The Relationship between Fruit Size and Phenolic and Enzymatic Composition of Avocado Byproducts (Persea americana Mill.): The Importance for Biorefinery Applications

Abstract

Avocado byproducts are a rich source of health-promoting biomolecules. The purpose of this work is to study three groups of statistically different avocado fruit sizes (Persea americana Mill.) (small (S), medium (M), and large (L)), and their relationship with total phenolic and flavonoid contents (TPC and TFC, respectively), DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging capacity and individual phenolics, and the activities of phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS), and polyphenol oxidase (PPO) in avocado peel extract (APE). The results indicated that TPC, TFC, and antioxidant and enzymatic activities were higher in the APE of the S group (p < 0.05). The flavonoids (flavanols and flavonols) and phenolic acids were also significatively concentrated in S group’s APE. Overall, the phenolic content was significantly lower in the L group. Positive correlations (p < 0.0001 and p < 0.05) were observed between TPC, TPF, DPPH, and enzymatic activity, and negative correlations resulted for avocado weight and volume. The outstanding phenolic content and enzymatic activity of avocado peels from low-cost avocado byproducts are ideal for biorefinery applications, thereby increasing the bioeconomy of the avocado industry.

Persea Americana Agro-Industrial Waste Biorefinery for Sustainable High-Value-Added Products

“…The study reported higher TPC, TFC, and antioxidant and enzymatic activities in avocado peel extract from the small size group, while these parameters were significantly lower in the other groups. These results suggest avocado by-products' suitability for biorefinery applications [13].…”

Tropical Fruits and Their Co-Products as Bioactive Compounds and Their Health Effects: A Review

“…Araujo et al [61] identified 15 major compounds in the peel, such as 11 procyanidins, dimers and trimers in different isomer shapes. Trujillo-Mayol et al [31] identified that the main flavonoids present in avocado peel were epicatechin (0.02 mg/g) and hesperidin (0.01 mg/g). In addition, there were non-flavonoid phenolics such as caffeic acid (0.2 mg/g), coumaric acid (0.1 mg/g) and ferulic acid (0.01 mg/g) [62].…”

“…This fruit is also considered very valuable because it has a complete nutritional content associated with many health benefits due to the high levels of unsaturated fatty acids, minerals, fiber, proteins, vitamins and phenolic compounds [102,152]. This high content of phenolic compounds confers to avocado numerous biological activities, including antifungal, antibacterial, antidiabetic, antihypertensive, anti-inflammatory, anticancer, and hypo-cholesterolemic properties [31,61,103,153,154]. Ervianingsih et al [155] used avocado seed waste in biscuits as an alternative food for people with diabetes, because studies demonstrated that the flavonoids could reduce blood glucose levels through glucose absorption or by increasing insulin secretion, can stimulate glucose absorption in peripheral tissues, and regulate the work of enzymes involved in carbohydrate metabolic pathways.…”

“…Figure 1. Flavonoid family and non-flavonoid phenolics found in tropical fruits and their coproducts [25][26][27][28][29][30][31][32][33][34][35][36].…”

Fractionation and Hydrolyzation of Avocado Peel Extract: Improvement of Antibacterial Activity

“…The peels from avocado Hass ( Persea americana Mill) were obtained from small-sized avocado fruits from the north part of Chile, according to a previous characterization [ 85 ]. Then, an hydroethanolic avocado crude extract was obtained by the optimal condition of the ultrasound–microwave combined method developed in our previous work [ 3 ].…”