Evaluation of the physico-chemical properties of jam made from star fruit and cape gooseberry

Abstract

The growing consumer interest in naturally derived, health-oriented, and shelf-stable food products has created a significant opportunity for the utilization of underexplored fruits and herbs in functional food development. Among such promising candidates are Cape gooseberry (Physalis peruviana) and Star fruit (Averrhoa carambola) nutrient-dense tropical fruits known for their abundance of vitamin C, antioxidants, polyphenols, and dietary fiber. This research was undertaken with the objective of developing herbal-flavoured preserved food products, including Jam by integrating the nutritional and therapeutic benefits of these fruits with selected herbs such as mint, rose petals and basil leaves. The initial phase of the study involved the determination of the nutritional composition of the selected fresh fruits and herbs. Parameters such as moisture content, ash, total soluble solids (TSS), titratable acidity, pH, vitamin C content, and antioxidant potential were analysed using standard protocols. This baseline nutritional data provided a foundation for formulation decisions. Star fruit (Averrhoa carambola) and cape gooseberry (Physalis peruviana) are nutrient-rich fruits characterized by high levels of organic acids, vitamins, and antioxidant compounds. This study aimed to develop a blended best treatment of jam from star fruit and cape gooseberry with herbs and evaluate its physico-chemical properties. Different formulations were prepared by varying pulp ratios of star fruit and cape gooseberry Jaggery/Sugar, with the value addition of Mint, Rose Petals, Basil Leaves and Cinnamon (35g,23g,25g,6g,4g,3g,4g). The jams were analyzed for pH, total soluble solids (TSS), titratable acidity, moisture content, ash content, vitamin C, and sensory attributes. The results indicated that increasing the proportion of cape gooseberry significantly increased titratable acidity and antioxidant content, while star fruit contributed to improved pectin content and texture, showing desirable TSS (-65.12°Brix), pH (-2.35), and high sensory acceptability. The study demonstrates that blending star fruit with cape gooseberry improves both nutritional quality and physico-chemical stability of jam products, providing potential for commercial fruit preservation and functional food development.