Papaya is a tropical fruit; hence it is readily available throughout the year and economical. The primary by-products of the papaya processing industry include papaya peel and papaya seed, which accounts for 12 and 8.5% of fruit weight. These peels and seeds are rich in several phenolic compounds, which can exert an anti-oxidant effect in aquatic animals when administered through feed as a nutraceutical. There are very few significant studies available using papaya processing waste in the case of aquatic animals.
Atshaya. S, N. Shamna, Parimal Sardar, Manish Jayant, N.P Sahu*
ICAR-CIFE, FNBP Divison, Mumbai. *Corresponding author ([email protected])
Papaya is a tropical fruit; hence it is readily available throughout the year and economical. The primary by-products of the papaya processing industry include papaya peel and papaya seed, which accounts for 12 and 8.5% of fruit weight. These peels and seeds are rich in several phenolic compounds, which can exert an anti-oxidant effect in aquatic animals when administered through feed as a nutraceutical. There are very few significant studies available using papaya processing waste in the case of aquatic animals.
Globally, aquaculture is the booming food-producing sector and the growth rate of the sector is constantly increasing in the last few decades. To gear up with the drastic increase of world population and to ensure food safety and security from fisheries sector, it is a must to increase the overall aquaculture production. The production from aquaculture is possible through vertical expansion because horizontal expansion is limited due to limitation in resource availability. Increasing production is made possible nowadays because of aquaculture intensification. But vertical expansion may challenge the growth and immunity of fish. Fishes maybe stressed, their immune system collapses, and feed intake gets reduced. Hence, such systems require nutraceuticals to boost the immune system of the fish. Whereas, oxidative stress occurs in fish when there is an imbalance between the reactive oxygen species and the body’s antioxidant system. In this case, we need to provide adequate anti-oxidants through diet to cope with the oxidative stress; commercially available synthetic antioxidants include ethoxyquin, BHA, BHT etc. where ethoxyquin cannot be used in the feed when exporting to Japan, whereas BHA, which is a possible human carcinogen, hence the best and sustainable switch is to move towards natural sources.
STATUS OF ORGANIC
WASTE GENERATION
Food waste is one of the deadly menaces generated by the human population and as per FAO statistics, 1/3 or 1.3 billion tons of food waste are generated annually. They contribute to environmental pollution and climate change through the humongous amount of carbon dioxide emissions globally. The United Nations have issued a warning stating that 10% of greenhouse gas emissions are mainly due to food waste accumulation. Fruit and vegetable waste occupy the top-most position among all types of food wastage which can reach up to 60%. They are usually power-packed with rich nutritional components, and account for almost 39% of total organic waste generation. Hence, it is the need of the hour to evaluate how best we can convert these fruit waste or vegetable waste into input of other sectors. There are multiple fruits available, ranging from local to exotic ones; wastage from these fruits can be utilized individually or in a mixture. One such strategy is to unlock the numerous bioactive substances imbibed within them and apply it in aquafeed as immunoceuticals. We all know that fruits are generally enriched with several antioxidant substances, utilizing their by-products as a natural antioxidant defence in the aquatic animals is the most remarkable approach one has to study in this climate crisis scenario.
PAPAYA BY-PRODUCTS
AS FUNCTIONAL ADDITIVES IN AQUAFEED
Papaya is a tropical fruit; hence it is readily available throughout the year and economical. It comes under the Caricaceae family. India is a top producer of papaya globally with an annual production of 5.95 million metric tons (Statista, 2021). Because of the numerous health benefits this fruit offers; it is popularly called human fruit/medicine tree/melon of health. Papaya is popular among all age groups because of its taste, and it has a vast industrial scope. The primary by-products of the papaya processing industry include papaya peel and papaya seed, which accounts for 12 and 8.5 % of fruit weight (Pathak et al., 2019). These peels and seeds are rich in several phenolic compounds (Table 1), which can exert an anti-oxidant effect in aquatic animals when administered through feed as a nutraceutical. There are very few significant studies available using papaya processing waste in the case of aquatic animals.
The proximate analysis of papaya peel meal showed that it has a crude protein ranging from 6 to 10% (Table 2). Among different fruits, papaya has the highest carotenoid concentration than other fruits like pineapple, olives, etc. Beta-Carotene is the most dominant carotenoid present in the papaya, providing an antioxidant defence as we as the precursor of Vitamin A. In general, papaya peel is rich in carbon and nitrogen; hence it can be used as the substrate for cultivating micro-organisms. The papaya is generally rich in several protease enzymes, which can impact animal digestion and growth. Papain is the popular proteolytic enzyme obtained from the latex of unripe papaya; it is widely used as the meat tenderizer in the food industry. Papaya is rich in several micronutrients, especially vitamins and minerals, which have a considerable role in cultured animals’ growth and health status. It was found that mineral content in peel and leaves are much higher than pulp (Asghar et al., 2016). Hence, papaya peel can be a potential feed additive in aquafeed as it is rich in several phenolic compounds such as gallic acid, ferulic acid, caffeic acid etc. These compounds have anti-inflammatory, anti-microbial, antioxidant and chelating properties. Here the waste product of one industry is used as the starting material for another industry; hence this approach is sustainable and can contribute towards the circular economy.
WAY FORWARD
Preparation of papaya extract and application of papaya peel meal can be a potential method for utilising papaya wastes in aquafeed. Studies showed that application of papaya seed is also beneficial for fishes (Farrag, F. H. et al., 2013).
CONCLUSION
Several studies from the by-products of fruit have already reported the potential of these phenolic compounds to be used as an additive in the aquafeed, whereas less significant studies were reported from papaya. Further studies on the effect of papaya peel meal and the extract can provide insights on the nutraceutical potential when administered as an additive in the aquafeed. It is a loss if these by-products of papaya with rich bioactive compounds dumped as waste. Moreover, it creates stress to environment and sustainability of the eco-system will be affected.
References:
Chukwuka,K.S., Iwuagwu, M., Uka, U.N.2013 Evaluation of nutritional components of Carica papaya L. At different stages of ripening IOSR journal of pharmacy and biological sciences. ;6(4):13–16.
Undugodage,Dulanjali.Rodrigo.,Bulathsinhalage,Gayani.Kanchana.Perera.2018. Important biological activities of papaya peel extracts and their importance in formulation of a low cost fish feed to enhance the skin colour and the healthiness of guppies, DOI: 10.29322/IJSRP.8.12.8490.
Pathak,N., Khan, S., Bhargava, A., Raghuram, G.V., Jain, D., Panwar, H., Samarth, R.M., Jain ,S.K., Maudar, K.K., Mishra, D.K., Mishra, P.K.2014. Cancer chemopreventive effects of the flavonoid-rich fraction isolated from papaya seeds. Nutrition and Cancer ,66(5):857–871.
FAO. The State of World Fisheries and Aquaculture 2020. Sustainability in Action http://www.fao.org/documents/card/en/c/ca9229en (FAO, 2020).
Mehrim, Ahmed. (2013). Pawpaw (Carica Papaya) Seeds Powder In Nile Tilapia (Oreochromis Niloticus) Diet 1- Growth Performance, Survival, Feed Utilization, Carcass Composition Of Fry And Fingerlings. J. Animal and Poultry Prod., Mansoura Univ., Vol.4 (6): 363 – 379, 2013.
Asimi,O. A., Sahu, N. P. 2013 Herbs/spices as feed additive in aquaculture. Scientific Journal of Pure and Applied Sciences 2:284-292.
Abani,Deka., Sahu,N.P., Jain,K.K. 2003.Utilization of fruit processing waste in the diet of Labeo rohita Fingerling. Asian-Australian journal of animal sciences, Vol 16, No11:1661-1665.
