Effect of ultrafine grinding on hydration and antioxidant properties of wheat bran dietary fiber

Wheat bran dietary fiber (DF) powders was prepared by ultrafine grinding, whose effects were investigated on the composition, hydration and antioxidant properties of the wheat bran DF products. The results showed that ultrafine grinding could effectively pulverize the fiber particles to submicron scale. As particle size decrease, the hydration properties (water holding capacity, water retention capacity and swelling capacity) of wheat bran DF were significantly (p < 0.05) decreased and a redistribution of fiber components from insoluble to soluble fractions was observed. The antioxidant activities of wheat bran and DF before and after grinding were in terms of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, ferrous ion-chelating activity, reducing power and total phenolic content (TPC). Compared with DF before and after grinding, micronized insoluble DF showed increased chelating activity, reducing power and TPC yet decreased DPPH˙ radical scavenging activity. Positive correlations were detected between chelating activity, reducing power and TPC.     

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.     

Purification and identification of antioxidant peptides from corn gluten meal

Corn gluten meal was hydrolyzed by alkaline protease and Flavourzyme to obtain the antioxidant peptides. The antioxidant activities of the hydrolysates or peptides were evaluated by free radical scavenging capacity (1,1-diphenyl-2-picrylhydrazyl/2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt/hydroxyl radical/superoxide radical anion), metal ion (Fe²⁺/Cu²⁺) chelating activity and lipid peroxidation inhibitory capacity. The hydrolysates were separated by ultrafiltration, and those with molecular weight <10 kDa exhibited highest antioxidant activity in all relevant assays. The hydrolysates were subsequently purified by gel filtration chromatography, and fraction F3 showed the highest antioxidant activity. Three peptides were identified from fraction F3 using LC–ESI–Q–TOF MS/MS as Leu-Pro-Phe (375.46 Da), Leu-Leu-Pro-Phe (488.64 Da) and Phe-Leu-Pro-Phe (522.64 Da). These peptides exhibited good free radical scavenging activity and lipid peroxidation inhibitory effect. Thus, corn gluten meal may be used as a potential source of antioxidant peptides for food and nutraceutical applications.     

Influence of postharvest gamma irradiation treatment on the content of bioactive compounds and antioxidant activity of fenugreek (Trigonella foenum–graceum L.) and spinach (Spinacia oleracea L.) leaves

Fenugreek and spinach leaves after irradiation in the dose range of 0.25–1.5 kGy were evaluated for the content of bioactive compounds and antioxidant activity using DPPH radical scavenging, ferric reducing ability power (FRAP), hydroxyl radical scavenging and ferrous ion chelating assays. Results of the study revealed that bioactive content except total ascorbic acid was significantly (p ≤ 0.05) higher in fenugreek compared to spinach. Data analysis revealed that gamma irradiation treatment significantly (p ≤ 0.05) enhanced the content of individual as well as total bioactive components of both vegetables. Positive correlation (r = 0.92) existed between gamma irradiation and total phenolics. The results of the antioxidant activity as determined by above mentioned assays revealed a significant (p ≤ 0.05) decrease in EC₅₀ values and a corresponding increase in antioxidant content and activity due to irradiation. Comparison of the increase in inhibition percentage, reducing power and chelating efficiency revealed that treatment of irradiation was significantly (p ≤ 0.05) effective in enhancing the ferric reducing power of both the vegetables (3.1–37.5% for fenugreek, 4.1–42.8% for spinach) and OH radical scavenging for spinach (1.5–22.4%) compared to fenugreek (0.78–13.1%). The present investigation suggested that postharvest radiation treatment to fenugreek and spinach has a potential to enhance their antioxidant content and activities, besides acting as a photo-sanitary treatment.Industrial relevanceThe increasing demand of convenience, wholesome and health promoting foods has resulted in search of new technologies to improve the shelf-life and at the same time preserve the nutritional quality. Prolonging postharvest storage, while enhancing the content of bioactive compounds will have a positive impact on both the industry and consumers. The present study demonstrated that postharvest radiation treatment of fenugreek and spinach can be used a novel approach to enhance their bioactive composition and antioxidant activity.     

Identification and characterization of papain-generated antioxidant peptides from palm kernel cake proteins

Novel peptides with antioxidant activity were isolated and identified from papain generated palm kernel cake (PKC) proteolysate. The proteolysate was fractionated into individual peptides based on hydrophobicity and isoelectric point using reversed-phase high-performance liquid chromatography and isoelectric focusing techniques. The individual peptides were identified by tandem mass spectrometry and their respective antioxidant activities were evaluated using 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and metal chelating activity assays. Peptide sequences, AWFS, WAF, and LPWRPATNVF showed the highest radical scavenging activities of 71%, 56%, and 50%, respectively, while peptide sequences GGIF, YGIKVGYAIP and YLLLK showed the highest metal chelating activities of 56%, 53%, and 50%, respectively. However, the best IC₅₀ values of peptides measured by DPPH assay were displayed by GIFE, GVQEGAGHYALL and GGIF at 0.02 μM, 0.09 μM and 0.35 μM, respectively, while the best half maximal inhibitory concentration values measured using metal chelating activity were shown by LPWRPATNVF, AWFS and YGIKVGYAIP at 0.001 μM, 0.002 μM and 0.087 μM, respectively. It can be concluded that the peptides derived from PKC proteolysate were more potent and distinctive compared to those previously reported from other plant protein sources.     

Investigation of the interaction between soluble antioxidants in green tea and insoluble dietary fiber bound antioxidants

This work investigates the possibility of interaction between insoluble dietary fiber bound antioxidants, specifically of wheat bran, and soluble antioxidants like those provide by aqueous infusions of green tea. Solutions of pure catechins were also assayed for comparison with those naturally found in tea. To accomplish this, the aqueous and alcohol soluble fractions as well as the lipid components of wheat bran were firstly removed and the freeze-dried insoluble residue was then treated with different concentrations of green tea infusions or aqueous solutions of epicatechin (EC) and epigallocatechin-3-gallate (EGCG) for certain time. Treatment with EC (0–200 μM) had no significant effect on the antioxidant capacity of insoluble bran fraction. However, treatment with EGCG significantly (p < 0.05) increased linearly the antioxidant capacity as a function of concentration (0–100 μM). Treatment with great tea infusions (1–3 g/100 ml) also increased the resulting antioxidant capacity of insoluble bran fraction, but the effect was lesser at higher infusion concentrations. Liquid chromatography couple to mass spectrometry (LC–MS) analyses of aqueous phases after treatment indicated comparable levels of decrease in the concentrations of catechins confirming their reaction with the radical forms of antioxidants bound to insoluble bran matrix.     

Triticale bran and straw: Potential new sources of phenolic acids,proanthocyanidins, and lignans

The distribution of phenolic acids (free and bound), proanthocyanidins, and lignans in defatted triticale bran and straw was determined. For comparison, wheat, rye and oat brans as well as triticale flakes and leaves were also assayed. Most phenolic acids were present in the bound form (89–98%), and released under alkaline extraction conditions. The content of phenolic acids ranged from 65.2 to 252.5 mg/100 g in samples in which ferulic acid predominanted. Triticale straw was the richest source of proanthocyanidins, containing 862.5 mg/100 g (catechin equivalents) of tissue. Triticale straw contained 0.27 mg/100 g of lignan secoisolariciresinol diglucoside (SDG), whereas the bran had only 0.01 mg/100 g. The oxygen radical absorbance capacity (ORAC, μM Trolox equivalents/g defatted material) showed that antioxidant activity of bound phenolics was higher than those of free phenolics. This is the first report on phenolic acids, proanthocyanidin, and lignans content of Canadian triticale by-products, indicating that they may have the potential for use as nutraceuticals and/or functional food ingredients.     

Antioxidant activities of five Chinese rice wines and the involvement of phenolic compounds

Chinese rice wine has been claimed to have health-promoting effects, which may be related to the antioxidant activity in vivo. In this study, total antioxidant, reducing, free radical scavenging, and superoxide anion radical scavenging activities were determined in five Chinese rice wines (Guyuelongshan, Hongqu, Shousheng, Foshou, and Nuomi) comparing with synthetic antioxidants, such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). Ten individual phenolic compounds including caffeic acid, syringic acid, and rutin, (−)-epicatechin, (+)-catechin, gallic acid, vanillic acid, p-coumaric acid, ferulic acid and quercetin, were identified and quantified by HPLC. Results indicated that rice wines exhibited high antioxidant power, and that total antioxidant activity, reducing capacity and free radical scavenging activity were highly correlated with total phenolic content. Nuomi with the highest content of phenolic compounds showed the highest antioxidant activity, while Foshou had the lowest content with lowest activity. Syringic acid and (+)-catechin contributed most to the phenolic compounds and were highly correlated with all antioxidant properties (r² > 0.75). However, vanillic acid, p-coumaric acid and quercetin showed little contribution to the antioxidant function.     

Mechanism of the interaction between insoluble wheat bran and polyphenols leading to increased antioxidant capacity

This study aimed to provide an in-depth investigation of the interaction between insoluble wheat bran and polyphenols. Treatment with tannic acid, but not gallic acid, increased the bound antioxidant capacity of insoluble wheat bran depending on its aqueous concentration (p < 0.05). Among the beverages tested (white and red wines, black and green tea infusions), treatment with green tea infusion caused the highest increase in the total antioxidant capacity. Temperature, time, air and pH were found to significantly affect the reaction between insoluble wheat bran and polyphenols. The bound antioxidant capacity of insoluble bran increased to above 100 mmol TE.kg^− 1 after treatment with green tea infusion at optimum conditions (50 °C, pH 9.0, no airflow). Concentration of free amino groups available in wheat bran significantly decreased (59.5%) after the treatment. The results suggested that polyphenols are oxidized to quinones under alkaline conditions further bound to free amino groups available on the surface of wheat bran.     

Effects of controlled pepsin hydrolysis on antioxidant potential and fractional changes of chickpea proteins

This study investigated the effects of controlled pepsin hydrolysis on antioxidant potential and fractional changes of chickpea protein extracts (CPE). The enzyme hydrolysis increased soluble protein content (1.2 to 2-fold) and free radical scavenging activity (1.9 to 3-fold) of hydrolyzed chickpea protein extract (HCPE), but almost unaffected its antioxidant potential in oil-in-water emulsion system and reduced its iron chelating capacity (1.3-fold) and functional properties. The chromatographic fractions of CPE are mainly acidic, while those of HCPE are mainly basic and neutral. The majority of chickpea proteins had pI between 4.5 and 5.5, and molecular weight (MW) between 15 and 40 kDa, while MW of their pepsin hydrolysis products ranged between 6.5 and 14.2 kDa. The main antioxidant proteins in CPE and HCPE fractionated by ultrafiltration had MW greater than 30 kDa and between 2 and 10 kDa, respectively. The chickpea proteins and hydrolysates showed different potentials as functional food ingredients.     

Assessment of the TEAC method for determining the antioxidant capacity of synthetic red food colorants

The TEAC method was used to evaluate the antioxidant capacity of six synthetic red food colorants (azorubine, amaranth, ponceau 4R, erythrosine, red 2G and allura red AC). This method assesses the ability of such compounds to scavenge the stable radical cation chromophore ABTS⁺, comparing it with that of Trolox, a water soluble vitamin E analogue. It is simple, fast (6 min) and, at the wavelength used for measurements (735 nm) does not interfere with the absorption maxima of the colorants. The experiments showed an antioxidant ranking of allura red AC > azorubine > amaranth > red 2G > erythrosine > ponceau 4R. Their corresponding TEAC values were 0.029, 0.026, 0.019, 0.018, 0.016 and 0.007, respectively.     

Evaluation of antioxidant activity of parsley (Petroselinum crispum) essential oil and identification of its antioxidant constituents

Antioxidant capacities of the essential oil extracted from parsley (Petroselinum crispum) were evaluated by three different in vitro assays: β-carotene bleaching assay, DPPH free radical scavenging assay and Fe²⁺-metal chelating assay. Results showed that the parsley oil (PO) possessed a certain degree of antioxidant activities in terms of β-carotene bleaching capacity and free radical scavenging activity, but its metal chelating capacity was negligible. The antioxidant EC₅₀ values of the β-carotene bleaching assay and DPPH free radical scavenging assay of the crude PO dissolved in methanol were measured in about 5.12 and 80.21 mg/mL, respectively. However, these values were much weaker than those of BHT in 0.01 and 0.58 mg/mL, and of α-tocopherol in 0.01 and 0.10 mg/mL. Isolation and identification of the inherent antioxidants in PO involved using various chromatographic techniques including silica gel open column chromatography, normal phase-HPLC and GC–MS. Myristicin in PO was found as a dominant compound (32.75%) that exhibited a moderate antioxidant activity. Apiol was the second dominant compound (17.54%), but it might be the major contributor to the antioxidant activity of PO. These results suggest that the PO and its two major components can be potential alternative natural antioxidants.     

Effect of plant extracts on the oxidative stability of sunflower oil and emulsion

The antioxidative activities of six plant extracts (catnip, hyssop, lemon balm, oregano, sage and thyme) were evaluated in sunflower oil and its 20% oil-in-water emulsion in the dark at 60°C. The oxidation process was followed by measuring the formation of primary (conjugated diene hydroperoxides) and secondary (volatile compounds) oxidation products. Sage extracts (600 and 1200 ppm) effectively inhibited the formation of conjugated dienes and volatile compounds (hexanal and pentanal) in oil and emulsion and showed the highest antioxidative activity compared with 300 ppm BHT. Thyme and lemon balm extracts inhibited hexanal generation more than formation of conjugated dienes in both oil and emulsion. Oregano extract was more active in oil than in emulsion. Catnip and hyssop extracts (600 ppm) showed prooxidative action to sunflower oil at 60°C. These two extracts increased the formation of conjugated dienes compared with the control oil. In emulsions, catnip extract (600 ppm) was active and significantly inhibited the formation of conjugated dienes more than BHT (300 ppm) during additional incubation.     

Antioxidant and Anti-diabetic Properties of Caryota Urens (Kithul) Flour

Starch extracted from pith of Caryota urens L. (Family: Arecaceae) palm is known as “Kithul flour” and is claimed to have health benefits according to folklore and Ayurveda. Antioxidants are believed to possess numerous health benefits. However, as yet, health benefits of C. urens flour have not been scientifically investigated. Antioxidant properties of C. urens flour were tested using different in vitro assays namely, 2,2-azino-bis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS⁺), ferric reducing antioxidant power, oxygen radical absorbance capacity and ferrous ion chelating assays. Total Phenolic Content (TPC) and Total Flavonoid Content (TFC) were also evaluated. Anti-diabetic properties were estimated using alpha amylase and alpha glucosidase enzyme inhibition assays. Dried methanolic extracts of both boiled and raw samples were used in all assays. Results of the study showed that C. urens flour possess free radical scavenging activity(raw 0.02± 0.01 and boiled 0.04±0.01 mg trolox equivalent (TE)/ g flour), electron donating reducing power (raw 0.10±0.03 and boiled 0.36±0.11 mg TE/g flour), oxygen radical absorbance capacity (raw 2.29± 0.71 and boiled 192.3 ± 57.71 mg TE/1 g flour) and metal ion chelating capacity (raw 0.03±0.01 and boiled 0.14±0.04 mg EDTA equivalents /g flour) exhibiting its antioxidant potential. TPC (raw 1.1±0.3 and boiled 5.12 ± 1.89 mg GAE/g flour) and TFC (raw 1.65 ± 0.47 and boiled 6.69 ± 1.27 μg QE/g flour) which are said to be contributed to antioxidant activities were also found. In addition, boiled flour which is generally consumed as a food has shown higher antioxidant activity. Caryota urens flour did not contain marked anti-diabetic properties. It is evident from results that Caryota urens flour has moderate antioxidant property which may associate with its traditional health claims.     

In-vitro mineral binding capacity of five fiber sources and their insoluble components for magnesium and calcium1

In-vitro binding of calcium (Ca) and magnesium (Mg) by total dietary fiber, hemicellulose A (HCL A), lignocellulose (LCL), cellulose (CL), and lignin (L) fractions isolated from rice bran (RB), wheat bran (WB), oat fiber (OF), apple fiber (AF) and tomato fiber (TF) was evaluated. At pH 6.8, significant amounts of Ca were bound by whole fibers, ranging from 800 μg g⁻¹ for RB to 10 097 μg g⁻¹ for TF. Mg bound by whole fibers varied from 496 μg g⁻¹ for OF to 2177 μg g⁻¹ for WB. Re-acid washing (pH<2.0) released 95–99% of the Ca and Mg bound to the fibers. Fibers with the highest endogenous Ca and Mg concentrations bound significantly (P<0.05) the highest amounts of the minerals studied. The Ca bound by HCL A varied from 9753 μg g⁻¹ for RB to 11 337 mg g⁻¹ for TF, whereas Mg bound varied from 1151 μg g⁻¹ for OF to 5626  μg g⁻¹ for TF hemicellulose fractions, respectively. Among the fiber components, Mg binding decreased in the order HCL A>LCL>L>CL, whereas Ca bound was in the order HCL A>LCL>CL>L. A relatively strong correlation was observed between the combined effects of protein content, hemicellulose, and lignin vs total Ca and Mg bound. 1998 Elsevier Science Ltd. All rights reserved     

Screening of whey protein isolate hydrolysates for their dual functionality: Influence of heat pre-treatment and enzyme specificity

Heat pre-treated and non heat pre-treated whey protein isolate (WPI) were hydrolysed using α-chymotrypsin (chymotrypsin), pepsin and trypsin. The in vitro antioxidant activity, ACE-inhibition activity and surface hydrophobicities of the hydrolysates were measured in order to determine if peptides with dual functionalities were present. Dual functional peptides have both biological (e.g. antioxidant, ACE-inhibition, opioid activities) and technological (e.g. nanoemulsification abilities) functions in food systems. Heat pre-treatment marginally enhanced the hydrolysis of WPI by pepsin and trypsin but had no effect on WPI hydrolysis with chymotrypsin. With the exception of the hydrolysis by trypsin, heat pre-treatment did not affect the peptide profile of the hydrolysates as analysed using size exclusion chromatography, or the antioxidant activity (P > 0.05). Heat pre-treatment significantly affected the ACE-inhibition activities and the surface hydrophobicities of the hydrolysates (P < 0.05), which was a function of the specificity of the hydrolysing enzyme. Extended hydrolysis (up to 24 h) had no significant effect on the DH and the molecular weight profiles (P > 0.05) but in some instances caused a reduction in the antioxidant activity of WPI hydrolysates. The chymotrypsin hydrolysate showed a broad MW size range, and was followed by pepsin and then trypsin. The bioactivities of the hydrolysates generally decreased in the order; chymotrypsin > trypsin > pepsin. This study showed that by manipulating protein conformation with pre-hydrolysis heat treatment, combined with careful enzyme selection, peptides with dual functionalities can be produced from WPI for use as functional ingredients in the manufacture of functional foods.     

Isolation of antioxidative and ACE inhibitory peptides from protein hydrolysate of skipjack (Katsuwana pelamis) roe

Bioactive peptides from protein hydrolysate of defatted skipjack (Katsuwonus pelamis) roe with 5% degree of hydrolysis (DH) prepared by Alcalase digestion were isolated and characterised. Two active fractions with ABTS radical scavenging activity (973.01–1497.53 μmol TE/mg sample) and chelating activity (0.05–0.07 μmol EE/mg sample) from consecutive purification steps including ultrafiltration, cation exchange column chromatography and reverse phase high performance liquid chromatography (RP-HPLC), were subjected to analysis of amino acid sequence by LC–MS/MS. Seven dominant peptides with 6–11 amino acid residues were identified as DWMKGQ, MLVFAV, MCYPAST, FVSACSVAG, LADGVAAPA, YVNDAATLLPR and DLDLRKDLYAN. These peptides were synthesised and analysed for ACE-inhibitory activity and antioxidative activities. MLVFAV exhibited the highest ACE inhibitory activity (IC₅₀ = 3.07 μM) (p < 0.05) with no antioxidative property, whilst DLDLRKDLYAN showed the highest metal chelating activity, ABTS radical and singlet oxygen scavenging activities. Therefore, peptides prepared from skipjack roe could be further employed as a functional food ingredient.     

Evaluating eggplant (Solanum melongena L) genotypes for bioactive properties: A chemometric approach

Thirty four genotypes of eggplant and its wild relatives were evaluated for their total phenolics, flavonoid content and antioxidant capacity. Free radical scavenging was evaluated using four in-vitro assays, viz. FRAP (Ferric reducing antioxidant power), CUPRAC (cupric reducing antioxidant capacity), TEAC (Trolox equivalent antioxidant capacity) and DPPH (2, 2-diphenylpicrylhydrazyl). Total phenolics in eggplant showed a wide variation, ranging from 22.62 to 234.46 mg gallic acid equivalents (GAE)/100 g fw (244.28 to 2990.64 mg GAE/100 g dw). With the exception of Solanum aethiopicum and its accessions (Ac-1, Ac-2 and Ac-3), all wild relatives had significantly (p < 0.05) higher total phenolics and flavonoid content than cultivated ones. Total antioxidant capacity (FRAP) in wild genotypes ranged from 1.13 to 8.04 μmol Trolox (TE)/g. The hierarchy in decreasing order was Solanum khasianum > Solanum torvum > Solanum sisymbriifolium > Solanum incanum > Solanum integrifolium > S. aethiopicum. The antioxidant capacity correlated high with total phenolics in all assays. In cultivated group, JBR-99 and RCMBL-3 possessed high antioxidant capacity than the rest. Principal component analysis (PCA) and Hierarchical cluster analysis (HCA) revealed distinct similarity between JBR-99 (green), S. sisymbriifolium, S. khasianum and S. torvum. Overall results indicate that the wild species of S. torvum, S. incanum and S. sisymbriifolium are potential candidates for improving the functional quality of cultivated eggplant.     

Amelioration of hyperglycemia,hyperlipidemia, oxidative stress and inflammation in steptozotocin-induced diabetic rats fed a high fat diet by riceberry supplement

Dark purple riceberry bran contains a higher dietary fiber and antioxidant compounds than unpigmented rice bran. Riceberry supplement (RB) was used to evaluate the effects on biochemical parameters, skeletal muscle glucose transporter 4 (GLUT4), oxidative stress and inflammation in a streptozotocin (STZ)-induced diabetes rat. To elucidate the effects were due to dietary fiber supplementation and/or bioactive components, equivalent amounts of dietary fiber present in RB were also fed to STZ-induced diabetic rats. Diabetes Sprague–Dawley rats (non-FBG ? 16.65 mM) were randomly divided into five groups: DM fed a high fat (HF) diet, DM-RB1 fed 5% RB, DM-RB2 fed 41% RB, DM-F1 fed 0.6% fiber and DM-F2 fed 5% fiber. After 12 weeks, significant improvement of BG, insulin, HbA1_C, IPGTT and GLUT4 levels were observed in DM-RB1 and DM-RB2 groups. Hyperlipidemia was significantly improved in DM-RB2 and DM-F2 groups. Oxidative stress (TBARS), antioxidant enzymes (SOD, CAT, and GPx), antioxidant capacity (ORAC), pro-inflammation cytokine (TNF-α and IL-6) were improved in DM-RB1 and DM-RB2 groups. Improvement of pancreas and spleen histology was found in DM-RB1 and DM-RB2 groups. These indicate the potential of RB to improve hyperglycemia and hyperlipidemia conditions as well as alleviate oxidative stress and inflammation.     

米糠贮藏时间对米糠可溶性膳食纤维抗氧化性质的影响

以新鲜米糠为原料贮藏0、1、3、5、10 d得到不同酸败程度的米糠,稳定化和脱脂后制备米糠可溶性膳食纤维,研究米糠贮藏时间对米糠可溶性膳食纤维抗氧化性质的影响。结果表明:随着新鲜米糠贮藏时间的延长,米糠可溶性膳食纤维的还原能力、金属离子螯合能力和清除ABTS~+·、DPPH·、·OH、O_2~-·能力均先上升后下降;米糠可溶性膳食纤维还原能力、金属离子螯合能力和清除ABTS~+·、DPPH·、·OH在新鲜米糠贮藏5 d时达到最大值,分别为0.943(OD_(700))、35.16%、32.28%、73.51%和13.83%,米糠可溶性膳食纤维清除O_2~-·能力在新鲜米糠贮藏1 d达到最大值,为60.58%。