Effect of ripening time on the content of bioactive peptides and fatty acids profile of Artisanal Coalho cheese.

The present study aimed to investigate the influence of ripening on the physicochemical, microbiological aspects, and fatty acid profile of Artisanal Coalho Cheeses and to detect if there are peptides with bioactive potential in their composition. Artisanal Coalho Cheese samples were kindly provided by a dairy farm located in Brazil in the Rio Grande do Norte state. A completely randomized design was adopted, with four maturation periods (0, 30, 45, and 60 days). Physicochemical traits (pH, total solids, moisture, non-fat solids, fat in total solids, protein, ash, fatty acid profile) and microbiological characterization (Salmonella sp, Listeria monocytogenes, total and thermotolerant coliforms, Staphylococcus aureus) were analyzed on cheese samples. Additionally, assays were performed for antioxidant and antihypertensive bioactivity through ACE and antimicrobial inhibition of the peptides extracted from the samples. There was a linear increase in total solids and ash content and a decrease in moisture content with increasing maturation time. The matured cheese samples had a lower pH than fresh Artisanal Coalho Cheese. Twenty-seven fatty acids were identified in the cheeses: 15 saturated, 07 monounsaturated, and 05 polyunsaturated, with a linear reduction of essential fatty acids (n6 and n3) during maturation. The microbiological quality of the cheeses was satisfactory, with an absence of undesirable bacteria in 92% of the cheese samples. Water-soluble peptide fractions from all periods tested showed antioxidant and antihypertensive potential with ACE control, and the maturation process potentiated these capacities, with a decline in these activities observed at 60 days. The antimicrobial activity against Gram-positive and Gram-negative bacteria increased with maturation, reaching better results until 60 days. The maturation process on wooden planks in the periods of 30, 45, and 60 days allows the production of Artisanal Coalho Cheese of an innovative character, safe to consumers from the microbiological point of view, with differentiated physicochemical and functional characteristics and good quality of lipid fraction compared to fresh cheese, enabling the addition of value to the dairy chain.

Chemical composition and lipid profile of mare colostrum and milk of the quarter horse breed.

The objective of this study was to characterize the chemical composition and lipid profile of colostrum and milk of purebred Quarter Horse mares. Thirty-four (34) purebred mares were selected, which were then separated into groups according to age, birth order and lactation stage. Colostrum samples were collected in the first six hours after delivery and milk samples from the 7th postpartum day, with intervals of 14 days until the end of lactation. The samples were refrigerated and sent to the Milk Laboratory of the University (Laboleite-UFRN), where they were analyzed for chemical composition. Colostrum was assessed by refractometry. The lipid profile was determined by gas chromatography through a separation of methyl esters. The data were tabulated and subjected to descriptive statistics and analysis of variance by the F-Test, and the groups were compared by the Tukey test using a significance level of 5%. There was high protein content and reduced lactose content for the colostrum of the Quarter Horse mares, differing from other breeds. The milk composition was not influenced by the mares' age. However, variations in the lactation stage and in the birth order of the Quarter Horse mares altered the milk's chemical composition. There is variation in the lipid composition of milk according to the lactation stage, without changing the characteristic profile of the mares' milk or diminishing the nutritional quality of the lipid fraction.

Enterotoxin-encoding genes in Staphylococcus aureus from buffalo milk / Genes codificadores de enterotoxinas em Staphylococcus aureus no leite de búfalas

This paper investigated the occurrence of Staphylococcus aureus and the detection of enterotoxin-encoding genes of these strains in milk collected from 30 Murrah buffaloes used to produce dairy products in Brazil. A total of 68 strains of Staphylococcus aureus were found as identified by conventional laboratory tests, and thus screened for sea, seb, sec, sed, see, seg, seh and sei enterotoxin-encoding genes by polymerase chain reaction (PCR). Twelve strains containing enterotoxin-amplified genes were found, with higher expression for the sei and seh genes. These results can be attributed to animal health and inadequate cleaning of the equipment, indicating the need for better quality control in animal production and health lines. The results of this study with the presence of pathogens and their enterotoxigenic potential indicate a source of food poisoning, as well as being a pioneering study in the detection of new enterotoxins for buffalo milk.(AU)

Este estudo investigou a ocorrência de isolados de Staphylococcus aureus e a detecção de genes que codificam a enterotoxigenicidade dessas cepas em leite de búfala utilizado na produção de laticínios no Brasil. As amostras foram coletados em 30 búfalos da raça Murrah, identificado por testes laboratoriais convencionais, foram identificados um total de 68 cepas de S. aureus e rastreados para os genes que codificam a enterotoxina sea, seb, sec, sed, see, seg, seh and sei por reação em cadeia da polimerase (PCR). Doze cepas contendo genes da enterotoxina foram amplificadas, com maior expressão para os genes sei e seh. Esses resultados podem ser atribuídos à saúde animal e à higiene inadequada do equipamento, indicando a necessidade de melhor controle de qualidade nas linhas de produção e saúde animal. Os resultados desta pesquisa, com a presença de patógenos e seu potencial enterotoxigênico, indicam uma fonte de intoxicação alimentar, além de ser uma pesquisa pioneira na detecção de novas enterotoxinas para o leite de búfala.(AU)