Influence of season on milk fatty acid profile and sensory characteristics of grazing goats in a Mediterranean environment: a sustainable agro-food system

Abstract

Context Pasture is widely used in rural Mediterranean areas as a local resource for animal feeding in a sustainable food system. Aims The present study aimed at evaluating the effects of pasture from a Mediterranean environment on milk fatty acid profile and organoleptic characteristics in grazing Cilentana goats bred in Cilento (Salerno province, southern Italy). Methods Twelve Cilentana dairy goats, grazing on local feeding resources were studied for 5 months (from May to September), starting from 60 days after kidding. Bodyweight and milk yield were recorded, whereas milk samples were collected and analysed for milk chemical composition and fatty acid profile. Milk organoleptic characteristics were analysed using an instrumental sensory platform. Key results Season significantly (P < 0.01) affected the pasture fatty acid profile, with the highest polyunsaturated fatty acid (PUFA) content (64.83%) occurring in May. Results of the milk fatty acid composition, permitted to classify as ‘High quality’ the goat milks sampled in May and June, with the significantly (P < 0.01) highest monounsaturated fatty acid (MUFA; 23.98% and 25.37%) and PUFA (4.74% and 4.43%) contents and lowest saturated fatty acid:unsaturated fatty acid (SFA:UFA) ratio (2.50 and 2.36), and as ‘Low quality’ those sampled in August and September with the significantly (P < 0.01) highest SFA (75.79% and 75.84%) content. Milk n-6:n-3 polyunsaturated fatty acid ratio was always lower than 4. Some sensory differences in milk organoleptic characteristics were detected by the artificial senses platform, which would be almost impossible to detect by a human panel. Conclusions Milk samples obtained from grazing goats were influenced by the quality of local feeding resources in terms of nutraceutical value and sensory profile. Implications Pasture influenced the composition of milk functional compounds, improving the UFAs and conjugated linoleic acid isomers, widely recognised as having beneficial effects on human health. The n-6:n-3 PUFA ratio, lower than 4, confirms the positive effects of pasture on nutritional characteristics of goat milk and underlines the important role of pasture of marginal areas for the quality of livestock products in the frame of a sustainable agro-food system. Some differences were detected by the artificial senses platform among milk samples, which were almost impossible to detect by a human panel, highlighting the potentiality of the artificial senses to link animal-sourced foods to a territory.