Effect of cutting edge drying technology on the physicochemical and bioactive components of mango (Langra variety) leather

Mango (Mangifera indica) leather has been mostly known as a popular traditional snack of India. Though in recent days contemporary processing methodologies like hot air drying, microwave drying and freeze-drying are replacing the traditional approach (sun drying) of mango leather preparation. This study makes a unique combination of traditional ways of processing and modern technologies. Freeze dried sample with 2.19% protein and 78.30% carbohydrate content was found superior over all other differently dried samples. Different drying techniques significantly affect the moisture content of the final product, freeze dried sample has been found with the lowest moisture content of 16.31% while the same was observed maximum in sun dried sample (17.22%). Freeze-dried product has been found to be significantly (p < 0.05) different and nutritionally better from all the other products. Freeze dried sample was found best in terms of total phenolic content or TPC (7.2 mg/g db), total flavonoid content or TFC (3.27 mg/g db) and total carotenoids content (205.1 μg/g db). Whereas, minimum TPC of 4.1 mg/g db and TFC of 4.1 mg/g db was observed for sun-dried mango leather. Hot air dried sample has been found with the lowest carotenoid content of 102.5 μg/g. In terms of DPPH, FRAP and ABTS antioxidant activity freeze dried sample has been found superior over hot air, microwave and sun dried samples. Maximum hardness (3.81 N) was observed for sun dried product while the same for lowest was 1.56 N for hot air dried sample. Hierarchical Cluster Analysis (HCA) shows the sun-dried, microwave and hot air-dried mango leather share the same cluster whereas freeze-dried mango leather has been placed in a different cluster depending on physicochemical properties studied.