Antioxidant and Antimicrobial Activity of Secondary Metabolites Extracted from Bakery Yeast Saccharomyces cerevisiae

The deterioration problem of fruits and vegetables after harvesting, marketing and transportation until they reach the consumer is a significant challenge to overcome.

Use secondary metabolites produced from bakery yeast as an edible coating to extend the shelf life of strawberries through the extraction of secondary metabolites from commercially available bakery yeast and determination of protein, detection of bioactive compounds, estimation of antioxidant activity and antimicrobial activity, Then estimation of weight loss, deterioration value, soluble solids content and sensory evaluation characteristics during storage of coated strawberries.

The protein content of secondary metabolites produced from bakery yeast was (0.521 mg mL^-1). The detection of bioactive compounds refers to the finding of glycosides, alkaloids, terpenes, saponins, tannins, coumarins and flavonoids. the antioxidant activity was 86.9, 88.2 and 91.8% at 5, 10 and 20 mg mL^-1, respectively and antimicrobial activity at the same concentration was 51, 62 and 69%, respectively, for Escherichia coli; 47, 52 and 58%, respectively, for Salmonella typhimurium; 64, 69 and 76%, respectively, for Bacillus cereus; and 60, 66 and 71%, respectively, for Staphylococcus aureus. The results of coating strawberries with Sm1, Sm2 and Sm3 showed that the weight loss was 4.15, 3.74 and 2.38%, respectively; the deterioration value was 3.25, 2.08 and 1.34%, respectively; and the soluble solids content was 8.5, 7.9 and 7.3°Brix, respectively, during storage at 4°C for 10 d. The sensory evaluation revealed significant differences among the treatments, as well as sensory characteristics and an interaction between treatment and day, which were strongly positively correlated with overall acceptability. The treatment Sm3 showed the best effect during storage at 4°C for 10 d.