Dynamic, shear and pasting behaviour of native and octenyl succinic anhydride (OSA) modified wheat starch and their utilization in preparation of edible films.

Starch-based edible films could offer non-chemical means for preserving perishable commodities. The present research investigated the effectiveness of native and heat treated Octenyl succinic anhydride (OSA) modified wheat starch in edible film making. Pasting and rheological properties of the native and OSA modified starch as well as antioxidants and sensorial attributes of coated and non-coated grapes were evaluated. The peak and final viscosity of the OSA modified wheat starch (1270 Pa and 1589 Pa) was found to be higher than native starch (1120 Pa and 1490 Pa). Magnitude of G' and G″ was slightly increased with the increase of frequency. Modified starches showed lesser values for Peak G' as compared to native starch. G' and G″ values of native starch were 2145 and 250 Pa whereas for OSA modified starch, these values were 1780 and 190 Pa. Results exhibited that starch based coating have potential to maintain total phenolic content, total carotenoids and scavenging activities as well as the shelf life and quality of grapes for 13 days. The coated grapes were also found microbiologically safe for human consumption. OSA modified starch based coating was found to be more effective as compared to native wheat starch. Therefore, this study suggested that the edible coating with good water barrier properties will be beneficial for fruit processors to enhance the shelf-life of fresh produce.