Utilization of [Bmim]BF4-MAE on enhancement of γ-oryzanol extraction from rice bran and its tyrosinase inhibitory activity

Abstract

This study investigated the effect of ionic liquid (IL)-microwave assisted extraction (MAE) on γ-oryzanol extraction from rice bran (Oryza sativa L.). The conditions included the concentration of IL, liquid (IL)/ solid (sample) ratio, extraction time, and microwave power. The use of 1-butyl-3-methylimidazolium ([Bmim]BF 4 ) as a selected solvent in IL-MAE method was developed for extraction of γ-oryzanol from rice bran. The Box-Behnken design on four factors with response surface methodology (RSM) was used to optimize the experimental conditions. The optimum conditions for the MAE were a [Bmim]BF 4 concentration of 0.7 M, liquid/solid ratio of 15 mL/g, extraction time of 10 minutes, and 30% microwave power with a γ-oryzanol value of 0.41 mg/g. The experimental values agreed with those predicted by the RSM models. A microplate reader method was used to determine the IC 50 value in tyrosinase inhibitory activity of the extract. An IC 50 value of the extract obtained from IL-MAE was 1240 µg/mL. This study suggests that IL-MAE is suitable for the extraction of γ-oryzanol from rice bran and that under the optimum conditions the extract has low activity as a tyrosinase inhibitor. Keywords[Bmim]BF 4. Ionic liquid. IL-MAE. γ-oryzanol. Tyrosinase. Xu Z, Godber JS. Comparison of supercritical fluid and solvent extraction methods in extracting gamma-oryzanol from rice bran. Ionic liquid-based ultrasound assisted extraction of fangchinoline and tetrandrine from Stephaniae tetrandrine.

Emerging Green Techniques for the Extraction of Antioxidants from Agri-Food By-Products as Promising Ingredients for the Food Industry

“…Antioxidant, anti-inflammatory properties, improvement of immune response [32] Onion peels Flavonoids (quercetin and kaempferol) Anti-inflammatory and anti-cancer effects [33] Potato peels Polyphenols, phenolic acids (caffeic acid, syringic acid) LDL-lipoprotein oxidation, prevention of platelet aggregation, and red blood cell damage [34] Eggplant peels Phenolic compounds, ascorbic acid, anthocyanins (tulipanin, nasunin) Antioxidant properties [35] Mushroom stalks Ergosterol Antioxidant properties [36] Cereals Rice bran Tocopherols, tocotrienols, γ-oryzanol, tannins Antioxidant, antihypertensive, antimicrobial, antidiabetic, anticancer properties, cholesterol-reducing effect [37] Wheat, barley, millet, sorghum Phenolic acids, vitamins, minerals [38] Brewer's spent grain minerals, vitamins, polyphenols, arabinoxylan, β-glucan Enhanced glycaemic control, cholesterol-lowering effect, prebiotics effect, immunomodulatory activity, increased minerals absorption [39] Buckwheat sprouts Flavonoids (rutin, quercetin), vitamins Hypocholesterolemic, hypotriglyceridemic, anti-inflammatory properties [40] Oil crops Olive mill wastewater Tyrosol, hydroxytyrosol Prevention of Parkinson's disease, hyperglycemia, cerebral ischemia [41] Olive pomace Phenolic compounds, secoiridoids Antioxidant and anti-inflammatory properties [42,43] Sesame cake Polyphenols, lignan glucosides Prevention of obesity and hyperglycemia, reduction of cholesterol levels [44] Pistachio hulls Phenolic acids (gallic acid), gallotannins, flavonoids (quercetin, myricetin glycosides) Prevention of cardiovascular disease, diabetes, high cholesterol levels [45] Herbs and spices Wild thyme by-product Flavonoids, phenolic acids, essential oils (thymol) Antimicrobial, antioxidant, anti-aging, anti-inflammatory, immunomodulatory and anti-cancer, liver protective, gastroprotective activities [46] Rosemary by-products Polyphenols (rosmarinic acid, carnosolic acid, carnosol), essential oils [47] Sage by-products [48] Tea by-products Phenolic compounds (chlorogenic acid), flavonoids (apigenin, luteolin), essential oils [49] Table 2. Cont.…”