The impact of double-distilled glycerin supplementation on the quality of goat milk and cheese

Abstract

The objective of this study was to evaluate the effects of replacing corn by double-distilled glycerin, a co-product of the biodiesel industry, on goat curd cheese in terms of physical-chemical, microbiological and sensory aspects. Twelve multiparas Saanen goats weighing 47.07 ± 2.41 kg and at 90 ± 5 days of lactation. The experimental design was completely randomized with two treatments (0 and 15% inclusion of glycerin). The physicochemical parameters analyzed were: fat (%), non-fat solids (%), protein (%), lactose (%), salts (%), relative density at 15/15 °C (gmL-1), index cryoscopic (°C), electrical conductivity (mScm-1), pH and acidity. The milk from each treatment was used to make the rennet cheese. The fat had a significant effect (P < 0.05) with inclusion of glycerin in the diet. The physicochemical characteristics of the cheese were influenced (P < 0.05) by feeding up to 15% of glycerin. Regarding sensory attributes, only firmness was influenced (P < 0.05) by the inclusion of glycerin in the diet of dairy goats. Bidistilled glycerin, when inserted in the diet of dairy goats at a level of 15%, causes a reduction in the lipid content of milk and cheese, consequently affecting the cheese yield, and the parameter of firmness in the sensory of the evaluated cheeses.