Changes of liposome and antioxidant activity in immature rice during seed development

For the past several decades, only a few studies were conducted on the change in immature rice liposomes during seed development. To evaluate and compare the lipid material of different degrees of developing rice grains, this paper focused on fresh rice seeds from only one most popular species of Dasan divided into five growth periods. The lipid components of fresh rice, especially γ-oryzanol and fatty acids equipped with extremely beneficial phytonutrients, were investigated. The results illustrated that the level of extracted liposome increased gradually along with the development of rice and in the third stage of development, the level of liposome achieved maximum. And then, instead of increasing, it was decreased at later stages of development. Moreover, the antioxidant activity of fresh edible rice (FER) was also evaluated by DPPH and ABTS assay. It was shown that FER has the higher antioxidant activity than the ripened rice seed on lipids, which will improve FER using on the functional foods and help provide certainly theoretical basis in food processing industry.     

米糠深加工技术的分析与评价(Ⅰ)--米糠制油及脱脂米糠的利用

米糠富含脂质、蛋白质、矿物质、维生素等多种营养物质,是一种具有很大潜力的食品资源、化工原料和药物原料.对米糠制油技术及脱脂米糠的利用技术进行了综合性评述,为米糠的综合开发利用提供参考.     

Bioactive compounds in rice during grain development

The bioactive compounds in two developing rice grains, KFSW (a waxy indica red rice) and TK16 (a non-waxy japonica rice), were investigated. The total phenolics and total flavonoids of two developing rice grains were significantly higher than those in mature seeds. The phenolics extract was further fractionated into three fractions, free, soluble-ester and insoluble-bound; ferulic acid was the most abundant compound in each fraction, in both immature grain and mature seed. α-Tocopherol was the most abundant vitamin E homologue, followed by γ-tocotrienol in KFSW and α-tocotrienol in TK16. High contents of free and soluble-ester ferulic acids, soluble dietary fibre, total tocols and oryzanols were found in the 15th and 18th DAA (days after anthesis) grains, which were suitable for dehulling, with a reasonable brown rice yield. Immature rice grains, containing a remarkable amount of bioactive compounds with a high reducing power, have a great potential for applications in nutraceutical foods.     

超声波处理对黑米酒中酚类物质、颜色及抗氧化性的影响

研究了超声处理对黑米酒中酚类物质、颜色及羟基自由基清除能力的影响。结果显示:超声波处理后黑米酒中总酚含量、总黄酮含量、总花青素含量及清除自由基能力均有不同程度下降,而黑米酒亮度(L*)、红色(a*)及黄色(b*)的颜色特性均有一定程度增加;不同超声条件处理后,黑米酒中总花青素含量与其a*有明显相关性,表明总花青素是黑米酒呈现红色的主体物质;超声处理后黑米酒清除羟自由基的能力与黄酮、花青素等的变化呈明显相关性。上述部分指标的变化与自然熟化过程变化基本一致,表明超声在一定程度上可以起到辅助黑米酒熟化的作用。     

稻米中抗营养因子的研究进展

植酸是稻米的天然组分，是稻谷种子生长和活动所必需的。在稻谷的生长过程中，不仅对灌浆十分有利，而且对稻谷成分的形成和工艺品质也有很大的促进作用，但是对人类营养而言，植酸是一种抗营养物质，植酸可与钙、锌、铁等物质螯合，降低钙、锌、铁等的生理利用率；植酸还能与蛋白质等形成不溶性复合物，降低氨基酸的利用率；一些消化酶的作用也受到植酸的抑制，从而影响到蛋白质、淀粉、脂肪的利用率。     

Ascorbic acid improves the antioxidant activity of European grape juices by improving the juices' ability to inhibit lipid peroxidation of human LDL in vitro

Antioxidant activities of red and white European grape juices towards copper induced lipid oxidation of human low-density lipoproteins (LDL) were examined in vitro . LDL lipid peroxidation was assessed spectrophotometrically by monitoring the development of conjugated lipid hydroperoxides at 234 nm. Red grape juice concentrate inhibited lipid peroxidation of LDL by prolonging the lag phase by 2.7 times relative to a control when evaluated at a total phenolic concentration of 10 μM gallic acid equivalents (GAE). Both red grape juices tested blocked lipid peroxidation of LDL at 20 μM GAE. White grape juice exerted prooxidant activity at 5–20 μM GAE. The antioxidant activity, inhibition of lipid peroxidation of LDL in vitro , was correlated with the juices' levels of total phenols ( r  > 0.98, P  < 0.01), anthocyanins ( r  > 0.99, P  < 0.01), flavan-3-ols ( r  > 0.97, P  < 0.05), and hydroxybenzoates ( r  > 0.96, P  < 0.05) when the phenolic composition of each grape juices was analysed by HPLC. 5 μM ascorbic acid alone did not exert antioxidant activity towards LDL, but combinations of 5 μM ascorbic acid with 5 μM GAE juice phenols eliminated the prooxidant activity of white grape juice, and significantly improved the antioxidant activities of red grape juices.     

Phenolic compounds profile and antioxidant activity of Dorystoechas hastata L. Boiss et Heldr

Phenolic compound profile and antioxidant activity of methanol, acetone, ethyl acetate, water and petroleum ether (b.p. 40–60 °C) extracts of Dorystoechas hastata, endemic to Turkey and being consumed as herbal tea by local inhabitants, have been investigated. HPLC–DAD analysis indicated the presence of chlorogenic, caffeic, p-coumaric, ferulic and rosmarinic acids as phenolic acids, quercetin, kaempferol and apigenin as flavonoids and carnosic acid and carnosol as diterpenoid antioxidants in the plant. Petroleum ether, methanol and water extracts of D. hastata were found to be very effective antioxidative extracts. Petroleum ether extract, having the highest amount of carnosic acid and carnosol contents (531.3 and 389.9 mg/g DW, respectively) among all solvent extracts, was found to have the highest antioxidative potential based on the individual antioxidant activity assays; DPPH, ABTS⁺, TBARS and total phenolic content, expressed as IC₅₀, TEAC, EC₅₀ and TPC values, respectively, and also on the principal component analysis. It exhibited significantly high TEAC (7.1 mM trolox) and low EC₅₀ (54.5 μg/mL) values, indicating the strong potential in in vitro radical scavenging and in inhibiting lipid oxidation. Water extract, with its extremely low IC₅₀ value of 4.9 μg/mL in DPPH radical scavenging and significant TEAC (4.8 mM trolox), EC₅₀ (64.4 μg/mL) and TPC (116.7 mg GAE/g DW) values, was found to be the second highest in antioxidative potential among all extracts. TPC value of methanol extract (147.3 mg GAE/g DW) was found to be significantly higher than the other extracts studied. The results showed that D. hastata can be used as a potential antioxidative edible source due to its different classes of phenolic compounds and strong antioxidative capacity.     

吡喃型花青素类化合物的研究进展

吡喃型花青素类化合物为近年来新发现的一类花青素衍生物,主要存在于陈年葡萄酒或久置果汁中,其化学结构与自然界中常见花青素类区别较大,因在原有花青素C4位及C5位羟基间经环化加成增加一个吡喃环D,进而形成新的吡喃型花青素。该文整理了国内外有关农产品或食品中吡喃型花青素类化合物的相关研究报道,分别就其来源、种类、形成过程、分离纯化及结构鉴定技术、稳定性评价、对葡萄酒品质影响及功能活性方面进行了概述。鉴于吡喃型花青素独特化学结构、良好色泽稳定性及潜在功能活性,未来吡喃型花青素将在农产品加工或食品领域中展现出巨大应用潜力。该文旨在为吡喃型花青素类化合物的深入纯化鉴定、功能特性研究及综合开发利用提供参考依据。     

Industrial processing effects on chestnut fruits (Castanea sativa Mill.) 3. Minerals,free sugars,carotenoids and antioxidant vitamins

The major aim of this study was to evaluate the effects of industrial processing on the composition of minerals, free sugars, vitamins and pigments in fruits of chestnut cultivars at four stages of industrial processing (A–fresh; B–after 3 months storage at ± 0 °C and relative humidity = 90%; C–after flame peeling at 800 °–1000 °C for 1–2 s; D–after freezing in a tunnel with a CO₂ flow at ?65 °C for 15–20 min) from two harvest years. Potassium and phosphorous were predominant in the fruits of all cultivars for both harvest years. Calcium, magnesium, iron, zinc and manganese were also present in the fruits. Fruits from both harvest years had a significant content of free sugars, with sucrose predominating, and these sugars were more affected by the processing stage. Significant levels of lutein, lutein esters, γ‐tocopherol and vitamin C were also found in the chestnut fruits. Fruit carotenoids and vitamin C significantly decreased during the industrial processing.     

Distribution of phenolic compounds in the graded flours milled from whole buckwheat grains and their antioxidant capacities

Whole buckwheat grains were milled into 16 flour fractions using the gradual milling system and the phenolic compounds and the antioxidant capacity of each flour fraction were investigated. The phenolic and flavonoid contents of both free and bound phenolic extracts of buckwheat flour fractions significantly increased in the order from the fraction number 1 (phenolics less rich fraction) to the fraction number 16 (phenolics rich fraction). The phenolic compounds in buckwheat existed primarily in free form, whereas the flavonoids existed in grain in insoluble bound forms, bound to cell wall materials. The amounts of ferulic acid and rutin increased from 2.5 and 2.5 μg/g flour of the phenolics less rich fraction to 609.5 and 389.9 μg/g flour of the phenolics rich fraction of grain, respectively. The higher phenolic contents in the phenolics rich fractions exhibited the stronger antioxidant capacity than the phenolics less rich fractions. As a result, the flour milled from the outer layers of buckwheat grains with large amount of phenolic compounds and antioxidant capacity are considered to have significant health benefits.     

Effect of germination on vitamin C,phenolic compounds and antioxidant activity in flaxseed (Linum usitatissimum L.)

Flaxseed (Linum usitatissimum L.) is well known for its health benefits and chemical composition. This study aimed to evaluate the dynamic changes caused by germination in vitamin C, phenolic compounds and antioxidant activities of flaxseed. It was observed that eight‐day germination of flaxseed sprouts caused increases in phytochemical contents, that is 22.1‐fold increase in vitamin C, 2.67‐fold increase in phenolics and 5.48‐fold increase in flavonoid contents as compare to initial concentration in flaxseeds on dry weight basis. The stimulation was also noted in the three identified phenolic acid ingredients including caffeic acid, p‐coumaric acid and ferulic acid. Similarly, the total PSC and ORAC values of flax sprouts at day 8 increased by 3‐ to 4‐folds compared to nongerminated flaxseeds. It is revealed that comparatively, 8‐day germination of flax sprouts leads to a significant increase in vitamin C, phenolic constituents and total antioxidant activities than those of flaxseeds.     

分子蒸馏法从大豆油脚中提取维生素E的研究

利用分子蒸馏技术从大豆油脚中提取维生素E及脂肪酸甲酯，大豆油脚经皂化、酸解、甲酯化、冷析沉淀、醇洗、结晶后可得到大豆甾醇；上层油相在130～210℃、10～40 Pa条件下进行分子蒸馏可得到93%～98%的脂肪酸甲酯；在210～240℃、10 Pa条件下可蒸馏含量为10%的维生素E，再经浓缩可达到50%以上。     

Phytochemicals and antioxidant capacities in rice brans of different color

Rice bran, a byproduct of the rice milling process, contains most of the phytochemicals. This study aimed at determining the concentrations of lipophilic, solvent-extractable (free), and cell wall-bound (bound) phytochemicals and their antioxidant capacities from brans of white, light brown, brown, purple, and red colors, and broccoli and blueberry for comparison. The concentrations of lipophilic antioxidants of vitamin E (tocopherol and tocotrienols) and γ-oryzanols were 319.67 to 443.73 and 3861.93 to 5911.12 μg/g bran dry weight (DW), respectively, and were not associated with bran color. The total phenolic, total flavonoid, and antioxidant capacities of ORAC (oxygen radical absorbance capacity), DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging, and iron-chelating in the free fraction were correlated with the intensity of bran color, while variations of these in the bound fraction were less than those in the free fraction among brans. Compounds in the bound fraction had higher antioxidant capacity of ORAC than DPPH, relative to those in the free fraction. The bound fraction of light-color brans contributed as much to its total ORAC as the free fraction. Total proanthocyanidin concentration was the highest in red rice bran, while total anthocyanin was highest in purple brans. The predominant anthocyanin was cyanidin-3-glucoside. Red and purple brans had several fold higher total phenolics and flavonoids as well as ORAC and DPPH, from both free and bound fractions, than freeze-dried blueberry and broccoli. These results indicate that rice brans are natural sources of hydrophilic and lipophilic phytochemicals for use in quality control of various food systems as well as for nutraceutical and functional food application.     

发酵法降解油菜籽废水中植酸的工艺研究

水酶法提取菜籽油工艺产生了大量废水,其中含有丰富的水溶性蛋白、碳水化合物和抗营养因子。为了降解水中的抗营养物质植酸,利用筛选出的酵母菌对其进行发酵,并通过正交试验优化培养条件,得出K酵母在32℃,pH 7条件下培养36 h,可将废水中植酸降解87%,从而为废水的循环利用或达标排放打下了基础。     

Phytic Acid Degradation in Complementary Foods Using Phytase Naturally Occurring in Whole Grain Cereals

Complementary foods based on cereals and legumes often contain high amounts of phytic acid, a potent inhibitor of mineral and trace element absorption. The possibility to degrade phytic acid during the production of complementary foods by using whole grain cereals as the phytase source was investigated. Whole grain rye, wheat, or buckwheat (10%) were added to cereal‐legume‐based complementary food mixtures, and phytic acid was shown to be completely degraded in a relatively short time (1.5 to 3 h) when incubated at optimal conditions for cereal phytase. The potential usefulness of the method for industrial production was demonstrated with a complementary food based on wheat and soybean.     

超声波辅助提取水酶法豆渣中植酸的工艺优化

以水酶法提油后的副产物豆渣为原料,探索超声波辅助技术提取植酸的工艺条件,并与振荡浸提法对比。首先选取超声功率、超声温度、超声时间进行单因素实验,通过正交实验选出最佳的超声参数。然后在最优超声参数的基础上,以植酸得率为响应值,利用Box-Behnken中心组合设计原理和响应面分析法,确定提取植酸的最佳条件。结果表明,超声提取植酸的条件为:超声温度50℃,超声功率500 W,超声时间20 min;醋酸浓度4.1%、料液比1∶17 g/m L、提取温度64℃、提取时间33 min。在以上条件下,平均植酸得率为1.23%,与振荡提取法相比,提高41.3%。