Acceleration of mackerel fish sauce fermentation via bromelain addition

Abstract
Purpose The purpose of this study was to accelerate the fermentation process of minced mackerel fish (Scomber scombrus L.) mixed thoroughly with 20 per cent salt (w/w) and hydrolyzed by 0.2 and 0.4 per cent bromelain at 37 degrees C. Design/methodology/approachS. scombrus L. was mixed thoroughly with 20 per cent salt (w/w) and hydrolyzed by the bromelain at levels of 0.2 and 0.4 per cent at 37 degrees C. The physicochemical and sensory properties were evaluated after 60 and 90 days. Findings In a comparison of all of the aforementioned treatments, the results showed that the samples with higher bromelain levels (0.4 per cent) had higher concentrations of formal nitrogen (622 mg/100 mL) and total volatile base nitrogen (TVB-N, 0.3 g/dL) after 90 days of fermentation (p < 0.01) . The sample with 0.4 per cent bromelain showed total free amino acids content of 13.3 g/100 g after 90 days of fermentation (p < 0.01). High levels of total fatty acids (15.6 mg/100 g) were found in samples treated with 0.4 per cent bromelain and allowed to ferment for 90 days (p < 0.01). The sauce colour became significantly highly saturated (p < 0.01) with the increase in fermentation time. Chroma was significantly increased by 44 and 66 per cent in fermented sauce samples with 0.2 and 0.4 per cent bromelain during fermentation for as long as 90 days (p < 0.01). Moreover, the addition of bromelain (0.4 per cent) resulted in mackerel fish sauce that was organoleptically preferred at the end of fermentation. Originality/value The results showed that an acceptable fish sauce could be produced from mackerel fish with supplementation with 0.4 per cent of bromelain, which reduced the fermentation time to 90 days and resulted in the most satisfactory results without compromising the product quality.