Effect of season on fatty acid and terpene profiles of milk from Greek sheep raised under a semi-extensive production system

Abstract

The objective of the study was to investigate the effect of season on the fatty acid and terpene composition in ewe milk. A total of 760 samples of bulk sheep milk were collected during winter (147 samples), spring (314 samples) and summer (299 samples) of 2011, from 90 commercial farms of dairy sheep from the prefecture of Grevena, Greece. Regarding fatty acid composition, summer samples had higher concentrations of α-linolenic acid, cis-9, trans 11- CLA, trans-11, C18 : 1 and PUFAs but lower content of saturated fatty acids particularly C12 : 0, C14 : 0 and C16 : 0. The winter milk had the lowest content of terpenes, in particular sesquiterpenes, compared to spring and summer milk. The terpene profile of milk samples, in all three seasons, revealed the presence of monoterpenes: a-pinene, b-pinene and D-limonene, especially with a higher frequency of appearance in summer. The most common and abundant sesquiterpenes found in milk samples were β-caryophyllene and α-caryophyllene with a higher frequency of appearance in summer. In conclusion, the available pastures in semi-extensive farming systems can contribute to the production of high quality milk.

Seasonal variation of fatty acids composition of milk from grazing ewes in Thessaly, central Greece

“…Similarly, other major FAs were the myristic (C14:0) and stearic (C18:0) among SFA, cis-9 oleic (C18:1 cis-9) among MUFA, and cis linoleic (C18:2 cis) among PUFA. In line with the present study, previous studies on FA profile of ovine milk produced by sheep under grazing pasture (Atti et al, 2006;Carloni et al, 2010;Papaloukas et al, 2016) or conventional feeding conditions (Castro et al, 2009;De La Fuente et al, 2009), showed the same predominant FAs. Mean values followed by different letters in the same column are significantly different (P<0.05).…”

“…Carloni et al, (2010) examined ovine milk produced by various sheep breeds (Suffolk, Fabrianese, Sopravvissana, Sarda) in the plains and mountainous areas in Marche region (central Italy) under combined conventional or grazed pasture feeding conditions and reported seasonal variations of cis-9, trans-11 CLA values ranging from 0.01 to 0.07%, 0.08 to 1.96% and 0.50 to 2.22% FAME in December, May and July, respectively. Papaloukas et al, (2016) reported that bulk ovine milk produced by various sheep breeds fed on grazing pasture in mountainous areas in Northern Greece showed cis-9, trans-11 CLA values of 0.58, 0.98 and 1.12% FAME in winter, spring and summer, respectively. Seasonal variations of C18:2 cis-9, trans-11 CLA in milk from cows (Chion et al, 2010;Sasanti et al, 2015) or goats (Milewski et al, 2018) produced under grazing pasture feeding conditions were also reported.…”

Effects of Intensive and Semi-Intensive Production on Sheep Milk Chemical Composition, Physicochemical Characteristics, Fatty Acid Profile, and Nutritional Indices

“…Fatty acid composition was determined by gas chromatography (GC) as described by Papaloukas et al [ 18 ]. Briefly, lipids were extracted with a chloroform/methanol solution (1:2 v/v ) that contained 0.01% ( w/v ) of t-butyl-hydroxytoluene (BHT) to prevent fatty acid oxidation during extraction, according to the Bligh and Dyer method [ 19 ].…”

Determination of Fatty Acids Profile in Original Brown Cows Dairy Products and Relationship with Alpine Pasture Farming System

“…Milk and cheese samples fatty acids composition was determined by gas chromatography (GC) according to Bligh and Dyer method [38] and International Organization for Standardization (ISO) [39] as has been reported previously by Papaloukas et al [40]. A total of 37 fatty acids (16 saturated fatty acids, 9 monounsaturated fatty acids, 7 n6 polyunsaturated fatty acids, 4 n3 polyunsaturated fatty acids, and 1 stereoisomer of conjugated linoleic acid) were evaluated.…”