Evaluation of Storage Stability of Milk-flaxseed-based Probiotic Composite Beverage

Abstract

The study was conducted during September, 2022 to April, 2023 at National Dairy Research Institute and aimed to investigate the storage stability of a novel milk-flaxseed-based probiotic composite beverage under refrigerated conditions. The beverage was developed by combining skim milk with roasted flaxseed flour and fermenting it with Lactiplantibacillus  plantarum NCDC-21. The product was evaluated for various quality attributes over a 14 days storage period at 4±2°C, using both PET and glass packaging materials. Sensory analysis revealed a gradual decline in quality attributes such as color, consistency, and overall acceptability, with a significant changes observed after the 8^th day of storage. Physicochemical analysis indicated a decrease in pH and an increase in titratable acidity over time, while viscosity initially increased followed by a declining trend after the 8^th day of refrigerated storage. L. plantarum count decreased from 8.8 log cfu ml^-1 to 8.26 log cfu ml^-1 in PET bottles and 8.35 log cfu ml^-1 in glass bottles by the 10^th day of refrigerated storage. The study concluded that the milk-flaxseed-based probiotic beverage maintained the acceptable quality up to 10 days under refrigerated storage conditions, with glass bottles offering slightly better preservation in terms of sensory and microbial quality as compared to PET bottles. Additionally, the study also highlighted the potential of flaxseed incorporation in fermented dairy beverages for enhancing functional and nutritional properties while maintaining probiotic viability during refrigerated storage.