Osmo-sonication drying and their effect on bioactive compounds, antioxidant and colour properties of apple rings

Abstract

The effect of osmo-sonication (OS) drying on retention of bioactive compounds i.e. total phenolic content (TPC), total flavonoids content (TFC) and antioxidant power capacity (DPPH) of apple rings under convective dryer was investigated. Thickness of 4mm apple rings, sucrose concentration of 500B and osmo-sonication time for 30 min optimized through Response Surface Methodology (RSM) were convectively dried until the weight of samples did not change. Thereafter, the effect of osmo-sonication on quality characteristics were evaluated and compared with osmotically dried rings. Results concluded that osmo-sonication improved the preservation of total phenolic content (TPC) (30.53 mg /100g), total flavonoids content (TFC) (12.00 %) and antioxidant power capacity (DPPH) (30.92 %) as compared to osmotically dried rings. Besides this, osmo-sonication retained the color quality of dried apple rings than the osmotically dried rings. Moreover, osmo-sonication results in lower total color change (ΔE) (4.21) in dried apple rings samples compared to osmotically dried rings (10.59).