The aim of this paper was to determine the causes of spoilage and odorous compounds in two different lots of traditional Friuli sausages produced by two small-scale facilities in San Daniele del Friuli. In spoiled sausages the water activity (Aw) was higher than in unspoiled sausages (0.94 vs. 0.91). Moreover, the pH of the spoiled tested sausages remained high despite the presence of acidifying bacteria (6.5±0.4 log CFU g -1 ), such as lactic acid bacteria (LAB) and coagulase negative catalase positive cocci (CNCPC). Conversely, in unspoiled sausages the pH value was 5.5±0.02. For this reason, the spoilage (mephitic type) can be attributed to the high pH (6.3±0.2 units) of the pork meat used, which was classified as a dark, firm, dry type (DFD), to the high Aw, and to the activity of LAB, CNCPC cocci, and Enterobacteriaceae. Because of the high pH and the lack of naturalor added sugars, these bacteria degraded the proteins via amino acid metabolism to produce ammonia, hydrogen sulphur, and methanethiol, which were responsible for the mephitic and putrid odour of the sausages.
Microbial spoilage of traditional dry sausages produced in small-scale facilities in Friuli, a northeastern region of Italy.
COMI, Giuseppe;VENDRAME, Marco;IACUMIN, Lucilla
2013-01-01
Abstract
The aim of this paper was to determine the causes of spoilage and odorous compounds in two different lots of traditional Friuli sausages produced by two small-scale facilities in San Daniele del Friuli. In spoiled sausages the water activity (Aw) was higher than in unspoiled sausages (0.94 vs. 0.91). Moreover, the pH of the spoiled tested sausages remained high despite the presence of acidifying bacteria (6.5±0.4 log CFU g -1 ), such as lactic acid bacteria (LAB) and coagulase negative catalase positive cocci (CNCPC). Conversely, in unspoiled sausages the pH value was 5.5±0.02. For this reason, the spoilage (mephitic type) can be attributed to the high pH (6.3±0.2 units) of the pork meat used, which was classified as a dark, firm, dry type (DFD), to the high Aw, and to the activity of LAB, CNCPC cocci, and Enterobacteriaceae. Because of the high pH and the lack of naturalor added sugars, these bacteria degraded the proteins via amino acid metabolism to produce ammonia, hydrogen sulphur, and methanethiol, which were responsible for the mephitic and putrid odour of the sausages.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
