ABSTRACT
AIM To optimize the decolorization technique for Boletus edulis polysaccharides and to evaluate the antioxidant activity.METHODS With decolorization temperature,resin consumption,polysaccharide concentration and decolorization time as influencing factors,decolorization rate and polysaccharide recovery rate as evaluation indices,orthogonal test was applied to optimizing the decolorization technique on the basis of single factor test.Then the antioxidant activity was determined by Fe2+ chelating power,hydroxyl free radical scavenging activity and reducing power tests.RESULTS The optimal conditions were determined to be 30 ℃ for decolorization temperature,7.5 g/100 mg polysaccharides for S8 resin consumption,1 g/L for polysaccharide concentration,and 2 h for decolorization time,the decolorization rate and polysaccharide recovery rate were 89.34％ and 49.26％,respectively.The polysaccharides demonstrated strong Fe2+ chelating power and hydroxyl free radical scavenging activity with weak Fe3+ reduction power.CONCLUSION This stable and reliable method can be used for the decolorization for Boletus edulis polysaccharides with good antioxidant activity.
ABSTRACT
Los antioxidantes son esenciales en el cuerpo humano para prevenir el daño oxidativo. Estas sustancias pueden obtenerse de diferentes fuentes como frutas, plantas y hongos. En Guatemala, diversas especies de hongos comestibles son comercializadas y consumidas, sin embargo su actividad antioxidante no ha sido documentada en el país. El objetivo de este estudio fue determinar la actividad antioxidante de extractos acuosos y etanólicos obtenidos de diez especies de basidiomicetos comestibles (Agaricus aff. bisporus, Agaricus brunnescens, Armilla-riella polymyces, Amanita garabitoana, Boletus edulis, Cantharellus lateritius, Laccaria amethystina, Lactarius deliciosus, Neolentinus ponderosus y Pleurotus ostreatus). Se utilizó un método cualitativo por cromatografía en capa fina (CCF) y tres ensayos macrométricos in vitro de cuantificación de fenoles totales, reducción del radical 1,1-difenil-2-pricrilhidrazilo (DPPH) y decoloración del radical catiónico del reactivo ácido 2,2-azinobis-(acido-3-etilbenzotiazolina-6-sulfónico)(ABTS). Los extractos acuosos mostraron mayor actividad antioxidante que los extractos etanólicos en todas las técnicas cuantitativas realizadas. La especie que mostró mayor actividad antioxidante en ambos extractos fue B. edulis, cuyos resultados en el extracto acuoso fueron: fenoles totales 93.46 ± 18.17 mg/g, DPPH CI 50 0.93 mg/mL (IC95% 0.65-1.28) y en ABTS CI50 0.96 mg/mL (IC 95% 0.63-1.35); los resultados en el extracto etanólico fueron: Fenoles totales 42.70 ± 3.48 mg/g, DPPH CI50 2.75 mg/mL (IC 95% 2.46-3.07) y 4.13 mg/mL (IC 95% 2.67-5.88). Se evidencia de esta forma que las especies de basidiomicetos estudiadas presentan actividad antioxidante por lo cual pueden ser una fuente potencial de antioxidantes naturales.
Antioxidants are essential in the body to prevent oxidative damage. These antioxidant substances are obtained from different sources such as fruits, plants and mushrooms. In Guatemala, diverse species of mushrooms are commercialized and consumed, however their antioxidant activity has not been documented in Guatemala. The goal of this study aimed to determine the antioxidant activity of aqueous and ethanolic extracts obtained from edible basidiomycetes species: Agaricus aff. bisporus, A. brunnescens, Armillariella polymyces, Amanita garabitoana, Boletus edulis, Cantharellus lateritius, Laccaria amethystina, Lactarius deliciosus, Neolentinus ponderosus and Pleurotus ostreatus. Thin layer chromatography (TLC) was used as a qualitative method to determine the presence of antioxidant activity, subsequently, three in vitro macrometric assays were used: the quantification of total phenolics, reduction of 1,1-diphenyl-2-pricrilhidrazil (DPPH) radical, and discoloration of the acid reagent 2.2 -azinobis-(acid-3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation. Aqueous extracts exhibited higher antioxidant activity than ethanolic in all the quantitative techniques used. The specie that showed greater antioxidant activity in both extracts was B. edulis, whose results of aqueous extract were as follows: Total phenolics 93.46 ± 18.17 mg/g , DPPH IC50 0.93 mg/mL (CI95% 0.65-1.28) and ABTS IC50 0.96 mg/mL (CI95% 0.63-1.35); results of ethanolic extract were: Total phenolics 42.70 ± 3.48 mg/g, DPPH IC50 2.75 mg/mL (CI95% 2.46-3.07) and ABTS IC50 4.13 mg/mL (CI95% 2.67-5.88). Based in the result of the study all the basidiomycetes species that were evaluated have antioxidant activity, therefore, are potential sources of natural antioxidants.