Harnessing the potential of bitter gourd seeds for food and nutrition- A comprehensive review

Approximately 5 % of all seeds at a seed company are discarded because of their underutilization. Bitter gourd contains a large number of seeds that are discarded, which are difficult to treat and cause severe environmental pollution. However, these seeds are a rich source of bioactive metabolites (such as glycosides, saponin, alkaloids, triterpenes, steroids, dietary fibers, essential oils, and saturated and unsaturated fatty acids) with antioxidant, antimicrobial properties, and health-promoting effects. So, it is important to find ways to treat this waste and use it in various food products and health-promoting effects to benefit humans and prevent environmental pollution as per Goal 12 (responsible consumption and production) of 17 sustainable development goals (SDGs) set by the United Nations. This review discussed the extraction of different functional compounds by using traditional and modern extraction techniques, nutraceutical and food applications, as well as the toxicological effects of the bitter gourd seeds, aiming to give a new research direction to the researchers of concerned fields to find more potential applications of this natural waste. Both in vivo and in vitro study results showed that bitter gourd seeds in powder, extract, and oils can be used as antioxidant and antitumor agents and showed antidiabetic, anti-obesity, antibacterial, anti-inflammatory, and anticancer activities. Bitter gourd seeds also have healthy and technological compounds that could be used in food industries to improve food products' quality, stability, and nutritional characteristics. Bitter gourd seeds can also be used to purify drinking water. Further studies are needed to find more applications of this natural by-product in developing functional and nutritious foods.