Rubber tree seed utilization for green energy, revenue generation and sustainable development– A comprehensive review

With the growing awareness and sensitivity towards green energy, it makes an excellent opportunity to promote rubber trees [Hevea brasiliensis (Willd. ex A.Juss.) Muell.Arg.] as an alternate source for sustainable development and cleaner production. In recent years, rubber tree has extensively been used only for its latex. The most neglected yet abundant by-product of the rubber tree is the seed biomass. The rubber tree seeds can yield a constant source of biomass which would need a little care, financial investment, and time. This biomass efficiently can be used in several small-scale or medium-scale industries, and one of the positive aspects of using this biomass is its zero or neutral CO2 emission. A little effort, if given into its resource utilization, can go a long way in augmenting the income and improving the livelihood of the rubber tree cultivators, as well as help to develop a cleaner and sustainable environment. Instead of using the seeds as mere propagating material, these can otherwise be used in organic farming. Rubber tree seeds being protein-rich, the seed cakes and seed meal after the oil extraction can act as an abundant source of organic manure and a potential natural fertilizer. The seeds have an intrinsic property of acting as herbicides and fungicides. The seed cake, owing to its nutritional value, can be used as cattle and poultry feed. The problem of food scarcity is a major contributing factor to malnutrition in the underprivileged sections of society. The rubber tree seeds can play an influential role by supplementing protein and as an alternate source of food, thereby helping the developing nations combat the food crisis. The few available reports regarding rubber tree seeds consumed by the tribes inhabiting the Amazon basin are worth mentioning. Rubber tree seeds contain cyanogenic compounds, and extensive research is needed to develop a methodology to eliminate such toxic compounds, which can help humanity overcome the challenges of food shortages in underdeveloped and developing nations. In today’s COVID-19 pandemic scenario, there is a multiple-fold increase in demand for soaps and handwash for personal hygiene. This demand shall continue to grow in the coming days, and the inclusion of rubber tree seed oil (RSO) in producing soaps may ease the burden on vegetable oil, which can be used for human consumption. Rubber tree seed oil can also be used effectively in the cosmetics industry. Several encouraging reports support the idea of the inclusion of RSO in cosmetics to minimize the detrimental effects of harmful chemicals on the human body. The use of rubber tree seed oil as an alternate energy source cannot be downplayed. Rubber tree seed oil not only has a high ability to become an excellent source of biofuel but also has enormous potential in other industrial sectors. Products derived from RSO are used in several industrial sectors, including the paint industry, soap industry, and engineering sector as core binders. All products obtained from rubber trees can clearly show a path for cleaner green energy production and help to establish a rapport between nature and livelihood generation. The present review investigates the overall possibilities of rubber tree seed utilization as an alternate source of biomass and its venture into the various fields of biological utility and possible means of revenue generation in developing countries.