Implications of Substitution of Natural Sweeteners in Guava Nectar on Qualitative Characteristics and Storage Stability

Research background. Lately, extensive use of refined sugars and artificial sweeteners has led to negative heath implications. Therefore, natural or unrefined sweeteners such as honey, date syrup and jaggery are explored in the present study as a potential alternative ascribed to its nutritional and therapeutic properties. Experimental approach. The study aimed to optimize level of honey, jaggery and date syrup to substitute sucrose in guava nectar prepared through two processing treatment including hot filling (HF) and cold filling (CF). It was further evaluated for its bioactive properties, rheological characteristics, mineral composition (in-vitro bioavailable iron) and storage stability. During storage, formation of 5-hydroxymethylfurfural (HMF), effect on antioxidant activity and non-enzymatic browning was focused to indicate changes in overall quality. Results and conclusions. The level of substitution was optimized at 50, 25 and 30 % in honey, jaggery and date syrup-based guava nectar, respectively, based on organoleptic properties. The optimized formulations depicted a significant improvement in total phenolic content and radical scavenging activity. The guava nectar was found to have pseudo-plastic behavior with a weak gel structure due to the presence of dispersion of pulp particles contributing to its viscoelastic nature below low strain levels (<10 %). The substitution of sweetener resulted in enhanced mineral content; however, the bioavailability of iron (%) considerably decreased. During storage, degradation of ascorbic acid and colour, acceleration of non-enzymatic browning, and development of 5-hydroxymethyl furfural were notably high by the end of the 6th month, but formulations were microbiologically stable. Novelty and scientific contribution. New products can be formulated using natural sweeteners instead of sucrose which can imply higher nutritional and therapeutic value. However, in the present study, the product can be improved by further research to reduce negative implications on quality characteristics during storage.