Abstract: Free amino acids, organic acids and volatile flavor components in samples of tofu coagulated with fermented tofu whey collected at different ripening stages were determined. The results showed that free amino acids and organic acids were the major sources of taste substances; sour-taste amino acids were the major taste components, accounting for 33%–35% of the total amino acids at all tested ripening stages. Lactic acid, acetic acid and citric acid were the most abundant flavor substances during the ripening process, accounting for approximately 50.08%–65.00% of the total organic acids. A total of 84 flavor compounds, including aldehydes, alcohols, phenols, furans and other compounds, were detected in the tofu samples, together endowing the tofu with a unique fermented flavor.

Key words: tofu coagulated with fermented soybean whey; ripening process; free amino acids; organic acids; flavor components