Effects of adlay bran and its ethanolic extract and residue on preneoplastic lesions of the colon in rats

BACKGROUND: Adlay (Coix lachryma‐jobi L. var. ma‐yuen Stapf) is a cereal crop used in traditional Chinese medicine and as a nutritious food. Epidemiologists have suspected that the low cancer rates in southeastern China might be related to adlay. Previous studies have shown that adlay has anti‐tumour and anti‐inflammatory activity. This study investigated the effect of adlay bran and its fractions on chemically induced colon carcinogenesis in rats. RESULTS: Adlay bran and its ethanolic extract and residue significantly reduced the number of preneoplastic aberrant crypt foci (ACF) and modified their mucin composition. The inhibitory effect of adlay bran ethanolic extract on ACF showed a dose dependence. Adlay bran and its ethanolic extract suppressed small ACF (one, two or three crypts) and ACF in the distal colon, while the residue suppressed large ACF (four or more crypts). CONCLUSION: These findings suggest the possibility that adlay bran and its ethanolic extract and residue inhibit colonic preneoplastic lesions in an early stage. Adlay and its fractions may have the potential to be developed as chemopreventive cereal products. Copyright © 2010 Society of Chemical Industry     

薏仁米糠蛋白酶法提取工艺的优化

为了研究酶法提取薏仁米糠蛋白的最佳工艺,在单因素试验的基础上,采用Box-Benhnken试验设计,利用响应面法优化薏仁米糠蛋白的提取条件。分析回归方程确定薏仁米糠蛋白提取率的影响因子,确定最佳提取工艺为料液比1∶29（g∶mL）,酶解温度50 ℃,酶解时间1.5 h,酶解pH 9.8。在此最佳提取工艺条件下,薏仁米糠蛋白平均提取率79.66%,产品纯度为73.42%。     

米根霉发酵对脱脂薏米麸皮营养组成及抗氧化活性的影响

本文研究了米根霉发酵对脱脂薏米麸皮游离氨基酸、多肽、多酚、黄酮、酚类物质组成及抗氧化活性的影响。结果表明,脱脂薏米麸皮在发酵过程中总游离氨基酸含量逐渐增加,低分子量多肽比例逐渐提高。脱脂薏米麸皮的游离型多酚和黄酮含量在发酵过程中呈逐渐上升的趋势,72 h后分别较发酵前提高了111.7%和168.6%（P<0.05）,而结合型多酚和黄酮含量未发生显著变化（P>0.05）。米根霉发酵显著增加了脱脂薏米麸皮中游离态3,4-二羟基苯甲酸、4-羟基苯甲酸、丁香酸、绿原酸、齐墩果酸和阿魏酸的含量。此外,与未发酵脱脂薏米麸皮相比,发酵脱脂薏米麸皮的游离型酚类物质提取物的FRAP和ABTS+.清除能力分别提高了119.6%和52.1%（P<0.05）。 本研究可为脱脂薏米麸皮的高值化利用提供参考。     

Chemopreventive properties of the bran extracted from a newly-developed Thai rice: The Riceberry

The potential anti-cancer activity of compounds extracted from Riceberry bran was evaluated in human cancer cell lines (Caco-2, MCF-7 and HL-60). Anti-proliferation and BrdU incorporation assays indicated a time–dose dependent effect of dichloromethane (DCM) and methanol (MeOH) extracts, and that HL-60 was the most sensitive cell. DNA fragmentation assay revealed that both extracts could induce different degrees of apoptosis. The apoptotic induction pathway of each extract determined by flow cytometry and immunoblotting assays revealed various phases of cell cycle arrest with alteration of pro-apoptotic p53, caspase-3, and cyclin proteins. The bioactive compounds in each extract were chemically analysed by GC–MS and LC–ESI–MS/MS. Results revealed the presence of two major anthocyanins, cyanidin-3-glucoside and peonidin-3-glucoside, in the MeOH extract, while the DCM extract contained higher content of plant sterols. The latter constituents are considered the major contributors to apoptotic mechanism in the sensitive cell. These bran products are worth developing into medicinal supplements.     

Enrichment of β -glucan in Oat Bran by Fine Grinding and Air Classification

Oats contain soluble dietary fiber, a major component of which is β -glucan. Oat bran is an oat dry milling fraction enriched in β -glucan. Our objective was to optimize β -glucan enrichment from oat bran by an inexpensive method. The defatted oat bran was ground 1×9,000, 1×14,000, or 3×14,000 rpm in a pin mill. Analysis of β -glucan for fine and coarse fractions for each milling speed indicated the highestβ -glucan content was obtained in fractions larger than 30 μ m from 3×14,000 rpm. This fraction accounted for 393 g/kg of defatted oat bran, and it contained 188 g/kg β -glucan and 302 g/kg protein. With further fractionation of this fraction by sieving, it was observed that fractions of particle size greater than 90μ m contained 200 g/kg β -glucan and less than 100 g/kg of starch. The enriched β -glucan fraction was obtained in good yield and has commercial potential as a food ingredient or for further processing.     

薏米糠蛋白的提取工艺优化及其功能性质

以超临界脱脂薏米糠粉粕为研究对象,采用正交试验优化碱提蛋白工艺,并以酶法提取水相液蛋白为对照,比较两种蛋白的功能性质。结果表明,最佳的碱提条件为料液比1∶8、提取温度45 ℃、提取时间4 h、pH 9,平均提取率为63.75%;两种蛋白均含16 种氨基酸,且7 种必需氨基酸齐全;水酶法提取蛋白的溶解性、乳化性及其稳定性、起泡性均优于粉粕碱提蛋白。     

蛋白酶辅助孵育对薏米麸皮抗氧化活性的影响

分别选用酸性蛋白酶、木瓜蛋白酶、中性蛋白酶和碱性蛋白酶辅助孵育处理脱脂薏米麸皮,考察了蛋白酶辅助孵育对麸皮抗氧化活性的影响。结果表明：蛋白酶辅助孵育处理后麸皮微观结构发生明显改变,蛋白质被显著降解,总游离氨基酸含量较单独孵育时增加了45.33%-120.01%（P<0.05）。蛋白酶辅助孵育后游离型多酚、黄酮含量分别较单独孵育时提高了3.93%-19.21%和21.89%-39.00%（P<0.05）,而结合型多酚、黄酮含量未发生显著变化（P>0.05）。与单独孵育时相比,蛋白酶辅助孵育后游离型酚酸含量显著增加（P<0.05）,游离型铁离子还原能力（FRAP）和ABTS·＋清除能力分别增加了1.68%-14.61%和1.51%-8.93%（P<0.05）。此外,相关性实验发现总酚含量、总黄酮含量、FRAP和ABTS·＋清除能力之间呈极显著正相关（P<0.01）。综合比较后中性蛋白酶的辅助孵育提高抗氧化活性的效果最好。     

On-line separation and structural characterisation of feruloylated oligosaccharides from wheat bran using HPLC-ESI-MS

Water-soluble feruloylated oligosaccharides (FOs) from wheat bran, ferulic acid esters of arabinoxylan oligosaccharides, have been reported as natural antioxidants. In this study, structure features of FOs were studied by FT-IR spectroscopy, and high-performance liquid chromatography (HPLC) coupled to electrospray ionisation (ESI) mass spectrometry (MS) was used for separation and characterisation of FOs. Four components of FOs were resolved on a Dikma Technologies Diamonsil™ C₁₈ column eluted with water/acetonitrite (90:10) containing 0.5% HCOOH (V/V) and further analysed by ESI-MSⁿ. In ESI-MSⁿ, a predominant [M+NH₄]⁺ ion in positive mode and [M−H]⁻ ion in negative mode were observed for molecular mass information. The ESI-MSⁿ spectra of the deprotonated molecular [M−H]⁻ ion were used for structural elucidation. The structures of four isolated compounds were confirmed for the first time by on-line HPLC-ESI-MSⁿ.     

响应面法优化薏仁米糠蛋白碱提工艺的研究

该试验以贵州兴仁县产纯种小薏仁米米糠作为研究对象,采用碱提酸沉法提取薏仁米糠中的蛋白质。考察料液比、碱提温度、碱提时间、碱提pH对蛋白提取率的影响。在单因素试验基础上,采用4因素3水平响应面优化试验,并对试验数据进行多元回归拟合分析,建立各因素对提取率的二次多项式回归预测模型,确定最佳碱提工艺参数。结果表明,碱提酸沉法提取薏仁米糠蛋白最佳提取工艺为料液比1∶22（g∶mL）,碱提温度45.5 ℃,碱提时间3 h,碱提pH9.6,平均蛋白提取率为78.9%。     

Xylanase-mediated in situ production of arabinoxylan oligosaccharides with prebiotic potential in whole meal breads and breads enriched with arabinoxylan rich materials

Multiple studies have revealed the prebiotic activity of cereal derived arabinoxylan oligosaccharides (AXOS). This study investigated the in situ production of AXOS during bread making. In the first part, the AXOS producing capacity of different xylanases was compared in whole meal bread making. Three mesophilic xylanases originating from Bacillus subtilis, Aspergillus niger and Hypocrea jecorina, and one thermophilic xylanase from H. jecorina (HjXynA), were used in different dosages. At dosages that did not impair dough manageability, HjXynA solubilised and cleaved the arabinoxylan fraction to the largest extent, resulting in an AXOS content of 2.1% (dry basis) and an average degree of polymerisation (avDP) of 9. In the second part, the impact of HjXynA on the AXOS levels in dietary fibre enriched breads was studied. Rye or wheat bran fortified breads treated with HjXynA yielded good quality breads with AXOS levels above 2.0% with an avDP of 26 and 19, respectively.     

Extraction of α-tocopherol and γ-oryzanol from rice bran

The aim of this research was to study the effect of operating mode (continuous versus batch+continuous), temperature, pressure and solvent on α-tocopherol and γ-oryzanol extraction from rice bran (Oryza sativa Linn.) and compare the efficiency of three extraction methods: SC-CO₂ extraction, solvent extraction and soxhlet extraction. Three sets of experiments were performed. First, extraction using SC-CO₂ was performed over a range of temperatures and pressures (45-65 °C and at 38 and 48 MPa), and at a CO₂ flow rate of 0.45 mL/min. The results showed that the best conditions for α-tocopherol extraction were 55 °C, 48 MPa in the batch+continuous mode. For γ-oryzanol, the best conditions were 65 °C, 48 MPa and in the continuous mode. In the second set of experiments, solvent extraction using hexane and ethanol at 32 and 55-60 °C was studied. The results showed that none of the solvents could extract α-tocopherol; however, ethanol at 55-60 °C was suitable for γ-oryzanol extraction. Finally, soxhlet extraction experiments using hexane for α-tocopherol and ethanol for γ-oryzanol were also performed. In summary, SC-CO₂ was found to be the best solvent for extracting both α-tocopherol and γ-oryzanol from rice bran, because of its higher yields and extraction rate.     

Effects of enzymatically-extracted purple rice bran fiber as a protectant of L. plantarum NRRL B-4496 during freezing,freeze drying,and storage

This study investigated purple rice bran fiber (PRF) as a protectant for Lactobacillus plantarum NRRL B-4496 (LP) during freezing, freeze drying and storage. PRF was enzymatically extracted from purple rice bran. L. plantarum NRRL B-4496 was grown in MRS broth, centrifuged, and immobilized on PRF suspension. LP cells immobilized on PRF (LP-PRF) and free LP cell (control) samples were frozen in either air blast (AF) or cryogenic freezing (CF) before freeze drying. Freeze-dried (FLP) samples were stored either at room temperature or at refrigerated temperature. For either freezing method, PRF protected cells had less than one log reduction of viable cells while the control had reductions greater than six logs after freeze drying. The log reductions of viable LP cells protected with PRF after freeze drying and 12 weeks storage at 4° C for AF and CF treatments were 0.7 and 1.3 log cycle, respectively. The viable LP-PRF cell count for CF was significantly lower than for AF after 12 weeks at room temperature. PRF improved LP survival in both AF and CF samples in bile. This study demonstrated that freezing methods affected LP viability during storage and that PRF could protect at both refrigerated and room temperatures.     

Evaluation of antioxidant activity of aqueous extract of some selected nutraceutical herbs

The objectives of this study were to examine the antioxidant activities and free radical scavenging effects of extracts of aqueous leaves of Psidium guajava L. (PE), Camellia sinensis (GABA tea; CE), Toona sinensis Roem. (TE) and Rosemarinus officinalis L. (RE). Among the four extracts, PE exhibited the strongest efficiency and showed over 50% scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals at the concentration of 100 μg/mL. The reducing power of four nutraceutical herbs was in the order of PE > RE > CE > TE. The antioxidant activities of nutraceutical herbs were evaluated in a liposomes oxidation system promoted by Fe³⁺/ascorbic acid/H₂O₂. PE still showed the strongest antioxidant activity and exhibited over 95% inhibition at concentration of 50 μg/mL. The antioxidant activity of TE was still lower than that of other herbal plants; however, it also displayed 89% inhibition at concentration of 250 μg/mL. RE exhibited well inhibitory effects on the UVB-induced oxidation of erythrocyte ghosts at lower concentration (100 μg/mL). However, the protection of PE on the UVB-induced oxidation was significantly raised with increasing the concentrations and reached 95.4% inhibitory effects at concentration of 500 μg/mL. These results show that the tested herbal tea, especially PE could be considered as a natural antioxidant source.     

Kinetics of browning onset in white wines: influence of principal redox-active polyphenols and impact on the reducing capacity

The browning capacity of white wines was studied, employing an accelerated test and samples produced and stored under identical conditions. Browning was approached from a kinetic point of view and efforts were focussed on the investigation of plausible correlations with major redox-active polyphenols, including substances with an o-diphenol feature, such as gallic acid, caftaric acid, 2-S-glutathionylcaftaric acid (GRP), caffeic acid, catechin, and epicatechin. Over a period of ten days, browning development was shown to obey zero-order kinetics from the third day of the treatment, and browning rate constants (k) varied from 15.3 to 74.5 × 10⁻³ day⁻¹. Regression analysis between k values and concentration of individual phenolics provided strong evidence that epicatechin is the principal browning agent (r² = 0.8033, P < 0.01). Furthermore, the monitoring of the reducing power (P_R), throughout treatments, indicated that increases in browning are accompanied by a commensurate decline in the reducing ability, raising concerns about the impact of browning reactions on the in vitro antioxidant properties of white wines.     

Green and gold kiwifruit peel ethanol extracts potentiate pentobarbital-induced sleep in mice via a GABAergic mechanism

Kiwifruit is one of the most popular fruits worldwide, and it has various biological properties, including antioxidant, anti-allergic, and cardiovascular protective effects. The peel of kiwifruit, which is a by-product of processing, is a good source of flavonoids; however, its bioactivity has not been widely investigated. In this study, we evaluated the hypnotic effects of green (GRPE, Actinidia deliciosa) and gold (GOPE, Actinidia chinensis) kiwifruit peel ethanol extracts and their solvent fractions, and the possible underlying mechanisms. Oral GRPE and GOPE administration (125–1000 mg/kg) produced a dose-dependent decrease in sleep latency and an increase in sleep duration in pentobarbital-treated mice. Among three different solvent fractions of GRPE and GOPE, ethyl acetate (EA) fractions had the greatest effect on sleep duration at 250 mg/kg. The total flavonoid contents of solvent fractions were proportional to sleep duration. Like diazepam (a GABA_A–benzodiazepine (BZD) receptor agonist), the hypnotic effects of GRPE, GOPE, and their EA fractions were fully inhibited by flumazenil (a GABA_A–BZD receptor antagonist). These results suggest that potentiation effects of GRPE and GOPE on pentobarbital-induced sleep in mice may be modulated by a GABAergic mechanism.     

薏米中多酚化合物的分离纯化及抗氧化活性分析

利用葡聚糖凝胶将薏米中两类多酚类物质进行分离纯化,从而得到6个不同的组分。采用Folin-Ciocalteu法测定该6个组分总酚含量,采用氧自由基吸收能力(oxygen radical absorbance capacity,ORAC)、过氧化氢自由基清除能力(peroxyl radical scavenging capacity,PSC)和细胞内抗氧化能力(cellular antioxidant activity assay,CAA)分析法测定所得6个组分抗氧化能力。在所得的6个组分中选择抗氧化活性最强的3个组分进行半制备,可制得4种薏米多酚纯化物,并测定其4种纯化物的抗氧化活性。结果发现,所分离的6个组分中,薏米中的多酚主要存在于组分2、组分3及组分5中,其总酚含量分别为(30.56±2.25)、(17.40±2.76)、(25.18±1.10)mg GAE/100 g薏米粉末,结合型酚类化合物占薏米总酚含量1/3以上。组分2、组分3及组分5薏米多酚的抗氧化能力较强。经过半制备液相得到的4种多酚纯化物质分别为N_1,N_5-双(对香豆酰)亚精胺、对香豆酸、阿魏酸及芦丁,其中N_1,N_5-双(对香豆酰)亚精胺为游离型多酚的主要物质,而阿魏酸为结合型多酚的主要物质,但在游离型多酚中也有少许存在。4种酚类化合物均具有强抗氧化活性,是薏米中多酚类物质发挥抗氧化作用的主要活性成分。     

Matrix effects on the bioavailability of resveratrol in humans

The pharmacokinetics of resveratrol in 11 healthy male volunteers has been assessed in a randomized, crossover, controlled clinical trial after the administration of three grape products: red wine (250 mL), grape juice (1/L), or tablets (red wine extracts enriched with trans-resveratrol). Doses of trans-resveratrol independently of the product administered, were about 14 μg/kg. Biological samples were collected and analysed by capillary gas chromatography–mass spectrometry. cis-Resveratrol, trans-resveratrol and dihydroresveratrol were determined in plasma and urine. Plasma concentration of trans-resveratrol after hydrolysis increased as a response to all grape products and that of cis-resveratrol after wine and grape juice. Free forms of these phenolic compounds were deemed undetectable in plasma. Despite similar trans-resveratrol doses being administered, its bioavailability from wine and grape juice was 6-fold higher, than that from tablets. Resveratrol was better absorbed from natural grape products than from tablets, pointing out the importance of the matrix in its bioavailability.     

Evidence for galloylated type-A procyanidins in grape seeds

In this work, procyanidins were extracted with methanol from the seeds of white and red grape varieties, and fractionated using graded methanol/chloroform precipitation in order to obtain the oligomers of lower molecular weight. These were analyzed by electrospray ionization-mass spectrometry (ESI-MS and ESI-MS/MS) in the positive mode. Protonated molecules, [M+H]⁺, of procyanidin species of nongalloylated and monogalloylated type-A and type-B oligomers, with degree of polymerisation 2–5, and digalloylated oligomers, with degree of polymerisation 2–3, were observed in the ESI-MS spectra. Type-A procyanidin abundance accounted for 60–80% of the abundance of the corresponding type-B species. Independent of the interflavanic linkage, the abundance of monogalloylated dimers accounted for 20% of the abundance of the corresponding nongalloylated ones. For the higher degrees of polymerisation, the abundance of galloylated oligomers was shown to reach up to 60% of the abundance of the corresponding nongalloylated oligomers. Thiolytic analyses showed that the type-A interflavanic linkages were present in the terminal units whereas the type-B interflavanic linkages were present as extension units. Although many reports are already available regarding the analyses of procyanidin polymers and grape seed procyanidins, this is the first report for the occurrence of type-A galloylated procyanidins. The similarity of the relative abundances and structural features observed in the samples of both white and red grape varieties, shows that these are characteristic of grape seeds.     

Extraction of water-soluble xylan from wheat bran and utilization of enzymatically produced xylooligosaccharides by Lactobacillus, Bifidobacterium and Weissella spp.

Xylan was extracted from wheat bran after heat pretreatment in water using either an autoclave or a microwave oven. Xylooligosaccharides (XOS) were produced from the xylan using the thermostable xylanase RmXyn10A and the potential prebiotic properties of XOS were studied in vitro with different human gut bacteria: Lactobacillus brevis (DSMZ 1269), Bifidobacterium adolescentis (ATCC 15703) and two strains of recently isolated lactic acid bacteria from the species pair Weissella cibaria/confusa. The highest yield of (arabino)xylan with the heat pretreatment was obtained at 185 °C for 10 min. Higher temperature led to fewer arabinose substitutions present on the backbone which in turn resulted in a slightly more efficient enzymatic hydrolysis by RmXyn10A.     

Antioxidant properties of methanolic extracts from monascal adlay

Both the fungus Monascus sp. and adlay possess functional components effective in improving human health. The fungus was inoculated into adlay and a new product was produced after the colonization of fungal mycelia. Our objective was to evaluate the antioxidant properties of methanolic extracts from inoculated products [monascal polished adlay (MPA) and monascal dehulled adlay (MDA)] as compared to uninoculated products [polished adlay (PA) and dehulled adlay (DA)]. With regard to EC₅₀ values (mg extract ml⁻¹) of methanolic extracts, antioxidant activities were excellent and in the descending order of MDA (0.05) ? MPA (0.75) > DA (0.83) ? PA (6.35). Effectiveness in reducing powers was in a descending order of MPA (0.78) > MDA (1.53) ? PA (13.24) ∼ DA (13.67 mg ml⁻¹). Scavenging abilities on 1,1-diphenyl-2-picrylhydrazyl radicals and chelating abilities on ferrous ions were in the descending order of MPA > MDA > DA > PA. Total phenols were the major naturally occurring antioxidant components found. Overall, monascal adlay products displayed higher antioxidant activity, reducing power, scavenging and chelating abilities and higher in total phenol content than uninoculated adlay products.