Relationship between carbohydrate composition and fungal deterioration of functional strawberry juices preserved using non-thermal treatments

Abstract

BACKGROUND: The quantification of the main carbohydrates present in strawberry juices enriched with inulin and fructo-oligosaccharides (FOS) and preserved by non-thermal techniques (vanillin and ultrasound) were studied, as well as the evolution of these compounds and their relationship with fungal deterioration during 14 days of refrigerated storage. RESULTS: A simple and environmentally friendly analytical approach based on high performance liquid chromatography with reflection index detector was developed for simultaneous determination of inulin, FOS and mono and disaccharides present in the juices. When analyzing the evolution of carbohydrates during storage, a direct relationship between the consumption of sucrose and the growth of yeasts and molds (main spoilage flora in strawberry) was observed, especially in untreated samples (control). On the contrary, no sucrose consumption was observed during storage of treated sample, thus demonstrating the efficiency of the non-thermal treatments to control yeasts and molds growth. In turn, inulin and FOS added to juices were not degraded during storage. CONCLUSION: The results demonstrated that non-thermal treatments are adequate to prevent the growth of deteriorative flora in strawberry juices and adding inulin and FOS can be a good strategy to functionalize them, improving their nutritional properties.