Resveratrol-loaded β-Lactoglobulin Nanofibrils to Prevent Enzymatic Browning on Sliced Apple

Background and Objective: Resveratrol is a polyphenol with nutraceutical health benefits used as anticancer, antioxidant and anti-inflammatory with cardio protective effects. However, resveratrol lacks solubility and bioavailability and is affected by UV light, which decrease its use in food industries. It is possible to overcome these problems by loading resveratrol with appropriate biomaterials. Beta-lactoglobulin is known to form well-defined nanofibrils with various uses. The objective of this study was to use β-lg nanoscaled fibrils to increase bioavailability of resveratrol as well as preserving freshness and preventing enzymatic browning of sliced apples. Material and Methods: Novel composite nanofibrils were prepared by loading resveratrol on Beta-lactoglobulin nanofibrils using simple self-assembly method. Furthermore, atomic force microscopy, scanning electron microscopy, in-vitro release assay, weight loss, total acidity, total phenolic content and antioxidant activity studies were carried out to verify the biochemical sustainable release and bioavailability.  Results and Conclusion: Atomic force microscopy and scanning electron microscopy images showed the formation of well-defined composite nanofibrils with an average aspect ratio of 1000; as shown in other studies. In-vitro release assay revealed that resveratrol was successfully loaded on nanofibrils due to possible hydrogen bonding interactions and other non-covalent linkages. The highest encapsulation efficiency of 61.1% was achieved using low concentrations of resveratrol (10mg in 1ml), whereas encapsulation efficiency of 48.3% was achieved for high concentrations of resveratrol (20mg in 1ml). The assessed weight loss, total acidity, color, total phenolic content and antioxidant activities showed ~50% increases in the shelf-life and prevention of enzymatic browning due to improved bioavailability of resveratrol. The current study could successfully demonstrate antioxidant potency of resveratrol in sliced apples and help better protections against ageing. The formula can be used as a protective layer on high-value food products such as fruits susceptible to deteriorative conditions.