Biological Activity of Avocado By-Products: A Review Focusing on Farm Animals’ Health

Abstract

The avocado industries produce a large amount of waste, which constitutes a threat to the environment. In this work, the complete set of bioactive compounds from avocado by-products (AP), their biological activities, and the experimentation accomplished using AP in farm animals’ diets are reviewed. AP, that is seeds and peels, are raw sources of phenolic compounds (flavanol monomers, procyanidins, and hydroxycinnamic acids), furan derivatives, aliphatic acetogenins (which have antimicrobial and spore germination inhibiting effects), carotenoids, phytates, polyols, and sterols. Moreover, AP contain valuable nutrients (proteins, lipids, and carbohydrates) that could effectively contribute to farm animals’ diets. Among the biological properties of AP, highlight their antimicrobial, antioxidant, and anti-inflammatory ones. Ill effects of avocado by-products seem to be animal species-dependent, given that AP has been cited as conditionally toxic for some animals. Conversely, feeding AP has positive effects on pigs, and these have been used successfully to feed goats and sheep, and in aquaculture. To use AP as livestock feed, the excessive amount of bioactive compounds could be decreased by hydrothermal treatment. This was successfully applied to avocado seeds to reduce bioactive compounds and fiber contents to safe levels. Overall, AP could be used for extracting healthy compounds to be used as nutritional supplements, and for improving the health of selected farm animals. Furthermore, AP-derived compounds could be useful in reducing the emergence of antibiotic-resistant bacteria, which has been linked to the abusive use of antibiotics when used as growth promoters in farm animals' production.