Subcritical Water Extraction of Mango Seed Kernels and Its Application for Cow Ghee Preservation

Mango seed kernel (MSK) extract contains phytochemicals, bioactives, and fatty acids that are of interest to food and nutritional scientists. The subcritical water extraction process (SCWE) can be effective in extracting valuable bioactives from MSK. In this study, SCWE was investigated and optimized for the extraction of bioactives from MSK using Box–Behnken experimental design. The extract yield was examined as a function of various process variables, namely, solvent-to-feed (L/S) ratio, extraction temperature (T), and extraction time (t). Analysis of variance (ANOVA) for experimental results showed that extraction temperature was the most significant variable that impacted the extract yield. A maximum yield of 52.3% was obtained at optimized extraction conditions of L/S ratio = 20.7, T = 116.5 °C, and t = 45 min. Antioxidant assessment of the SCWE extract obtained at the optimized conditions showed higher total phenolic content (19.2 mg GAE/g), and DPPH and ABTS radical scavenging activity (>91%), than the extracts obtained by conventional hot water extraction and ultra-sound assisted extraction. Furthermore, an assessment of the MSK extract as a natural preservative showed that its inclusion (20% v/v) improved the oxidative stability of cow ghee with a par performance to synthetic butylated hydroxyanisole antioxidant (0.02% w/v). Thus, the study demonstrated SCWE as an effective green method for the production of MSK extract that could be applied for the preservation of oxidative food products.