Intermediate moisture kinnow bar from low grade kinnow mandarins: Phytonutritional profile, morphological characterization, and storage stability

Abstract

Low grade kinnow have less commercial value but are rich in bioactive compounds and have enough potential for value addition. The present study aimed at utilizing kinnow juice extracted from low-quality kinnow to develop a convenient ready-to-eat phytonutrients-rich fruit bar. Pectin was added at different concentrations (1–4%) to improve the quality of the formulated bar. Increasing the pectin levels increased the hardness of formulated bars while decreasing moisture and water activity, without affecting color and nutritional properties. Developed bars showed high minerals and phytochemical constituents (8.41 mg/100 g ascorbic acid, 591.48 mg GAE/100 g total phenolic, 388.56 mg QE/100 g total flavonoids, 3.28 mg/100 g total carotenoids, 20 ppm limonin, and 68.12% antioxidant activity) as confirmed using colorimetric and ICP-AES analysis. The microstructure of the bars was consistent with the texture values. Based on desirable sensory and textural properties, kinnow bars formulated with 4% pectin was selected for product development and evaluation of shelf life under room (25 ± 2 °C) and refrigerated (4 ± 2 °C) conditions. A significant (p < 0.05) difference was observed in physicochemical, phytochemical, and microbiological attributes during storage at both temperatures. However, the loss of quality was rapid at room temperature. Kinnow bars were shelf-stable for up to 4 months at room temperature and 6 months under refrigeration conditions, respectively. Valorization of low grade kinnow can provide the dual benefit of producing phytonutrient-rich snack product along with kinnow waste management.