Umami taste amino acids produced by hydrolyzing extracted protein from tomato seed meal

Enzymatic hydrolysis was performed for extracting protein to prepare umami taste amino acids from defatted tomato seed meal (DTSM) which is a by-product of tomato processing. Papain was used as an enzyme for the hydrolysis of DTSM. The particle size distribution of DTSM, protein concentration and free amino acids of the hydrolysate were analyzed. Response surface methodology was used in the design of experiments and analysis of results. The protein extraction ratio of greater than 85.64% was obtained when the DTSM with particle size ≤0.25 mm was hydrolyzed by papain for 5 h. The optimum extraction conditions to produce maximum concentration of umami taste amino acids were enzyme activity of 18.22%; pH of 3; hydrolysis temperature of 40 °C; and hydrolysis time of 6 h, which resulted in glutamic acid and aspartic acid concentrations of 727.6 μg/mL and 149.9 μg/mL, respectively.