RESUMO
The influence of the autochthonous CLA-producing Lactobacillus plantarum TAUL 1588 and Lactobacillus casei subsp. casei SS 1644 strains and the ripening time on the fatty acid (FA) content and sensory characteristics of sheep cheese were investigated. Three cheese types with different cultures and the control cheese were produced in duplicate and ripened for 8â¯months. 86 individual FA were determined by gas chromatography. Ripening time (2, 90, 180 and 240â¯days) did not have a significant effect (Pâ¯>â¯.05) on the FA content. However, the presence of both Lactobacillus CLA-producing strains led to a decrease of the saturated FA content and to 1.30, 1.19 and 1.27 times higher levels of vaccenic acid, CLA and omega-3, respectively, when compared to the control cheese. This combination allowed obtaining sheep milk cheeses with a healthier FA content, without appreciable changes on sensory characteristics. This work could be a promising approach to increase the bioactive fatty acid content of cheeses.
Assuntos
Queijo/microbiologia , Microbiologia de Alimentos , Lacticaseibacillus casei/metabolismo , Lactobacillus plantarum/metabolismo , Ácidos Linoleicos Conjugados/metabolismo , Valor Nutritivo , Adulto , Animais , Cor , Feminino , Dureza , Humanos , Masculino , Pessoa de Meia-Idade , Carneiro Doméstico , Olfato , Paladar , Adulto JovemRESUMO
Biogenic amines are toxic substances that appear in foods and beverages as a result of AA decarboxylation. The enzyme histidine decarboxylase catalyzes the decarboxylation of histidine to histamine, the biogenic amine most frequently involved in food poisoning. The aim of the present work was to develop a real-time quantitative PCR assay for the direct detection and quantification of histamine-producing strains in milk and cheese. A set of primers was designed, based on the histidine decarboxylase gene sequence of different gram-positive bacteria. The results show the proposed procedure to be a rapid (total processing time < 2 h), specific and highly sensitive technique for detecting potential histamine-producing strains. Chromatographic methods (HPLC) verified the capacity of real-time quantitative PCR to correctly quantify histamine accumulation.