Effect of pacific white shrimp (Litopenaeus vannamei) protein hydrolysates (SPH) and (-)-epigallocatechin gallate (EGCG) on sourdough and bread quality

The effects of (-)-epigallocatechin gallate (EGCG) and shrimp protein hydrolysates (SPH) (100-1000 mg/kg) alone or in mixtures on sourdough and bread quality were investigated. Both EGCG and SPH at 1000 mg/kg had the greatest effect on Lactobacillus plantarum PTCC (1896) and Saccharomyces cerevisiae PTCC (5052) growth in vitro. The combined treatment (50% EGCG + 50% SPH) led to the highest growth of L. plantarum (12.2 Log cfu/ mL) and S. cerevisiae (8.66 Log cfu/mL). This combination at 3000 mg/kg significantly increased total titratable acidity (TTA) of sourdough after 20 h of fermentation at 30 degrees C compared with control. The combined treatment increased the specific volume and TTA of bread whereas it decreased hardness, cohesiveness, and chewiness of bread compared to the control. Compared to the control, 50% EGCG +50% SPH also resulted in a lower retrogradation enthalpy and staling, and gave a desirable sensory characteristic to the bread. It also increased the shelf-life of the bread by 2 days at room temperature compared with the control. Thus, 50% EGCG +50% SPH might be suggested for improving dough fermentation and bread quality.