The largest revenue generating sector for the Nestlé corporation is beverages, sold in both powdered and liquid form. In 2020, beverages, aside from bottled water, accounted for approximately 26% of Nestlé sales, or around £17.3 billion. Nearly 40% of this revenue came from soluble coffee and other coffee products. On a global scale, coffee is the 98th most traded product.
Coffee products starts their life as the edible seeds of the coffee plant. Coffee requires a humid, tropical climate to grow and its production is localised to equatorial nations. Beans are extracted from the ripe fruit of the coffee plant, known as the cherry. The remaining parts of the cherry, including the skin and the pulp, account for around 45% of the entire mass of the fruit. This accounts for the primary food loss in the initial farming of coffee beans.
The skin, husks, peels and pulp of the fruit contain many of the compounds present in the bean themselves including complex polysaccharides and phenolic compounds. The peel and pulp are traditionally fermented to create alcoholic beverages or lactic acid. This indicates a high carbohydrate content which could have a number of promising value streams. Studies have indicated that coffee cherries make a fantastic feeding material for the growth of edible fungi, specifically shiitake mushrooms. Shiitake mushrooms originate from East Asia and are a low-calorie and nutrient rich food. This can provide a promising new venture for growers and the communities surrounding coffee farms.
Additionally, there is an emerging market for beverages made from the coffee cherry itself, retaining some of the antioxidants and caffeine lost in the cherry pulp. Cascara, or cherry pulp tea is expected to join the European market once it gains approval from the European Food Standards Agency, which is required for all novel foods. It is already manufactured by Swiss company La Semeuse SA and an Austrian coffee importer, Panama Varietals, is looking to put its own cascara-based drink on the market after approval.
The hard skin of the coffee cherry has been identified for its high fibre content. The skins could be used as a dietary supplement for fibre, aiding proper digestion. The silver skin, the film-like layer covering the bean has been found to contain starches and antioxidants. This also makes them a potential pollutant when disposed of carelessly. Caffeine, phenols and tannins present in coffee beans and by-products can be highly disruptive to soil ecosystems, rising from the high oxygen demand required to break down the biomass. Coffee beans themselves also contain thousands of different chemicals.
Once separated from the fruit, coffee beans are roasted to generate the aromatic flavour associated with coffee, then ground into a coarse powder and treated with hot water, creating the end product, a cup of coffee. It is these coffee grounds that present the largest food waste stream associated with coffee. Around 60% of the original biomass of the beans ends up as waste grounds. Coffee grounds are also an inevitable by-product of instant coffee production, in which freshly brewed coffee is dried by either spray-drying or freeze-drying then packaged and sold as instant coffee.
The chemical composition of coffee beans and used coffee grounds has been analysed with an interest in repurposing the chemicals going unused in the spent grounds. Until recently, the primary focus has been the conversion of the lipids in coffee to biofuels. Companies such as the UK-based BioBean dedicate their business to the manufacturing of fuel pellets from coffee grounds collected from businesses. However, it is the philosophy of IntelliDigest that nutrient recovery should come first before being used as combustible fuels.
For shareholders this should be an exciting venture as well. Chemical recovery and extraction of nutrients, commodities and feedstocks has been shown to be between 3.5 to 7.5 times more profitable than converting to animal feed or fuels (Pfaltzgraff, 2013).
The lipids, extractable from coffee grounds, that are currently being mass produced into fuel logs, biodiesels and other energy sources can also be repurposed into dozens of novel applications. The oil extracted from waste coffee grounds can be used as a starting material for the renewable polymer poly(3-hydorxybutyrate) (PHB). PHB can be used for similar purposes as similar plastics such as polythene, but unlike polythene it is quickly and rapidly biodegradable. An advantage PHB has over other renewable polymers is that it is intrinsically water insoluble and will be able to weather getting wet or even being used to contain liquid whilst still retaining the ability to be broken down rapidly by microorganisms. Production of a renewable and biodegradable polymer by Nestlé could improve public perception of the company as being committed to cutting down pollutions, transitioning from plastics and taking climate change seriously.
Other studies have demonstrated that the high polysaccharide content of spent coffee grounds could be exploited with enzymatic hydrolysis to release sugars and primary alcohols that can be used as food additives, including mannitol, a useful low-calorie sweetener.
IntelliDigest is a biotechnology company specialising in establishing innovative solutions for businesses in the food system, from farm-to-fork, to become more sustainable. Prioritising the elimination of edible food waste and the efficient upcycling of inedible food wastes back into the food system. We draw on our cutting-edge research, consulting, and training capabilities to address the global food sustainability challenges.
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