Nasunin, an Amazing Chemical Constituent in Eggplants (Solanum melongena L.): A Review of Its Major Properties and Health-Promoting Effects

Due to its high antioxidant content, eggplant (Solanum melongena L.) is regarded as a valuable fruit among the top ten vegetables. The nutritional value of eggplant comes from the fact that it is considered a significant source of bioactive substances, such as phenolics and anthocyanins. These kinds of phytochemicals can be employed in food products as natural antioxidants or colors. Nasunin or delphinidin-3-(coumaroylrutinoside)-5-glucoside is a main flavonoid present in eggplant fruit, particularly the peels, which has recently drawn much consideration because of its positive effects on human well-being and potential applications in the food industry. The eggplant's peels, which are the fruit's outer layer, are widely available as agricultural byproducts for the extraction of nasunin. Such waste products constitute a significant loss of precious resources and have negative effects on the environment and the economy. Consequently, this review paper tries to highlight the main properties of the nasunin such as its antioxidant activity, gastrointestinal uptake, and the extraction approaches used for its isolation. Then, the major benefits of nasunin in human nutrition are described comprehensively. Finally, the potential applications of nasunin in different areas, especially its potential use as a natural pigment in the food sector, are discussed.