Effect of different mixed starter cultures and fermentation conditions on biological safety of ‘Zha fish'

The purpose of this paper was to explore the influence of different starter cultures and fermentation conditions on biological safety of ‘Zha fish '(a fermented grass carp). Taken Lactobacillus plantarum(Lp),Pediococcus pentosaceus(Pp),Staphylococcus xylose(Sx),Saccharomyces cerevisiae(Sc) as starter culture,which was mixed with methods of Lp+Sx+Sc,Lp+Pp+Sc,and Sx+Pp+Sc under a ratio of 1∶1∶1(v/v/v). Tthe harmful bacterial count and biogenic amine(BA) content of ‘Zha fish' was assayed periodically under different fermentation conditions. The results showed that inoculation fermentation( IF) exhibited better antibacterial effects against harmful bacteria than that of the natural fermentation(NF)(p<0.01). Among three mixed starter cultures,Lp+Sx+Sc exhibited the best effect on inhibiting the formation of BA(p<0.05). With 20%(m/m) KCl substituted for Na Cl,it showed better inhibition effect on BA formation than that of samples no KCl substitution(p <0.05). The suitable content of composited salt was 2.4% Na Cl +0.6% KCl. From the point of view of BA control and production efficiency,20 ℃ was a suitable one. As to the sensory quality and BA control,5.0%mixed sugar was preferred. The total content of BA in ‘Zha fish' was as low as 43.50 mg/kg,and an excellent sensory quality could be achieved using Lp +Sx +Sc as starter culture to fermentation for 50 d under above-mentioned optimal conditions. The data obtained in this study suggested that biological safety of ‘Zha fish 'products could be ensured if Lp +Sx +Sc was taken as starter culture under an appropriate fermentation conditions.