This study aims to characterize the physicochemical properties of cocoa’s residual honey and evaluate its fermentative capacity as a substrate, using
One good application for fruit wastes is in the production of fermented foods.
Thus, this study aims to characterize the physical and chemical properties of cocoa’s residual honey and to evaluate its fermentative capacity as a substrate, using
The raw material of the cocoa’s residual honey was donated by producers from farms in the rural area of Uruçuca, Bahia, Brazil (latitude: 14° 47′ 20′′ S; longitude: 39° 02′ 58′′ W; altitude: 52 m). The cocoa honey was collected before cacao bean fermentation (Figure
Stages for obtaining cocoa’s residual honey.
The determination of soluble solids, expressed as °Brix, was performed in a portable digital refractometer (Biobrix, MecLab). The pH was determined with a benchtop pH meter (Hanna Instruments, HI 221). The moisture, ash, total lipids, protein, acidity, and calcium pectate (gravimetric method) were determined according to AOAC methods [
The mineral profile of cocoa’s residual honey was determined according to the method used by Brito et al. [
The methodology proposed by Dias et al. [
To calculate concentration of cells, 10 mL samples of the cell suspension were collected every 24 hours. The cell suspensions were centrifuged at 4000 x g for 20 minutes at 20°C. The cell pellet was recovered and washed with distilled water, centrifuged at 4000 x g for 10 minutes, and dried at 105°C to constant weight. The concentration of cells in suspension was determined by dry weight of yeast (g.L−1).
The identification and monitoring of sugars and ethanol in the fermentation process of cocoa’s residual honey was conducted by HPLC-RI (Perkin-Elmer Series 200) using a pre-Polypore Ca column (30 mm x 4.6 mm x 10
The response variables
P0 and P are the concentrations (g.L−1) of the initial and final ethanol
X0 and X are the concentrations (g.L−1) of the initial and final cells
S0 and S are the concentrations (g.L−1) of the initial and final sucrose
t is time
The data were subjected to analysis of variance (ANOVA) and Tukey’s post hoc tests at a significance level of
The physicochemical composition of cocoa’s residual honey, which is summarized in Table
Physicochemical characterization of cocoa’s residual honey compared to other fruit pulps (the mean ± standard deviation).
Parameters | Cocoa’s | Cocoa | Cocoa | Graviola pulp3 | Cupuaçu pulp4 |
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Total soluble solids (°Brix) | 13.30±0.01 | 16.17±0.74 | 20.50±0.15 | 13.98±0.54 | 9.00±0.00 |
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Moisture (g.100 mL−1) | 85.86±0.09 | 85.30±8.60 | - | 80.57±0.45 | 89.20±0.3 |
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Dry material (g.100 mL−1) | 14.14±0.09 | 14.70±8.60 | - | 19.43±0.45 | 10.80±0.3 |
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Ash (g.100 mL−1) | 0.59±0.15 | 3.76±0.84 | - | 0.71±0.00 | - |
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Total lipids (g.100 mL−1) | 0.19±0.08 | 3.54±0.20 | - | 0.15±0.01 | 0.30±0.00 |
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Crude protein (g.100 mL−1) | 1.20±0.49 | 7.20±0.21 | - | 0.88±0.00 | - |
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Carbohydrate (g.100 mL−1) | 11.80±0.09 | - | - | 17.69±0.09 | - |
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Glucose (g.100 mL−1) | 4.58 ± 0.12 | - | - | - | - |
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Fructose (g.100 mL−1) | 3.25 ± 0.03 | - | - | - | - |
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Pectin (g.100 g−1 calcium pectate) | 0.36±0.02 | - | 0.57±0.00 | - | - |
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pH | 3.51±0.04 | 3.75±0.81 | 3.20±0.02 | 3.53±0.00 | 3.50±0.02 |
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Titratable acidity (meq NaOH.100 g−1) | 10.34±0.01 | 17.0±6.28 | 1.00±0.01 | 1.27±0.06 | 3.50±0.00 |
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C/N ratio | 9.83 | - | - | 20.10 | - |
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Ba (mg.100 mL−1) | 0.38 ± 0.01 | - | - | - | - |
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Fe (mg.100 mL−1) | 1.35 ± 0.02 | - | - | - | - |
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Mn (mg.100 mL−1) | 0.30 ± 0.01 | - | - | - | - |
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Al (mg.100 mL−1) | 0.15 ± 0.07 | - | - | - | - |
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Cu (mg.100 mL−1) | 0.07 ± 0.00 | - | - | - | - |
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Na (mg.100 mL−1) | 0.48 ± 0.04 | - | - | - | - |
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Se (mg.100 mL−1) | 0.19 ± 0.00 | - | - | - | - |
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Zn (mg.100 mL−1) | 0.40 ± 0.01 | - | - | - | - |
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K, Ca, Mg, and P | n.d. | - | - | - | - |
Average values marked with the same letter in the same line do not differ significantly (
1Anvoh et al. [
Approximately 85% of the dry matter of cocoa’s residual honey is represented by carbohydrates (Table
The pectin content of cocoa’s residual honey was significantly lower (
The C/N ratio of 9.83 obtained for cocoa’s residual honey (Table
The pH of the cocoa’s residual honey (3.51, Table
The fermentation processing of the cocoa’s residual honey (19 °Brix) was conducted at 20°C for 240 hours, and the free sugar and ethanol content and cell biomass were monitored every 24 hours (Table
Consumption of sucrose, glucose, and fructose and the formation of ethanol during submerged fermentation of cocoa’s residual honey by
Time (h) | Sucrose | Glucose | Fructose | Total | Ethanol | Cell | Sugar |
---|---|---|---|---|---|---|---|
0 | 147.51±0.45 | 22.98±0.12 | 16.37±0.03 | 186.78±0.19 | 0.00±0.00 | 0.40±0.03 | 0.00 |
24 | 61.34±0.16 | 1.80±0.53 | 4.79±0.02 | 67.83±0.21 | 6.52±0.22 | 3.27±0.13 | 63.69 |
48 | 50.35±0.55 | 1.78±0.16 | 4.96±0.11 | 56.99±0.25 | 10.56±0.33 | 5.67±0.01 | 69.52 |
72 | 42.84±0.67 | 1.67±0.06 | 5.68±0.14 | 50.00±0.27 | 10.37±0.50 | 5.47±0.06 | 73.22 |
96 | 36.04±1.15 | 1.58±0.03 | 5.88±0.02 | 43.31±0.31 | 11.64±0.50 | 6.27±0.25 | 76.81 |
120 | 32.65±0.78 | 1.41±0.04 | 5.88±0.01 | 39.83±0.24 | 12.85±0.76 | 3.47±0.29 | 78.68 |
144 | 25.34±0.63 | 1.35±0.06 | 5.86±0.02 | 32.43±0.21 | 14.24±0.53 | 6.40±0.09 | 82.65 |
168 | 18.79±0.51 | 1.32±0.04 | 6.01±0.02 | 26.06±0.18 | 15.51±0.23 | 4.60±0.06 | 86.07 |
192 | 13.13±0.55 | 1.22±0.03 | 6.11±0.10 | 20.41±0.17 | 15.79±0.40 | 1.13±0.09 | 89.07 |
216 | 8.80±0.63 | 1.24±0.03 | 6.12±0.07 | 16.11±0.20 | 15.81±0.61 | 2.93±0.20 | 91.38 |
240 | 0.00±0.00 | 0.84±0.05 | 4.21±0.30 | 5.02±0.05 | 15.96±0.63 | 2.73±0.03 | 97.32 |
Production of ethanol and cell biomass (a) and the total percentage of sugar consumption (b) during submerged fermentation of cocoa’s residual honey by
Ethanol is the major component of alcoholic beverages and determines the viscosity (body) of the wine, while also acting as a fixative [
Table
Ethanol yield (
Time (h) | | | |
---|---|---|---|
0 | 0.000 | 0.000 | 0.000 |
24 | 0.373 | 0.168 | 0.299 |
48 | 0.000 | 0.000 | 0.034 |
72 | 0.190 | 0.018 | 0.008 |
96 | 0.348 | 0.013 | 0.002 |
120 | 0.188 | 0.012 | 0.007 |
144 | 0.199 | 0.009 | 0.001 |
168 | 0.050 | 0.002 | 0.004 |
192 | 0.005 | 0.000 | 0.024 |
216 | 0.014 | 0.001 | 0.031 |
240 | 0.000 | 0.000 | 0.011 |
The results of the fermentation of cocoa’s residual honey confirmed that
Cocoa’s residual honey presents adequate nutritional composition for use as a fermentative substrate by
No data were used to support this study.
The authors declare that there are no conflicts of interest.
The authors gratefully acknowledge the financial support of FAPESB (Proc 029/2012), CAPES (Project 6245/2014), and CNPq (Processo 103361/2018-9).