Tomat terlalu matang sebagai perasa alami: karakteristik fisikokimia, glutamat, antioksidan, dan mutu mikrobiologi

Abstract

This study aimed to evaluate the physicochemical characteristics, glutamate content, bioactive compounds, antioxidant activity, and microbiological quality of tomato (Solanum lycopersicum) at different maturity stages and in puree and powder forms, with and without blanching treatment. The samples consisted of overripe tomato puree (ORP), blanched overripe tomato puree (ORPB), maturity index 6 tomato puree (T6P), overripe tomato powder (ORS), blanched overripe tomato powder (ORSB), and maturity index 6 tomato powder (T6S). The evaluated parameters included water activity, pH, total soluble solids, viscosity, color, moisture content, glutamate, total phenolic content, total flavonoid content, antioxidant activity measured using FRAP, DPPH, and TEAC assays, and microbiological quality. The results showed that the powder samples had lower moisture contents (3.57–5.79%) than the puree samples (94.32–94.89%). T6S exhibited the highest total phenolic content at 1,274.607 mg GAE/100 g dry weight and the highest antioxidant activity, with FRAP, DPPH inhibition, and TEAC values of 1,681.079 mg FE/100 g dry weight, 86.850%, and 867.432 mg TE/100 g dry weight, respectively. The highest glutamate content on a fresh-weight basis was observed in ORS at 638.864 mg/100 g, while ORS also showed the highest total flavonoid content at 84.147 mg QE/100 g dry weight. Microbiological results indicated lower measured microbial counts in the powder samples than in the puree samples. Overall, processing form and maturity stage were associated with differences in the measured characteristics and quality of the tomato samples. However, statistical analysis and confirmation of microbiological units are required to strengthen the interpretation of these findings.