Avaliação do leite e do queijo minas frescal de cabras alimentadas com dietas contendo glicerina bruta em substituição parcial ao milho

Abstract

The effects of partial replacement of corn by crude glycerin on the physico-chemical characteristics and chemical composition (pH, dornic acidity, fat, protein, lactose, total solids, defatted dry extract, urea nitrogen and casein), somatic cell count were evaluated (CCS), microbiological and sensory analysis of goat's milk, the attributes evaluated were aspect, odor, texture, flavor, overall impression, purchase intention and preference scale for acceptability of goat's milk), physicochemical characteristics were evaluated of the type fresh cheese (pH, dornic acidity, moisture, ash, fat, protein), microbiological of pasteurized milk and the type fresh cheese (count of aerobic mesophiles, Staphylococcus aureus Salmonela spp., Listeria spp., total coliforms). The experiment was carried out at the Federal Rural University of Pernambuco (UFRPE). Were used 16 Saanen goats, after the peak of lactation, with an average body weight of 50 kg and an average production of 3.5 kg / milk/day. A Latin square design with 4 experimental units per treatment was used, the goats were distributed in the treatments with different levels of crude glycerin, being treatment GB0 - control without addition of glycerin, GB5 - 5%, GB10 - 10% GB15 - 15% of glycerin in the dry matter of the diet. Official analytical methods were used for microbiological analysis to control products of animal origin. Variance analysis was performed using the General Linear Models (GLM) procedure of the Statistical Analysis System program (Sas Institute, 2009). The means were compared using the Tukey test (P <0.05). The inclusion of GB in the goat diet promoted a quadratic effect for protein (0.0062) and casein (0.0047) and a reduction in fat content (2.50 to 2.12 g / kg), total solids (10.05 to 9.57g / kg) and urea nitrogen (19.26 to 15.89 mL / dL) with decreasing linear effect. The partial replacement of corn by glycerin up to the level of 10% in the goats' diets does not alter the physical chemical characteristics of the milk and the fresh Minas cheese of goat milk. At the level of 10% replacement of corn by crude glycerin, there was greater acceptance of the Minas Frescal cheese. Milk and cheese minas frescal met the microbiological standards of identity and quality according to Brazilian legislation.