Enzymatic, Antioxidant, and Antimicrobial Activities of Bioactive Compounds from Avocado (Persea americana L.) Seeds

Abstract

The aim of this research was to identify and quantify biologically active compounds from avocado (Persea americana L.) seeds (AS) utilizing different techniques with the use of ultrasound (US), ethanol (EtOH), and supercritical carbon dioxide (scCO2) for possible applications in (bio)medicine, pharmaceutical, cosmetic, or other relevant industries. Initially, a study of the process efficiency (η) was carried out, which revealed yields in the range of 2.96–12.11 wt%. The sample obtained using scCO2 was found to be the richest in total phenols (TPC) and total proteins (PC), while the sample obtained with the use of EtOH resulted in the highest content of proanthocyanidins (PAC). Phytochemical screening of AS samples, quantified by the HPLC method, indicated the presence of 14 specific phenolic compounds. In addition, the activity of the selected enzymes (cellulase, lipase, peroxidase, polyphenol oxidase, protease, transglutaminase, and superoxide dismutase) was quantified for the first time in the samples from AS. Using DPPH radical scavenging activity, the highest antioxidant potential (67.49%) was detected in the sample obtained with EtOH. The antimicrobial activity was studied using disc diffusion method against 15 microorganisms. Additionally, for the first time, the antimicrobial effectiveness of AS extract was quantified by determination of microbial growth-inhibition rates (MGIRs) at different concentrations of AS extract against three strains of Gram-negative (Escherichia coli, Pseudomonas aeruginosa, and Pseudomonas fluorescens) bacteria, three strains of Gram-positive (Bacillus cereus, Staphylococcus aureus, and Streptococcus pyogenes) bacteria, and fungi (Candida albicans). MGIRs and minimal inhibitory concentration (MIC90) values were determined after 8 and 24 h of incubation, thus enabling the screening of antimicrobial efficacy for possible further applications of AS extracts as antimicrobial agents in (bio)medicine, pharmaceutical, cosmetic, or other industries. For example, the lowest MIC90 value was determined for B. cereus after 8 h of incubation in the case of UE and SFE extracts (70 μg/mL), indicating an outstanding result and the potential of AS extracts, as the MIC values for B. cereus have not been investigated so far.

Chemical analysis and bioactive compounds from agrifood by-products of peruvian crops

“…The extracts of avocado seeds and mango peel did not present antimicrobial and antifungal activity. Other researchers point out that Hass avocado seed extract (Romaní et al, 2017), avocado seed (Kupnik et al, 2023), and mango peel (Lozoya-Castillo et al, 2018) inhibit the microbial growth of S. aureus and E. coli. This difference can be attributed to the extraction conditions.…”

“…Antimicrobial and antifungal activity is assigned to phytochemical compounds such as polyphenols. The mechanism of action is due to the change in the function of cell membranes and the consequent slowing of growth and inhibition of microorganisms' reproduction (Singh et al, 2018;Kupnik et al, 2023). Moreover, seeds and agribusiness waste extracts also have many health-related bioactive properties, such as antihyperglycemic, anticancer, antihypercholesterolemic, antioxidant, anti-inflammatory, and antineurogenerative effects, which can be used to formulate or fortify foods (Kupnik et al, 2023;Sławińska and Olas, 2023;Sorrenti et al, 2023).…”

Waste Rubber Incorporated in the Alkali-Activated Metakaolin’s Aluminosilicate Network Enhanced by Microwave Irradiation

“…AS are rich in biologically active substances such as polyphenols, acetogenins, triterpenoids, and K. Kupnik et al: Bacterial Cellulose Membranes Enriched With Bioactive Compounds From Avocado Seeds 63 others (Jimenez et al 2021). In our recent study (Kupnik et al 2023), AS extracts exhibited significant antimicrobial activity against 13 out of 15 tested microorganisms, which often pose a problem in antimicrobial resistance, are transmitted by food or are colonized during food packaging. High concentrations of antimicrobial compounds, i.e., hesperidin, 2,3-dihydroxybenzoic acid, and vanillin, were found in AS extracts, which can synergistically contribute to high antimicrobial properties of AS extracts.…”

Quality attributes and shelf-life of freshly cut beef coated with waste feather keratin-ginger starch composite enriched with avocado peel polyphenolic-rich extract

“…Previous research has demonstrated the rich phenolic content of avocado peel, highlighting its potent antioxidant and antimicrobial properties against foodborne pathogens (Kupnik et al, 2023;Sadiye, 2021). However, integrating avocado extract into composite coatings for extending the shelf life of perishable foods remains a relatively unexplored avenue.…”