Influence of starter cultures and KCl on some biochemical, microbiological and sensory features of soppressata molisana, an Italian fermented sausage

The effect of a multiple strain starter (KSL: Kocuria varians, Staphylococcus xylosus and Lactobacillus sakei) on the quality of soppressata molisana was investigated during 50 days of ripening. When compared with control batches (C, traditional production without starter and KS, addition of K. varians and S. xylosus as starter), soppressata produced with KSL showed positive results in terms of proteolysis progression, reduction of biogenic amines (BA) and sensory features. The partial substitution of 50 % NaCl with 50 % KCl further improved the quality of soppressata molisana produced with KSL as starter. In fact, the K+ ions seemed to stimulate the growth of added bacteria, with a resulting additional lowering of the pH and BA formation, and higher proteolysis. Moreover, the addition of KCl did not alter the sensory profile of final products. The analysis of data collected during the fermentation and the drying phases, which followed one other, allowed the individuation of different proteolytic events. Specifically, the proteolysis of the myofibrillar fraction occurred more slowly than that of the sarcoplasmic one. Also, the analysis of fractionated muscle proteins allowed to appreciate that sarcoplasmic proteins were hydrolyzed by both endogenous and microbial enzymes, whereas myofibrillar proteins showed a higher resistance to microbial enzymes, and were primarily hydrolyzed by endogenous ones. In conclusion the combined use of KSL and KCl as partial substitute of NaCl, allowed the production of soppressata molisana having an excellent quality, and features consistent with the guidelines of WHO on the sodium and potassium intake.