New sauces produced by koji fermentation of kamaboko show acceptable sensory characteristics, improved antioxidant activities, and high angiotensin-converting enzyme inhibition

Abstract

In our previous study, kamaboko was fermented in koji to prolong its shelf life and to increase its health-promoting effects. After fermentation, the texture of the kamaboko became cheese- or tofuyo-like. In the present study, sauces were produced by the fermentation of kamaboko in fermentation beds of wheat (WS), rice (RS), brown rice (BS), or soybean koji (SS), and their sensory qualities examined. WS, RS and BS had similar qualities to commercial oyster sauce. Fried cabbage with RS had significantly better overall acceptance than fried cabbage with oyster sauce. SS had significantly higher ash, protein and fat contents, and significantly lower carbohydrate contents than WS, RS, and BS. Free amino acid contents increased following fermentation for all sauces, and were highest in SS. The sugar contents of WS, RS, and BS were significantly higher than that of SS. SS had the highest phenolic content followed by BS, WS and RS. Antioxidant activity and angiotensin-converting enzyme (ACE) inhibition were highest in SS. All the new sauces had significantly higher free amino acid contents than the equivalent fermentation beds without kamaboko.