Avocado peel: a source of bioactive compounds

Avocado peels are often regarded as a wasted by-product. However, as sustainability awareness increases among consumers and key stakeholders of the agri-food industry, there has been higher demand to push for a circular economy in the production process—focused on reducing food waste and turning by-product waste into valuable products. Researchers from Spain and Ecuador investigated the potential of using avocado peels extracts for nutraceutical purposes to further the idea of repurposing what otherwise would be wasted. According to the paper published in Food Chemistry (DOI: https://doi.org/10.1016/j.foodchem.2021.129300), avocados’ peels show antioxidant and other properties of interest to the nutraceutical industry.

Researchers extracted avocado peel’s bioactive compounds via Microwave Assisted Extraction (MAE)—a modern, quick, efficient, and sustainable technique. They then tested the extractions’ matrix metalloproteinases (MMP) inhibition, antioxidant capacity, and antimicrobial activity against Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli, Enterobacter hormaechei bacteria, Kluyveromyces marxianus yeast and Galactomyces candidus mould.

Avocado peel MAE extractions led researchers to identify 53 compounds, including organic acids, phenolics, flavonoids, catechins, procyanidins and other polar compounds. Interestingly, 25 of those compounds were procyanidins. “Among them, dimers and trimers of procyanidin (type A and B) were the most abundant phenolic compounds,” researchers added.

They concluded, “Regarding potential applications of the optimized avocado peel MAE extract, the high MMP inhibitory capacity at relatively low concentrations and the high antioxidant capacity suggest its interest for the food industry as an antioxidant ingredient with preserving properties or for the formulation of functional foods and nutraceuticals with antioxidant and anti-ageing activities.”