Spent coffee grounds (SCG) are produced in massive quantities globally. This project focuses on the "zero-waste" cosmetic potential of SCG. By recovering residual oils rich in fatty acids and combining them with the abrasive texture of the grounds, we create a circular economy product that replaces synthetic microbeads and petroleum-based oils in premium skincare lines.
SCG are collected from commercial brewing sites and immediately stabilized via dehydration. Bio-active oils are extracted using cold-press or Soxhlet extraction. The remaining solid residue is sterilized and micronized to specific particle sizes for use as natural exfoliating agents.
While coffee beans are the primary product, coffee leaves are often neglected. This study identifies that coffee leaves contain higher levels of mangiferin and antioxidants than green tea or coffee beans. By processing these leaves into tea, we offer a low-caffeine, high-nutrient beverage that utilizes the entire plant infrastructure.
The leaves are harvested from pruning waste, withered, and rolled similarly to traditional tea. They undergo a light oxidation and drying process to lock in the polyphenolic compounds and create a smooth, earthy flavor profile.
Traditional hydrogen peroxide production is energy-intensive. This project demonstrates a photocatalytic pathway using tea and coffee waste as biomass-derived catalysts. The polyphenols in the waste assist in the reduction of oxygen to hydrogen peroxide under light irradiation, providing a decentralized, carbon-neutral chemical source.
The biomass is carbonized to create bio-based carbon dots or hydrochars. These materials act as photocatalysts in an aqueous solution. When exposed to sunlight and air, they facilitate the two-electron oxygen reduction reaction (ORR) to generate H2O2.
Coffee grounds are rich in cellulose. This study highlights the extraction of Cellulose Nanofibers (CNF) from SCG using sustainable methods. These nanofibers act as "reinforcing rods" at the molecular level, allowing bioplastics to achieve the strength and durability required to replace conventional petroleum-based plastics in commercial packaging.
The SCG undergo a delignification process to remove lignin and hemicellulose. The purified cellulose is then subjected to high-pressure homogenization or mechanical grinding, which "unfolds" the fibers into nano-sized strands with high aspect ratios.
Rejected coffee beans that don't meet roasting standards are a prime source of bio-active compounds. This project converts these low-grade beans into premium face creams. The high concentration of chlorogenic acid provides powerful antioxidant protection, while the natural oils deeply hydrate the skin, replacing synthetic emulsifiers with natural coffee-derived lipids.
Green (unroasted) broken beans are cold-pressed to extract "green coffee oil." This oil is then emulsified with distilled water and natural waxes. Caffeine is isolated from the remaining bean pulp and re-introduced into the cream for localized skin tightening effects.
