Exploration of avocado by-products as natural sources of bioactive compounds

Abstract

This study aimed to evaluate the antioxidant, anti-inflammatory, and cytotoxic properties and phenolic composition of peel and seed of avocado varieties Hass and Fuerte using green solvents. Ethanol soluble compounds were identified in peel and seed of both varieties using HPLC-MS/MS and quantified using HPLC-DAD. Agro-industrial by-products of both varieties exhibited high radical scavenging activity against synthetic free radicals (DPPH and ABTS) and reactive oxygen species (peroxyl, superoxide, and hypochlorous acid) and high ability to reduce Fe3+ to Fe2+. The main compounds with significant contribution to the antioxidant activity determined by online HPLC-ABTS●+ analyses were procyanidin B2 and epicatechin in the peel and trans-5-O-caffeoyl-D-quinic acid, procyanidin B1, catechin, and epicatechin in the seed. Peel of Fuerte significantly suppressed TNF-α and nitric oxide (NO) release (459.3 pg/mL and 8.5 μM, respectively), possibly because of the high phenolic content and antioxidant activity detected. Avocado agro-industrial by-products can be used for food and pharmaceutical purposes due to their antioxidant and anti-inflammatory properties.

Improvement of the polyphenol extraction from avocado peel by assisted ultrasound and microwaves

“…While MAE and UAE did not show significant differences ( p > .05) between the antioxidant indicators; maceration presented the lower FRAP, but the lipidic peroxidation inhibition was statistically equal ( p > .05) to UAE and MAE. Even though this is the first work reporting the comparison of different extraction methods on the biological activity of avocado peel phenolic extracts; the results are in good agreement with Tremocoldi et al (), Melgar et al () and Morais et al (), whereas, the antioxidant indicators here, were entirely satisfactory.…”

“…Recently, it was reported the extraction of phenolics from avocado peel var. Hass yielded 63.5 mg GAE/g using the same solvent system for this study and sonicated for 15 min at room temperature (Tremocoldi et al, ). Alike, the application of pressurized liquids on avocado peel yielded 57 mg GAE/g with ethanol/water (50:50, v/v) at 200°C (Figueroa, Borrás‐Linares, Lozano‐Sánchez, Quirantes‐Piné, & Segura‐Carretero, ).…”

“…The recent studies about phenolic extraction from avocado by‐products employed the conventional maceration (Melgar et al, ; Torres et al, ) or less affordable non‐conventional methods (Figueroa, Borrás‐Linares, Lozano‐Sánchez, & Segura‐Carretero, ). Regarding UAE, it was performed in another study to characterize the phytochemicals of two varieties of avocado fruits and their by‐products (Tremocoldi et al, ). However, the optimal extracting parameters were not evaluated, consequently, is unknown the effect of sonication time and temperature for the maximum TPC recovery.…”

“…(Epi) Catechins, quercetin, hydroxycinnamic acids, chlorogenic acids, and its derivatives, as well as procyanidins A and B, are some of the main identified phenolics in avocado peel (Figueroa, Borrás-Linares, Lozano-Sánchez, Quirantes-Piné, & Segura-Carretero, 2018;Torres et al, 2018). Therefore, there is a growing interest in obtaining these extracts and the purified compounds to be used by the food industry as innocuous clean label ingredients (Rodríguez-Carpena, Morcuende, Andrade, et al, 2011;Tremocoldi et al, 2018).…”

Fruits By-Products – A Source of Valuable Active Principles. A Short Review

“…Nevertheless, regardless the benefits which are obtained by processing fruits by-products within food industry, current preliminary scientific evidence confirms that fruits waste can be considered as a valuable source of phytoconstituents for medicinal applications. Anti-inflammatory potential of avocado peel and seed extracts was reported to suppress the release of tumor necrosis factor-α and generation of nitric oxide in lipopolysaccharide-stimulated RAW264.7 macrophages (Tremocoldi et al, 2018). Gastroprotective activity was reported for avocado seeds extract against indomethacin-induced gastric ulcer in mice (Athaydes et al, 2019).…”