Effect of raw material pretreatment and drying methods on mango seed kernel flour (<i>Mangifera indica</i> Linn.) properties: nutrition, physicochemical, and antibacterial activity

Abstract In this study, pretreatment methods such as water soaking at 25 °C (WS), hot water soaking (HS), and salt soaking combined with blanching (SSB) were applied to reduce astringency and enhance the usability of mango seed kernel flour (MSKF) through three different drying methods: convective drying (CD), heat pump drying (HPD), and freeze drying (FD). The evaluation results showed that MSKF treated by WS was selected for all three drying techniques. The scanning electron microscopy images revealed that the surface morphology of the starch particles was either spherical or elliptical. Meanwhile, FTIR confirmed the presence of functional groups (-OH, -C=O) and bioactive compounds, which were correlated with antioxidant and antibacterial activities. FD demonstrated the highest capability in preserving nutritional, physicochemical, and chemical properties, followed by HPD and CD. Due to its superior retention of total phenolic and tannin content, FD exhibited the highest free radical scavenging ability against DPPH and ABTS, as well as the strongest antibacterial activity, followed by HPD and CD.