2005年下半年稻米市场分析

<正>今年稻米市场行情一直比较低迷,截今为止,基本没有出现大范围上涨或阶段性上涨行情;尤其是第三季度,早稻米、中稻米和晚稻米在一般年景下会依次有一轮季节性上涨行情,但今年第三季度行情没有任何起色。第三季度标一早籼米和晚籼米全国平均价格比第二季度分别下降6.1%和4.1%,比去年同期分别下降10.2%、10.8%,弱市行情明显。而第三季度标一粳米价格却比第二季度上升1.7%,但比去年同期下降0.8%,基本保持稳定走势。相对籼稻米而言,粳稻米走势比较坚挺,籼稻米和粳稻米走势己出现分化;随着行情发展,这种分化有可能进一步加剧。1供求分析     

品种对稻谷吸湿产生裂纹的影响

本文研究了不同品种的稻谷在同一吸湿环境中产生裂纹的差异 ,结果表明 :品种对稻谷吸湿产生裂纹的影响大 ,不同品种的稻谷在同一吸湿环境中裂纹产生情况的差异显著 ,极差为63 % ,方差分析极显著。其中早稻、晚稻产生的裂纹比中稻多 ,粳稻比籼稻易产生裂纹。     

2006年第二季度我国稻米市场分析

<正>2006年第二季度粳稻米和籼稻米价格走势依然背离,籼稻米振荡下行,粳稻米高位调整,总的来说,整个稻米市场在第二季度走势偏弱。1籼稻米2006年第二季度早籼稻米和晚籼稻米价格持续震荡下行,除4月中下旬受“五一”节日需求效应拉动而有一个小的回调外,整个第二季度籼稻米都处于疲弱之中(见图1、图2)。由于影响早籼稻米和晚籼稻米因素大致相同,本文将早、晚籼稻米合并论述。     

2007年1～4月份稻米市场分析

<正>1 2007年1～4月份稻米市场主要特点2007年1～4月,稻米市场粳稻米和籼稻米走势出现明显分化,粳稻米价格全线下跌,且幅度较大;籼稻米价格处于窄幅振荡整理之中,不瘟不火。尤其是在2月份后,这种分化更加明显,粳稻米快速下跌,籼稻米弱市整理,使先前两者间价差得以缩小(见图1),从图1可明显看出“喇叭口”呈趋缩小态势。进入4月份后,整     

2006年第一季度稻米市场分析

<正>2006年第一季度稻米市场供求基本相当,除部分地区因集中轮换造成价格较小波动外,稻米市场行情总体较稳定,籼稻米和粳稻米分化现象依然存在。 1 早籼稻米     

完善我国稻米质量标准指标及相关检验技术的思考

通过对中国稻米质量标准中有关垩白、黄粒米指标和稻米食味感官评分评价员筛选方法的验证试验,提出了重新设置稻米质量标准中有关垩白、黄粒米指标及建立科学的稻米食味感官评分评价员筛选方法体系的建议,并对稻米质量指标评价的数字化、物理化进行了展望。     

相同水分活度的粳米和籼米吸湿产生裂纹的研究

本文研究了在不同湿空气热力学环境中，品种、垩白、水分活度及环境相对湿度对精白米吸湿产生裂纹的影响。结果表明：水分活度和垩白对精米吸湿产生裂纹的影响极显著，环境相对湿度的影响显著，品种的影响不显著，认为采用水分活度来评定稻谷的储藏安全性比安全含水量更能反映稻谷储藏的真实情况。     

我国2006年第三季度稻米市场分析

<正>1第三季度稻米市场综述1．1价格平稳运行2006年第三季度稻米价格整体走势平稳,高位盘整,在第二季度下调基础上,进入第三季度后开始缓慢回升,并逐步回调到第一季度水平,相对而言,粳稻米价格走势强于籼稻米(见图1)。稻米价格在第三季度整体回暖主要是受益于两个方面因素:一是暂停“托市稻谷”竞价销售;二是扩大“最低价格”收购数量。     

粳稻品种新米和储藏米品质性状的比较研究

本文以常温下储藏8个月的7个粳稻品种糙米和相应的新米为研究材料，比较分析了加工和营养品质、稻米淀粉粘滞特性（Viscosity）、食味品质、游离脂肪酸含量及米饭质地的动态粘弹性（Dynamic viscoelas-ticities）。结果表明：短期储藏对粳稻直链淀粉、蛋白质含量和加工品质没有明显影响；储藏米食味普遍比其相应的新米要差，但新米食味好的品种其储藏米也相对较优，储藏米的综合食味评价值与新米一样和米饭外观、滋味、粘性有很高的正相关；粘度谱的衰减值和峰值粘度有所上升；米饭质地的粘弹性和动态损失正切值（Loss tangent）分别比新米上升21．47％和下降26．76％；粳稻储蓄米游离脂肪酸含量的增加是导致食味变差的主要原因，这在食味相对较差的品种中尤为明显。通过米饭质地动态粘弹性和游离脂肪酸含量的测定可以评价储藏米的食味特性。     

大米硒营养及生产富硒留胚米原料的选择

综述了硒与人体健康的关系,分析了稻米籽粒硒营养的特点。试验研究了加工过程对富硒留胚米硒含量的影响。结果表明,采用富硒籼稻糙米加工富硒留胚米,加工精度达国标(GB 1354—2009)四级、三级时,留胚率分别达95%、83%,硒含量为糙米硒含量的97.0%、94.0%;采用富硒粳稻糙米加工富硒留胚米,加工精度达国标(GB 1354—2009)四级、三级时,留胚率分别达90%、81%,硒含量为糙米硒含量的98.3%、95.3%。     

Effect of drying and tempering on rice fissuring analysed by integrating intra-kernel moisture distribution

The fissure generation of one short- and two long-grain rough rice dried at different air conditions for 15, 30 and 60 min, and respectively, tempered at 20, 30, 40 and 50 °C for tempering duration ranging from 0 to 330 min was analysed by integrating moisture gradients in rice kernels. Results indicated that drying and tempering processes had significant effects on the moisture gradient and rice fissuring. The percentage of fissured kernels increased with increasing drying time and decreasing tempering time. The tempering duration required for long-grain rice was shorter than that for short-grain rice to prevent kernel fissuring. Higher tempering temperatures can effectively eliminate moisture gradients and then lower the rice fissuring generation. Tempering at 50 °C reduced fissuring incidence by 32 to 50% compared to tempering at 20 °C. Moreover, short-grain rough rice was very susceptible to fissure whereas long-grain rough rice with a high amylose content was much more fissure-tolerance.     

原料种类对米酒滋味品质影响的研究

分别采集了籼糯米、粳糯米和大米样品各5个,在同一发酵条件进行了米酒的酿造,并采用电子舌技术和多变量统计学方法相结合的手段,对米酒样品的滋味品质进行了评价分析。通过主成分分析、聚类分析和多元方差分析发现以籼糯米和粳糯米为原料酿造的米酒其滋味品质差异不显著,而两者与以大米为原料酿造的米酒滋味品质存在显著差异（P＜0.05）。通过冗余分析发现该差异是由于酸味、涩味和后味A（涩的回味）3个指标造成的。通过方差分析发现,以大米为原料酿造的米酒其酸味和涩味要显著偏高（P＜0.05）。由此可见,以糯米为原料酿造的米酒其滋味品质要优于以大米为原料酿造的米酒。     

Effects of rice harvest moisture on kernel damage and milled rice surface free fatty acid levels

ABSTRACT:  Surface free fatty acid (FFA) on milled rice is a key factor in determining rice quality and acceptability to the brewing industry. Rice FFA oxidizes, causing off-flavors and odors to develop, compromising the brewing quality of milled rice. The effect of harvest moisture (13%, 16%, and 20%), harvester type (1688 Case and 9500 John Deere), and rice variety (Cocodrie and Bengal) on harvest damaged rough rice and milled rice surface FFA after drying to 12% moisture and 6 mo rough rice storage was examined. The Case harvester produced more damaged kernels than the John Deere harvester, but this was not reflected in surface FFA development. There were no significant FFA differences in variety or harvester type. Rice harvested at a higher moisture content (20%) produced significantly greater FFA values, with a peak near 0.1%, than rice harvested at lower moisture contents (13% and 16%), which had FFA values near 0.08%. Retention of bran by damaged kernels at high harvest moisture probably was responsible for promoting surface FFA development, but if bran was lost at lower harvest moistures, surface FFA, development was limited. Harvest moisture affected milled rice FFA, although rough rice was dried to 12% immediately after harvesting.     

Gelatinization,Pasting Characteristics and Cooking Behaviour of Egyptian Rice Varieties in Relation to Amylose and Protein Contents

Gelatinization and pasting characteristics of milled powder of shortgrain rice varieties gave Amylograms which generally exhibited lower gelatinization temperatures and longer gelatinization times than long-grain varieties. Galatinization temperatures and peak viscosities were independent of amylose and protein contents; the drop in viscosity at 94 °C generally was negatively correlated with protein content but positively correlated with amylose content. The maximum volume-expansion ratio and water absorption ratio for short-grain varieties were lower than with the long-grain varieties, and the two ratios were also related to the amylose content. Apparently cooking period was the principle factor for controlling the degree of cooking.     

籼米多孔淀粉的研制

试验以籼米淀粉为原料,通过α-淀粉酶水解籼米淀粉制备籼米多孔淀粉,探讨并获得了酶水解法制备籼米多孔淀粉的较优工艺：酶解反应温度为35℃,酶解反应时间为12 h,加酶量为酶解40%淀粉量,酶解体系pH值为4.0。并利用砂芯漏斗测定淀粉对液体的吸附能力,观察到大米多孔淀粉对液体的吸附能力大大强于大米原淀粉。     

不同类别大米糊化特性和直链淀粉含量的差异研究

对不同类别的市售大米样品（籼米,粳米,杂交稻米,籼糯米,粳糯米,黑米和香米）的糊化特性和直链淀粉含量进行了测定并进行了比较研究。结果表明,籼型,籼型,粳型和糯型大米的直链淀粉含量和糊化特性贡线及主要特征值（峰值粘度,最终粘度,回生值）均有明显的差异,并与其食用品质有密切相关,糊化特性曲线和相关特征值可用于鉴别市售大米的品质也可用于判别信有直链淀粉含量划分的大米类型。     

稻谷整精米率检验影响因素探讨

整精米率是反映稻谷品质的重要指标,对稻谷整精米率的检验影响因素进行了试验,探讨了不同水分的稻谷整精米率检验影响因素及影响程度。     

Effects of milling on functional properties of rice flour

ABSTRACT:  A commercial long-grain rice flour (CRF) and the flours made by using a pin mill and the Udy mill from the same batch of broken second-head white long-grain rice were evaluated for their particle size and functional properties. The purpose of this study was to compare the commercial rice flour milling method to the pin and Udy milling methods used in our laboratory and pilot plant. The results showed that pin milled flour had more uniform particle size than the other 2 milled flours. The chalky kernels found in broken white milled rice were pulverized more into fines in both Udy milled flour and CRF than in the pin milled flour. The excessive amount of fines in flours affected their functional properties, for example, WSI and their potential usage in the novel foods such as rice breads (RB). The RB made from CRF collapsed more than loaves made from pin milled Cypress long-grain flours.     

Rice Cake Production using Long-grain and Medium-grain Brown Rice

Puffing of rice cakes using both long-grain and medium-grain brown rice was studied. The effects of tempering moisture, heating temperature, and heating time on various rice cake quality attributes were investigated. A greater specific cake volume was obtained at a lower tempering moisture, higher heating temperature, and longer heating time for long-grain brown rice. For medium-grain rice, a higher tempering moisture yielded a larger specific cake volume. The lightness of rice cakes correlated well with their expansion; the less expanded cake always had a lighter color. Medium-grain brown rice also produced cakes that were much more fragile than those produced from long-grain brown rice.     

Characterisation of Brown and Milled Yellow Rice and Development of an Expanded Snack

Brown rice and yellow milled rice were characterised in relation to milling properties, cooking, processing quality and microbial testing, and utilised to develop an expanded snack. The extrusion process was done in a Mapimpianti single screw cooker-extruder. A flour sample feed rate of 70 g (dry matter) min⁻¹ was maintained by varying the force-feeder speed. A screw speed of 150 rev min⁻¹ and a die with 20 die-nozzle orifices (2 mm in dia) were used. The die zone was heated at 110°C by electrical resistance. Compressed air was circulate around the barrel to maintain precise control of the temperature. The moisture content of the samples was 120, 150 and 180 g kg⁻¹. The grains were classified as long-thin with an average size of 2·13 mm×6·79 mm. The milling yields obtained in the laboratory with paddy rice were 700 g kg⁻¹ brown rice and 600 g kg⁻¹ milled rice. Brown rice and yellow milled rice had similar amylose contents, 225 and 256 g kg⁻¹, respectively. Gel consistency was soft with low gelatinisation temperature (63–68°C) for both samples. Field fungi such as Helminthosporium oryzae and storage fungi as Aspergillus spp were present in paddy, yellow milled and commercial rice. Helminthosporium oryzae was not present in extruded products. The extruded products showed low density and a high degree of expansion, with the optimum degree of expansion obtained in flours processed with moisture at 150 g kg⁻¹ in both milled and brown rice. The highest values for water solubility index were obtained with flours from milled yellow rice and none of the extruded products showed significant differences on water absorption index. Sensory analyses carried out on the snack products showed them to be acceptable, with the bent acceptance for products made from milled yellow rice processed with 150 g kg⁻¹ moisture.