Characterisation of changes in physicochemical, textural and microbiological properties of Njeguška sausage during ripening

Abstract

The purpose of this paper was to investigate effect of ripening time on physicochemical, textural and microbiological properties of Njegusˇka (dry fermented sausage) during ripening and to conduct sensory and free fatty acid characterization of final product. Ripening time significantly (p \ 0.05) affected all physicochemical parameters. Moisture content dropped below national regulation limit (35%) after 12 days, which indicates that production process could be shortened for 4 days. Total weight loss was 36.34%. Due to its final pH (5.54), Nje-gusˇka can be classified as low-acid sausage which microbial safety mostly relies on its low water activity (\ 0.80). Final TBARS value was 0.27 mg MDA/kg. Levels of tyramine (36.9 mg/kg) and putrescine (16.7 mg/kg) were the highest among all biogenic amines while levels of remaining amines were under 5 mg/kg. Hardness, gumminess and chewiness significantly (p \ 0.05) increased during processing to reach final values of 65.59 N, 33.60 N and 19.12 N, respectively. Ripening time had significant effect on color (L * , a * and b * ) of surface, meat and fat parts which were all measured separately. Total viable count, lactic acid bacteria and Micrococcaceae counts increased from 5.11 log cfu/g, 3.90 log cfu/g and 2.41 log cfu/g to 7.96 log cfu/g, 7.04 log cfu/g and 4.86 log cfu/g, respectively. Results of sensory characterization showed high scores for smoky flavor, consistency, fattiness, fat/meat cohesiveness and saltiness while lactic acid odor and overall acidity were rated low.

Digital Evaluation of Nitrite-Reduced “Kulen” Fermented Sausage Quality

“…e batter was stuffed into 55 mm diameter collagen casings using vacuum filler VF616 (Handtmann, Biberach an der Riss, Germany). After a resting day, sausages were traditionally cold smoked for 2 days as previously described by Simunovic et al [9] and transferred to a ripening chamber where they were kept until the end of production under the following conditions: 3 days (23 °C, 90%-95% RH), 4 days (20 °C, 85% RH), 8 days (18 °C, 80% RH), and 23 days (12-15 °C, 70% RH). Samples for the analyses were taken on the production day, after 8, 16, 24, 32, and 40 days of manufacturing.…”

“…Physicochemical Analysis. Water activity (a w ), pH, moisture, and biogenic amine contents were determined as previously described by Simunovic et al [9]. Nitrite and nitrate levels were measured according to EN 12014-4: 2005 ion-exchange chromatography method [24], using 858 Professional Sample Processor autosampler (Metrohm, Herisau, Switzerland) and 930 Compact IC Flex with Oven/ SeS/PP system consisting of column oven, sequential suppression, peristaltic pump, built-in degasser, and conductivity detector (Metrohm, Herisau, Switzerland).…”

“…ese results indicate the possibility of weight loss and moisture content evaluation through shrinkage determination using 3D laser imaging. Moisture content is often defined by meat quality regulations and it represents an important economic parameter in fermented sausage production [9]. Determination of moisture content is time consuming because it involves homogenisation, drying, and cooling of the sample until it reaches constant mass.…”

“…Counts. e increase in pH during ripening is a result of proteolysis and the formation of peptides, ammonia, amino acids, and biogenic amines [2,9]. Biogenic amine levels are an important food safety parameter as some of them are reported to be hazardous to humans if consumed at critical levels [44].…”

“…In recent years, as a result of consumers becoming more aware of the potential health risks of food additives, demand for "clear label" food is constantly increasing [9].…”