SHELF LIFE OF SPRAY‐DRIED MILK FORMULATIONS SUPPLEMENTED WITH N‐3 FATTY ACIDS

Studies were carried out to assess the shelf life of spray‐dried milk formulation containing linseed oil (LSO) or fish oil (FO) as a source of n‐3 polyunsaturated fatty acids (PUFA) in comparison with a milk formulation containing groundnut oil (GNO) stored at 4, 27 and 37C in tin cans for a period of up to 6 months. Total protein, fat, carbohydrate, moisture and solubility index of formulations stored for 6 months were comparable with fresh samples. The fresh samples containing LSO contained 20% ∝ linolenic acid (LNA). At the end of 6 months, the ∝ LNA levels were found to be 18.4, 18.0 and 16.2% in samples stored at 4, 27 and 37C, respectively. The fresh samples containing FO had 2.4% eicosapentaenoic acid (EPA). At the end of 6 months, the EPA levels were found to be 2.2, 2.0 and 1.6% in samples stored at 4, 27 and 37C, respectively. The docosahexaenoic acid (DHA) level in the freshly prepared sample containing FO was 2.1%. At the end of 6 months, the DHA levels were found to be 1.7, 1.6 and 1.3% in samples stored at 4, 27 and 37C, respectively. The whiteness of the formulation containing GNO, LSO or FO remained unaltered for a period of 5 months, but dropped marginally when n‐3 PUFA‐containing formulations were stored at 37C for 6 months. Acceptability scores of formulations were similar for 5 months storage but declined significantly in the FO formulation at the end of 6 months of storage. All n‐3 PUFA‐enriched milk formulations were stable and accepted well for up to 5 months when stored at different temperatures.