玉米粒与干磨组分的食品用途（续）

6 玉米快餐 米快餐主要有三类：1）碱蒸煮玉米，2）主要由玉米细粉、玉米粗粉或淀粉制的挤压产品，3）爆裂玉米产品（Matz，1984）。玉米及玉米产品的风味和功能性质要求取决于玉米基本快餐。     

玉米粒与干磨组分的食品用途（续）

玉米在墨西哥和中美州是用于制造玉米饼的传统谷物，在美国约10％的玉米用来生产食品，在墨西哥总玉米量的72％用于生产食品，主要为玉米饼，特别是低经济群体依靠玉米饼作为热量和蛋白质的主要来源（Cortez and Wild-Altamirano，1972）。Trejo-Gonzahz在（1982）指出，墨西哥人均年消耗玉米186kg，在乡村热量供应约占70％。     

低能量食品组分的现状与未来

<正> 世界在变化,人们对膳食与健康的关注已达到一个新阶段,低能量食品就是在这种背景下问世的。这不仅仅是一种时尚,同时包括了消费知识与价值观的变化。现在,空气与水源污染加剧,各种恶性疾病(如癌症、心脏病和高血压等)的发病率增加,这些事实使人们更加重视自己的健康。     

膳食纤维在特殊医学用途配方食品的应用研究进展

随着人民生活水平的提高和饮食习惯的改变,膳食纤维对于人类健康的作用愈发重要,将膳食纤维添加至特殊食品中已成为一大研究热点。本文结合特殊医学用途配方食品对膳食纤维的要求,综述膳食纤维的生理功能及在特殊医学用途配方食品中的应用,以期为膳食纤维在特殊医学用途配方食品中的进一步开发和应用提供参考。     

闰胶与食品中组分的反应特性和机理

本文对近年来国际上对卡拉胶与食品中一些组分的反应特性和机理的研究作一简要的综合论述。     

超高压下食品组分与包装材料的相互影响

研究超高压技术对薄膜的结构和性能产生的影响及超高压作用下薄膜与食品模拟物的相互作用。对以大豆蛋白、油脂等食品组分为内容物的尼龙/聚乙烯(PA/PE)、聚酯/聚乙烯(PET/PE)两种聚合物包装材料进行超高压处理,并贮藏一定周期,测定不同压强及保压时间下食品内容物与包装材料在不同贮藏周期内的相互影响。结果表明:贮藏周期一定,经过超高压处理的两种聚合物包装材料的性能要优于未经过处理的;在保压时间一定的情况下,增加压力会提升食品组分的货架期,压力越高,效果越明显;在压力一定的条件下,保压时间的变化并未对食品组分、包装材料产生规律性的影响。压力和贮藏周期的变化对食品组分和包装材料会产生一定的影响。     

蛋白质水解物与食品中不同组分之间交互作用的研究进展

通过酶水解的方式能够获得具有较强抗氧化活性的蛋白质水解物,如果将其添加到食品当中,不仅可以抑制脂肪和蛋白的氧化,而且还可以通过蛋白质水解物与食品组分间的交互作用改善食品的一些功能性质,进而提高食品的品质。本文主要综述不同蛋白质来源的蛋白质水解物与食品组分(主要包括蛋白质、碳水化合物以及脂质)之间的交互作用、作用机理及其对食品功能性质的影响,从而为蛋白质水解物在食品中的应用提供理论研究参考。      

盘磨机械浆的特征与用途(续)

<正> 3.1.4 高级纸 最佳质量的BCTMP与BKP以1:1的配比生产高级纸,再加入20％CaCO_3填料,纸的表面施胶用3％的普遍淀粉。云杉BCTMP在游离度200mL时,抗张指数44N·m/g,白度77％～78％ISO,长纤维含量42％～44％,密度350kg/m~3。有这种特性的浆适合生产压感纸、书本印刷纸和胶印纸等。     

食品组分与天然抑菌剂对芽孢耐热性的影响

研究了不同浓度的NaCl、乳清蛋白、蔗糖、表没食子儿茶素没食子酸酯（EGCG）、乳酸钠和乳酸链球菌素（Nisin）以及不同pH对于嗜热脂肪芽孢杆菌芽孢耐热性的影响。结果显示,pH对芽孢耐热性有显著影响,D值随着pH的降低而逐渐减低;乳清蛋白在115℃和118℃条件下对芽孢耐热性有保护作用,但在121℃时无显著保护性;在115℃条件下,8%以内NaCl对芽孢耐热性无显著影响,但在118℃和121℃条件下,NaCl浓度在4%～8%之间时,对芽孢耐热性有降低效应;蔗糖只在10%浓度时对芽孢的耐热性有保护作用外,其余浓度对芽孢耐热性无显著影响。在三种报道的具有抑菌物质中,0.4mg/mLEGCG和4%乳酸钠对芽孢耐热性无显著影响,而Nisin则可以显著降低芽孢D值,而且随着浓度提高,对芽孢耐热性的降低效果越明显。     

食品组分与天然抑菌剂对芽孢耐热性的影响

研究了不同浓度的NaCl、乳清蛋白、蔗糖、表没食子儿茶素没食子酸酯(EGCG)、乳酸钠和乳酸链球菌素(Nisin)以及不同pH对于嗜热脂肪芽孢杆菌芽孢耐热性的影响。结果显示,pH对芽孢耐热性有显著影响,D值随着pH的降低而逐渐减低;乳清蛋白在115℃和118℃条件下对芽孢耐热性有保护作用,但在121℃时无显著保护性;在115℃条件下,8%以内NaCl对芽孢耐热性无显著影响,但在118℃和121℃条件下,NaCl浓度在4%～8%之间时,对芽孢耐热性有降低效应;蔗糖只在10%浓度时对芽孢的耐热性有保护作用外,其余浓度对芽孢耐热性无显著影响。在三种报道的具有抑菌物质中,0.4mg/mLEGCG和4%乳酸钠对芽孢耐热性无显著影响,而Nisin则可以显著降低芽孢D值,而且随着浓度提高,对芽孢耐热性的降低效果越明显。      

Distribution of aflatoxins and fumonisins in dry-milled maize fractions

The aim was to evaluate the distribution of aflatoxins and fumonisins in fractions derived from the dry-milling of contaminated maize. Two maize lots with different contamination levels were processed and sampled: the first (maize 1) had aflatoxin B₁ (AFB₁) and fumonisin B₁ (FB₁) levels of 3.6 and 5379 µg kg^?1, respectively; the second (maize 2) had corresponding levels of 91.1 and 8841 µg kg^?1, respectively. The cleaning step reduced AFB₁ and FB₁ levels by 8 and 11% in maize 1 and by 57 and 34% in maize 2. The subsequent removal of bran and germ led to a further decrease in contamination levels in the products destined for human consumption. In the latter, AFB₁ was uniformly distributed, while FB₁ was concentrated in the finer size fractions. Contamination of raw maize 1 (3.6 µg kg^?1) was below the European Union AFB₁ limit of 5 µg kg^?1 for unprocessed maize, but among the final products only coarse flour (1.7 µg kg^?1) was within the European Union limit of 2 µg kg^?1, while grits and fine flour showed higher levels (2.7 and 2.5 µg kg^?1, respectively). As regards cleaned maize, a different distribution of the two toxins was observed in the kernels: AFB₁ contamination was more superficial and concentrated in germ, while FB₁ contamination affected the inner layers of the kernels.     

Distribution of fumonisins in dry-milled corn fractions in Argentina.

Corn samples and different dry-milled fractions collected from an industrial mill in Argentina were analysed. Average contaminations were FB(1) 1540 microg kg(-1), FB(2) 716 microg kg(-1) and FB(3) 152 microg kg(-1) in whole corn; FB(1) 135 microg kg(-1), FB(2) 39.1 microg kg(-1) and FB(3) 10.2 microg kg(-1) in corn grits; FB(1) 358 microg kg(-1), FB(2) 122 microg kg(-1) and FB(3) 45.9 microg kg(-1) in 'C' flour; FB(1) 148 microg kg(-1), FB(2) 52.5 microg kg(-1) and FB(3) 28.3 microg kg(-1) in corn meal; and FB(1) 4210 microg kg(-1), FB(2) 2010 microg kg(-1) and FB(3) 447 microg kg(-1) in germ and bran together. The fumonisin contamination level was approximately three times higher in germ and bran than in whole corn, 13 times higher than in 'C' flour and 29 times higher than in corn meal and corn grits. Taking into account the distribution of fumonisins in commercial dry-milled corn fractions and corn meal consumption in Argentina, a theoretical whole corn level of 6640 microg kg(-1) maximum of total fumonisins could be processed to obtain products considered safe for human health.     

N-acetyl-beta-D-glucosaminidase activity in whole milk and milk fractions

Experiment 1 was conducted to determine NAGase activity in skim, fat, and cell pellet fractions of foremilk and stripping milk from infection-free quarters. Changes in milk NAGase activity during a 12 h in vitro incubation were also determined. Eight cows, two quarters per cow, were used. One quarter of each cow received an intramammary infusion of oyster glycogen. N-Acetyl-beta-D-glucosaminidase activity was highest in stripping milk and in milk from infused quarters. The percentages of NAGase activity in skim, fat, and cell pellet fractions were 62.6, 22.4, and 12.6. The NAGase activity of milk incubated in vitro did not significantly change over time. Experiment 2 was conducted to determine if neutrophils lost NAGase activity during extravasation into milk. Leukocytosis was induced in infection-free quarters of five cows. The NAGase activities of peripheral neutrophils and milk neutrophils were not significantly different. Results from both studies suggest that the major source of milk NAGase is the mammary epithelial cell and that milk somatic cells contribute less than 15% of the total milk NAGase activity.     

Food uses of pineapple waste and by-products: a review

Waste from fruits and vegetable processing industry is produced in large quantities worldwide and it contains high levels of lignocellulose, fibre, sugar, bioactive and functional compounds. Their utilisation has become one of the main important and challengeable aspects due to the generation of large quantities of by-products including peels, seeds, leaves and unused flesh in different steps of processing chain. Many researches have validated the waste utilisation as novel, low-cost, economical and natural sources of dietary fibre, antioxidants, pectin, enzymes, organic acids, food additives, essential oils, etc. through different methods of extractions, purifications and fermentations. Though, obtaining these by-products from such a variable substrate requires an understanding of the composition of the polysaccharides and their associations within the overall substrate. Focus on the pineapple fruit, scientific and technological studies have already highlighted and confirmed the potential of better and more profitable markets for pineapple wastes. This review is first of all the collection of previous reports about valorisation of food processing waste, deepening the possibilities of pineapple waste utilisation and to promote the integral exploitation of the by-products rich in bioactive compounds, even as multifunctional food ingredients. More in detail, this review aims at identifying those processes that can be implemented even in disadvantaged areas by means of technologies that allow recovering waste directly on site, thus reducing pollution and providing ingredients/food products with high nutritional values that could be integrated into the diet.     

Antioxidant and free radical scavenging activities of whole wheat and milling fractions

The effects of milling on the phenolic content and antioxidant capacity of two wheat cultivars, namely CWAD (Canadian Western Amber Durum; Triticum turgidum L. var. durum) and CWRS (Canadian Western hard red spring; Triticum aestivum L.) were studied. The milling of wheat afforded several fractions, namely bran, flour, shorts and feed flour. In addition, semolina was the end-product of durum wheat milling. Among different milling fractions the bran had the highest phenolic content while the endosperm possessed the lowest amount and this was also reflected in free radical and reactive oxygen species (ROS) scavenging capacity, reducing power and iron (II) chelation capacity of different milling fractions in the two cultivars. This study demonstrated the importance of bran in the antioxidant activity of wheat, hence consumption of whole wheat grain may render beneficial health effects.     

The in vitro lipolysis and biohydrogenation of monogalactosyldiglyceride by whole rumen contents and its fractions

The contribution of bacterial, protozoal, participate and cell-free fractions of rumen fluid to the lipolysis of monogalactolipid and the hydrogenation of its acyl constituents has been examined. Each of these fractions hydrolysed monogalactolipid and free fatty acids were the major acyl products. Almost all the radioactivity added as monogalactolipid to rumen fluid was distributed between the particulate and bacterial fractions and half to two-thirds of the radioactivity in each of the four fractions was recovered as free fatty acids. Both 16:3 and 18:3, after release from monogalactolipids, were hydrogenated to 16:2 and 18:2 at short incubation times. As incubation was continued there was a rapid decline in dienoic fatty acids and an increase in saturated and monoenoic fatty acids. There was a greater accumulation of trans-18: 1 than cis-18:1. Only the particulate fraction of rumen fluid gave patterns of hydrogenation similar to that obtained with rumen fluid. Bacteria in free suspension had little ability to hydrogenate trienoic fatty acids beyond the dienoic stage and neither protozoa nor the cell-free supernatant gave significant biohydrogenation of trienoic fatty acids. On the other hand, the presence of monoenoic and dienoic fatty acids in the bacterial, protozoal and cell-free fractions isolated from total rumen fluid after incubation with monogalactolipid indicated their transfer to these fractions after biohydrogenation in the particulate fraction.     

Small-scale production and storage quality of dry-milled degermed maize products for tropical countries

Summary A small‐scale, single operation, dry degerminator, originating from Brazil was tested on six maize samples (from France and Mali) at two moisture contents (10 and 15% wb). The yield of brewery maize grits (<1% lipids) was higher for extensively dry (10% mc) and hard grains. It ranged from 50 to 70% for four cultivars, which was equivalent or higher than for industrial plants. The rancidity of the products was controlled by the fat acidity level, which was 40–60 mg KOH 100 g^?1db, after 4 months storage of degermed flour. This indicates that degermed products can be stored at 35 °C for up to 6 months without developing significant rancid off‐flavour. Thus the Brazilian dry degerminator appears suitable for the treatment of maize in the tropical zone of Africa.     

海捕水产品全过程食品防护的研究

目的通过对海捕水产品全过程特别是捕捞与卸货过程中食品防护的研究,为海捕水产品加工企业建立全过程的食品防护计划提供参考,也为官方监管提供借鉴。方法结合法规和标准要求,确定海捕水产品全过程食品防护内容,对其进行评估,找出薄弱环节,制定食品防护计划并实施控制。结果海捕水产品加工企业可以通过对捕捞与卸货过程7个方面与食品防护有关的内容评估,以及对加工过程9个方面的评估,找出薄弱环节,制定并实施适合企业特性的食品防护计划。结论通过16个方面的评估,并采取相应的食品防护措施,海捕水产品加工企业可以有效控制故意污染或蓄意破坏的发生,满足法规的要求。     

Kinetics and equilibria of tea infusion: Theaflavin and caffeine concentrations and partition constants in several whole teas and sieved fractions

Concentrations of theaflavin and caffeine were determined in whole Kapchorua Pekoe Fannings and in six of its sieved fractions, as well as in Kapchorua Pekoe Dust, Betjan Flowery Broken Orange Pekoe and Rupai Flowery Orange Fannings and in one sieved fraction of each. The partition constants of theaflavin and caffeine between these leaves and water at 80°C were also determined. Neither property varied significantly with leaf size but did depend on leaf origin and manufacture. The concentration and partition constants for caffeine were greater than for theaflavin. As a corollary, the ratio of caffeine to theaflavin is larger in tea initially drawn from the teapot than in the beverage prepared after topping up with fresh hot water.