Qualidade do queijo e do leite de vacas F1 Holandês x Zebu alimentada com níveis crescentes de casca de banana

Abstract

This study aimed to evaluate the effects of inclusion levels of dry banana peel in the sun in the diet of F1 Holstein x Zebu cows lactating on the physicochemical, sensory quality, and fatty acid profile of milk and Minas fresh cheese. The diets were composed of 0, 15, 30, 45 and 60% in replacement of sorghum silage by banana peel. They were used 10 cows F1 Holstein x Zebu, with 70 ± 11 days in milk at the beginning of the experiment. The experimental design was a Latin square 5 x 5, simultaneous with five periods of 16 days with 12 days of adaptation and four days of collection. Samples of milk from each cow were analyzed for physico-chemical composition and fatty acid profile. On the fourth day of collection, the oil obtained was pasteurized for the production of Minas Fresh cheese, which was weighed to determine the gross and adjusted income, and analyzed for texture and physicochemical characteristics (fat, protein, lactic acid, moisture, pH, Aw, total solids and ash), fatty acid profile, general acceptance test by the consumer and order of preference. There was a linear decrease for the urea nitrogen milk (NUL) with the inclusion of banana peel in the diet. The remaining items evaluated in the physical and chemical composition of milk and cheese, as well as the general acceptance tests by the consumer and ordering preferably not influenced by diets with banana peel inclusion. Quadratic effect for the sum of milk polyunsaturated fatty acids, with the maximum level of 23,54% replacement. There was a decreasing linear effect for C15:0 iso and C16: 0 iso fatty acids, presenting difference from the control treatment at the level of 60% replacement for these fatty acids in milk. The heneicosanoic fatty acids (C21: 0), linoleic (C18: 2c9c12), CLA (C18: 2c9t11) and arachidonic (C20: 4n6) showed quadratic effect, being that the linoleic acid and CLA, obtained from maximum points 19,63 and 35.64% of substitution, respectively. The level of CLA (C18: 2c9t11) in milk cows receiving diet containing 30% banana peels was significantly greater from those fed with 0% banana peel). There was no effect (p> 0.05) of banana peel inclusion levels about fatty acids, as well as their summations over cheese. Since the ratio of polyunsaturated and saturated fatty acids in milk, as well as the ratio of fatty acids ω6 and ω3 cheese and milk, and milk ω6 fatty acids presented a quadratic effect (P <0.05) due to the inclusion levels. Replacement of up to 60% of the silage of a banana peel in the diet of cows with average production of 16.49 kg milk with 3.5% fat day-1, can be an alternative to milk production and processing, maintaining quality, and improve the nutritional value of the lipid fraction of the milk with increased conjugated linoleic acid concentration (CLA).