碾白精度对稻米营养成分及氨基酸组成的影响

为了减少过度加工,最大限度地保留稻米中固有的营养成分,促进国民健康,我们以早籼米为研究对象,研究碾白精度对大米营养成分及氨基酸组成的影响.结果表明,随着碾白精度的提高,稻米中蛋白质含量、脂肪含量、灰分、必需氨基酸组成都呈下降趋势,碳水化合物含量则呈上升趋势.     

储藏温度对大米蛋白功能特性的影响

为了探究储藏温度对不同大米蛋白功能特性的影响,本实验以中国东北地区‘稻花香二号’‘辽星’和‘盐丰’大米为对象,以大米蛋白的溶解性、持水性、持油性、起泡性质和乳化性质为指标,分析其在4、30 ℃和70 ℃储藏期间的变化情况,以期为优质大米储藏过程中蛋白品质控制提供参考。结果表明,蛋白持水性和起泡性在不同储藏温度下随时间延长总体呈下降趋势,而持油性总体呈上升趋势。‘稻花香二号’和‘辽星’蛋白的泡沫稳定性在不同储藏温度下随时间延长总体呈上升趋势,而‘盐丰’蛋白总体呈下降趋势。在4 ℃储藏期间,3 种大米蛋白的乳化稳定性总体呈下降趋势,‘稻花香二号’和‘辽星’的蛋白溶解度和乳化性总体呈下降趋势,而‘盐丰’的蛋白溶解度和乳化性呈显著上升趋势（P＜0.05）。在30 ℃储藏期间,3 种大米蛋白溶解度总体呈下降趋势,而乳化性和乳化稳定性总体显著上升（P＜0.05）。在70 ℃储藏期间,3 种大米蛋白的溶解度和‘辽星’蛋白的乳化稳定性总体显著下降（P＜0.05）,而‘稻花香二号’蛋白乳化性总体呈上升趋势。综上,在不同温度储藏期间,3 种大米蛋白的功能特性均发生显著变化。     

2010年中国粳稻米市场供求和价格分析

2009年我国稻谷生产再获丰收,而大米消费则基本稳定,稻谷总体上产大于销,但在国家粮食购销政策的支持下,稻米价格仍呈上升态势,尤其是粳稻米价格涨势强劲,粳籼稻米之间价格之差拉大。展望2010年我国稻米市场,虽然稻米总体上仍供大于求,但各品种的供求却不均衡,"粳紧籼松",粳稻价格仍呈上涨趋势。     

世界高粱供需格局变动及趋势分析

分析了世界高粱生产、消费和贸易的历史发展趋势及格局变化特征。从生产方面看,世界高粱种植面积相对稳定、单产水平大幅提升、总产量逐步趋稳以及生产区域集中度较高;消费方面,中国、尼日利亚、墨西哥是三大主要高粱消费国,世界人均高粱消费量有较大幅度的下降;贸易方面,世界高粱贸易波动较大,总体呈现先降后升再降的趋势。中国作为世界上最大的高粱进口国,对世界高粱贸易量变动发挥着决定性影响。未来,世界高粱生产和消费将继续保持相对稳定的规模水平,贸易量或有小幅增长。     

世界大米未来10年的发展趋势

据《粮食科技与经济》讯，预计世界大米未来10年增长率不到0．3％。由于高产稻米品种的研究与推广，世界大米年增长率为1．0％，在未来10年里，世界大米消费量平均年增长率为0．9％，预计在2013年将达到45120万t。预计在2013年国际市场的大米价格将达到326美元／t。泰国、越南和印度预计将主导全球稻米出口市场。2003年，这三个国家的大米出口占全球的57％，到2013年，预计将达到63％。中国由于大米种植面积的减少，在未来的10年里，大米的出13预计将会减少。     

稻米市场月度分析报告

<正>一、八月份稻米市场整体行情回顾八月份,国内大米市场整体稳定,购销仍处清淡格局,大米走货缓慢,销区局部略跌;国内稻谷市场呈现早籼稻收购价稳中有涨、粳稻稳定局部略跌状态;国内稻米市场呈现稻强米弱格局。籼稻市场:今年早籼稻播种面积下降导致总体产量下滑,市场总供给较上年有所下降;早籼稻生长期遭遇洪涝等不利气候影响导致质量下降,优质稻占比减少;今年早籼稻最低收购价下调,各级地方储备纷纷增加早籼稻轮入量。受以上因素的影响,致使收购     

大米营养化被提上日程是一种必然

稻米是全世界最重要的粮食之一。在中国,稻米是单产最高、最稳定的粮食作物,2／3以上的人口以大米为主食,年人均大米消费量占年人均消费谷物的一半以上,是国人整个膳食的基础和营养的基础。     

美国稻米分级标准与检测技术研究

美国通过出台严格、科学、合理的稻米分级标准和采用先进的检测技术来保证大米的质量达到出口要求,赢得市场的做法为我国稻米生产和贸易提供了有益的借鉴.面对竞争激烈的国际大米生产,我国惟有完善稻米标准,加大投入,提高检测水平,才能突破技术壁垒和绿色壁垒,实现由稻米生产大国向稻米生产强国的转变.     

2005年稻米市场行情分析与2006年展望

<正>在国家系列扶持粮食生产政策支持下,2005年稻谷播种面积和产量继续保持恢复性增长,并一举扭转 2000年以来当年产不足需供求格局,这也是6年来首次当年供给量大于消费量。与往年相比,2005年稻米市场行情表现出一些新特点,这些新特点对今后若干年行情发展均具有较好指导意义。 1 2005年稻米市场行情基本回顾 2005年稻米行情整体比较平稳,除局部地区出现阶段性价格较小波动外,没出现较大市场行情变动。 1．1 稻米价格总体稳定,局部稍有涨落以标准一级大米全年平均价格为基准,粳米价格上下波动不超过5％,籼米波动不超过4％,与2004年度相比,粳米价格上涨3．6％,早籼米下跌5．7％,晚籼米下跌5．6％(见表1),粳稻价格上升较为明显,升幅 9．1％,早籼稻和晚籼稻则分别下跌3．2％和2．9％。需要特别指出的是,2005年粳稻谷价格比2004年明显上     

我国大米加工业呈现快速发展后期前景广阔——国内大米加工业发展现状及前景展望

当前,我国稻米加工基本处在一个初级加工阶段.近几年,低水平的重复建设,造成碾米工业生产能力大大过剩;企业规模小、分布散等问题严重制约着稻米资源的深加工利用;而长期以来产业分工的局限,也影响着米制食品工业的发展.最近两年,受原料价格高、大米需求不振等影响,我国大米加工企业利润空间不断被压缩,开工率普遍不高,整体收益有所下降.后期经营策略和发展前景亟待改善.     

Rodent outbreaks and rice pre-harvest losses in Southeast Asia

There is momentous pressure on world cropping systems to provide more food in order to satisfy future demand. However, focus should not only be on increasing production but on reducing harvest losses too. Pests contribute to huge quantities of food losses every year and rodents are arguably one of the most damaging, causing annual losses globally of an estimated 77 million tonnes. Rice, which is the greatest food commodity produced for human consumption, is particularly vulnerable. The paper reviews the extensive amount of research on rodent outbreaks and chronic yield losses due to rodents in rice cropping systems, with particular focus on Southeast Asia. Rodent outbreaks are expected to become more serious and destabilizing for food security in this region in the future, but ecologically-based rodent management can act as an effective tool in addressing this issue.     

Crops that feed the world 7: Rice

Fears about global food security led to a spike in food prices in 2008, social unrest and pushed a further 100 million people into poverty. Prices remain high and volatile. In this paper we take a closer look at rice, a crop that feeds billions of people in the world, and focus in particular on Asia and Africa. On both continents, rice is grown in a wide range of climatic conditions, from river deltas to mountainous regions. Irrigated systems dominate in Asia and rainfed systems in Africa. Predicted demands for rice remain strong. An additional 116 million tons of rice will be needed by 2035 to feed growing populations. In Africa, where rice is the most rapidly growing food source, about 30 million tons more rice will be needed by 2035, representing an increase of 130% in rice consumption from 2010. About one-third of this extra rice will be needed in Nigeria alone. In Asia, per capita consumption of rice may go down in some mid- and high-income countries. Rice farming will need to produce about 8–10 million tons more paddy per year over the next decade. Without area expansion this will require an annual yield increase of about 1.2–1.5%, equivalent to an average yield increase of 0.6 t ha⁻¹ world-wide. Improving global food security will, therefore, necessitate concerted efforts to increase the productivity of rice per unit of land, water and/or labor in Asia and Africa, and the development of new land and water resources in a responsible and equitable manner to counteract losses due to urbanization and industrialization. During 2007–2011, productivity increases in Africa have been leading the way, with paddy rice production levels increasing by 9.5% per year, compared to 1.6% in Asia. Priorities for rice sector development include (i) continued and increased research efforts to close yield gaps and raise yield ceilings across rice growing environments through varietal development and improved rice production methods, and coping with climate change in both continents and (ii) strengthened and equitable public-private sector partnerships and conducive policy environments in Africa, with special emphasis on mechanization of rice farming from land preparation to harvest and rice processing practices.     

重视黄酒肽类物质的研究

黄酒是我国的民族特产，与啤酒、葡萄酒并称为世界三大古酒，享有“国酒”之美誉。黄酒中肽的含量是各种酿造酒中最高的，且其他酒无可比拟。研究表明，许多肽具有促进钙吸收、降血压、降胆固醇、镇静神经、免疫调节、抗氧化、清除自由基，抗癌等功能。重视黄酒保健养生功能的研究与宣传，可推动黄酒消费．促进黄酒行业的发展。(孙悟)     

2012年一季度禽蛋市场形势分析与展望

我国是世界上禽蛋生产与消费的第一大国。近年来我国禽蛋产量逐年增加,禽蛋市场的变化对居民食物消费生活产生一定影响。本文对近期我国禽蛋市场生产、市场、贸易现状进行分析,对未来我国禽蛋市场的价格走势进行了展望。     

大米中无机砷风险评估方法学研究

目的研究风险评估在大米中无机砷健康风险防控的应用。方法以评估中国东南沿海A县县域大米中的无机砷及其干预或控制措施对当地人群的致癌风险的影响为例,将大米中无机砷的检测数据、消费量调查数据、生物利用率和剂量-反应关系模型相结合,使用@RISK 7.5对不同情景下样品来源地一般人群的膀胱癌和肺癌风险进行概率评估。结果国标限量和正常消费情景下大米来源的无机砷暴露导致的25年后膀胱癌和肺癌年新发病例数约为0.045例/10万人,在25年后一切原因导致的年新发病例数(约209.2例/10万人)中几乎可以忽略不计(约占0.021 5%),由此造成的平均预期寿命损失约为0.000 529岁/0.193 1 d。改变国标限量和/或消费结构的再干预或控制措施对风险的影响很小,即使假设无机砷限量和大米消费量均降为原来的1/2,肺癌的发病率也仅下降2.16%。结论研究显示改变消费结构和/或国标限量对降低大米中无机砷的风险意义不大,当前的假设情景也存在较大的局限性和不确定性,但本研究为整合、评价和应用新的公共卫生科学信息提供了一个方法框架。     

低蛋白调制大米的研究进展

慢性肾脏病(chronic kidney disease,CKD)发病率在我国呈逐年上升趋势,低蛋白饮食(low protein diet,LPD)是延缓CKD病情发展有效的食疗方法之一。本文就近年来日益受到广泛关注的低蛋白调整大米的研究方法进行了综述和展望,分析了包括育种栽培、物理方法、化学方法、生物技术降解等方法的优势与不足。其中利用生物技术降解整粒大米蛋白,能够在保持大米原有完整性和口感的同时大幅度降低其蛋白含量,产品更适合肾病患者长期食用。我国约2/3居民以大米为主食,肾病患者人数越来越多,而国内相关的低蛋白产品还相对较少,无法大众化,故从改善患者主食方面研制出符合患者饮食习惯的低蛋白大米的市场前景非常可观。     

我国稻米加工产业发展若干问题的探讨

稻米是我国大宗传统主食,在我国粮食生产中具有举足轻重的地位。目前我国正处于产业结构与消费结构转型的关键时期,稻米加工产业进入到了追求美味、安全放心、营养健康、便捷、多样化发展新阶段。文章分析了稻米在世界及我国主食产业中的地位、我国稻米加工产业发展现状,并对现阶段我国稻米加工产业发展中的若干问题进行了探讨。     

Brown Rice Versus White Rice: Nutritional Quality,Potential Health Benefits,Development of Food Products,and Preservation Technologies

Obesity and chronic diet‐related diseases such as type 2 diabetes, hypertension, cardiovascular disease, cancers, and celiac are increasing worldwide. The increasing prevalence of these diseases has led nutritionists and food scientists to pay more attention to the relationship between diet and different disease risks. Among different foods, rice has received increasing attention because it is a major component of billions of peoples’ diets throughout the world. Rice is commonly consumed after polishing or whitening and the polished grain is known a high glycemic food because of its high starch content. In addition, the removal of the outer bran layer during rice milling results in a loss of nutrients, dietary fiber, and bioactive components. Therefore, many studies were performed to investigate the potential health benefits for the consumption of whole brown rice (BR) grain in comparison to the milled or white rice (WR). The objective of this work was to review the recent advances in research performed for purposes of evaluation of nutritional value and potential health benefits of the whole BR grain. Studies carried out for purposes of developing BR‐based food products are reviewed. BR safety and preservation treatments are also explored. In addition, economic and environmental benefits for the consumption of whole BR instead of the polished or WR are presented. Furthermore, challenges facing the commercialization of BR and future perspectives to promote its utilization as food are discussed.     

Pre‐ and Postharvest Strategies to Minimize Mycotoxin Contamination in the Rice Food Chain

Rice is part of many people's diet around the world, being the main energy source in some regions. Although fewer reports exist on the occurrence of mycotoxins in rice compared to other cereals, fungal contamination and the associated production of toxic metabolites, even at lower occurrence levels compared to other crops, are of concern because of the high consumption of rice in many countries. Due to the diversity of fungi that may contaminate the rice food chain, the co‐occurrence of mycotoxins is frequent. Specific strategies to overcome these problems may be applied at the preharvest part of the crop chain, while assuring good practices at harvest and postharvest stages, since different fungi may find suitable conditions to grow at the various stages of the production chain. Therefore, the aim of this review is to present the state‐of‐the‐art knowledge on such strategies in an integrated way, from the field to the final products, to reduce mycotoxin contamination in rice.     

The impact of cooking method on the phenolic composition,total antioxidant activity and starch digestibility of rice (Oryza sativa L.)

This study investigated changes in the phenolic composition, total antioxidant activity (TAA) and starch digestibility in white and brown rice due to three different cooking procedures, and subsequent reheating of cooked rice after storage. Among the analyzed samples, brown rice showed the highest TAA and phenolic content (622.5 mg/kg DW). All cooking methods resulted in significant decrease of phenolic content and TAA of rice (p < 0.05). The greatest loss was observed after processing in rice cooker, which reduced phenolic content of both brown and polished rice by ～30% and ABTS radical‐scavenging activity by 20 and 28%, respectively. In general, the levels of polyphenols and TAA of cooked rice tended to further decline after storage and reheating, but to a much lesser extent when rice was prepared using microwaves. The application of in vitro digestion system disclosed that the microwave cooking resulted in the highest starch digestibility among cooking methods used.

Practical applications

Rice is one of the most commonly consumed staple foods worldwide. Scientific and epidemiological studies have showed that their phytochemicals exhibit antioxidant, anti‐inflammatory, antihypertensive and chemopreventive effects. Therefore, their high consumption, easy availability throughout the year and use as an additive to meat and high‐fat foods may make rice, especially in the form of whole grains, potentially important chemopreventive component of the diet. The appropriate cooking procedure of rice is crucial for preservation of bioactive compounds as well as digestion of starch and thus duration of the glycemic response. Preferably, this study is focused on the evaluation of the effect of cooking methods on the health‐related quality of rice. The results provide practical advice that the consumption of freshly cooked rice ensures its highest nutritional quality, while rice microwaving is recommended both when cooked rice will be reheated after storage (e.g., in restaurants) and accelerated starch digestion is in favor.