Natural products particularly natural colorants have attained worldwide importance and being eco-friendly can be considered an alternative to toxic dyes in order to reduce environmental pollution. The current study is based on the exploration of natural coloring behavior of bitter gourd leaves extract for cotton dyeing. Colorant was extracted using different extraction media like aqueous, alkali, organic, and acidic at different conditions. It has been found that on application of 50 ml of acidic extract having 6 g/100 ml of table salt for 55 min at 60 C°, maximum color yield has been obtained onto cotton. Upon using chemical and bio-mordants, new shade with good color fastness rating was obtained. FTIR analysis of extract showed the presence of flavonoids. It is concluded that under mild condition, bitter gourd leaves extract can be considered potential source of natural colorant for cotton dyeing and the presence of bio-mordant has made the process more soothing and sustainable in nature.

India is one of the highly developing countries in the world and it has the second-largest agricultural source of income, which covers 61% of the entire income of the country. The most valuable income group, by giving the appropriate training in this technology, will make their entire country to become one of the most highly developing counties in the world. In recent years, many developing, developed, and underdeveloped countries face shortages of fish, fruits, and vegetables due to natural disasters like earthquakes, tsunami, and any other unexpected events. Now the main issue of this paper is to preserve the food products from post-harvest to consumer-level, which cover 60% of losses due to the unavailability of preservative methods. This paper mainly focused on the conventional methods to advanced solar drying technologies for perseverating fish, fruits, and vegetables and also it discusses the technology used for drying the yield range of fish like Atheriniformes, Catfish, Chilwa, etc. Fruits like banana, mango, and papaya, and vegetables like bitter gourd, cabbage, and cocoa beans have been reviewed and also discussed some problems along with their solutions in concern with food products drying, thereby the selection of dryer for drying products will be made easy by this review article. On the whole, this investigation would help researchers in fish drying to choose the better drying methods for acquiring better results for particular fish, fruits, and vegetables that enable any entrepreneur to select the appropriate method reducing the cost and time.