Incorporation of nisin in natural casing for the control of spoilage microorganisms in vacuum packaged sausage

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.

Avaliação das características microbiológicas, físico-químicas e sensoriais de queijo Minas Frescal elaborado com culturas probióticas de Lactobacillus acidophilus / Microbiological, physico-chemical and sensorial characteristics of Minas Frescal cheese prepared with probiotic Lactobacillus acidophilus strains

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...