Effect of Container Type on the Physicochemical, Structural and Sensory Stability of Dahi during Refrigerated Storage

Abstract

Container material can influence fermented-dairy quality during both fermentation and subsequent refrigerated storage. Across five independent production batches, dahi was fermented in theki, clay pot, stainless-steel, plastic and aluminium containers and retained in the same containers at 4 ± 1 °C. Samples were evaluated on days 0, 7 and 14 for pH, titratable acidity, dry matter, water-holding capacity (WHC), syneresis, viscosity, instrumental texture, near-infrared (NIR)-estimated composition and sensory characteristics. Across storage, mean pH decreased from 4.45 to 4.31, titratable acidity increased from 0.62 to 0.84%, WHC decreased from 63.42 to 61.71%, syneresis increased from 10.79 to 12.93%, and viscosity decreased from 893.34 to 853.04 cP. Firmness and cohesiveness decreased, whereas adhesiveness increased numerically. Protein, fat and ash changed little, whereas lactose showed a clearer numerical decline. Theki-stored dahi had the highest mean dry matter (18.70 g/100 g), WHC (64.31%) and viscosity (913.93 cP), the lowest mean syneresis (10.47%), and comparatively limited acid development. Overall acceptability declined in all treatments but remained highest numerically in theki, decreasing from 8.43 to 8.03. The combined profile indicates container-associated differences in quality over the fermentation-and-storage system, with theki showing the most stable descriptive pattern. Because the same test containers were used during fermentation and storage, phase-specific container effects cannot be separated, and mechanistic interpretations require targeted confirmation.