Physical-chemical and microbiological quality of milk and cheese of goats fed with bidestilated glycerin

The objective of this study was to evaluate the effects of replacing corn with bidistilled glycerin from the biodiesel industry on the physicochemical, microbiological, and sensory quality of milk and goat cheese. Twelve Saanen multiparous goats weighing 40 +/- 6 kg and 30 +/- 5 days of lactation were used. The physicochemical parameters analyzed were: fat (%), non-fat solids (%), protein (96), lactose (96), salts (%), relative density at 15/15 degrees C (gmL(-1)), index cryoscopic (degrees C), electrical conductivity (mScm(-1)), pH and acidity. The milk from each treatment was used to make the rennet cheese. The physicochemical variables: pH, lipids, ESD, and cheese yield had a significant effect (P < 0.05) for the increasing use of bidistilled glycerin in the goat feeding. The pH, acidity, EST, ESD, and yield variables presented linear regressive effect and lipids quadratic regressive effect. The softness sensory attribute had a significant effect (P < 0.05) for the increasing levels of bidistilled glycerin in the goat diet; the softness decreased as the glycerin level increased. Bi-distilled glycerin, when inserted in the diets of dairy goats at increasing levels, promotes a reduction in the lipid content of milk, consequently affecting the cheese yield and the sensory softness parameter.