Effect of Blackcurrant Juice Soaking on Anthocyanin Stability, Color Development, and Quality Characteristics of Semi-Hard Ripened Cheese

The application of natural colorants in cheese manufacture is gaining increasing interest as an alternative to synthetic additives. This study investigated the incorporation, stability, and technological effects of blackcurrant (Ribes nigrum L.) anthocyanins on semi-hard Trappist cheese during eight weeks of storage under simulated commercial refrigerated display conditions. Cheese samples were soaked in natural blackcurrant juice for seven days and subsequently evaluated for anthocyanin composition, color characteristics, texture properties, microbiological quality, and sensory acceptance. HPLC analysis confirmed the successful incorporation of blackcurrant anthocyanins into the cheese, with delphinidin-3-rutinoside(D-3-R) being the predominant compound. D-3-R concentration decreased from 20.23 to 5.88 mg/100 g dry matter during storage, corresponding to an approximately 71% reduction, while cyanidin-3-rutinoside content became below the detection limit by week 8. Significant changes were observed in all quantified anthocyanins (p ≤ 0.05), indicating progressive pigment degradation. The maximum image-based color difference reached ΔE = 38.20 under standardized imaging conditions. Interestingly, color development followed a biphasic pattern, characterized by initial pigment redistribution and color intensification despite decreasing anthocyanin concentrations, followed by progressive color fading associated with anthocyanin degradation. Texture analysis revealed significant storage-related changes in the mechanical properties of the rind, suggesting structural reorganization of the cheese matrix. Microbiological analyses demonstrated the persistence of technologically important lactic acid bacteria throughout storage, indicating compatibility of the treatment with the cheese microbiota. Sensory evaluation performed by 60 consumers showed high acceptance of blackcurrant-treated cheese. The results indicate that blackcurrant juice soaking is an effective strategy for producing naturally colored semi-hard cheeses enriched with anthocyanins while maintaining desirable microbiological, textural, and sensory characteristics. The observed degradation kinetics under the storage conditions applied in this study emphasize the importance of optimizing storage conditions for anthocyanin-enriched dairy products.