | Y = 59.96 - 0.057 | 0.55 | 1.77 | 3.97 |
TSS | Y = 16.87 + 1.14 | 0.70 | 0.44 | 3.97 |
TC | Y = 622.84 - 3.34 | 0.50 | 8.07 | 3.97 |
TP | Y = 2764 - 39.14 | 0.93 | 0.26 | 3.97 |
| | | | |
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Vitamin C | Y = 56.42 - 0.35 | 0.64 | 5.26 | 3.97 |
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DPPH | Y = 14.29 - 0.14 | 0.71 | 21.68 | 3.97 |
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| | | | |
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Vitamin C | Y = 56.61 - 0.26 | 0.64 | 5.26 | 3.97 |
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DPPH | Y = 14.86 - 0.21 | 0.76 | 21.68 | 3.97 |
TA: titratable acidity; SS: soluble solids; TSS: total soluble sugars; TC: total carotenoids; TP: total phenolics; Fc: F calculated; Ft: F tabulated; antioxidant activity: DPPH.
Regression models at a 5% level of significance were established from the experimental results of the variables studied. The suitability of complete models can be verified (Table
According to the results, it appears that for the parameters pH, SS, and TC (Table
Damiani et al. [
Mesquita et al. [
Policarpo et al. [
The variables titratable acidity, total sugars, and total phenolic were adjusted to the mathematical model, presenting determination coefficients between 70 and 93%.
It was observed that the titratable acidity increased from 0.41 to 1.2% during the storage period of 0-140 days (Figure
Titratable acidity behavior during storage.
Mesquita et al. [
With respect to the variable soluble solids (Figure
Total soluble solids during storage.
Damiani et al. [
With respect to total sugars (Figure
Total sugar behavior during storage.
Assis et al. [
Phenolic compounds are potentially bioactive substances that naturally occur in plants and derived foods; scientific evidence has emphasized their beneficial role in health and disease prevention in humans [
For total phenolics, only the retention time was statistically significant. There was a marked decrease up to 140 days (320 mg/100g DM) with a slight increase at 180 days (380 mg/100g DM).
Phenolic compounds are directly related to the organoleptic characteristics of a particular product because this reduction may influence the changes in flavor, color, and aroma of the product.
According to Fennema [
With regard to vitamin C and antioxidant activity, DPPH, there was no significant interaction between time and storage temperature. For vitamin C, there was no adjustment of the mathematical model for both temperatures (R2 =. 64%); however, for the DPPH, the mathematical model presented a coefficient of determination between 71 and 76% at temperatures 25 and 35° C, respectively (Table
Regarding the vitamin results C, in Figure
Vitamin C behavior during storage.
Importantly, although quantitatively the vitamin C loss was considered reasonable during storage, it was not enough to compromise the nutritional value of the product, since the mixed jam vitamin C content is comparable to foods that present average levels, ranging 30-50mg.100g−1 according to Ramful et al. [
Prati et al. [
Regarding the antioxidant activity there was no effect of the interaction between storage time and temperature, where at both temperatures, 25 and 35°C, there was a decrease up to 105 days with subsequent increase at 180 days. At 25°C there was a less marked decrease than at 35°C (Figure
Antioxidant activity behavior during storage.
Rababah et al. [
Patras et al. [
Regarding microbiological analyzes in mixed jam during storage, we observed that the findings presented in Table
Mold and yeast count in the dietetic functional mixed cerrado fruit jam during storage.
Storage time (days) | Temperature (°C) | |
---|---|---|
25 | 35 | |
0 | 1.44x103CFU/g | 1.44x10 3CFU/ g |
70 | 1x103 CFU/g | 6x102CFU/g |
105 | 5.3x102CFU/g | 8.7x103 CFU/g |
140 | 7.6x103CFU/g | 5.1 x 102CFU/g |
180 | 3.3 x 103 CFU/g | 2.7 x 102CFU/g |
CFU: colony-forming units.
Therefore, the mixed jam presented satisfactory health condition, meeting the sanitary standards established by RDC No. 12 of January 2, 2001, of the Secretary of Health Surveillance [
Similar results were obtained by Policarpo et al. [
The production of dietetic functional mixed cerrado fruit jam is an attractive option of using these fruits and is an alternative for processing of the cerrado fruits at harvest period. The storage time was the factor that most influenced the physicochemical changes in dietetic functional mixed cerrado fruit jam. The titratable acidity, soluble solids, and total sugar values increased and the values found for total carotenoids and total phenolics verified that there was a slight decrease during storage. As for vitamin C and antioxidant activity, their values showed a decrease at the two temperatures, 25 and 35°C, during storage. Regarding the microbiological analysis, we observed that there were fluctuations in yeast and filamentous fungi growth, but the results, during storage and at both temperatures, were within the standards required by law.
All experimental data used to support the findings of this study are available from the corresponding author upon request.
The authors declare that they have no conflicts of interest.
The authors would like to acknowledge CNPq and FAPEMIG for financial support.