Effect of pH and Temperature on Antioxidant Levels of Tomato Wine

Patulin, ergosterol and Howard mold count (HMC): Which one is the best quality indicator for tomatoes?

Ergosterol, an important constituent of fungal cell wall, was started to be used as a quality parameter for the tomatoes and derivatives instead of Howard mold count (HMC). In addition, patulin is another important microbiological quality indicator of molds such as Penicillium, Aspergillus, and Byssochlamys. In this study, it is aimed to identify the relationship between HMC, patulin, and ergosterol in juices produced from the tomatoes which has the surface rotten of 0% (sound), 25%, 50%, 75%, and 100%. As the rotten proportion increased, HMC, ergosterol, and patulin values increased. Linear correlations (r) between HMC, ergosterol, patulin, and rotten proportion were calculated as 0.99, 0.99, and 0.98, respectively. In addition, linear correlations between HMC and ergosterol (r = 0.95), HMC and patulin (r = 0.95) and ergosterol and patulin (r = 0.98) were found. In contrast, non-linear correlation between pH, brix and titratable acidity, and the rotten proportion was determined. PRACTICAL APPLICATIONS: The manuscript has provided the relationship between HMC, patulin, and ergosterol in juices produced from the tomatoes which have the surface rotten of 0% (sound), 25%, 50%, 75%, and 100%. Linear correlations between rotten proportions of tomatoes and HMC, ergosterol, patulin and between HMC and ergosterol, HMC and patulin, and ergosterol and patulin were determined in juices produced from rotten tomatoes. Patulin indicated correlation with HMC and ergosterol in juices produced from rotten tomatoes. In addition to HMC and ergosterol, patulin has great potential for the assessment of tomato products as associated with the rotten proportion.

Optimization of Cactus Pear Fruit Fermentation Process for Wine Production

Cactus pear fruit (Opuntia ficus-indica) has a chemical composition that renders it an attractive substrate for wine fermentation. However, there have been serious post-harvest losses of cactus fruit due to its short shelf life. This study aims to investigate wine production from cactus pear fruit juice by optimizing fermentation temperature, pH, and inoculum concentration (Saccharomyces cerevisiae) to obtain optimum quality-indicative responses. Response surface methodology coupled with central composite rotatable design was adopted in the present study to achieve optimized fermentation process conditions. The fermentation process was carried out for 6 days with varied input variables, and all the models showed significant p-values for interaction of variance (<0.05). Cactus pear fruit wine with a total acidity of 12.39 ± 1.32 g/L equivalent to tartaric acid (TTAE), alcohol content of 9 ± 0.31%, v/v, total antioxidant concentration of 235.3 ± 9.15 mg/L AAE (Ascorbic acid equivalent), and sensory acceptance of 7.74 ± 0.34 was produced at an optimized temperature of 30 °C, pH of 3.9, and inoculum concentration of 16%. The developed models could predict the quality of wine developed from cactus pear fruit.

Effect of tamarind (Tamarindus indica L.) seed on antioxidant activity, phytocompounds, physicochemical characteristics, and sensory acceptability of enriched cookies and mango juice

Tamarind seeds are not consumed despite their high antioxidative activity. In this study, 0-10% tamarind seed powder (TSP) was incorporated into mango juice and cookies. Total phenolics (Folin-Ciocalteu assay), antioxidant activity (2,2-diphenyl-1 picrylhydrazyl (DPPH) radical scavenging assay), flavonoid (aluminum chloride assay), condensed tannins content (Vanillin-HCl assay), and consumer acceptability (n = 50) of the products were determined. TSP increased the pH and viscosity and reduced titratable acidity of juice. Incorporation of TSP increased the: total phenolic content (6.84 ± 0.21 to 88.44 ± 0.8 mg GAE/100 mL); flavonoid (4.64 ± 0.03-21.7 ± 0.36 mg CE/100 mL); condensed tannins (0.24 ± 0.01-21.81 ± 0.08 mg CE/100 mL) and total antioxidant activity (4.65 ± 0.88-21.70 ± 0.03 mg VCE/100 mL) of juice. A similar trend was observed for cookies. Maximum sensorially acceptable TSP levels were 1.5% and 6%, respectively, for juice and cookies. TSP can thus be utilized as a source of natural antioxidants in food products.