Physico-chemical, Biochemical and Microbiological Properties of Traditional Polish Pork Fermented Products During Ripening

Abstract

The physico-chemical and biochemical properties of the raw pork products, spontaneously fermented as entire primal cuts of ham hock (raw smoked ham hock (RSR)) and loin (raw smoked loin (RSL)), were estimated during the 4-week ripening period. A decrease in water content (4 % in RSR and 7 % in RSL) and an increase in protein (2 and 4.5 %, respectively), fat and salt content (1–2 % for both products) were associated with the phenomena of slight drying. An almost 2.5-fold increase of free amino groups dissolved in water, from 480 to 1,100 μMGly/100 g and from 490 to 1,200 μMGly/100 g, accompanied by a gradual increase of total free fatty acids, from 250 to 530 mg/kg and from 270 to 460 mg/kg, was indicated in the RSR and RSL, respectively. The fermentation and accumulation of free fatty acids affected the pH decrease in the RSL, particularly with a low fat content. The increase of tyramine, tryptamine, putrescine and spermine amounts confirm the activity of bacteria strains in the RSR and RSL during ripening. The considerable part of the “house microflora” included the species fermenting in the presence of air or in anaerobic conditions—in the presence of nitrogen. The presence of volatile cell metabolism products (3-hydroxy-2-butanone, 3-methyl-1-butanol and butanoic acid) confirmed a greater amino acid transformation and saccharide fermentation activity of microflora in the RSR. Similarly, products of free fatty acid degradation (pentanal, hexanal and butanoic acid) as well as products of lipid oxidation (e.g. 3-methyl-3-buten-1-ol and 3-methyl-1-butanol) confirmed the far advanced ripening in the RSR with a greater fat content.