Bioactive phytochemicals and antioxidant activity in fresh and dried lychee fractions1

Abstract

-Fruit of the lychee cv. Bengal are approximately 50% peel and seeds, which are discarded. These byproducts have antioxidant compounds which are capable of blocking the harmful effects of free radicals in the body. Bioactive compounds (ascorbic acid, beta-carotene, lycopene and phenols) and antioxidant activity were evaluated in different extracts, both fresh and dried at 45 °C, of the skin, pulp and seeds of the lychee, which were subjected to principal component analysis to clarify which of the compounds are responsible for this activity. Principal component analysis explained 82.90% of the variance of the antioxidant profile of the lychee. The peel displayed higher levels of phenols, ascorbic acid, beta-carotene and antioxidant activity, while the seeds stood out due to their levels of lycopene. With drying, there was a decrease in the levels of ascorbic acid and beta-carotene and in antioxidant activity, with an increase in the levels of phenols and lycopene. The antioxidant activity found in the peel and seeds of the lychee is high, and is mainly due to ascorbic acid and beta-carotene, as demonstrated by principal component analysis, allowing the use of these fractions as sources of natural antioxidants.Key words: Lychee. Antioxidants. Principal component analysis. RESUMO -Os frutos da lichieira cv. Bengal possuem aproximadamente 50% de casca e semente, que são descartadas. Estes subprodutos apresentam compostos antioxidantes capazes de bloquear os efeitos danosos dos radicais livres, no organismo. Foram avaliados os compostos bioativos (ácido ascórbico, betacaroteno, licopeno e fenóis) e a atividade antioxidante, em diferentes extratos da casca, polpa e semente de lichia, in natura e secas a 45 ºC, os quais foram submetidos à análise de componentes principais, para elucidar quais compostos são responsáveis por esta atividade. A análise de componentes principais explicou 82,90% da variância do perfil antioxidante da lichia. A casca apresentou maiores teores de fenólicos, ácido ascórbico, betacaroteno e atividade antioxidante, enquanto a semente destacou-se pelos teores de licopeno. Com a secagem, houve decréscimo nos teores de ácido ascórbico e betacaroteno e na atividade antioxidante e aumento nos teores de fenólicos e licopeno. A atividade antioxidante encontrada na casca e semente de lichia é elevada e se deve, sobretudo, ao ácido ascórbico e ao betacaroteno, conforme demonstrado pela análise de componentes principais, o que possibilita o uso destas frações como fontes de antioxidantes naturais.Palavras-chave: Lichia. Antioxidantes. Análise de componentes principais.

Extraction, chemical characterization and antioxidant activity of Litchi chinensis Sonn. and Avena sativa L. seeds extracts obtained from pressurized n-butane

“…For instance, Queiroz et al (2015) reported the litchi antioxidant capacity of 47.92% for aqueous extract, 27.67% for acetone extract, 39.12% for the extract with 70:30 (v/v) acetone:ethanol and 78.42% for the methanol extract. It can be stated that n-butane has better ability to extract compounds with antioxidant activity than water, ethanol and acetone, while methanol is equivalent.…”

Polyphenols derived from four indigenous Indian fruits for cancer chemoprevention and chemotherapy

“…Polyphenolic compounds with ortho-diphenolic structure are abundant in litchi pericarp. Flavonoids and anthocyanins, like procyanidin B2, B4, epicatechin, cyanidin-3-retinoside, cyanidin-3-glucoside, quercetin-3-retinoside and quercetin-3-glucoside constitute significant percentage of bioactive principles of litchi pericarp (Queiroz et al, 2015;Lin et al, 2013;Wang et al, 2006). Phenolic constituents of litchi pup may exist in free or bound form and their composition depends greatly on selection of proper extraction solvent mixture.…”

Evaluation of Lychee Fruits and Effect of Osmotic Treatments on Flesh Quality

“…The peel and seed are rich in antioxidants such as ascorbic acid, phenolic compounds including gallic acid, flavonoids (procyanidin B4, procyanidin B2 and epicatechin) and anthocyanins (cyaniding 3-rutinoside, cyanidin-3-glucoside, quercetin3-rutinoside and quercetin 3-glucoside). Pharmacological studies indicate that the by-products of the lychee have various effects including anti-inflammatory, anti-hyperlipidemic, anti-hyperglycemic, hepatic and cardioprotective, as well as having high antioxidant activity [7].…”