Antioxidant properties of commercial soft and hard winter wheats (Triticum aestivum L.) and their milling fractions

The total phenolic content (TPC), total antioxidant activity (TAA), 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) scavenging capacity, inhibition of coupled oxidation in a β‐carotene–linoleate model system, iron(II) chelation activity and inhibition of copper‐induced oxidation of human low‐density lipoprotein (hLDL) cholesterol of 80% ethanolic extracts of soft and hard winter wheat samples and their milling fractions, namely flour, germ, bran and shorts, were investigated. Soft wheat extracts examined demonstrated higher TPC and TAA compared to those of hard wheat extracts. The germ fraction possessed the highest TPC, followed by bran, shorts, whole grain and flour for both wheat types examined. The TAA of both wheat types showed similar results except that shorts performed better than bran in this assay. Free radical scavenging properties of whole grain and milling fractions of both soft and hard wheat samples were examined against DPPH radical. The germ and flour fractions demonstrated the highest and lowest DPPH radical scavenging activity, respectively, among wheat fractions. Wheat extracts were also efficient in preventing bleaching of β‐carotene, which is also known to be free radical mediated. In the iron(II) chelation assay the flour extracts demonstrated excellent activity, while the germ extracts showed a weak activity. The trends were similar in both soft and hard wheat for the iron(II) chelation assay. Wheat extracts also inhibited copper‐induced oxidation of hLDL. In LDL oxidation assay, wheat extracts performed better than the reference antioxidant, ferulic acid. Thus wheat phenolics may serve as effective antioxidative components as measured by in vitro techniques. Copyright © 2005 Society of Chemical Industry     

Antioxidant Effects of Herbal Tea Leaves from Yacon (Smallanthus sonchifolius) on Multiple Free Radical and Reducing Power Assays,Especially on Different Superoxide Anion Radical Generation Systems

Yacon (Smallanthus sonchifolius), a native Andean plant, has been cultivated as a crop and locally used as a traditional folk medicine for the people suffering from diabetes and digestive/renal disorders. However, the medicinal properties of this plant and its processed foods have not been completely established. This study investigates the potent antioxidative effects of herbal tea leaves from yacon in different free radical models and a ferric reducing model. A hot‐water extract exhibited the highest yield of total polyphenol and scavenging effect on 1,1‐diphenyl‐2‐picryl hydrazyl (DPPH) radical among four extracts prepared with hot water, methanol, ethanol, and ethylacetate. In addition, a higher reducing power of the hot‐water extract was similarly demonstrated among these extracts. Varying concentrations of the hot‐water extract resulted in different scavenging activities in four synthetic free radical models: DPPH radical (EC₅₀ 28.1 μg/mL), 2,2′‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid) cation radical (EC₅₀ 23.7 μg/mL), galvinoxyl radical (EC₅₀ 3.06 μg/mL), and chlorpromazine cation radical (EC₅₀ 475 μg/mL). The yacon tea‐leaf extract further demonstrated superoxide anion (O₂^?) radical scavenging effects in the phenazine methosulfate‐NADH‐nitroblue tetrazolium (EC₅₀ 64.5 μg/mL) and xanthine oxidase assay systems (EC₅₀ 20.7 μg/mL). Subsequently, incubating human neutrophilic cells in the presence of the tea‐leaf extract could suppress the cellular O₂^? radical generation (IC₅₀ 65.7 μg/mL) in a phorbol 12‐myristate 13‐acetate‐activated cell model. These results support yacon tea leaves may be a good source of natural antioxidants for preventing O₂^? radical‐mediated disorders.     

植物提取物抗运动性疲劳作用的研究进展

运动性疲劳是人体脑力和体力持续活动到一定阶段时出现的一种生理现象,表现为机体生理过程不能维续其机能在特定水平上和(或)不能维持预定的运动强度。持续性的运动疲劳极易诱发运动损伤,从而给运动员或长期运动者的身体和运动表现能力带来隐患。因此,如何有效预防运动性疲劳的发生,以及如何有效恢复运动性疲劳是当前需要重点考虑的问题。近年研究表明,植物提取物在人体抗疲劳的预防和消除中有着十分重要的作用。故本文结合近些年国内外关于植物提取物的研究,综述了常见的多种植物类提取物如：多酚类、生物碱类、皂苷类、多糖类等在人体抗疲劳中的作用,及其对人体不同疲劳部位(外周疲劳、神经中枢疲劳)的抗疲劳作用机制,以期为研发新型抗运动疲劳功能产品遴选绿色、有效、安全的食源性活性成分提供一定的理论指导依据。     

Dietary plant materials reduce acrylamide formation in cookie and starch-based model systems

BACKGROUND: Dietary plant materials have attracted much attention because of their health benefits to humans. Acrylamide is found in various heated carbohydrate‐rich foods. Our previous results showed that crude aqueous extracts from diverse dietary plants and some phenolic compounds could mitigate acrylamide formation in an asparagine–glucose model system. Based on our previous study, several plant materials were selected to further investigate their inhibitory effects on acrylamide formation in cookies and starch‐based model systems. RESULTS: Addition of raw powders from selected dietary plants and their crude aqueous extracts could considerably reduce acrylamide formation in both cookie and potato starch‐based models. Aqueous extracts of clove at 4% caused the largest reduction (50.9%) of acrylamide in cookies, whereas addition of 2% proanthocyanidins from grape seeds gave the greatest acrylamide reduction (62.2%) in a starch‐based model system. CONCLUSION: It may be feasible to use some of the tested dietary plant materials to reduce acrylamide formation in cookies and other starchy foods. Copyright © 2011 Society of Chemical Industry     

咖喱粉两种提取物的抑菌作用研究

通过水蒸气蒸馏法和乙醇回流抽提法两种方法对咖喱粉进行提取,分别得到了咖喱粉水蒸馏精油和乙醇提取液,并测试了这两种提取物对几种常见细菌、霉菌、酵母菌的抑菌活性(抑菌圈直径大小)、最低抑菌浓度(MIC值)及气态防腐效果,探讨和比较了咖喱粉两种提取物的抗菌作用,结果表明:咖喱粉水蒸馏精油和乙醇提取液有不同程度的抑菌作用,比较而言, 水蒸馏精油的抑菌能力远强于乙醇提取液。     

Naturally occurring phenolic compounds as promising antimycotoxin agents: Where are we now?

Mycotoxins are metabolites produced by molds that contaminate food commodities, are harmful to both humans and animals, as well as cause economic losses. Many countries have set regulatory limits and strict thresholds to control the level of mycotoxins in food and feedstuffs. New technologies and strategies have been developed to inhibit toxigenic fungal invasion and to decontaminate mycotoxins. However, many of these strategies do not sufficiently detoxify mycotoxins and leave residual toxic by-products. This review focuses on the use of phenolic compounds obtained from botanical extracts as promising bioagents to inhibit fungal growth and/or to limit mycotoxin yields. The mechanism of these botanicals, legislation concerning their use, and their safety are also discussed. In addition, recent strategies to overcome stability and solubility constraints of phenolic compounds to be used in food and feed stuffs are also mentioned.     

密度法测试落叶松浓胶干物含量的研究

探讨了落叶松浓胶的密度与其干物含量之间的关系 ,并求出了相应的回归方程式 ,用密度法测试落叶松浓胶的干物含量 ,操作简单 ,准确度达到较高要求     

The development of fruit‐based functional foods targeting the health and wellness market: a review

Functional foods and their health benefits beyond individual nutrients present challenges to the traditional ‘nutrition’ approach to foods. Epidemiological studies suggest that regular or increased consumption of fruits may promote general health and well‐being as well as reduce the risk of chronic diseases. Therefore, a broad range of research amongst academic, industry and government institutes has been stimulated in attempts to add the goodness of fruits into popular consumer foods. This article provides a brief overview of the research opportunities in the emerging functional foods area, with an emphasis on fruit‐derived products. Based on recent research in the fruit‐based functional food area, a structured approach for designing and developing functional finished products is presented. Included are the technical challenges and their associated solutions during food design, formulation, processing and storage. A consumer‐oriented food product development process is highlighted. Controlling the interactions among the targeted bioactives and other food components during food processing, handling and storage is the key to ensure that a stable and appealing functional food is produced. Manipulating the beneficial synergies among food ingredients, and among food formulation and processing methods, has the potential to lead to substantial food innovations.     

Antibacterial and antifungal activities of selected microalgae and cyanobacteria

In vitro activity of nine cyanobacterial and ten microalgal newly isolated or culture collection strains against eight significant food‐borne pathogens has been evaluated and compared. Water extracts and culture liquids of Gloeocapsa sp. and Synechocystis sp. demonstrated the widest spectrum of activity with minimal inhibitory concentration (MIC) ranging from 1.56 to 12.5 mg mL^?1. Culture liquid of Anabaena sp. had the highest activity (MIC = 0.39 mg mL^?1) but only to Gram‐positive bacteria. Ethanol extracts and fatty acids from all cyanobacteria and microalgae were active against Streptococcus pyogenes and/or Staphylococcus aureus. The fatty acids of Synechocystis sp. inhibited the growth of Bacillus cereus, Escherichia coli and Candida albicans (MIC values of 2.5–1.25 mg mL^?1, respectively). Exopolysaccharides (EPS) of Gloeocapsa sp. were the sample that exhibited activity against all test pathogens with lowest MIC values (0.125–1 mg mL^?1). High activity with a narrower range of susceptible targets demonstrated the exopolysaccharides of Synechocystis sp. and Rhodella reticulata. Antimicrobial activity was proven for phycobiliproteins isolated from Synechocystis sp., Arthrospira fusiformis, Porphyridium aerugineum and Porphyridium cruentum, respectively. In conclusion Gloeocapsa sp. and Synechocystis sp. and especially their exopolysaccharides showed the most promising potential against the examined food pathogens.