膳食纤维在特殊医学用途配方食品中的应用

特殊医学用途配方食品在糖尿病、肿瘤、肾病、肝功能衰竭、胃肠道吸收障碍等临床患者的营养支持和营养治疗方面起着举足轻重的作用。特殊人群的核心问题是消化吸收,肠道健康和肠道微生态平衡对营养物质的消化和吸收起着关键作用,膳食纤维,尤其是可溶性膳食纤维对于调节肠道菌群、维持肠道微生态平衡、促进消化道健康、降低血脂和胆固醇、提高免疫力、促进矿物质元素的吸收等方面具有重要的生理作用,其在特殊医学用途食品的开发、临床肠内营养治疗中起着重要作用。     

The dietary fiber fraction in raw and processed foods

The purpose of the present study was to estimate dietary fiber components in raw vegetables and processed by different methods. Samples of 8 raw, 15 boiled, 5 fermented, 5 fried and 2 canned vegetables were analyzed. Results indicated the sample vegetables after being boiled, canned, fermented and fried, presented alterations in the dietary fiber insoluble and soluble components, e.i., by interaction or solubility tending to an increase or decrease of its components. Results obtained in the dietary fiber components of processed vegetables, in the sample analyzed, presented variations among them with the different processing techniques.     

Hibiscus sabdariffa L: source of antioxidant dietary fiber

Dietary fiber and antioxidants are food constituents and functional ingredients that are generally addressed separately. Nowadays there is scientific evidence that primary characteristics of DF assigned to non starch polysaccharides and lignin (resistance to digestion and absorption in the small intestine and fermentation in the large intestine) can be extended to other indigestible food constituents that are resistant to digestion and absorption in the human small intestine with complete or partial fermentation in the large intestine. The antioxidant dietary fiber concept was defined as a dietary fiber concentrate containing significant amounts of natural antioxidants associated with non digestible compounds. Hibiscus sabdariffa L flower shows in its composition an important percentage of dietary fiber and high antioxidant capacity. The infusion obtained by decoction of flowers, had been extensibility studied due to the healthy properties. In this work the principal nutritional aspects from Hibiscus sabdariffa L and its use as a possible antioxidant dietary fiber source had been considered.     

Proposals for the residues recovery: Orange waste as raw material for new products

The production of orange juice on an industrial level leads to a considerable quantity of solid and liquid residue (around 8–20 million tons y^?1 globally), which is still considered as waste or used as a complement in agriculture. In general, orange residues have no economic value, even though their composition is rich in soluble sugars, cellulose, hemicellulose, pectin and essential oils that could form the basis of several industrial processes. In this study, information was collected on the technological potential of the solid and liquid residues generated in the processing of orange juice. Possible applications include human consumption, fertilizer, animal feed, charcoal, adsorption of chemical compounds, bio-oil production and extraction of essential oils and pectin. In this preliminary study, alternatives are proposed for the minimization and recovery of solid and liquid residues generated in the production of orange juice with a view to the implantation of industrial plants which can reuse this material, in order to add value to this solid and liquid waste and provide environmental benefits. The alternatives were proposed based on information and data available in the literature and the concepts of clean technologies.     

Comparative study of analytical methods for determination of dietary fiber insoluble fraction, in starch rich foods

The objective of this work was to compare two enzymatic methods for determination of the neutral detergent fiber (NDF) in starch-rich foods. The samples analyzed were foods from the legume group, cereals and derivatives, roots, tubers and similars. The results obtained by the Robertson and Van Soest method showed markedly higher values of the NDF fraction when compared with those found following the procedure of Mendez et al. The percentage differences in NDF values found between the two methods were not constant in the food samples analyzed. These differences were not related with the starch content present in the samples nor with the type of processing to which the foods were subjected. The Mendez et al. method is recommended for the samples tested.     

食品中野燕枯残留量的测定

建立了气相色谱-质谱选择离子法（GC-MSD）测定食品中野燕枯残留量的检测方法。试样用水．丙酮（体积比为1：4）振荡提取,经二氯甲烷液-液分配,以凝胶色谱柱净化,再经氟罗里硅土（Florisil）固相柱净化。洗脱液浓缩并溶解定容后,供气相色谱,质谱仪检测,外标法定量。回收率范围为84．5％。98．0％;相对标准偏差为3．19％-6．74％;测定低限为0．010mg／kg。     

Use of polyester/glass‐fiber residues as fillers for composites

In this work, the performance of polyester (P)/glass fiber mats (G) and P/G/calcium carbonate (CaCO₃) composites was compared with that of P/G/fiberglass waste composites. The residues used were conventional P/G postconsumer light resin‐transfer‐molding parts, obtained via knife or ball milling. Composites with up to 50 wt % reinforcement were prepared by hot compression molding and characterized via physical (density and water sorption), thermal (thermogravimetry and burnout), and mechanical (impact, Barcol hardness, and tensile) testing. The results show that the simple grinding and reincorporation of the composite residues yielded new composites with generally worse characteristics than the ones with calcium carbonate. Then, the waste was sorted by removing most of the pure resin particles from it. This yielded a resin‐rich fraction, which could be better used for energy recovery and resin‐covered fibers. The use of the latter as a filler yielded composites with better overall properties than those with calcium carbonate for a controlled amount of W; thus showing potential use as a replacement for the commonly used inorganic filler, maintaining the mechanical properties, decreasing the raw material cost, and reducing the amount of composite waste discarded in the environment. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Determination vitamin A source foods by pregnant women,using a simplified dietary assessment (SDA)

The International Vitamin A Consultative Group (IVACG) developed a research instrument based on consumption of vitamin-A food sources to classify populations into groups of high, moderate and low deficiency risk in the consumption of this nutrient. The instrument was tested on a population of 91 pregnant women who attended prenatal health care service run by School of Public Health of the University of S?o Paulo. Such instrument was termed Simplified Dietary Assessment (SDA) and it is comprised of a 24-hour dietary recall--Consumption Index (CI) and consumption frequency questionnaire--Usual Food Pattern (UFP). SDA pointed out the most consumed daily and weekly foods as being milk in liquid form, tomato, lettuce, margarine and banana. All these food sources belong to groups of low and moderate vitamin A content. Assignment in risk groups was based on the recommended dietary intake proposed by the Food and Agriculture Organization of the United Nations--(FAO/OMS--1991) and two-thirds of the recommended intake was considered the cutting off point. According to data obtained by the SDA, more than 50% of the population interviewed was assigned to the High and Moderate risk groups for deficiency in vitamin A intake. Statistical analysis of the data revealed a significant statistical correlation r = 0.50 (p > 0.005) and a weighted Kappa value of (kw = 0.207), which suggests that the SDA is a useful instrument and is a reasonable means for risk assignment of vitamin A deficiency among groups with inadequate levels of intake of foods as sources of this nutrient. However, the results suggest that in order to evaluate vitamin A intake appropriately, a larger number of applications of the IC questionnaires would be required.     

Effect of the formulation of 2 diets of rats, with wheat bran as a source of dietary fiber, on various biochemical and nutritional parameters

The type of diet formulation was considered in our study on the effects of wheat bran on some parameters obtained in a biological assay, for 28 days. Weanling, male Holtzman rats were divided in three groups. Two of them were fed ad libitum on diets containing 25% of wheat bran, prepared in two ways: balanced (FB) and conventional (FC). In the first case, the fiber source was added at the expense of every other ingredient, whereas in the second, only of starch. The control group received a wheat bran-free diet. Comparison among the groups showed the highest weight gain for group FB, and the lowest protein efficiency ratio (PER) for group FC. Fecal weight and the weight of the cecal contents were significantly higher for the test groups. Mean activity of the alkaline phosphatase from the jejunal mucosa was lower in group FB than in the other two. The activities of this enzyme in serum, were significantly higher for groups FB and FC. Serum cholesterol level was slightly lower for the group fed the balanced diet, than for the one receiving the conventional diet. Therefore, some parameters such as weight gain, PER, alkaline phosphatase activity of the intestinal mucosa, and serum cholesterol, were influenced by the type of diet formulation. Nevertheless, these results are not enough to substantiate a conclusive answer to the question: which diet formulation is more adequate for biological assays, when using wheat bran as a fiber source?     

介质液液萃取-高效液相色谱法快速测定蜜桃汁中的多菌灵农药残留

建立了一种以支撑介质液液萃取．高效液相色谱法为基础,快速经济测定果汁中多菌灵农药残留的分析方法。以经过特殊工艺处理的硅藻土为介质液液萃取的吸附填料,对苯并咪唑类农药中有代表性的多菌灵样品进行前处理,结合高效液相色谱法进行分析检测。在优化液相检测条件和萃取条件的同时,从添加回收率、精密度、方法定量限等方面对该方法进行了评价与验证。结果表明,使用介质液液萃取的方法萃取蜜桃汁样品中的多菌灵,添加回收率的平均值在94％以上,方法最低检出限为0．014μg/mL,方法定量限为0．04μg／mL。方法具有前处理简单、分析速度快、经济、重复性好、分析时间短等优点,可推广于其它果汁中多菌灵农药残留的检测。     

高效液相色谱法测定动物源性食品中甲氧苄氨嘧啶残留量

建立了高效液相色谱法测定鸡肉中甲氧苄氨嘧啶残留量的方法。试样中残留的甲氧苄氨嘧啶用酸性甲醇提取,提取液调至碱性后再用二氯甲烷液液分配,浓缩后,残渣用甲醇-0.5%高氯酸水溶液(30+70)溶解,经三氯甲烷净化后,用Inertsil ODS-3(250mm×4.6mm(id),5μm)柱分离,以甲醇-0.5%高氯酸(30+70)作流动相,流速1.0mL.min-1,于230nm波长处检测。结果表明,样品的加标平均回收率为94.6%~81.2%,相对标准偏差为2.88%~4.31%,方法的测定低限(LOQ)为0.04mg.kg-1。该方法具有简便、快捷、灵敏、重现性好。     

Influence of dietary fiber on bile acid metabolism

Fiber, when fed to animals or man, will generally cause increased excretion of bile acids. The level of bile acid excretion appears to be a function of the structure of the fiber. Fiber binds bile acids and bile salts in vitro. The extent of binding is characteristic for each type of fiber and each substrate. Bile acid binding may be one mechanism of the physiological action of fiber.     

Sesame seed is a rich source of dietary lignans

The variation in the contents of sesamin and sesamolin was studied in oils extracted from 65 samples of sesame seeds (Sesamum indicum L.) from plants with shattering (n=29), semishattering (n=7), and nondehiscent (n=29) capsules. The oil content ranged from 32.5 to 50.6% and was greater in white than black seeds (P<0.001). The sesamin and sesamolin contents in seeds ranged from 7 to 712 mg/100 g (mean±SD, 163±141 mg/100 g) and from 21 to 297 mg/100 g (101±58 mg/100 g), respectively, with no difference between black and white seeds. Thus, there was a wide variation in the contents of sesamin and sesamolin, which were positively correlated (R ²=0.66, P<0.001). There were negative correlations between the contents of sesamin and the contents of sesaminol (R ²=0.37) and sesamolinol (R ²=0.36) and between the content of sesamolin and those of sesaminol (R ²=0.35) and sesamolinol (R ²=0.46) (P<0.001). Sesame seeds had an average of 0.63% lignans, making them a rich source of dietary lignans.     

香菇膳食纤维挤压改性的研究

采用挤压改性方法处理两种不同工艺制备的香菇膳食纤维 ,在不同的挤压处理条件下 ,香菇膳食纤维的总膳食纤维的量均未改变 ,水溶性膳食纤维的含量分别提高 6%～ 1 5%和 2 %～ 8% ,被改性的物质主要是不溶性纤维中的半纤维素。