ABSTRACT
Abstract Soymilk was produced from vegetable soybean and fermented by probiotics (Lactobacillus acidophilus La-5, Bifidobacterium animalis Bb-12) in co-culture with Streptococcus thermophilus. The composition of the fermented beverage and oligosaccharides content were determined. The effect of fructooligosaccharides and inulin on the fermentation time and viability of probiotic microorganisms throughout 28 days of storage at 5 °C were evaluated. The soymilk from vegetable soybeans was fermented in just 3.2 h, when pH reached 4.8. Fermentation reduced the contents of stachyose and raffinose in soymilk. Prebiotics had no effect on acidification rate and on viability of B. animalis and S. thermophilus in the fermented beverage. The viable counts of B. animalis Bb-12 remained above 108 CFU mL-1 in the fermented soymilk during 28 days of storage at 5 °C while L. acidophilus La-5 was decreased by 1 log CFU mL-1. The fermented soymilk from vegetable soybeans showed to be a good food matrix to deliver probiotic bacteria, as well as a soy product with a lower content of non-digestible oligosaccharides.
Subject(s)
Beverages/analysis , Soy Milk/metabolism , Streptococcus thermophilus/metabolism , Synbiotics , Bifidobacterium animalis/metabolism , Lactobacillus acidophilus/metabolism , Oligosaccharides/analysis , Temperature , Colony Count, Microbial , Soy Milk/isolation & purification , Streptococcus thermophilus/growth & development , Microbial Viability/drug effects , Microbial Viability/radiation effects , Fermentation , Bifidobacterium animalis/growth & development , Hydrogen-Ion Concentration , Inulin/analysis , Lactobacillus acidophilus/growth & developmentABSTRACT
This study aimed to evaluate the effectiveness of natural casing treatment with nisin and phosphoric acid on control of spoilage microorganisms in vacuum packaged sausages. Ovine casings were dipped in the following baths: 1) 0.1 percent food grade phosphoric acid; 2) 5.0 mg/L nisin; 3) 0.1 percent phosphoric acid and 5.0 mg/L nisin; and 4) sterile water (control). The sausages were produced in a pilot plant, stuffed into the pretreated natural casings, vacuum packaged and stored at 4 and 10 °C for 56 days. The experiments were performed according to a full factorial design 2³, totalizing 8 treatments that were repeated in 3 blocks. Aerobic plate counts and lactic acid bacteria analysis were conducted at 1, 14, 28, 42 and 56 days of storage. Treatment of casings with phosphoric acid 0.1 percent alone did not inhibit the growth of lactic acid bacteria and reduced the aerobic plate count by 1 log. The activity of nisin against lactic acid bacteria was enhanced by the addition of phosphoric acid, demonstrating a synergistic effect. Furthermore nisin activity was more evident at lower storage temperature (4 ºC). Therefore treatment of the natural casings with nisin and phosphoric acid, combined with low storage temperature, are obstacles that present a potential for controlling the growth of lactic acid bacteria in vacuum packaged sausage.
ABSTRACT
Bactérias probióticas apresentam inúmeros benefícios à saúde, incluindo redução da intolerância à lactose, tratamento e prevenção de diarréias e estímulo do sistema imune. Devido à essas características, essas bactérias têm sido muito utilizadas para fabricação de alimentos probióticos. O mercado de alimentos probióticos no Brasil está aumentando rapidamente, mas a variedade de produtos está limitada a iogurtes e outros leites fermentados. O presente trabalho teve como objetivo o desenvolvimento de queijo Minas Frescal probiótico contendo uma cultura de lactobacillus acidophilus. Avaliou-se a capacidade de três cepas comerciais (145, La-5 e NCFM) inibirem o crescimento de Escherichia coli e Staphylococcus aureus durante a produção e armazenamento do queijo. Avaliou-se também as características físico-químicas e sensoriais do produto durante o armazenamento em refrigeração...