Use of proteases to improve oxidative stability of fermented sausages by increasing low molecular weight compounds with antioxidant activity

Forty fermented sausages from Iberian pigs were manufactured using 3 different proteases with a potential antioxidant activity (batch 1: without proteases, batch 2: neutral bacterial protease, batch 3: fungal protease and batch 4: fungal protease concentrate). The antioxidant properties of extracts (< 3 kDa) from Iberian dry-cured sausages were assessed using four different methods: (i) 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (RSA), (ii) metal chelating assay (MQA), (iii) reducing power (RP) and (iv) inhibition of linoleic acid autoxidation (ILAA). Dry-cured sausage extracts from of all the manufactured batches showed antioxidant activity as indicated by RSA, MQA and ILAA. Manufacturing sausages with the used proteases increased the antioxidant activity of the sausage extracts, except for the MQA. Moreover, extracts from dry-cured sausages which were manufactured without proteases showed the highest levels of both thiobarbituric acid-reactive substances (TBARs) and hexanal content.

Research highlights
► We used 3 different proteases to make Iberian fermented sausages.
► The 3 proteases increased antioxidant activity using different antioxidant methods.
► Sausages without proteases showed the highest level of TBARs and Hexanal content.