Nitrate reduction in the fermentation process of salt reduced dry sausages: Impact on microbial and physicochemical parameters and aroma profile

Abstract

Slow fermented sausages with reduced ingoing amounts of sodium nitrate were manufactured: control (250 ppm), 15% (212.5 ppm) and 25% (187.5 ppm) reduction. The effect of nitrate reduction on microbiology and chemical parameters, volatile compounds and aroma production was studied. Parameters like, pH, a and colour decreased during ripening, without being affected by nitrate reduction. Lipid oxidation increased during ripening and it was higher in control sausages due to fat content. Residual nitrite was below the detection limit during the whole process and residual nitrate decreased during ripening, with higher reduction in RN25 sausages. Lactic acid bacteria, total mesophilic bacteria and yeasts and moulds increased during ripening but Gram positive cocci decreased. Microbial counts from nitrate reduced sausages at the end of the manufacturing process were not statistically different from the control sausages with nitrate. Regarding volatile compounds formation, compounds derived from amino acid degradation were increased by nitrate reduction. Aroma compounds derived from amino acid degradation and responsible for strong odours, dimethyl disulphide (toasted, garlic) and methional (cooked potato) and, to a lesser extent, compounds derived from esterase activity producing fruity odours (ethyl acetate, ethyl butanoate, ethyl‑2‑hydroxypropanoate, ethyl‑2‑methylbutanoate and ethyl‑3‑methylbutanoate) and several compounds from carbohydrate fermentation acetic acid (vinegar odour) and 2-butanone (fruity) were related to the high nitrate reduction (25%). Despite nitrate reduction up to 25% produced minor effect on microbial growth, their metabolism is regulated by nitrate content and therefore by nitrite generation affecting the production of key aroma compounds that alter the sausage aroma profile.

Aromatic Profile, Physicochemical and Sensory Traits of Dry-Fermented Sausages Produced without Nitrites Using Pork from Krškopolje Pig Reared in Organic and Conventional Husbandry

“…One explanation may be their higher degradation in organic sausages due to more oxidative conditions, indicated by oxidation markers carbonyls and TBARS as well as higher concentrations of PUFA. Many compounds of spices (for example, terpenoids) are relatively unstable [36] and disposed to oxidation as shown, for instance, on black pepper oleoresin [37]. Initially formed oxidation products from terpenoids were also reported to decompose upon increasing acidity, while volatile stability may also be compromised by the presence of moisture [36].…”

Red Wine and Garlic as a Possible Alternative to Minimize the Use of Nitrite for Controlling Clostridium Sporogenes and Salmonella in a Cured Sausage: Safety and Sensory Implications

“…The nitrite and nitrate content was reduced to about 10% of the added amount. These levels of nitrite in the finished product are due to its reduction to nitric oxide, which in turn reacts with the hemic group of the myoglobin and with other components of the sausage, resulting in a very small concentration in the finished product [19]. Residual nitrite at the end of the manufacturing process depends on several factors supporting the reduction of nitrite to nitric oxide, such as the pH of the medium, time and temperature of processing, microbial load present in the raw material, and addition of antioxidants [40].…”

“…The knowledge available is also limited with respect to safety and sensory characteristics of products in which the additive is suppressed or reduced. The elimination of nitrite without assessing the risk factors involved may result in uncontrolled growth of pathogens of high concern in this industry or in lower acceptability or other undesirable sensory changes, causing economic losses [18][19][20].…”

Chlorogenic acid osmosis of snakehead fish: a novel approach to maintain quality and suppress deterioration during storage

“…A similar mechanism has been reported that the absence of oxygen and permeated salt into the fillets could prevent oxidative deterioration of fish fat. [38,39] Lower POV means higher quality of snakehead fish fillet; CGA treatment obtained better quality. However, POV content of the controlled sample increased slowly, and reached the peak and dropped rapidly.…”

“…It has been reported that CGA penetration could contribute to high food microorganism safety. [39] Previous studies showed that in vacuum-packaged meat, microbiological metabolism caused the increase in pH value and TVB-N, which increased the risk of microbial safety and accelerate meat spoilage. [6,7] In this study, CGA osmosis was found as an effective way to maintain quality of meat by suppressing microbial growth.…”