Flavor characteristics of Indonesian soy sauce (Kecap manis)

Kecap, manis is a typical Indonesian soy sauce prepared from black soybeans. The beans are mold and brine fermented to produced moromi which is then filtered and cooked with coconut sugar and spices for 1 h to afford kecap manis. The brine fermentation took up to 4 months, during the first month of which the content of glutamic acid reached a maximum of 14.33%, based on the dried matter. The content of glutamic acid was then decreased and a similar trend was observed for some of the amino acids. The flavor volatiles of kecap manis were then studied after different fermentation periods for moromi preparation (0, 1, 2, 3, 4 months). The volatiles contained 16 acids, 4 aliphatic aldehydes, 1 phenol, 6 aliphatic ketones, 21 furans, 10 pyrazines, 1 pyran, 3 pyrroles, 1 thiazole, 1 pyridine, 4 alicyclic hydrocarbons, and 11 unknowns. While these volatiles were qualitatively similar, there were quantitative differences. Thus, the content of pyrazines and acids increased as the fermentation progressed. However, the highest gurih (tasty, umami) taste was attained for kecap manis prepared from 1-month-fermented moromi. Analysis of sensory description, consumer preference and volatiles composition of seven commercial kecap manis showed that the preference of consumer to kecap manis was more affected by its taste where sweet and gurih (tasty, umami) were the taste that the consumer like. Volatile composition apparently do not correlated well with the aroma of kecap manis.