Quality parameters and lipid composition of oil extracted from spent coffee grounds: A promising alternative to vegetable oils used for consumption and cosmetic purposes

Abstract

Coffee grounds are the most commonly generated daily waste in the world, raising numerous questions regarding their proper management and their environmental impact. The present study focuses on the physical and chemical characterization of oil extracted from spent coffee grounds (SCG), with the aim of valorizing this by-product as a potential source for oil production. The results obtained from the analysis of SCG oil were also compared to those of some edible oils (soybean, corn, and sunflower oils) and cosmetic oils (lentisc, sweet almond, and castor oils). The results revealed that spent coffee waste yielded an important amount of oil, specifically 17.19%, as compared to corn (4.31%) and soybean (19.52%) seeds. Regarding the fatty acids composition of SCG oil, eight components were identified, with a high percentage of polyunsaturated fatty acids accounting for more than 45% of total fatty acids. The phytosterols composition of SCG oil revealed the presence of seven components, with β-sitosterol being the predominant one. The tocopherol analysis showed that SCG oil contained only α and β isomers, with β-tocopherol being the dominant form at over 68%. These findings accentuate the potential of spent coffee waste as a promising alternative for oil production and open up new applications for SCG oil, such as in the food industry, pharmaceutical applications, and cosmetics.

Practical Application: Given the significant increase in the demand for vegetable oils, the oil industry has recently begun to explore new plant matrices, particularly those having low costs. SCG are the most commonly generated daily by-product in the world. The present investigation aims to characterize and valorize the oil extracted from SCG. The obtained results revealed the potential of SCG as a promising alternative for oil production. Consequently, valorizing spent coffee waste as a natural by-product for oil production can be an ideal solution to address numerous issues related to its proper management and its environmental impact. Hence, the oil industry can promote spent coffee waste, cheapest by-products, as a promising alternative for oil production. Moreover, the present investigation represents a commendable model of the circular economy since the remaining waste obtained after extracting lipids from the coffee grounds waste can be used as natural fertilizer rich in protein for plant development.