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1.
Electrochemistry of malePeriplaneta americana perception of naphthoquinones as allelochemicals is presented. Importance of the oxidation-reduction potential and hydrogen-bonding capabilities of the naphtho-quinone messenger to its exchange of energy with the information-encoding, redox protein of the chemosensory neuron is considered. Evidence that the required information is initially encoded by an electroreactive protein in dendritic membrane is analyzed. A sulfhydryl-disulfide protein-based electrochemical mechanism for the demonstrated linear conversion of a molecular messenger energy state into whole insect behavior (avoidance or feeding inhibition) is elucidated. Even though the information-encoding mechanism is genetically conserved (kept electrochemically similar) within the species, behavioral biotypical differences regarding sensitivity to naphthoquinones are allowed through a group of proteins in the outer aqueous medium in the chemosensory sensillum. Such proteins electrochemically interface the dendritic membrane of the chemosensory neuron in the sensillum with the environment external to the sensillum. These interfacing proteins bind (complex) with chemical messengers (e.g., naphthoquinones) and/or variously degrade them, and thus determine the amount (moles) that is required in the environment to result in stimulation of the underlying sensory neurons and in a changed behavior.  相似文献   
2.
BACKGROUND: Cynara cardunculus is a species native to the Mediterranean basin. It includes globe artichoke and cultivated cardoon as well as their progenitor wild cardoon. The species is a source of biophenols, and its leaf extracts have been widely used in herbal medicine as hepatoprotectors and choleretics since ancient times. The aim of this study was to determine the effect of increasing the level of salinity in the nutrient solution (1 or 30 mmol L?1 NaCl) on biomass production, mineral composition, radical‐scavenging activity, caffeoylquinic acids and flavonoids in three artichoke (‘Romolo’, ‘Violetto di Provenza’ and ‘Violetto di Romagna’) and three cultivated cardoon (‘Bianco Avorio’, ‘Bianco Gigante Inerme’ and ‘Gigante di Romagna’) cultivars grown in a floating system. RESULTS: Increased salinity in the nutrient solution decreased the leaf dry biomass and leaf number of artichoke and cultivated cardoon cultivars. Salinity reduced macro‐ and microelement accumulation in leaves (e.g. N, K, Ca, Mg, Fe, Mn and B) but improved their antioxidant activity, total polyphenols, chlorogenic acid, cynarin and luteolin. The cultivated cardoons, especially ‘Bianco Avorio’ and ‘Gigante di Romagna’, showed higher biomass and leaf number than those observed in artichoke genotypes. ‘Violetto di Provenza’ exhibited the highest content of chlorogenic acid, closely followed by ‘Violetto di Romagna’, whereas for cynarin content the highest values were recorded in ‘Violetto di Provenza’, ‘Bianco Avorio’ and ‘Gigante di Romagna’. The highest content of luteolin was recorded in ‘Gigante di Romagna’ and ‘Bianco Avorio’, while the highest content of apigenin was observed in ‘Gigante di Romagna’. CONCLUSION: The results showed that the floating system could be considered an effective tool to improve quality aspects through proper management of the salt concentration in the nutrient solution. They also suggest that specific cultivars should be selected to obtain the desired profile of bioactive compounds. © 2012 Society of Chemical Industry  相似文献   
3.
Grape Phytochemicals and Associated Health Benefits   总被引:3,自引:0,他引:3  
The phytochemicals present in fruits and vegetables may play an important role in deceasing chronic disease risk. Grapes, one of the most popular and widely cultivated and consumed fruits in the world, are rich in phytochemicals. Epidemiological evidence has linked the consumption of grapes with reduced risk of chronic diseases, including certain types of cancer and cardiovascular disease. In vitro and in vivo studies have shown that grapes have strong antioxidant activity, inhibiting cancer cell proliferation and suppressing platelet aggregation, while also lowering cholesterol. Grapes contain a variety of phytochemicals, like phenolic acids, stilbenes, anthocyanins, and proanthocyanidins, all of which are strong antioxidants. The phytochemical composition of grapes, however, varies greatly among different varieties. While extensive research exists, a literature review of the health benefits of grapes and their phytochemicals has not been compiled to summarize this work. The aim of this paper is to critically review the most recent literature regarding the concentrations, biological activities, and mechanisms of grape phytochemicals.  相似文献   
4.
综述了小麦中的一些植物化学素如酚类、低聚糖类、植物甾醇等及其生理活性与人类健康的关系。  相似文献   
5.
Understanding the influence of processing operations such as drying/dehydration, canning, extrusion, high hydrostatic pressure, pulsed electric field, and ohmic heating on the phytochemicals of fruits, vegetables, and grains is important in retaining the health benefiting properties of these antioxidative compounds in processed food products. Most of the previous investigations in the literature on the antioxidants of fruits, vegetables, and grains have shown that food-processing operations reduced the antioxidants of the processed foods, which is also the usual consumer perception. However, in the last decade some articles in the literature reported that the evaluation of nutritional quality of processed fruits and vegetables not only depend on the quantity of vitamin C but should include analyses of other antioxidant phytochemicals and antioxidant activity. Thermal processing increased the total antioxidant activity of tomato and sweet corn. Most importantly, analysis also depends on the condition, type, and mechanism of antioxidant assays used. This review aims to provide concise information on the influence of various thermal and nonthermal food-processing operations on the stability and kinetics of health beneficial phenolic antioxidants of fruits, vegetables, and grains.  相似文献   
6.
来自饮食和药用植物的天然植物非营养成分(Phc)具有重要的健康保护和临床应用潜力,这已经得到了全世界的密切关注。主要来自果蔬的植物非营养成分是功能性食品的重要来源,而植物非营养成分已经证明在健康保护、抗癌、防癌,特别是预防现代文明病方面表现出巨大的应用潜力。研究证明,Phc 可以上调表达抗化作用的酶类,促进癌症和突变细胞凋亡、调节,特别是下调免疫应答,改变细胞相Ⅰ和相Ⅱ酶的表达,改变细胞因子网络,从而发挥重要的防病治病作用。大量研究表明,Phc 通过和受体相互作用向机体、组织和细胞传递信号。其信号途径主要涉及:丝裂原- 活化蛋白激酶(MAPK)、蛋白激酶C(PKC)、磷酸肌醇3 激酶(PI3K)、Toll 样受体(TLRs)、异常环氧酶-2(COX-2)、活化因子蛋白-1(AP-1)、核因子κB(NF-κB)等。其中,尤其是NF-κB 与AP-1 直接和炎症、免疫调节和癌症相联系。细胞信号的级联放大作用及不同信号途径之间的交谈和相互作用构成了一个非常复杂的调控网络。MAPK 途径异常,或者其下游转录因子的异常都会造成细胞的异常增殖、免疫功能过头、慢性炎症性疾病、现代文明病和细胞恶性转化。因此,抑制这些信号途径可以提供一个避免现代文明病、各种慢性病和癌症的有效战略。本文就这些信号途径进行综述,并提出自己的观点。  相似文献   
7.
There is strong scientific evidence suggesting that regular consumption of fruits and vegetables is negatively associated with risk of developing chronic diseases. The 2010 Dietary Guidelines for Americans recommend at least 9 servings of fruits and vegetables a day based on a 2000 kcal diet. However, the average person in the United States consumes 3.6 servings of fruits and vegetables per day. In order to achieve the goal of at least 9 servings, we should continue educating Americans about the health benefits of fruits and vegetables and recommend consumers to eat a wide variety of fruits and vegetables. The key is to increase the amount up to 9 to 13 servings of fruits and vegetables a day in all forms. Fresh, cooked, and processed fruits and vegetables including frozen and canned, 100% fruit juices, 100% vegetable juices, and dried fruits are all considered as servings of fruits and vegetables. A wide variety of fruits and vegetables provide a range of nutrients and different bioactive compounds including phytochemicals (phenolics, flavonoids, and carotenoids), vitamins (vitamin C, folate, and provitamin A), minerals (potassium, calcium, and magnesium), and fibers. More and more evidence suggests that the health benefits of fruits and vegetables are attributed to the additive and synergistic interactions of the phytochemicals present in whole foods by targeting multiple signal transduction pathways. Therefore, consumers should obtain nutrients and bioactive compounds from a wide variety of whole foods for optimal nutrition and health well‐being, not from expensive dietary supplements.  相似文献   
8.
A conductometric analysis of the effect of condensate of peroxides generated during lipid oxidation in an accelerated stability test was adapted to test the hypothesis that total antioxidant capacity of tomato products would sometimes increase during processing and in storage. Tomato pulp blends made from a mixture of tomato (Lycopersicon esculentum var Roma VF), watermelon (Citrullus vulgaris var Babylack) and pineapple (Ananas comosus var Smooth cayennes) were analysed for basic quality profiles of dry matter, Brix, titratable acidity (TTA) and pH, total reducing sugars, Component antioxidants phytochemicals and total antioxidant capacity. The lowest sensory score (overall impression) of 4.80 ± 2.59 was recorded for tomato juice while, blend TWP 111p had highest score of 6.20 ± 1.99. There was significant difference (P < 0.05) in the basic quality profile of the pulp blends except for TTA values (0.37 ± 0.02 to 0.45 ± 0.05) and 2‐Furfurals (2.47 ± 0.03 to 2.71 ± 0.01). The fresh blend of 50% tomato, 25% watermelon and 25% pineapple had the highest total antioxidant capacity of 3.69 ± 0.52 mg 100 mL?1 catechin equivalent. The total antioxidant capacity of the stored pulp increased from 2.95 ± 0.13 to 6.22 ± 0.32 mg 100 mL?1 catechin equivalent in pasteurised TWP 211p blend by 60 days when stored at 40 °C. Total antioxidant status of tomato‐based fruit mix increased during the first 80 days.  相似文献   
9.
An apple puree formulated with red grape skins was developed on pilot scale as a new beverage with antiglycation properties. The addition level of grape skins was selected by a liking test with 70 consumers. The selected formulation was a fibre‐rich source and delivered grape anthocyanins, flavonols and flavanols resulting in ~ twofold higher antiglycation activity than the apple puree. Pasteurisation (3‐D in the target microorganism Alicyclobacillus acidoterrestris) did not affect the antiglycation activity, which decreased by 30% upon sterilisation. Storage for 1 month in the temperature range 15–35 °C affected the contents of anthocyanins, monomeric, dimeric and oligomeric flavanols, while chlorogenic acid, flavonols and dihydrochalcones were stable. About 90% antiglycation activity was retained after one‐month storage at 15 °C. The use of red grape skin as ingredient could represent an opportunity for the apple processing industry to develop a value‐added product.  相似文献   
10.
Berry antioxidants: small fruits providing large benefits   总被引:1,自引:0,他引:1       下载免费PDF全文
Small berry fruits are consumed because of their attractive colour and special taste, and are considered one of the richest sources of natural antioxidants. Their consumption has been linked to the prevention of some chronic and degenerative diseases. The term ‘berry fruits’ encompasses the so‐called ‘soft fruits’, primarily strawberry, currants, gooseberry, blackberry, raspberry, blueberry and cranberry. The objective of this review is to highlight the nutraceutical value of berries and to summarize the factors affecting berry fruit antioxidants. Particular attention is given to postharvest and processing operation factors that may affect fruit phytochemical content. The structure–antioxidant relationships for phenolic compounds – the main group of antioxidants in this fruit group – are presented and major areas for future research are identified. © 2013 Society of Chemical Industry  相似文献   
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