Chemical-nutritional characteristics and aromatic profile of milk and related dairy products obtained from goats fed with extruded linseed

Asian-Australas J Anim Sci. 2020 Jan 1;33(1):148-156. doi: 10.5713/ajas.18.0868. Epub 2019 Apr 15.

Abstract

Objective: This study aimed to evaluate the effect of dietary integration with extruded linseed (EL) on fatty acid (FA) and aromatic profile of goat cheese after 60 (T60) days of ripening.

Methods: Thirty goats were divided in two groups. The control group (CG) was fed with conventional diet, whereas the experimental group (EL+) was fed with conventional diet supplemented with 10% of EL. Milk samples were collected on 30 and 60 days of trial to determinate chemical-nutritional composition and FA profile. At the end of experiment, six cheese-making session (3 for each group) were carried out using a pooled milk sample obtained from the 15 goat of each group. At 60 days of ripening, cheeses were analyzed for chemical-nutritional composition, FA and aromatic profile.

Results: An increase in the milk production, protein, fat and lactose were evidenced in the EL+ goats. Conversely, a reduction of somatic cells was observed in the EL+ compared with the CG. However, no variation was observed for urea and casein levels content in milk samples, and no changes in protein and lipid content were found for cheeses in the two experimental groups. Dietary supplementation with EL modified the FA profile of milk. There was a decrease in saturated fatty acids (SFA) and an increase in polyunsaturated fatty acids (PUFA). Chemical composition of T60 cheese did not differ between the two groups but a different FA profile was observed. In particular, in T60 cheese obtained from EL+ milk, an increase in short-chain FA (SCFA) and a decrease in medium and long-chain FA (MCFA and LCFA) were observed. The EL diet led to cheeses with butanoic acid 2 time higher compared to CG cheeses. Moreover, a greater presence of aldehyde compounds and alcohols were observed in the cheeses of experimental group.

Conclusion: The present study pointed out that EL supplementation may improve the chemical and physical qualities of goat milk and cheeses.

Keywords: Extruded Linseed; Fatty Acids; Ripened Goat Cheeses; Volatile Compounds.