Viability of Shiga Toxin–Producing Escherichia coli, Salmonella spp., and Listeria monocytogenes during Preparation and Storage of Fuet, a Traditional Dry-Cured Spanish Pork Sausage

Abstract

We monitored viability of Shiga toxin-producing Escherichia coli (STEC), Salmonella spp., and Listeria monocytogenes during preparation and storage of fuet. Coarse ground pork (ca. 35% fat) was mixed with salt (2.5%), dextrose (0.3%), starter culture (ca. 7.0 log CFU/g), celery powder (0.5%), and ground black pepper (0.3%), and then separately inoculated with a multi-strain cocktail (ca. 7.0 log CFU/g) of each pathogen. The batter was stuffed into a ca. 42-mm natural swine casing and fermented at 23°C and ca. 95% relative humidity (RH) to ≤pH 5.3 (≤ 48 h). Sausage were then dried at 12°C and ca. 80% RH to a w 0.89 (within 33 days) or a w 0.86 (within 60 days). A portion of each batch of fuet was subjected to high pressure processing (HPP; 600 MPa/3 min) before chubs were vacuum-packaged and stored for 30 days at 20°C. After fermentation, pathogen numbers remained relatively unchanged (≤0.35 log CFU/g reduction), whereas reductions of ca. 0.8 to 3.2 log CFU/g were achieved after drying fuet to a w 0.89 or 0.86. Regardless if fuet was or was not pressure treated, additional reductions of ca. 2.2 to ≥5.3 log CFU/g after drying were achieved following 30 days of storage at 20°C. For non-HPP treated fuet dried to a w 0.89 and stored for 30 days at 20°C, total reductions of ≥5.3 log CFU/g in levels of STEC or Salmonella spp. were achieved, whereas levels of L. monocytogenes were reduced by ca. 3.6 log CFU/g. Total reductions of ≥5.3 log CFU/g in levels of all three pathogens were achieved after drying non-HPP treated fuet to a w 0.86. For fuet dried to a w 0.89 or 0.86, pressure treated, and then stored for 30 days at 20°C, total reductions of >6.2 log CFU/g in levels of all three pathogens were achieved. The processing parameters tested herein, with or without application of HPP, validated reductions of ≥2.0- or ≥5.0-log CFU/g in levels of STEC, Salmonella spp., and L. monocytogenes were achieved during preparation and storage of fuet.

Control of Listeria monocytogenes in chicken dry-fermented sausages with bioprotective starter culture and high-pressure processing

“…During the last week, a considerable increase in the pH above 7 was observed, which can be attributed to the decrease of lactic acid concentration and particularly to a thick mold layer covering the surface of the sausages. Though the increase of the pH is typical by the end of the ripening of Mediterranean DFS due to the proteolysis and ammonia production from amino acid (Thévenot et al, 2005;Rubio et al, 2014;Porto-Fett et al, 2022), the magnitude of observed in the present study was not expected. In this type of sausages, the a w decreased similarly to FT sausages during the first week, however, during the second week, the thick mold layer grown on the surface resulted in a slower drying process (Toldrá et al, 2014), thus resulting in a final product with higher a w (p < 0.05), corresponding to worst-case scenarios for these types of fermented sausages.…”

The effect of different sterilization methods on the shelf life and physicochemical indicators of fermented pork jerky

“…A lower pH value can inhibit or delay the microbial degradation of various meat products ( 36 ), so pH value needs to be considered during the production of meat jerky ( 37 ). Fermented meat products require a rapid decrease in pH to below 5.3 within 48 h during fermentation ( 38 ). As shown in Figure 3 , the initial pH of ultraviolet sterilization is higher than 5.3.…”

Impact of packaging atmosphere, oregano essential oil, and storage temperature on cold-adapted Salmonella Enteritidis and Salmonella Typhimurium on ready-to-eat smoked turkey

“…However, by raising the storage temperature to 15°C, the pathogen was able to grow in the sliced meat and reach its maximum growth, reaching levels of about 8 log CFU/g in just 3 d. Salmonella sp. cannot grow when meat products are stored at 6°C, according to ( Jofré et al, 2008 ; Porto-Fett et al, 2022 ).…”