CERELA   05438
CENTRO DE REFERENCIA PARA LACTOBACILOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
DEVELOPMENT AND IN VITRO BEAKER SAUSAGE EVALUATION FOR SELECT NATURAL STRAIN FOR PROTEOLYTIC ACTIVITY IN LOW SALT DRY SAUSAGES
Autor/es:
DE ALMEIDA, M; FADDA S; VILLANUEVA, N
Lugar:
Madison
Reunión:
Simposio; American Meat Science Association Reciprocal Meat Conference; 2014
Institución organizadora:
Univ of Wisconsin
Resumen:
Objectives: To select the strain combination for salami production, with the biggest proteolytic activity under low sodiumconditions, using an in vitro Beaker sausage.Materials and Methods: The inner portion (aseptically extracted) of a meat piece (pork and beef) was grounded with addition ofsodium chloride and of the additives used for low sodium salami production: potassium chloride and calcium chloride. The Beakersausage was prepared as sterile as possible; therefore the additives were sterilized too. The sodium nitrite/nitrite and sodiumerythorbate were filtered and diluted separately. The other additives (sugars and salts) were diluted in water and autoclaved. Theamount of water used for the dilution was 5% of the mass of the meat. The meat with the additives were divided into three treatments:(T1) Enterococcus mundtii CRL35 + Staphylococcus vitulinus GV 318; (T2) Lactobacillus plantarum CRL 681 + Staphylococcusvitulinus GV 318, and Control with addition of antibiotics (20000UI penicillin, streptomycin 20mg, 50mg anfotercina / kg, and 0.01%sodium azide). Each strain was inoculated at a concentration of 108 UFC/ml. Each treatment was divided into four falcon tubes (15 geach) and incubated at 22 ° C, while the control was incubated at 7° C. At 0, 3, 6 and 10 days, the pH and PCA (total bacteria) wereread for the control, and the MRS (lactic bacterial) and MSA (Staphylococcus) were read for the other treatments using Bradfordproteins and monodimensional electrophoresis.Results: At day 0, the T2 presented a L. plantarum CRL 681 concentration of 2.7x109CFU/g and a S. vitulinus GV 318concentration of 2.7x107CFU/g, in day 10 the concentration of the first microorganism decreased one log and the identification ofthe second microorganism was impossible using the plate counting method. This proves that the addition of 1% dextrose / sugar isenough for the growth of L. plantarum, however, the rapid acidification of the medium, that causes a pH fall from 5.7 to 4.9 in threedays, inhibits the growth of S. vitulinus. Regarding T1, which was inoculated with 2.8x108CFU/g of Enterococcus mundtii CRL35and 2.1 x 108CFU/g S. vitulinus GV 318, it was observed that at day 10 the population of E. mundtii decreased one log, indicating abehavior similar to the one of L. plantarum. Meanwhile, the population of S. vitulinus diminished 3 logs. Also in T1, the pH felt from5.8 to 5.1 in 10 days, however it did not decline as sharply as it did in T2. Therefore, it can be said that the slight pH declination in T1favors the steady concentration of S. vitulinus at 1.6x104. Concerning the proteolytic activity, the results, as presented in Figure 1,showed that it was higher in T2 (no presence of bands under 24 kDa) and the control showed the lowest proteolityc activity (greaterpresence of bands of 24 kDa). This was confirmed by the Bradford protein analysis method, in which T1 had 8.47 mg/ml protein atday 0 and 4.92 mg/ml at day 10, while T2 had 6.65 mg/ml at day 0 and 2.92 mg/ml and day 10 as a consequence of the more intenseacidification.Image: