Starter Cultures For Fermented Sausages Research Articles

Selection of wild lactic acid bacteria for sausages: Design of a selection protocol combining statistic tools, technological and functional properties

The main topic of this paper was the combination of statistic tools, technological, and functional properties to select starter cultures for fermented sausages. One-hundred sixty-four isolates were recovered from pork meat, and studied for their enzymatic patterns, growth as a function of temperature, pH, NaCl, nitrites and nitrates, and acidification. The growth was assessed through a spectrophotometric approach to evaluate the Growth Index; then, the data were used as input variables to run Cluster and Principal Component Analyses. Fifty-three promising isolates were selected for their Growth Index in presence of salt, nitrites, at low temperatures, or acidification. These isolates were studied for some functional properties (survival at pH 2.0/2.5, and in presence of bile salts, hydrophobicity, auto-aggregation, antibiotic resistance, antimicrobial activity towards some foodborne pathogens). The results of these experiments were used to select 4 best candidates, using the statistical distribution of each trait (median and quartiles). As a final step, the isolates were identified as Lactobacillus plantarum and studied for their ability to inhibit foodborne pathogens, a mould (Mucor spp.) or for the lacking of negative interactions with an adjunct starter of fermented sausages (Staphylococcus xylosus).

Characterization of lactic acid bacteria isolated from infant faeces as potential probiotic starter cultures for fermented sausages

A total of 109 lactic acid bacteria isolated from infant faeces were identified by partial 16S rRNA, cpn60 and/or pheS sequencing. Lactobacillus was the most prevalent genus, representing 48% of the isolates followed by Enterococcus (38%). Lactobacillus gasseri (21%) and Enterococcus faecalis (38%) were the main species detected. A further selection of potential probiotic starter cultures for fermented sausages focused on Lactobacillus as the most technologically relevant genus in this type of product. Lactobacilli strains were evaluated for their ability to grow in vitro in the processing conditions of fermented sausages and for their functional and safety properties, including antagonistic activity against foodborne pathogens, survival from gastrointestinal tract conditions (acidity, bile and pancreatin), tyramine production, antibiotic susceptibility and aggregation capacity. The best strains according to the results obtained were Lactobacillus casei/paracasei CTC1677, L. casei/paracasei CTC1678, Lactobacillus rhamnosus CTC1679, L. gasseri CTC1700, L. gasseri CTC1704, Lactobacillus fermentum CTC1693. Those strains were further assayed as starter cultures in model sausages. L. casei/paracasei CTC1677, L. casei/paracasei CTC1678 and L. rhamnosus CTC1679 were able to lead the fermentation and dominate (levels ca. 108 CFU/g) the endogenous lactic acid bacteria, confirming their suitability as probiotic starter cultures.

Probiotic strains Lactobacillus plantarum 299V and Lactobacillus rhamnosus GG as starter cultures for fermented sausages

Probiotic food products are a fast growing area. Although probiotic strains are currently used in dairy products, their commercial application in fermented meat products is not yet common. The aim of this study was to assess the competitiveness of two probiotic Lactobacillus strains (Lactobacillus plantarum 299V and Lactobacillus rhamnosus GG) during the manufacture of Spanish fermented sausages and their effect on the hygienic and sensory qualities of the final products. The inoculated strains were successfully monitored by Randomly Amplified Polymorphic DNA (RAPD)-PCR. Both strains prevented the growth of Enterobacteriaceae throughout the entire ripening process. L. rhamnosus GG and L. plantarum 299V at high inoculum (ca. 107 CFU/g) produced a sharp decrease of pH values and low growth of Gram-positive Catalase-positive Cocci (GCC+), leading to a negative effect on the sensory attributes evaluated. Nevertheless, L. plantarum 299V inoculated at 105 CFU/g achieved and maintained high counts until the end of ripening and storage (ca.108 CFU/g), co-dominating (60%) with the endogenous microbiota, producing functional sausages with a satisfactory overall sensory quality. No major differences in physico-chemical parameters or sensory attributes were recorded when compared to spontaneously fermented sausages, thus adding further value to this type of meat product as a probiotic vehicle.

The effect of starter cultures on proteolytic changes and amino acid content in fermented sausages

The main objective of this work was to examine the effects of using five types of commercial starter cultures in fermented sausages. During the fermentation stage, changes in proteolytic characteristics were observed in fermented sausages. Proteolytic activity was high in Lsb + Sc:(Lactobacillus sakei + Staphylococcus carnosus) and Pp + Sx:(Pediococcus pentosaceus + Staphylococcus xylosus) starter-inoculated sausages during processing. Moreover, a slight increase in proteolytic activity was detected during storage in both these sausages. Sarcoplasmic and myofibrillar proteins were also affected by this starter culture addition, during the fermentation, ripening and intense proteolysis were observed in both the fermented sausages. The content of free amino acids was similar at the beginning of the fermentation stage for all the studied batches. However, the high differences in the content of free amino acids at the end of the process could be attributed to the starter culture activity.

Viability of Staphylococcus xylosus isolated from artisanal sausages for application as starter cultures in meat products

Viability of Staphylococcus xylosus isolated from artisanal sausages for application as starter cultures in meat products Viability of Staphylococcus xylosus strains AD1 and U5 isolated from natural fermented sausages was investigated as starter cultures in fermented sausages produced in the South Region of Brazil. The study demonstrated that the Staphylococcus xylosus strains AD1 and U5 showed significant growth during fermentation, stability over freeze-dried process, negative reaction for staphylococcal enterotoxins and viability for using as a single-strain culture or associated with lactic acid bacteria for production of fermented sausages.

Viability of Staphylococcus xylosus isolated from artisanal sausages for application as starter cultures in meat products

Viability of Staphylococcus xylosus isolated from artisanal sausages for application as starter cultures in meat products Viability of Staphylococcus xylosus strains AD1 and U5 isolated from natural fermented sausages was investigated as starter cultures in fermented sausages produced in the South Region of Brazil. The study demonstrated that the Staphylococcus xylosus strains AD1 and U5 showed significant growth during fermentation, stability over freeze-dried process, negative reaction for staphylococcal enterotoxins and viability for using as a single-strain culture or associated with lactic acid bacteria for production of fermented sausages.

Technological activities of Staphylococcus carnosus and Staphylococcus simulans strains isolated from fermented sausages

The aim of this study was to determine the technological properties of 2 strains of Staphylococcus simulans (Ssm12, Ssm21) and 4 strains of S. carnosus (SC28, SC31, SC54 and SC55) for the selection of a potential starter cultures to employ in the processing of dry fermented sausages. The strains were studied to evaluate nitrate reductase, proteolytic, lipolytic, decarboxylase and antioxidant activities as well as growth ability at different temperatures, pH and NaCl concentrations. Nitrate reductase activity was determined at 15, 20 and 30 °C. By spectrophotometric method all the strains were able to reduce nitrate to nitrite at the different temperatures but these results were not confirmed by the agar plate method. Antioxidant and lipolytic activities were evaluated by spectrophotometric assay. All the strains showed antioxidative enzymes superoxide dismutase (SOD) and catalase whereas all appeared unable to hydrolyse pork fat. Proteolytic activity was determined by agar plate method, spectrophotometric assay (OPA) and sodium dodecyl sulphate gel-electrophoresis (SDS–PAGE) and all strains appeared to be able to hydrolyse sarcoplasmic proteins but not myofibrillar proteins. Finally, all the strains grew at 15 and 20 °C, in presence of 10%, 15% and 20% of NaCl and at pH 5.0 and 5.5 and were unable to produce histamine, cadaverine and putrescine. The results showed that all strains studied possess useful technological activities that would make them eligible as a good starter cultures for fermented sausages.

Technological and sensorial evaluation of Lactobacillus strains as starter cultures in fermented sausages

The performance of several lactobacilli strains isolated from naturally fermented sausages as starter cultures was evaluated. Microbiological, physical and chemical changes, in addition to sensorial aspects were studied. From the 12 different strains tested, 10 were capable of leading the fermentation in every batch throughout the process. The monitoring of the inoculated strains was easily carried out by plasmid profiles and by checking the pH rate drop of the sausages, which was slower for the non-inoculated lots. Treatment using natural fermentation resulted in a product where hydrogen sulphide odours, which could be related to the higher content of Enterobacteriaceae throughout the ripening process, diminished its overall acceptability. The lots seeded with different L. sake strains were found to be low in acid in sensory evaluation, correlating with a low lactic acid content. In contrast, the L. plantarum lot gave rise to an overacidified product related to having the highest amount of lactic acid at the end of the process. As a general rule lactobacilli strains isolated from meat origins are good candidates as starter cultures in the manufacture of dry-fermented sausages and produce satisfactory products depending on the specific strains used more than on the species.