Produção e qualidade do leite de búfalas, antes e após fermentação, com suplementação de resíduos agroindustriais.

Abstract

The objective was to evaluate the effect of supplementation on production and milk composition of dairy buffaloes kept in pasture for Mombaça (Panicum maximum) as well as evaluate the influence of supplemental food, heat treatment and storage period on their physical, chemical, sensory and microbiological character, after fermentation. The field experiment was conducted at the Animal Research Unit "Dr. Felisberto Camargo "(01 º 26'S and 48 º 24'W), Embrapa Eastern Amazon, Belém-Pará, consisting of three experimental periods of 21 days, ten to the animals adapt of the diet and eleven for data collection. Twelve primiparous buffaloes were used, supplemented in individual troughs, distributed in four Latin squares 3 × 3. Used to concentrate, cupuaçu (Theobroma grandiflorum) pie and murumuru (Astrocaryum murumuru) pie, in partial substitution of corn and soy, the following treatments: 1 - Control - 75% corn bran and 25% soy bran; 2 - Cupuaçu - 50% cupuaçu pie + 30% corn bran and 20% soy bran, and 3 - Murumuru - 37% murumuru pie + 39% corn bran and 24% of soy bran. The animals were milked once a day during the experimental period and supplementation was offered morning and afternoon, adjusted based on milk production. Was analyzed nine samples of probiotic fermented milk, prepared from a mixture of milk of four animals from the third experimental period, under the same supplemental treatment (Control, Cupuaçu and Murumuru) and three heat treatments (80°C/15minutos, 90°C /10minutes, and 95ºC/5minutos). To evaluate the quality of the raw material used in preparing the derived, were analyzed for microbiological and physical-chemical properties. The fermented milk was analyzed in its microbiological, physical and chemical composition, fatty acid profile and sensory profile one day after manufacture and analyzed in relation to firmness, elasticity, cohesiveness, syneresis, rheological behavior and monitoring the pH and acidity during the storage period, cooled to 6 °C ± 2 ºC in 1 day, 14 and 28 after manufacture. For the determination of rheological properties were tested three models: Ostwald-de-Waelle (Power Law), Herschel-Bulkley and Bingham. All evaluations were performed in triplicate. Data were subjected to analysis of variance with means compared by the Tukey test, the 5% significance level. Milk production corrected or not and its components (fat, protein, total solids, solids non fat, lactose and ash) had no significant effect in the different treatments. In general, can conclude that the buffalo milk, independent of supplementation, has good omega n-6/n-3 ratio, within the limits recommended for human diet. However, the concentration of PUFA is low, considering that the ratio PUFA / SFA is very low, showing the presence of high percentage of saturated fat. Most of the fatty acid profile was not influenced by treatments. The firmness of the fermented milk was not affected by supplementation in the different treatments applied to milk, or the storage period. The elasticity has a significant effect of storage period, however, supplementation and heat treatment did not influence. The cohesiveness showed significant influence of different heat treatments applied to milk, while syneresis was influenced by food supplementation of animals, heat treatments applied to milk and storage period. The heat treatment applied to milk, using the binomial time/temperature of 95ºC/5 minutes, showed, in general, lower syneresis at 28 days of storage in all samples of fermented milk. The 10ºC fermented milk showed non-Newtonian behavior. The experimental data are more appropriate for model Oswald-Walle, with better results of rheological parameters and coefficients of determination. The samples presented with behavior index (n) less than one, characterizing pseudoplastic behavior, because the viscosity of samples decreased with the applied strain rate and also thixotropic, due to its reduced viscosity with shearing time. Monitoring the fermentation process of the derivative produced no significant differences between samples in 180 minutes. The fermented milk samples showed significant differences in their composition, in relation to fat and total solids, suggesting the influence of food supplementation. The nutritional quality of lipid fraction of fermented milk is not suitable for food consumption, the nutritional point of view, however, there was a reduction in the levels of myristic and palmitic fatty acids, considered to be hypercholesterolemic when the derivative was produced with milk from treatments Cupuaçu and Murumuru. The fermented milk of the Control treatment had a higher percentage of stearic acid (C18: 0), considered a neutral fatty acid, and linolenic (C18: 3), which promotes the beneficial effects on human health, and the ratio n-6/n-3 be considered ideal for the current nutritional standards. Regarding the micronutrients iron, zinc, copper, selenium and molybdenum, all samples were within expected levels for milk and derived. Was observed a slight increase of acidity and decreased pH during the storage period, characterizing the phenomenon of post-acidification. Sensorially, fermented milk samples, showed no significant differences in the attributes evaluated, except for the acidity. The derived elaborate from the Cupuaçu treatment milk had a higher percentage preferred by consumers.