Sweet and deproteinized sheep whey: A nutrient-rich coproduct with seasonal variability

This study evaluated the nutritional and physicochemical characteristics of sweet and deproteinized sheep whey across seasons. Whey type significantly affected composition, with deproteinized whey showing lower total solids (6.82%) than sweet whey (7.64%), primarily due to reduced protein (0.89% vs. 1.56%) and fat (0.19% vs. 0.55%) content. Both were lactose-rich (50 g/L). Seasonal variations were observed, with higher fat in summer and increased sugar in winter. Sheep whey consists primarily of saturated fatty acids (80%), with polyunsaturated fatty acids (2.6%) showing a favorable ω6/ω3 ratio (3.44-2.85) compared to cow whey (4.0). Seasonal diets influenced fatty acid composition, increasing MUFA in summer and SFA in winter. Essential (31,7%) and branched-chain (19%) amino acids were present, with proline and glutamic acid abundant. The study is limited to a single dairy over one year, and findings may not fully represent other dairies, breeds, or production conditions. These results highlight whey’s potential as a valuable cheese coproduct for innovative foods and sustainable artisanal sheep dairy. • Sheep whey composition varies by type and season: more fat in summer, sugar in winter • Whey type dictates protein composition, whereas season modulates fat and sugar • Essential and branched-chain amino acids are abundant, with proline as the major one • High short- and medium-chain fatty acids suggest nutritional and health advantages