Researchers flag coffee grounds as sustainable ingredient for cosmetic scrubs
A new study has revealed the potential for spent coffee grounds (SCGs) in cosmetic scrubs as consumer demand for sustainable personal care products grows.
Cosmetic scrubs are used in the beauty industry to exfoliate the skin by removing dead skin cells and hydrating the skin’s upper layer. SCGs can be found in the cosmetics industry in spent coffee oils, bioactive extracts, and exfoliating creams.
Published in the journal Cosmetics, researchers from the Institute of Chemical Technology and Engineering at Poznan University of Technology in Poland determined that SCGs can be suitable raw materials for producing cosmetic scrubs. They tout a stable chemical structure, sustainability benefits, exfoliating qualities, and a “pleasant coffee aroma.”
The study investigates the stability of emulsions, a core ingredient in cosmetic scrubs, by evaluating different emulsifiers such as apricot kernel oil, soya lecithin, and olive oil-based natural emulsifiers in combination with SCGs.
Research method
Emulsions are the base for producing scrubs but can destabilize quickly if not combined with a surfactant. Emollients keep skin soft, smooth, and supple by increasing the lipid content of the upper layers of the skin. The study explored multiple emollients to create a stable base for SCG-based cosmetic scrubs.
The SCGs were dried at 50 degrees for three days and then sieved to get particles between 150 and 300 micrometers. An emulsion base was created in 25 mL samples by combining glycerine, castor oil, and macadamia oil emulsifiers at a 40% concentration with added vegetable oils. The dried and sieved SCGs were added to the emulsion base at 1 g per sample and mixed for two minutes at 1000 rpm to create the scrub.
The final product was analyzed under a microscope and processed using Matlab software. The emulsions’ color, odor, and consistency were evaluated through sensory tests to determine their stability when combined with the SCGs.
The study concluded that apricot kernel oil was the only stable emulsifier used, providing a suitable base for coffee-based scrubs.
Circular cosmetics
Moreover, the study indicates that reusing food waste by producing other products is a growing area of the circular economy. Only 30% of coffee bean mass is transformed into coffee drinks, with most ending up as SCGs, which have been mainly disposed of as waste.
Therefore, using ingredients of natural origin, such as SCGs, can reduce environmental pollution by re-entering waste products into the market. As a result, less microplastics enter soil and water as the polymeric abrasive particles, traditionally used in cosmetic scrubs, are replaced by a natural, biodegradable raw material.
The demand for sustainable personal care products is rising as consumers become more concerned with the environmental impact of ingredient sourcing and decomposition after use.
Recently, the EcoBeautyScore Association unveiled a product scoring tool for the cosmetics industry. The tool aims to implement a user-friendly, science-based method for calculating products’ environmental impact.
The tool, created with software provider Pilario, hopes to empower cosmetic and personal care brands to understand their products’ sustainability impact. Brands can input data such as product descriptions, ingredients, and packaging information.
