Purification and identification of rice bran (Oryza sativa L.) phenolic compounds with in-vitro antioxidant and antidiabetic activity using macroporous resins

This study was designed to establish an efficient purification method for phenolic compounds from rice bran and to acquire insightful knowledge of purification impact on its chemical constituents, antioxidant and antidiabetic activity. Among the eight macroporous resins investigated, HPD-300 resin was verified to bosses superior adsorption and desorption qualities for the extract. Purification parameters were optimised. Eighteen phenolic compounds were identified using HPLC-PDA, the contents of ferulic acid and syringaldehyde were significantly (P < 0.05) higher than the other constituents. However, phenolic compounds concentrations varied significantly (P < 0.05) after HPD-300 resin purification. In addition, the extract exhibited a significant (P < 0.05) increase in total flavonoid contents, in vitro antioxidant (DPPH and FRAP) and antidiabetic (α-glucosidase and BSA-glycation inhibition) activity after HPD-300 resin treatment. These findings indicate that selection of resin and applying optimal purification condition is an appropriate economical approach for obtaining bioactive phenolic compounds from rice bran.     

Extraction of polyphenols and antioxidants from pomegranate peel using ultrasound: influence of temperature,frequency and operation mode

The objective of this research was to investigate the effects of temperature (40–70 °C), frequency (37 and 80 kHz) and ultrasonic operation mode (normal, pulse and sweep), and their interactions on the recovery of phenolic compounds and antioxidants present in pomegranate peel using ultrasound-assisted extraction. The content of individual phenolic compounds, total phenolic compounds (TPC), antioxidant capacity (AC) and total extract yield (X₀) were analysed. Significant effects were observed between some sources of variation in recovery of individual compounds at TPC and X₀, and no significant effect was observed for AC. The process and conditions studied shown to be interesting to extract antioxidants, since a high antioxidant capacity was verified in the extracts. Temperatures around 50–60 °C, using 37 kHz frequency, and normal or pulse modes were the conditions that provided better yields of phenolic compounds and X₀. Regarding AC, the best condition observed was at 70 °C, 80 kHz frequency and continuous mode.     

Gamma-oryzanol content,phenolic acid profiles and antioxidant activity of rice milling fractions

This study was aimed to determine γ-oryzanol content and total phenolics, individual phenolic acid profile and the antioxidant activity of the free and bound extracts of rice milling fractions namely, brown rice, unpolished rice, white rice, chalky rice, raw seed and rice bran. Gamma-oryzanol content of milling fractions which is designated with a simple chromatographic method was in the range of 12.19–3,296.5 mg/kg. The whitening and polishing steps reduced approximately 94% of γ-oryzanol of the brown rice when becoming the white rice. The contribution of bound phenolics to the total phenolic content was approximately 40%. Ferulic and p-coumaric acids were the most abundant phenolic acids in bound phenolic extracts and their amounts were 119.98 and 18.10 μg/g, respectively, in rice bran. The best source of γ-oryzanol, phenolics and antioxidants was clearly rice bran and followed by raw seed and brown rice.     

Three phase partitioning for simultaneous extraction of oil,protein and polysaccharide from rice bran

Three phase partitioning (TPP) technique was used to extract oil, protein and polysaccharides simultaneously from rice bran. The fatty acid composition of rice bran oil (RBO) and structure of rice bran protein (RBP) and rice bran polysaccharides (RBPS) were analyzed. Under the optimal conditions of (NH₄)₂SO₄ concentration 28% (w/v), slurry to t-butanol ratio 1:1.1 (v/v), pH 5.10, extraction temperature 40 °C and extraction time 1 h, the highest extraction yields of RBO, RBP and RBPS were 17.28%, 6.81% and 2.09%, respectively. The fatty acid composition of RBO was analyzed by GC, the structure of RBP was analyzed by FTIR and SDS-PAGE, and the structure of RBPS was analyzed by FTIR. The results were similar to those obtained by other methods. Therefore, TPP can be used as an effective technology for simultaneous extraction of oil, protein and polysaccharide from rice bran.     

Release of phenolic acids from defatted rice bran by subcritical water treatment

BACKGROUND: Oil production from rice bran, an undervalued by‐product of rice milling, produces defatted rice bran (DRB) as a waste material. Although it is considered a less valuable product, DRB still contains useful substances such as phenolic compounds with antioxidant, UV‐B‐protecting and anti‐tumour activities. In this study the phenolic acids in DRB were extracted with subcritical water at temperatures of 125, 150, 175 and 200 °C. RESULTS: Analysis of total phenolics using Folin–Ciocalteu reagent showed about 2–20 g gallic acid equivalent kg^?1 bran in the extracts. High‐performance liquid chromatography analysis showed low contents of phenolic acids (about 0.4–2 g kg^?1 bran). Ferulic, p‐coumaric, gallic and caffeic acids were the major phenolic acids identified in the extracts. Thermal analysis of the phenolic acids was also done. The thermogravimetric curves showed that p‐coumaric, caffeic and ferulic acids started to decompose at about 170 °C, while gallic acid did not start to decompose until about 200 °C. CONCLUSION: Subcritical water can be used to hydrolyse rice bran and release phenolic compounds, but the high temperatures used in the extraction can also cause the decomposition of phenolic acids. Copyright © 2010 Society of Chemical Industry     

Viability of Lactobacillus acidophilus in rice bran‐enriched stirred yoghurt and the physicochemical and sensory characteristics of product during refrigerated storage

This study was aimed at investigating the fortification of probiotic yoghurt with rice bran to increase nutritional properties of the product. The different levels of rice bran (0.3%, 0.6%, 0.9% and 1.2%) were incorporated into milk. The yoghurt samples were produced after pasteurisation, addition of starter culture and 1% Lactobacillus acidophilus suspension (6 × 10⁸ CFU mL^?1) and incubation. During sample storage in refrigerator, the viability of L. acidophilus, viscosity and physicochemical and sensory properties of product were investigated. Rice bran significantly increased the viability of L. acidophilus (P < 0.05). In addition, all probiotic yoghurts incorporating rice bran indicated higher viscosity and acidity and lower pH and syneresis compared to plain yoghurts. Furthermore, increments in rice bran incorporation levels resulted in a reduction in consumers' sample preferences. In general, the addition of rice bran at a suitable level could increase L. acidophilus viability and improve quality attributes of yoghurt.     

Effect of fermentation by Bacillus subtilis on antioxidant and cytotoxic activities of black rice bran

Black rice bran was fermented with Bacillus subtilis KU3 isolated from Korean traditional food, Kimchi. Antioxidant and cytotoxic activities of the fermented black rice bran were investigated. Total phenolic and anthocyanin contents decreased from 171.54 mg GAE g^?1 and 2.31 mg g^?1 to 139.13 mg GAE g^?1 and 2.12 mg g^?1, respectively, after fermentation. Antioxidant activities determined by 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging, β‐carotene bleaching and ferric thiocyanate assay were correlated with total phenolic and anthocyanin contents. Non‐fermented black rice bran extract (NFBE) showed greater antioxidant activities than fermented black rice bran extract (FBE). Cytotoxic activities measured by MTT assay showed that both NFBE and FBE had over 50% activities. The cytotoxic activities of FBE against MCF‐7 and HeLa cells were 71.65% and 68.07%, respectively, at 8.0 mg mL^?1, but those of NFBE were lower than 50%. These results suggested that the cytotoxic activity of black rice bran improved through fermentation, while antioxidant activity reduced.     

Effect of γ-irradiation on phenolic compounds in rice grain

Whole grain rice is rich in phenolic compounds. The effect of γ-irradiation on the main phenolic compounds in the rice grains of three genotypes (black, red, and white) was investigated. Three phenolic acids (p-coumaric acid, ferulic acid, and sinapinic acid) were identified as major phenolic compounds in all rice samples, while two anthocyanins (cyanidin-3-glucoside and peonidin-3-glucoside) were identified in pigmented grain samples. In general, γ-irradiation at most of doses could significantly (p < 0.05) decrease total phenolic acid contents in all samples and total anthocyanins contents in the black rice, but their decreases were not completely in a dose-dependent manner. Unexpectedly, 6 and 8 kGy significantly (p < 0.05) increased total contents of anthocyanins and phenolic acids in black rice. This study suggested that suitable doses of irradiation might be carefully selected and used to minimise the loss of antioxidant phenolic compounds in whole grain rice during storage.     

Influence of enzyme treatment of rice bran on gamma-aminobutyric acid synthesis by Lacto bacillus

Gamma-aminobutyric acid (GABA) is a major inhibitory neurotransmitter in the central nervous system. The production GABA from the cheaper glutamic acid is a valuable process. Rice bran is a potential source of glutamic acid decarboxylase which was therefore selected for production of gamma-aminobutyric acid (GABA) using lactic acid bacteria (Lactobacillus brevis (Lb.brevis) VTCC-B397). The influences of treatment of defatted rice bran with α-amylase, Alcalase (Al), Flavourzyme (Fl) and their combinations at different concentration ratios on the GABA synthesis were examined. With α-amylase impacts, concentration of GABA (6.41 mg mL⁻¹) was about 2.38 times higher than the control sample (2.69 mg mL⁻¹) under hydrolysis conditions of pH 6.5, temperature of 95 °C and α-amylase concentration of 0.15% (v/w) for 45 min. The α-amylase hydrolysis as prerequisite for protein hydrolysis using Al: Fl (ratio Al: Fl of 3: 7, concentration of 2% (w/w), pH = 8, temperature of 50 °C) reached the highest GABA synthesis efficiency, at 8.43 mg mL⁻¹. Results showed that the enzyme treatment positively affected the fermentation using Lb. brevis for GABA biosynthesis from defatted rice bran.     

Phytochemicals and antioxidant properties of solvent extracts from Japonica rice bran

The yield, major phytochemicals (oryzanols, tocopherols (T), and tocotrienols (T3)) and antioxidant properties of Japonica rice bran extracts were investigated, for illustrating the major effects from solvent property. Generally, the extract yield varied with the solvent used in the order of methanol (MeOH) > ethyl acetate (EtOAc) > hexane. In contrast to hexane extracts, both MeOH and EtOAc extracts exhibited a higher total content in phenolic compounds (∼2.5 g gallic acid equivalent/kg bran), oryzanols (1.6–1.8 g/kg bran), or tocols (126–130 mg/kg bran), and a higher T3% in tocols (24–26%). The MeOH extract (at 1 mg/ml) showed the greatest capability in inhibiting linoleic acid peroxidation (57%), scavenging DPPH radicals (93%), reducing power (78%), and Fe²⁺ chelating activity (∼1300 μg EDTA equivalent/g) than the other two extracts, partly attributed to its high antioxidant contents. It is newly found that the yield, total content in phenolic compounds, oryzanols, and tocols, and T3% in tocols of the extracts increased with increasing Synder’s polarity value in a quite good linear manner (R² = 0.923–1.000), associated with an increased solvent viscosity. This clearly suggests the potential of using Synder’s polarity value as an index in isolation of desired rice bran phytochemical extracts.     

Bioactive components,antioxidative and anti-inflammatory properties (on RAW 264.7 macrophage cells) of soaked and germinated purple rice extracts

The bioactive components, antioxidative properties and phenolic profile of Thai purple rice after 24 h soaking and 36 h germination periods were investigated. Anti-inflammatory properties of the rice extracts were also evaluated on macrophage cells, stimulated with Lipopolysaccharide. These conditions significantly increased the bioactive components and antioxidative properties. Total anthocyanin contents, total carotenoid contents and gamma-aminobutyric acid were increased more than twofold in the soaked sample. Protocatechuic, caffeic, p-coumaric, ferullic, rutin trihydrate, catechin and Trans-cinnamic acids were detected in the extracts. Gallic acid was only identified after soaking and germination. All the extracts led to cell proliferation and inhibited nitric oxide (NO) production. Twenty-four hour soaking exhibited highest bioactive compounds, antioxidative properties and showed greater NO inhibitory effects with IC₅₀ of 234.00 ± 0.01 μg mL⁻¹. In addition to established information on germination, soaking greatly improved the bioactive components and anti-inflammatory properties of the rice variety.     

Phytochemicals characterization of solvent extracts from taro-scented japonica rice bran

The major phytochemicals and antioxidant properties of taro-scented rice bran (TaiNung 71; TN71) extracts using 3 different solvents are characterized. Some progress is realized in creating an economic value for rice bran that has long been considered an agricultural waste. Various solvent extracts reveal the presence of phenolic compounds, oryzanols, tocopherols, and tocotrienols. Ethyl acetate (EtOAc) can extract more oryzanols (1.55 ± 0.20 g/kg rice bran). Meanwhile, the methanol (MeOH) extract possesses a higher yield in total contents (15.42 ± 1.41 g/kg bran), which includes phenolic compounds (2.69 ± 0.29 g gallic acid equivalent/kg bran), tocopherols (251 ± 26 mg/kg bran) and tocotrienols (111 ± 4 mg/kg bran). The MeOH extract exhibits more effective antioxidant activity against various oxidative systems in vitro, including the inhibition of linoleic acid peroxidation (33.89%), scavenging of DPPH radicals (83.88%), and reducing power. It is found that the yield, total content in phenolic compounds and tocols of the extracts increase with increasing Synder's polarity value and viscosity, which can then be used as the indices in isolation of the desired rice bran phytochemicals extracts.     

Innovative production of multistrain synbiotic product using Thai-pigmented rice and rice bran oil

This study found that the isolated probiotics Lactobacillus paracasei KUKPS6201, L. acidophilus KUKPS6107, L. reuteri KUKPS6103, L. rhamnosus KUKPS6007, L. salivarius KUKPS6202, Bacillus coagulans KPSTF02 and Saccharomyces boulardii KUKPS6005 had high potential for probiotic properties. All strains had antibacterial activity and high antioxidant activity of 1.654 ± 0.017 mg Trolox mL⁻¹ probiotic extract. The selected strains could survive in a simulated gastrointestinal tract under anaerobic conditions and showed no haemolytic activity. Furthermore, the probiotic strains were strongly auto-aggregated and also showed co-aggregated ability with pathogenic bacteria. The probiotic microorganisms demonstrated high ability to adhere to Thai-pigmented rice grains. The results of analysis of these probiotics showed that Riceberry rice bran oil was an excellent prebiotic. A synbiotic product containing Thai-pigmented rice grains (cultivar Riceberry, Luem Pua and Black Jasmine) and rice bran oil was produced. After 8 weeks of storage, the viability of the probiotics in terms of multistrains was 7.36 ± 0.04 log CFU g^–1 (85.78% survival rate). Microbiological safety testing indicated that the amounts of contaminants were acceptable. This study provided the first scientific report on the feasibility of applying Thai-pigment rice, rice bran oil and mixed-culture probiotics as a novel functional synbiotic product.     

Phenolic Profile and Antioxidant Activity of Extracts Prepared from Fermented Heat‐Stabilized Defatted Rice Bran

Heat‐stabilized, defatted rice bran (HDRB) serves as a potential source of phenolic compounds which have numerous purported health benefits. An estimated 70% of phenolics present in rice bran are esterified to the arabinoxylan residues of the cell walls. Release of such compounds could provide a value‐added application for HDRB. The objective of this study was to extract and quantify phenolics from HDRB using fermentation technology. Out of 8 organisms selected for rice bran fermentation, Bacillus subtilis subspecies subtilis had the maximum phenolic release of 26.8 mg ferulic acid equivalents (FAE) per gram HDRB. Response surface methodology was used to further optimize the release of rice bran phenolics. An optimum of 28.6 mg FAE/g rice bran was predicted at 168 h, 0.01% inoculation level, and 100 mg HDRB/mL. Fermentation of HDRB for 96 h with B. subtilis subspecies subtilis resulted in a significant increase in phenolic yield, phenolic concentration, and radical scavenging capacity. Fermented rice bran had 4.86 mg gentistic acid, 1.38 mg caffeic acid, 6.03 mg syringic acid, 19.02 mg (‐)‐epicatechin, 4.08 mg p‐courmaric acid, 4.64 mg ferulic acid, 10.04 mg sinapic acid, and 17.59 mg benzoic acid per 100 g fermented extract compared to 0.65 mg p‐courmaric acid and 0.36 mg ferulic acid per 100 g nonfermented extract. The high phenolic content and antioxidant activity of fermented HDRB extract indicates that rice bran fermentation under optimized condition is a potential means of meeting the demand for an effective and affordable antioxidant.     

Dephytinization of wheat and rice brans by hydrothermal autoclaving process and the evaluation of consequences for dietary fiber content,antioxidant activity and phenolics

Autoclaving process applied to wheat and rice bran samples to decrease the phytic acid content and to enhance the functional and nutritional properties (dietary fiber and phenolic content, antioxidant activity) of bran samples. All hydrothermal treatments caused significant decreases in phytic acid contents of both wheat (95.2%) and rice bran (95.6%) samples. The most effective process conditions on enhancing the total dietary fiber content for both bran samples were pH 4.0 level and 1.5 h holding time. Autoclaving treatment resulted in a decrease in total phenolic contents after holding for 90 min and at 121 °C at their native pH levels. Autoclaving for 90 min caused the greatest degree of increment in the total antioxidant activity of wheat (12%, pH 4.0) and rice bran samples (2%, pH 3.5). Autoclaving treatment was found as quite effective method for both dephytinization and enrichment of wheat and rice brans as a functional food ingredient.Industrial relevanceAuthors believe that the study presents important new information in terms of both enhancing functional properties of wheat and rice brans by hydrothermally dephytinization treatment and revealing the correlation between hydrothermal treatment and functional ingredients of brans. In this way, proposed method transforms inexpensive and easily accessible sources into important food ingredients and gives them added value. Hydrothermal treatment also enables food industry to use cereal brans as functional ingredients in the applications of both designing and enriching new and healthy food formulations.     

Isolation and Identification of Phenolic Antioxidants in Black Rice Bran

Black rice bran contains phenolic compounds of a high antioxidant activity. In this study, the 40% acetone extract of black rice bran was sequentially fractionated to obtain 5 fractions. Out of the 5 fractions, ethyl acetate fraction was subfractionated using the Sephadex LH‐20 chromatography. The antioxidant activity of phenolic compounds in the extracts was investigated by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical assay, 2,2‐azino‐bis‐(3‐ethylenebenzothiozoline‐6‐sulfonic acid) (ABTS) radical cation assay, reducing power. The subfraction 2 from ethyl acetate fraction had the highest total phenolic contents (TPC) (816.0 μg/mg) and the lowest EC₅₀ values (47.8 μg/mL for DPPH radical assay, 112.8 μg/mL for ABTS radical cation assay, and 49.2 μg/mL for reducing power). These results were 3.1, 1.3, and 2.6 times lower than those of butylated hydroxytoluene (BHT), respectively. At a concentration of 100 μg/mL, the antioxidant activity and TPC of various extracts was closely correlated, with correlation coefficients (R²) higher than 0.86. The major phenolic acid in subfraction 2 was identified as ferulic acid (178.3 μg/mg) by HPLC and LC‐ESI/MS/MS analyses. Our finding identified ferulic acid as a major phenolic compound in black rice bran, and supports the potential use of black rice bran as a natural source of antioxidant.     

High performance liquid chromatographic analysis of phenolic compounds and their antioxidant activities in rice varieties

The analytical method for the determination of phenolic compounds in rice varieties was developed. The method consisted of extraction of phenolic compounds from rice before analysis by high performance liquid chromatography (HPLC). Reversed phase HPLC equipped with photodiode array detection was used and the separation condition was optimized. Under the optimum condition, twelve phenolic compounds were separated within 24 min. Pressurized liquid extraction (PLE) was used to extract free phenolic compounds from rice with the optimum extraction condition of 70% methanol and extraction time of 15 min. While, bound phenolic compounds were extracted using alkaline hydrolysis for 15 min. Six varieties of Thai rice including pigment and non-pigment rice in their brown and polished forms were investigated. All of 12 phenolic compounds were detected as free phenolic compounds in all samples. Ferulic acid was the most abundant free phenolic compounds in all samples, while ferulic acid and p-coumaric acid were found as bound phenolic compounds in some samples. The content of phenolic compounds, total flavonoid and antioxidant activity detected in pigment rice and brown form were higher than non-pigment rice and polished form.     

Antioxidant activities and phenolic compounds of pigmented rice bran extracts

This study was carried out to investigate the antioxidant activities and phenolic compounds of pigmented rice (black, red, and green rice) and brown rice brans. Antioxidant activity was determined by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical assay, 2,2-azino-bis-(3-ethylenebenzothiozoline-6-sulfonic acid) (ABTS) radical cation assay, reducing power, and chelating ability. Phenolic compounds were measured by using HPLC. Pigmented rice brans were extracted by using aqueous mixtures of acetone, ethanol, and methanol to determine the most effective extraction solvent. Of all solvents examined, extract from 40:60 acetone-water mixtures (v/v) provided the highest DPPH radical assay as well as the highest total phenolic and flavonoid content. We finally selected 40% acetone as an extraction solvent for antioxidant study of pigmented rice bran. Antioxidant activities of 40% acetone extracts of pigmented rice bran, measured in the range of 0 to 1500 μg/mL. At 500 μg/mL concentration, red rice bran, which had the highest total phenolic (259.5 μg/mg) and total flavonoid (187.4 μg/mg) contents, showed the highest antioxidant activity: 83.6%, 71.5%, 1.2%, and 16.4% for DPPH radical assay, ABTS radical cation assay, reducing power, and chelating ability, respectively. Red rice bran showed a lower EC(50) value (112.6 μg/mL) than that of butylated hydroxytoluene (144.5 μg/mL) from the DPPH radical assay. The major phenolic acids of red rice bran were ferulic, vanillic and p-coumaric acids. The results indicated pigmented rice bran might be used as a natural antioxidant. PRACTICAL APPLICATION: The present study revealed black and red rice bran shows high antioxidant activities and they contain high amount of phenolic compounds. Indeed, black and red rice bran could be better raw materials for manufacturing the food with high antioxidant activity.     

Rice kernel phenolic content and its relationship with antiradical efficiency

Plant phenolics exert beneficial effects on human health and may also prevent oxidative deterioration of food. Two field experiments were carried out for characterising phenolics in rice. The first assay was conducted in 1999 and 2000 in Beaumont, TX and included five light‐brown, two purple and 10 red pericarp coloured cultivars. ‘Bran colour’ was highly statistically significant for both bran phenolic concentration and antiradical efficiency (p < 0.001). ‘Year’ and its interaction with bran colour were not significant for the analysed traits, suggesting that seasonal differences and their interactions may not affect phenolic content or antiradical efficiency. The accessions ranged from 3.1 to 45.4 mg gallic acid equivalents (GAE) g^?1 bran and from 10.0 to 345.3 µM trolox equivalents (TE) g^?1 bran for total phenolic content and antiradical efficiency respectively. The light‐brown bran genotypes exhibited the lowest values for phenolic content and antiradical efficiency, whereas red bran ones displayed ca 10 times higher total phenolic content and more than 50 times higher tannin content than light‐brown ones. The two purple lines showed either low or high values for the studied traits. Antiradical efficiency of rice bran extracts was highly positively correlated with total phenolic content (r = 0.99***), suggesting that phenolics are the main compounds responsible for the free radical‐scavenging activity in rice bran extracts. In the second field experiment (Stuttgart, AR, 2001 and Beaumont, TX, 2000), 133 coloured rice cultivars were analysed for total phenolic content in whole grain. The accessions showed a large variation for total phenolics, ranging from 0.69 to 2.74 mg GAE g^?1 grain. The data confirmed previous results suggesting bran colour as the main factor affecting phenolic concentration in rice kernel and seasonal effects and their interactions as not significant. The results also confirm that within red and purple bran groups can be found the highest phenolic concentrations in rice kernel. Published in 2004 for SCI by John Wiley & Sons, Ltd.     

Pressurized liquid extraction as an eco-friendly approach to recover anthocyanin from black rice bran

This study aimed to recover the anthocyanin-rich extract from black rice bran by pressurized liquid extraction (PLE) and compare with the conventional process (heating-stirring extraction - HSE). PLE performs fast and efficiently and results in high yields in less time and less solvent, being considered eco-friendly. The extracts were characterized for thermal and light stabilities, cytotoxicity, antitumoral activity, and cytoprotective effect. Optimum PLE conditions were: 55 °C, a flow rate of 5 mL/min, and solution ethanol:citric acid 0.1 mol/L (50:50, v/v). PLE recovered about 80% of total anthocyanins (2.33 mg/C3GE g), while HSE recovered 46% (1.17 mg/C3GE g). Cyanidin-3-O-glucoside (C3G) was identified (m/z 449) and quantified, 1.63 mg/g for PLE and 1.07 mg/g for HSE. Both anthocyanin-rich extracts in low temperature showed high thermostability, did not present cytotoxicity (normal fibroblast L929 cells), and showed cytoprotection of L929 cells when subjected to oxidative stress with H₂O₂. Overall, the anthocyanin-rich extracts obtained by PLE showed potential to be applied as natural colorants and possibly to improve wound healing.Industrial relevancePLE method is an eco-friendly technology that performs fast and efficient extractions under high temperature and pressure conditions. This study provides information about the extraction of anthocyanin-rich extracts from black rice bran by green PLE process under optimized conditions. The process allowed for obtaining antioxidant-rich extracts with no cytotoxicity and a high potential for application in the food, cosmetic, and biomedical industries.