Raisin processing: physicochemical,nutritional and microbiological quality characteristics as affected by drying process

Processing and conservation of grapes by suitable techniques has been a major challenging issue for a long time. Optimization of drying and pretreatment operations of this fruit have been extensively studied. However, in order to achieve the production of high-quality raisins and reach consumers’ acceptance, special attention for quality attributes should be taken into account. Quality characteristics of grapes such as color, texture, vitamins, phytochemicals, aroma profile and microbial stability are of paramount importance since they could vary throughout the dehydration procedure and would directly determine quality perception and consumer choice. This paper presents a comprehensive review of the physicochemical, nutritional and microbiological characteristics of dried grapes as affected by the drying process. In addition, it investigates the changes of different grapes quality attributes (mainly nutritional and aromatic proprieties) during processing, which enables professionals and scientists to better choose and optimize grape processing to deliver the highest raisin quality to consumers.     

大豆膳食纤维和大豆异黄酮对糖尿病影响

糖尿病已成为严重威胁人类健康疾病之一。多项研究表明,大豆膳食纤维可改善糖尿病白鼠高血糖、消瘦、多饮多食等症状,具有降血糖、降血脂、预防肥胖症等作用;且对糖尿病白鼠肝肾组织也有保护作用。大豆异黄酮不仅可增加胰岛素敏感性,增强胰岛细胞分泌胰岛素能力,增强糖尿病白鼠免疫力;且具有抗氧化、降低血清胆固醇和甘油三酯等功能,这对预防和减缓糖尿病白鼠并发症具有一定防治作用。该文主要介绍大豆膳食纤维和大豆异黄酮对糖尿病影响,为预防和控制糖尿病提供一定科学依据。     

膳食水果摄入与糖尿病风险

水果富含多种植物化学物和膳食纤维,它们对保持体内血糖稳态有一定作用。相关流行病学研究提示,合理摄入水果特别是浆果,可降低糖尿病的风险,但摄入果汁对糖尿病风险没有积极作用。水果类食品对糖尿病风险的影响与摄入水果的种类、摄入方式及整体膳食合理性有关。     

鸡蛋摄入与心脑血管疾病风险研究

鸡蛋是膳食胆固醇的重要来源,但也含有多种防治心血管疾病的成分.对相关流行病学研究的汇总分析表明,糖尿病患者每周超过4个鸡蛋可能增加死亡率,但健康人每日1个鸡蛋不会增加冠心病和中风的风险.对膳食胆固醇的反应因人而异,但来自蛋黄的胆固醇使脂蛋白颗粒发生有利减少心血管疾病风险的变化,而在降低碳水化合物摄入的减肥饮食中摄入蛋黄可增加高密度脂蛋白胆固醇水平.合理烹调的鸡蛋可作为健康膳食的一部分.     

Mediterranean Diet and Cardiovascular Risk: Beyond Traditional Risk Factors

A strict adherence to the Mediterranean Diet (MedDiet) has repeatedly been linked to a low risk of cardiovascular disease in several situations. Initially, the mechanisms considered as possible causes of this were based on the effects of this dietary pattern on the so-called traditional risk factors (especially lipids and blood pressure). However, the high relative reduction in the prevalence of cardiovascular morbidity and mortality were not proportional to the limited findings about regulation of those traditional risk factors. In addition to several studies confirming the above effects, current research on the MedDiet is being focused on defining its effects on non-traditional risk factors, such as endothelial function, inflammation, oxidative stress, or on controlling the conditions which predispose people to cardiovascular events, such as obesity, metabolic syndrome or type 2 diabetes mellitus. In the current article, after briefly reviewing the known effects of the MedDiet on the traditional risk factors, we will mainly focus on reviewing the current evidence about the effects that this dietary pattern exerts on alternative factors, including postprandial lipemia or coagulation, among others, as well as providing a short review on future directions.     

膳食纤维提取方法的研究进展

膳食纤维对人类健康有积极的作用,在预防人体胃肠道疾病和维护胃肠道健康方面功能突出.综述国内外膳食纤维的 4 种提取方法.指出较为温和的工艺方法和环保的高新技术是研究的重点,酶法结合膜过滤法提取分离膳食纤维是发展的方向.     

梨渣水不溶性膳食纤维的提取工艺研究

本实验以梨榨汁生产线上的废渣为原料,研究采用碱液浸提法制备水不溶性膳食纤维的工艺流程。采用L9（3^4）正交表进行试验设计,考察料液比、碱液浓度、提取温度及提取时间对提取率的影响,优化水不溶性膳食纤维的提取条件。提取得到的膳食纤维持水力为10．23g／g,溶胀性为6．67ml/g。产品无涩味,无粗糙感,色泽良好,可广泛应用于面包、饼干等多种食品中。     

膳食营养剂对灰褐牛肝菌中镉的生物可给性及其健康风险的影响

聚焦灰褐牛肝菌(Boletus griseus)富镉(Cd)问题,调研了云南3个地区B. griseus样本中的总Cd含量,选取了高、中、低3种不同Cd含量B. griseus样本,建立了一种更易实现、更易量化的体外全仿生消化方法,评价了B. griseus中镉的生物可给性(Cd-BAc),研究了单宁酸、CaCl₂、原花青素、葡萄糖酸锌钙、红毛丹果皮多酚5种膳食营养成分对Cd-BAc的影响,并以此为基础评价了B. griseus中Cd的食用健康风险。结果表明,采集的53个B. griseus样本均具有较高的总Cd含量,在胃部的Cd-BAc为55.30%~59.36%,但是小肠的弱碱近中性环境显著降低了B.griseus中Cd的溶出,Cd-BAc为39.59%~52.86%,大肠菌群发酵进一步降低Cd-BAc至21.41%~25.28%。5种膳食营养剂在胃部对Cd-BAc影响不大,在小肠部和大肠菌群发酵中,均显著降低了Cd-BAc,CaCl₂效果最为显著。以B. griseus中Cd总量计,摄食中镉、高镉含量的B. griseus,Cd对人体的风险熵为2.98和5.13;综合考虑Cd-BAc以及5种膳食营养剂的影响,其风险熵可降低至0~0.37。研究结果表明,B. griseus中Cd的食用健康风险很高,膳食营养剂可通过降低肠道Cd-BAc而调控其对人体的健康风险,因此,膳食营养剂可能是控制高镉食品健康风险的一种有效策略,但是该策略的有效性需要进一步的体内实验验证。     

Mediterranean Diet and Cardiovascular Risk Factors: A Systematic Review

The aim of this paper was to systematically review and analyze the epidemiological evidence on the role of Mediterranean diet (MD) in the prevention of cardiovascular diseases (CVD). Fifty-eight studies exploring the relation between MD and lipoprotein concentration, antioxidative capacity and inflammatory markers, hypertension, obesity, diabetes, and metabolic syndrome, were identified and selected. These included 33 cross-sectional, 9 cohort, and 16 intervention studies. Most of the studies showed favorable effects of MD on CVD, although a certain degree of controversy remains in the respect of some issues, as obesity. Important methodological differences and limitations in the studies make difficult to compare results, thus further studies, particularly randomized clinical trials, are needed to finally substantiate the benefits of MD and to shed some lights on mechanisms.     

燕麦膳食纤维对胃肠道消化吸收功能影响

一系列临床和流行病学研究表明,燕麦膳食纤维在保持肠道健康、预防慢性非传染性疾病方面具有重要作用.该文综述燕麦膳食纤维对胃肠道消化生理、在大肠发酵降解及对胃肠道形态结构影响,为进一步合理开发和应用燕麦膳食纤维提供参考.     

Effects of fat supplementation to diets high in nonforage fiber on production responses of midlactation dairy cows

The effects of dietary nonforage fiber sources on production responses of lactating dairy cattle have been well described, but interactions with other components of the diet have been less thoroughly explored. We investigated the effects of adding 2 commonly fed fat sources to a ration featuring high levels of nonforage fiber supplied by a corn milling by-product. Midlactation Holstein cows were blocked by parity, stratified by days in milk, and randomly assigned to 1 of 6 pens (12 cows/pen). Pens were randomly assigned to treatment sequences in a 3 × 3 Latin square design, where the treatments consisted of prilled saturated fat (SAT; Energy Booster 100, Milk Specialties Co., Dundee, IL), calcium salts of long-chain fatty acids (UNS; Megalac, Church and Dwight Co. Inc., Princeton, NJ), or no added dietary fat (control), with fat sources included to provide 1.2% added fat (dry matter basis). Treatment periods were 21 d; milk and feed samples were collected and milk yield and feed intake were recorded for the last 4 d of each period. Results were analyzed with mixed models with pen as the experimental unit, and orthogonal contrasts were employed to evaluate the overall effect of added fat and the effect of fat source. Dry matter intake and milk yield tended to increase with added fat. Protein content decreased with fat supplementation, to a greater degree for UNS than for SAT, but protein yield was not affected. Fat content, fat yield, and energy-corrected milk yield were not affected by treatment. Conversion of feed to milk tended to increase for UNS compared with SAT. Fat supplementation to diets high in nonforage fiber had effects that were similar to those reported for more traditional lactation diets, except for the dry matter intake response.     

Nondigestible Oligo‐ and Polysaccharides (Dietary Fiber): Their Physiology and Role in Human Health and Food

Nondigestible polysaccharides (NDP) and nondigestible oligosaccharides (NDO) occur naturally in many foods. The physicochemical and biological properties of these compounds, as they relate to dietary fiber, are associated with physiological actions in the small and large intestine, having important implications in human health. These properties include water dispersibility and solubility, viscosity effects, bulk, absorption and fermentability, and binding of other compounds. These features may lead to various physiological actions such as reducing cholesterol and attenuating blood glucose, maintaining gastrointestinal health, and positively affecting calcium bioavailability and immune function. Moreover, based on their physiochemical properties, many of the new oligosaccharides can help improve the organoleptic properties and nutritional value of foods.     

The Inhibitory Effects of Brans and Their Aqueous Extracts on the Lipolysis of Tributyrin Catalyzed by Calf Pregastric Lipase

The ability of red and white wheat brans and oat bran to inhibit calf pregastric lipase (CPGL)‐catalyzed hydrolysis of tributyrin has been studied in vitro at pH 6.5, 37 °C. Brans that had been presoaked in Bis‐Tris buffer at pH 6.5, 4 °C reduced CPGL activity by 13% to 20% after being soaked for 0.25 h and by 17% to 30% after being soaked for 24 h. Maximum reduction of CPGL activity was seen within 2 to 5 min incubation between coarse red wheat bran and CPGL. The results are discussed in terms of likely inhibitory components within the brans and their water‐soluble components and their roles in inhibiting pregastric and other lipase‐catalyzed hydrolysis of dietary lipids.     

加入膳食纤维与芦荟的开菲尔研制

以天然种子开菲尔粒为发酵剂,加入甜味剂,制备了口味良好的开菲尔。添加膳食纤维、芦荟于开菲尔,增加了开菲尔的功能。还以羊奶为原料制备了开菲尔。     

膳食纤维调控胃肠道营养健康研究进展

膳食纤维包括不易消化的碳水化合物和复杂的聚合物木质素,增加膳食纤维的摄入量可以减少胃肠道慢性发病率,该营养物质在食品加工领域和临床研究领域都被广泛应用。本文介绍了膳食纤维的定义及分类,并综述了膳食纤维对人体胃肠道的影响,膳食纤维对肠道微生物的作用及膳食纤维对肠道疾病的影响机制,以为之后膳食纤维在胃肠道营养健康方面的研究及开发提供理论基础。     

裙带菜膳食纤维对小鼠某些免疫功能指标的影响

用裙带菜膳食纤维饲喂BALB/C鼠,测定其耳片肿胀度、半数溶血值、碳粒廓清指数K和吞噬指数α、小鼠T细胞亚群、淋巴细胞增殖功能、NK细胞杀伤活性等指标,发现饲喂裙带菜膳食纤维显著增加了正常小鼠碳粒廓清指数K和吞噬指数α,提高了免疫低下小鼠的碳粒廓清指数K和吞噬指数α、HC50、免疫低下小鼠T细胞亚群、淋巴细胞增殖功能。这些结果表明,裙带菜膳食纤维对于免疫功能低下小鼠的免疫功能具有一定恢复作用。     

Roasting Effects on Dietary Fiber Composition of Cocoa Beans

The effect of roasting on dietary fiber fractions of cocoa beans was determined by gravimetric and fractionation procedures after enzymatic treatment. Roasting had no notable effect on total dietary fiber content (TDF). Components of insoluble dietary fiber (IDF) became redistributed after roasting. One of the largest changes was a sharp increase of Klason lignin. The noted decrease in sugar content without a change in IDF suggested that neutral sugars and uronic acids may be involved in Maillard polymer formation. Soluble dietary fiber (SDF) did not show large variations. Undigestible protein in IDF increased after roasting.