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151.
This review focuses on four new product categories of food supplements: pre-workout, fat burner/thermogenic, brain/cognitive booster, and hormone/testosterone booster. Many food supplements have been shown to be contaminated with unauthorized substances. In some cases, the ingredients in the new categories of dietary supplements were medicinal products or new synthetic compounds added without performing clinical trials. Some of the new ingredients in dietary supplements are plant materials that are registered in the pharmacopoeia as herbal medicines. In other cases, dietary supplements may contain plant materials that have no history of human use and are often used as materials to ‘camouflage’ stimulants. In the European Union, new ingredients of dietary supplements, according to European Food Safety Authority or unauthorized novel food. Furthermore, selected ingredients in dietary supplements may be prohibited in sports and are recognized as doping agents by World Anti-Doping Agency.  相似文献   
152.
利用顶空固相微萃取结合气相色谱-质谱联用技术对盛花期的香花秋海棠(Begonia handelii)雄花及其变种铺地秋海棠(B. handelii var. prostrata)雌花和红毛香花秋海棠(B. handelii var. rubropilosa)雄花的挥发性香气成分进行分析。结果表明,从铺地秋海棠花中鉴定出香气成分32 种,其中醇类物质含量最高,占总成分50.10,其次分别为碳氢类、醛类和酸类物质,分别占总成分25.39、13.87、4.34;从香花秋海棠花中鉴定出香气成分为21种,醛类物质含量最高,占总成分57.12,其次是醇类、碳氢类、杂环类物质,分别占总成分17.37、15.31、4.88;从红毛香花秋海棠花中鉴定出香气成分44 种,醇类物质含量最高,占总成分38.22,其次是碳氢类、醛类和醚类物质,分别占总成分34.36、16.83、6.91。铺地秋海棠和红毛香花秋海棠香气成分较接近,富含具有清香、甘甜气息的芳樟醇氧化物等物质;香花秋海棠花中醛类物质含量最高,具有淡焦甜香气。  相似文献   
153.
This study investigated the effect of adult associated cues of the multicolored Asian ladybird Harmonia axyridis Pallas (Coleoptera: Coccinellidae) on the foraging behavior of the aphid parasitoid, Aphidius gifuensis Ashmead (Hymenoptera: Aphididae) with three assays: 1) whole aphid leaf-disc with H. axyridis tracks; 2) aphid leaf-disc with only half contaminated with H. axyridis tracks; 3) aphid leaf-discs without H. axyridis tracks. Foraging behavior of A. gifuensis was recorded using the Observer® XT 11 and EthoVsion® XT 12. In addition, functional responses of A. gifuensis in patches with or without H. axyridis cues were also tested. Aphidius gifuensis females preferred oviposition in arenas where no adult tracks of H. axyridis were present. However, no significant difference between functional responses of A. gifuensis foraging in plants with and without H. axyridis cues was detected. Our study suggests that H. axyridis associated cues could influence the foraging behavior and activity of A. gifuensis under laboratory conditions. On the other hand, the foraging efficiency of A. gifuensis was not significantly affected by H. axyridis walking tracks in a single plant system. Aphidius gifuensis might exhibit flexible behavioral responses to predator associated cues. The risk of intraguild interactions and the possibility of mitigating such risks for parasitoids are important components for ultimately determining the compatibility of biological control agents.  相似文献   
154.
玉米作为主要的杂粮谷物,营养价值高,维生素、膳食纤维等含量丰富,可以预防多种亚健康疾病,受到市场追捧。但是玉米粉营养结构不均衡、加工性差,限制其应用。有研究表明,微生物发酵技术可以改善谷物的营养成分、大分子物质结构和加工特性。基于此,利用灵芝固态发酵玉米,得到玉米灵芝菌粮(简称菌粮),从营养成分、大分子物质结构和加工特性3个方面对其进行评价。结果显示,与未发酵玉米相比,菌粮中碳水化合物、蛋白质含量分别提高了748%、28.00%,且蛋白质的氨基酸评分提高,而脂肪含量降低了52.56%;维生素C、核黄素和烟酸含量均显著提高(P<0.05),分别提高了56.19%、73.91%和20.27%,且玉米中缺乏的硫胺素在菌粮中被检测到;菌粮中各类淀粉和纤维的含量也发生了显著变化(P<0.05),淀粉、支链淀粉含量分别降低了11.17%、34.70%,直链淀粉含量提高了26.66%,粗纤维、不溶性膳食纤维含量分别降低了21.07%、21.47%,可溶性膳食纤维含量提高了13.57%;菌粮粉粘度降低,水溶性指数提高,吸水性指数和溶胀力降低;此外,与灵芝子实体相比,菌粮中灵芝三萜和灵芝酸含量均显著提高(P<0.05),分别为灵芝子实体的1.68和2.07倍。灵芝固态发酵玉米得到的玉米灵芝菌粮,营养结构更加均衡,功能活性提高,具有更高的营养价值;大分子物质结构发生改变,加工特性得到改善,冲调特性更好。研究结果为食用菌发酵改良谷物特性的研究提供了参考和指导。  相似文献   
155.
何钊  孙龙  王成业  冯颖  赵敏 《生物资源》2021,(3):303-308
由于具有较好的营养价值以及较高的食物转化效率,食用昆虫特别是蟋蟀受到普遍关注。在双斑蟋(Gryllus bimaculatus,GB)营养成分测定的基础上,对比家蟋(Acheta domesticus,AD)和黑蟋(Gryllus testaceus,GT)的营养及含量,分析评价了双斑蟋的使用价值。结果显示:双斑蟋水分含量71.0%、粗蛋白含量58.60%(干重)、粗脂肪含量28.90%(干重)、粗纤维含量7.23%(干重)、灰分4.93%(干重);蛋白含量与黑蟋相当而高于家蟋,粗脂肪和灰分含量要高于家蟋和黑蟋;双斑蟋含有17种氨基酸,总氨基酸含量51.03%(干重),必需氨基酸含量24.76%(干重)、占总氨基酸的48.3%,氨基酸含量低于其他两种蟋蟀;双斑蟋中常量元素含量最高的为钾(6 416 mg/kg,干重)、含量最低的是钙(92 mg/kg,干重),微量元素中锌含量较高(241 mg/kg,干重);双斑蟋油脂中不饱和脂肪酸的相对含量为65.33%,以亚油酸(37.05%)和油酸(25.86%)为主、饱和脂肪酸以棕榈酸(25.44%)和硬脂酸(8.74%)为主。双斑蟋的脂肪酸组成、含量与家蟋相近,而与黑蟋的脂肪酸组成差别较大,三种蟋蟀中含量最高的饱和脂肪酸为棕榈酸,而含量最高的不饱和酸为亚油酸。结果表明,双斑蟋的必需氨基酸组成符合FAO/WHO推荐的氨基酸构成比例的蛋白条件,具有较高的营养价值和食用价值。  相似文献   
156.
Behavioural responses of the gastropod Nerita fulgurans Gmelin, 1791 to flat black rectangles and intraspecific mucus trails were measured in a circular arena. Snails were tested in water either in the presence or absence of chemicals generated from a predator gastropod, Chicoreus brevifrons (Lamarck, 1822). The test hypothesis was that this snail has different behavioural responses as result of visual and chemical cue integration. Nerita fulgurans has the capacity to orient to solid targets subtending angles larger than 10° and follow its own mucus trails. In water conditioned by the predator C . brevifrons, snails exhibited an avoidance response when 10°, 20° and 45° sectors were presented, demonstrating an integration of chemical and visual information. The simultaneous presentation of two orienting cues (black sectors and mucus trails) was tested to determine the nature of the interaction. When the two cues were oriented in the same direction there was no effect. When the two cues were presented from directions 180° apart a preference for visual cues over mucus trail cues was evident when the visual angle of the visual cue subtended angles greater than 90°. This result demonstrates a hierarchical usage of the orienting references.  相似文献   
157.
Many colour ornaments are composite traits consisting of at least four components, which themselves may be more complex, determined by independent evolutionary pathways, and potentially being under different environmental control. To date, little evidence exists that several different components of colour elaboration are condition dependent and no direct evidence exists that different ornamental components are affected by different sources of variation. For example, in carotenoid‐based plumage colouration, one of the best‐known condition‐dependent ornaments, colour elaboration stems from both condition‐dependent pigment concentration and structural components. Some environmental flexibility of these components has been suggested, but specifically which and how they are affected remains unknown. Here, we tested whether multiple colour components may be condition dependent, by using a comprehensive 3 × 2 experimental design, in which we carotenoid supplemented and immune challenged great tit nestlings (Parus major) and quantified effects on different components of colouration. Plumage colouration was affected by an interaction between carotenoid availability and immune challenge. Path analyses showed that carotenoid supplementation increased plumage saturation via feather carotenoid concentration and via mechanisms unrelated to carotenoid deposition, while immune challenge affected feather length, but not carotenoid concentration. Thus, independent condition‐dependent pathways, affected by different sources of variation, determine colour elaboration. This provides opportunities for the evolution of multiple signals within components of ornamental traits. This finding indicates that the selective forces shaping the evolution of different components of a composite trait and the trait's signal content may be more complex than believed so far, and that holistic approaches are required for drawing comprehensive evolutionary conclusions.  相似文献   
158.
Oxidized low density lipoprotein (LDL) plays an important role in atherogenesis. It is generally thought that LDL is mainly oxidized in the intima of vessel walls, surrounded by hydrophilic antioxidants and proteins such as albumin. The aim of this study was to investigate the possible interrelationships between oxidation resistance of LDL and its protein and lipid moieties. Proteins and to a lesser extent lipids, appeared to be the major determinants in the LDL Cu 2+ -oxidation resistance, which in turn depend on the ultracentrifugation (UC) procedure used. Comparing high speed/short time (HS/ST, 4 &#117 h), high speed/long time (HS/LT, 6-16 &#117 h) and low speed/long time (LS/LT, 24 &#117 h) conditions of UC, HS with the shortest time (4 &#117 h) led to prepare LDL (named LDL·HS-4 &#117 h) with higher total protein and triglyceride contents, unchanged total cholesterol, phospholipids and Vitamin E, and higher Cu 2+ -oxidation resistance. Among proteins, only albumin allows to explain changes. PAF acetyl hydrolase appeared to be unaffected, whereas its pro-oxidant role was established and found only in the absence of albumin. In contrast the pro-oxidant role of caeruloplasmin took place regardless of the albumin content of LDL. The antioxidant effect of albumin (the oxidation lag time was doubled for 20 &#117 mol/mol albumin per LDL) is assumed to be due to its capacity at decreasing LDL affinity for Cu 2+ . Interestingly, the LDL·HS-4 &#117 h albumin content mirrored the intrinsic characteristics of LDL in the plasma and was not affected by added free albumin. Moreover, it has been verified that in 121 healthy subjects albumin was the best resistance predictor of the Cu 2+ -oxidation of LDL·HS-4 &#117 h, with a multiple regression equation: lag time (min)=62.1+0.67(HSA/apoB)+0.02 (TG/apoB) &#109 0.01(TC/apoB); r =0.54, P <0.0001. Accounted for by lag time, the oxidation resistance did not correlate with &#102 -tocopherol and ubiquinol contents of LDL. The mean albumin content was about 10 &#117 mol/mol, and highly variable (0-58 &#117 mol/mol) with subjects. The LDL·HS-4 &#117 h may account for the status of LDL in its natural environment more adequately than LDL resulting from other conditions of UC.  相似文献   
159.
160.
The chemical modifications of rabbit liver carbonyl reductase (RLCR) with phenylglyoxal (PGO) and 2,3,4-trinitrobenzenesulfonate sodium (TNBS), which are respective chemical modifiers of arginine and lysine residues, were examined. RLCR was rapidly inactivated by these modifiers. Kinetic data for the inactivation demonstrated that each one of arginine and lysine residues is essential for catalytic activity of the enzyme. Furthermore, based on the protective effects of NADP +, NAD + and their constituents against the inactivation of RLCR by PGO and TNBS, we propose the possibility that the functional arginine and lysine residues are located in the coenzyme-binding domain of RLCR and interact with the 2′-phosphate group of NADPH.  相似文献   
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