Bioactive compounds, antimicrobial properties of Açaí (Euterpe oleracea mart.) and its processing residues – Insights for smart packaging and green chemistry

Euterpe oleracea Mart. is a palm tree native to the Brazilian Amazon, an important food source producing açaí fruit, rich in flavonoids of antioxidant and antimicrobial activities. Açaí oil pulp is a rich source of lipophilic antioxidants, rich in mono- and polyunsaturated fatty acids (60% oleic acid and 12% linoleic acid), vitamins A, E, D, and phytosterols. Açaí fruit comprises 10% of pulp and 90% of residues. Its processing also generates the seed as a by-product, and recent studies showed açaí seed oil (∼6% yields) rich in flavonoids, anthocyanins, oleic, linoleic, myristic, and palmitic acid. Herein, we provided a comprehensive overview of antimicrobial activity and bioactive compounds in açaí. We identified technical approaches to improve antimicrobial activity as the effect of solvent extract; combining bioactive compounds; encapsulation of açaí oil in inclusion complexes with potential as excipients and carriers; açaí oil as oily portion of nanoemulsions; incorporation in edible films and coatings to biodegradable packaging materials; açaí extract as natural pH indicator for colorimetric sensing in smart packaging; and synergism with non-thermal food processing methods. Phenolic acids and cyanidins were mainly found as bioactive compounds. Açaí showed antibacterial, antifungal, antiviral, and antiplasmodial activities and synergism with other antimicrobial drugs. Polyphenols of açaí can survive in vitro intestinal digestion and exert anti-genotoxic effects on gut health. We also identified açaí seed waste extracts in new insights for green synthesis in producing novel nanomaterials and intelligent packaging of antioxidant and antimicrobial potential.