稻米蒸煮特性QTL定位及与感官食味品质的相关性分析

稻米蒸煮特性和感官食味品质是稻米品质的重要评价指标,其遗传复杂.为挖掘与利用优异的稻米品质基因,本研究利用籼稻昌恢121为受体亲本和优质粳稻越光为供体亲本构建的一套染色体片段置换系(CSSL),对稻米的吸水率(WA)、延伸率(CRE)和膨胀率(VE)3个蒸煮特性进行QTL定位.共检测到4个QTL,分布于第8和第11号染...     

不同土壤耕作模式对冬小麦籽粒品质的影响

冬小麦籽粒的品质受土壤环境影响。为了研究不同土壤耕作模式对冬小麦籽粒品质的影响,采用了5种土壤耕作模式(常规耕作秸秆不还田、常规耕作秸秆还田、旋耕秸秆还田、缺口圆盘耙耕秸秆还田、免耕秸秆覆盖)在山东龙口进行了3年田间试验,测定了冬小麦籽粒蛋白质品质、面团流变学特性和淀粉糊化特性。结果表明：少耕模式特别是旋还模式有利于改善籽粒蛋白质质量、改善面粉的加工品质,免覆模式对改变面条蒸煮品质有利。土壤耕作可改变土壤环境,但耕作方式对冬小麦品质的长期影响仍有待于进一步研究。     

大气CO_2浓度升高对粳稻稻米物性及食味品质的影响

在2009和2010年利用独特的稻/麦轮作系统FACE（Free Air CO2 Enrichment,开放式空气CO2浓度增高）平台,以武运粳21、扬辐粳8号、武香粳14和武粳15为供试材料,研究了高浓度CO（2比大气背景CO2浓度高200 μmol·mol-1）对粳稻蒸煮米的硬度、粘性、香气、光泽、完整性、味道和口感等的影响。物性分析仪测定结果表明,高浓度CO2环境下粳稻熟米的硬度和粘性总体呈增加趋势,其中扬辐粳8号两指标的增幅均达显著水平。食味计测定结果显示,高浓度CO2对蒸煮稻米香气、光泽度、完整性、味道和口感等食味品质指标均没有影响。相关分析表明,CO2与品种的互作对米饭硬度和粘性有显著影响,但对食味品质参数均没有影响。CO2与年度、CO2与年度和品种间的互作对所有测定参数均无显著影响。两年数据一致表明,未来高浓度CO2环境下粳稻蒸煮米的硬度和粘性将呈增加趋势,增幅因品种而异,但米饭食味品质无显著变化。     

蒸煮过程中稻米水分状态的质子核磁共振谱测定

对3种稻米蒸煮过程中水分的状态进行了¹H-NMR测定。结果表明, 不同品种的原料稻米具有相近的弛豫特征。但在蒸煮过程中，纵弛豫时间会因品种的不同而呈现出显著的差异。分析结果认为，稻米中水分的存在状态有自由水、构造水和结合水等3种形式。蒸煮过程中各种稻米水分状态的差异与谷粒中有机物的理化特性密切相关，并可能是导致米饭具有不同食味特性的重要原因。     

欧姆加热对米饭蒸煮过程能耗及其品质的影响

电饭煲蒸煮米饭存在电热转化效率低、温度不易控制等不足。该研究设计了一种加热速率和保温温度自动可控的欧姆加热试验系统,并研究了浸泡时间和水米比对水米混合物的电导率、欧姆蒸煮加热速率、能耗以及米饭品质（膨胀率、吸水率、物性值和颜色）的影响,并与电饭煲蒸煮米饭的能耗和品质进行比较。结果表明：浸泡能够增大水米混合物电导率,水米比越小电导率增加越快,有效提高欧姆加热蒸煮米饭加热速率;浸泡还有利于减少米饭蒸煮能耗（P<0.05）,促进米饭软化;因此大米浸泡处理30 min后采用欧姆加热蒸煮米饭可行。欧姆蒸煮加热速率越快,米饭硬度上升（P<0.05）,而黏性和弹性则略有减小（P<0.05）,加热速率在3～9 ℃/min范围内为宜;水米比可取1.25∶1～1.50∶1 mL/g。蒸煮相同质量的大米,欧姆加热所需能耗仅为电饭煲蒸煮的20%～25%;相较于电饭煲蒸煮,欧姆加热蒸煮米饭硬度最大可减小21%,且膨胀率和吸水率较大（P<0.05）、亮度L*值较小（P<0.05）。研究结果可为研发基于欧姆加热的快速高效米饭自动蒸煮装置提供技术支撑。     

大米胶稠度近红外光谱分析数学模型的建立

胶稠度是评价大米蒸煮食用品质的重要指标之一。研究了运用近红外光谱分析技术检测大米胶稠度的测试原理，对60个样品的光谱数据用偏最小二乘法(PLS)建立了测定大米胶稠度的数学模型，其回判结果与化学分析值之间的相关系数为0.95，建模标准差为0.66；用41个样品对建立的数学模型进行了交叉验证，其检测结果与用标准化学分析方法测得结果的相关系数达0.92，预测标准差为0.78。试验证明，可以利用近红外光谱分析技术对大米胶稠度进行快速检测。     

适宜加热温度保持牦牛瘤胃平滑肌加工品质和组织结构

为研究不同温度对牦牛平滑肌加工品质和组织结构的影响。将牦牛瘤胃平滑肌分别在50、60、70、80、90、100℃条件下处理60 min后取样,考察不同温度对牦牛平滑肌蒸煮损失、热收缩率、剪切力、胶原蛋白含量和微观结构的影响。结果表明:随温度的升高,牦牛平滑肌的蒸煮损失、热收缩率、初级和次级肌束膜的厚度均显著增加(P0.05);剪切力、胶原蛋白含量和肌纤维直径均显著降低(P0.05);总体表现为牦牛平滑肌的加工品质随温度的升高而下降,组织结构随温度升高而收缩。80℃是平滑肌加工品质形成的关键温度,80℃处理60 min牦牛平滑肌的蒸煮损失为31.39%?3.08%、热收缩率为30.80%?2.15%、剪切力值为86.63 N?8.72 N、胶原蛋白质量分数为49.52 mg/g?2.84 mg/g。因此,推荐牦牛瘤胃平滑肌在80~90℃范围内熟制具有较好的加工品质和组织形态。研究结果将为含平滑肌的内脏等副产物的精深加工提供参考。     

基于CFD数值模拟的豆腐干软罐头杀菌工艺优化

针对豆腐干软罐头恒温热杀菌工艺中存在的因杀菌过度而品质不佳问题,开展了杀菌工艺优化。首先利用CFD软件数值模拟杀菌过程获取节点温度历史,筛选出杀菌值3 min且蒸煮值能够有效减小的梯度升温方法,再利用试验对该方法进行验证,通过比较实际杀菌过程的杀菌值、蒸煮值及具体品质指标,同时,结合工业生产的需要,最终确定一种升温模式作为优化杀菌工艺。研究最终得到一种即能满足安全指标且品质劣化程度显著降低的豆腐干软罐头梯度升温杀菌工艺:第一阶段升温到100℃恒温20 min;第二阶段继续升温到120℃保温杀菌15 min。该工艺杀菌值为3.739 23 min,表面蒸煮值和体积平均蒸煮值分别比原有的恒温杀菌工艺(30 min/116℃)降低10.1%和8.69%(P0.01);杀菌后豆腐干亮度值、红度值和黄度值分别比原有工艺提升3.75%、27.4%和43.4%,含水率提升1.58%,剪切力降低30.1%,表面硬度降低78.9%同时表面凝聚性提高551%;该杀菌工艺温度峰值能够满足工业化生产需求。研究结果为固体软罐头食品的变温杀菌工艺优化提供参考。     

复合无磷保水剂的配方优化及对PSE猪肉贮藏品质的影响

为了改善PSE猪肉的加工特性,明确L-精氨酸、碳酸钠、柠檬酸钠对PSE猪肉保水性的影响,本研究在单因素试验基础上,以蒸煮损失、离心损失、滴水损失为指标,通过L₉(3⁴)正交试验,确定最适添加量,并分析测定了在最适复合无磷保水剂配方下PSE猪肉贮藏过程中的品质变化。结果表明,L-精氨酸为0.40%、碳酸钠为0.60%、柠檬酸钠为0.60%的复合无磷保水剂处理,能显著提高PSE猪肉的保水性,并能有效改善PSE猪肉的贮藏品质。本研究结果为提高冷藏期PSE猪肉的保水性提供了一种新思路,同时为无磷保水剂提高PSE猪肉的利用价值提供了一定的理论支持。     

基于可见-近红外光谱的滩羊肉多品质指标无损检测

针对近红外光谱技术在生鲜肉品质检测中预测模型适用范围窄、检测指标单一、模型稳定性差、难以有效应用于生产检测等问题,本研究采集不同月龄宁夏滩羊宰后3个时期4个部位肉的可见-近红外光谱信息,测定色泽、pH值、蒸煮损失、剪切力以及蛋白质、粗脂肪和水分含量,利用2个波段(370~1 050 nm、900~1 700 nm)的光谱数据分别构建各个指标的偏最小二乘回归(PLSR)预测模型以实现滩羊肉多品质指标同步无损检测。结果表明,两波段中各品质指标的PLSR预测模型相关系数(R)均大于0.80,第二波段中水分含量PLSR模型预测集R可达0.941;两波段中各品质指标预测模型的性能较好,其中370~1 050 nm波段的光谱数据对样品色泽参数预测效果更好。综上所述,可见-近红外光谱技术可实现滩羊肉7个品质指标的快速无损检测。本研究结果为滩羊肉品质控制和滩羊屠宰加工企业优质特色产品的生产提供了技术支撑。     

早籼杂交稻稻米加工品质与外观品质的相关分析和改良途径

对16个早籼杂交组合稻米的加工品质和外观品质8项指标分析表明，现有早籼杂交稻无一组合的加工品质和外观品质全部指标能达到部颁食用优质米1级或2级标准，主要差距是精米率低、垩白米率高和垩白面积大；整精米率、垩白米率和垩白面积组合间差异较大。通过相关分析看出：糙米率与精米率、整精米率；整精米率与精米率呈极显著正相关，粒长与粒型呈极显著正相关，与垩白面积呈显著正相关；粒宽与粒型呈极显著负相关，与垩白米率呈显著正相关。在优质早籼稻选育中应把降低垩白面积和垩白米率作为主攻目标，对亲本改良首先改良不育系的垩白。     

Physicochemical Characteristics of Chalky Kernels and Their Effects on Sensory Quality of Cooked Rice

Physicochemical characteristics of chalky rice kernels were compared with those of vitreous kernels, and the effects of chalky kernels on sensory quality of cooked rice were investigated. Chalky kernels were compared with vitreous kernels using image analysis and amylose contents. Because cooked rice is prepared through soaking and cooking, the changes in water absorption index (WAI) during soaking (15, 30, 60, and 90 min) and the structural changes during cooking (0, 3, 6, and 9 min) in chalky and vitreous kernels were investigated using image analysis and scanning electron microscopy. The effects of various proportions (0, 4, 6, 8, 10, and 15%) of chalky kernels on sensory quality of cooked rice were also studied. The chalky kernels tended to be smaller in kernel area, maximum diameter, minimum diameter, and perimeter than vitreous kernels. Amylose content in chalky kernels was slightly lower than that in vitreous kernels. WAI of chalky kernels was higher than that of vitreous kernels. The effects of chalky kernels on the sensory quality of cooked rice were not significant unless the proportion of chalky kernels was ≥15%. A sensory panel agreed that the overall sensory quality of cooked rice with 15% chalky kernels was the lowest among the samples tested.     

Effect of Rice Blast and Sheath Blight on Physical Properties of Selected Rice Cultivars

Observations in 1997 indicated a significant reduction in kernel bulk density and head rice yield of rice cultivar LaGrue due to blast (Pyricularia grisea). A more detailed study on rice cultivar M202 in 1998 confirmed such observations but it also showed negative effects of blast on other physical properties of rice. Rough rice from blast‐infected panicles was drier by 7–10 percentage points and 10% thinner than rough rice from blast‐free panicles. Blast also caused incidences of chalky, unfilled, and fissured kernels that were 21, 30, and 7 percentage points higher, respectively. The effects of sheath blight (Rhizoctonia solani) on kernel thickness and moisture content of rice cultivars Cocodrie, Cypress, Drew, and LaGrue were similar to the effect of blast on M202. Sheath blight generally reduced kernel bulk density but did not significantly affect head rice yield of the cultivars in 1997 and 1998 (except in one sample of Drew). There was a general trend toward higher incidences of unfilled, chalky, and fissured kernels in sheath‐blight‐infected samples. The data indicated that blast could be a significant preharvest factor in causing high variability in physical properties as well as in reducing the milling quality of rice. Sheath blight is also a potentially significant preharvest factor in affecting these properties in situations where sheath blight pressure is high.     

普通野生稻稻米加工品质和外观品质性状QTL定位

本研究利用一套以籼稻品种“特青”为遗传背景的云南元江普通野生稻（Oryza rufipogon Griff.）渗入系为材料，采用单标记回归分析和渗入片段叠代法，对出糙率、整精米率、垩白粒率、垩白度、长宽比等5个品质性状的QTL进行了分析，初步定位了16个QTL，有10个QTL来自野生稻的等位基因能改良群体的品质性状。在第5染色体RM289附近检测到了同时影响长宽比、垩白粒率QTL，来自野生稻的等位基因能增加长宽比、降低垩白粒率，贡献率也较高。在第8染色体RM152附近检测到降低垩白粒率和垩白度的QTL，其贡献率分别为14％和9%。本研究结果不仅为品质性状分子标记辅助选择提供参考，而且充分显示了利用野生稻的优异基因改良栽培稻品质性状的巨大潜力。     

早籼突变体稻米品质变化的研究

本试验分析测定了 1 1个优质早籼品种 (系 )及从其中诱变获得的 1 9个突变体的稻米品质。结果表明 ,与原亲本相比 ,辐射诱发突变体的精米率、整精米率、垩白米率、垩白度、直链淀粉含量、碱消值、胶稠度和蛋白质含量等品质指标以及淀粉粘滞性谱 (RVA谱 )发生了明显或比较明显的变化 ;大多数突变体同时在一个或多个主要品质性质上产生了正向和负向变异 ,少数突变体基本保持了原亲本的稻米品质 ,个别的甚至在此基础上还有若干品质性状得到显著改进。     

Effects of Cultivars,Transplanting Patterns,Environment, and Their Interactions on Grain Quality of Japonica Rice

With the increasing scarcity of rural labor, the rice transplanting pattern is encountering a shift from artificial transplanting (AT) to mechanical transplanting (MT) in numerous rice‐growing districts of China. The shift of transplanting patterns combined with altered growing environment during the grain‐filling stage in different years presumably affects rice quality. Nevertheless, related information is currently limited. This study investigated the effects of cultivars, transplanting patterns, environment, and their interactions on appearance, milling, eating, and nutritional qualities of four japonica rice varieties. The significant interactive effects of cultivars, environment, and transplanting patterns on almost all rice quality parameters (except Thr, Met, and Ile) were observed. Cultivars and environment were the main factors influencing rice appearance and milling and eating qualities. Cultivar was the primary factor affecting rice nutritional quality. Among all treatments, environment showed the strongest effect on percentage of chalky kernel, milled rice yield, peak viscosity, breakdown, setback, consistence, amylose, Glu, Tyr, and Met contents. However, Leu and Phe contents were unaffected by environment but only by cultivars and transplanting patterns. In addition to amylose and protein, Glu and Met contents were also involved in determining rice eating quality. Amino acid contents (except Cys, Tyr, and Met) were significantly negatively correlated with head rice yield, showing the function of amino acids in controlling rice milling quality. Percentage of chalky kernel as well as protein and almost all amino acid contents were significantly negatively correlated with the difference of maximum and minimum temperature (DMMT) and positively correlated with relative humidity (RH), whereas head rice yield did it reversely. Amylose content and setback were significantly negatively related to daily maximum temperature (DMAT), daily minimum temperature (DMIT), daily average temperature (DAT), and effective temperature accumulation (ETA). However, peak viscosity, breakdown, and consistence had contrary performances. According to these results, we can infer that DMMT and RH are important environmental factors affecting rice appearance, milling qualities, and nutritional qualities and that DMAT, DMIT, DAT, and ETA are key environmental factors influencing rice eating quality.     

不同稻蟹生产模式对稻蟹产量和稻米品质的影响

采取田间定位试验与室内分析相结合的方法,研究了有机稻蟹(M1～M4)、常规稻蟹(MNP)与单作水稻(CK)生产对水稻产量、河蟹产量、稻米品质的影响。结果表明,与MNP和CK相比,有机稻蟹各处理的水稻穗粒数、实粒数和结实率显著提高,尤其以M1处理增加最为明显,但有效穗数却显著减少;2009年M1处理稻谷产量显著高于CK;有机稻蟹各处理的稻米品质也得到不同程度改善,稻米的糙米率、精米率及整精米率随有机肥施用量的增加有显著提高趋势,稻米的垩白粒率、垩白度及直链淀粉含量显著降低,而稻米的蛋白质、胶稠度、食味值明显提高。2年间河蟹产量的变化趋势相同,均表现为M1>M2>M3>MNP>M4。因此,有机稻蟹生产可在一定程度上提高稻蟹产量和改善稻米品质,为优质稻米的生产以及有机肥的合理利用提供了一条较好的生态技术途径。     

Effects of Nighttime Temperature During Kernel Development on Rice Physicochemical Properties

Rice quality can vary inexplicably from one lot to another and from year to year. One cause could be the variable temperatures experienced during the nighttime hours of rice kernel development. During the fall of 2004, a controlled temperature study was conducted using large growth chambers, testing nighttime temperatures of 18, 22, 26, and 30°C from 12 a.m. until 5 a.m. throughout kernel development, using rice cultivars Cypress, LaGrue, XP710, XL8, M204, and Bengal. As nighttime temperature increased, head rice yields (HRY) significantly decreased for all cultivars except Cypress and Bengal, for which HRY did not vary among nighttime temperature treatments. Kernel mass did not vary among temperature treatments for any cultivar. Grain dimensions generally decreased as nighttime temperature increased. The number of chalky kernels increased with an increase in nighttime temperature for all cultivars but Cypress. The amylose content of Cypress and LaGrue was significantly lower at the nighttime temperature of 30°C, while total brown rice lipid and protein contents did not vary among temperature treatments for all cultivars.     

Fine structures and physicochemical properties of starches from chalky and translucent rice kernels

This work compared the molecular structures and physicochemical properties of starches obtained from chalky and translucent kernels of six rice cultivars. Starch samples were prepared according to a modified alkali steeping method. Crystallinity, pasting characteristics, and thermal properties were studied by X-ray diffraction, rapid viscosity analysis, and differential scanning calorimetry, respectively. Starch molecular size fractions (amylopectin, amylose, and intermediate material) were estimated by high-performance size exclusion chromatography, and the chain length profiles of isoamylase-debranched amylopectin were evaluated by high-performance anion-exchange chromatography with pulsed amperometric detection. Starches from chalky kernels contained less amylose (more amylopectin) and more short branch-chain amylopectin (less long branch-chain amylopectin) compared with the translucent kernel starches. Differences in starch structural features significantly correlated with observed variation in grain translucency, starch X-ray diffraction patterns, thermal properties, and pasting characteristics. Starch synthesis in chalky kernels may slightly favor glucan chain branching over chain elongation.     

垩白米粒的计算机图像识别

自行开发研制了计算机图像处理系统，用于优质稻谷国家标准GB/T 17891-1999中质量指标垩白度及垩白粒率的检测。利用该系统对6种粳米和2种籼米进行测定，结果表明，该方法具有客观性、准确性、快速性和可重复性等特点，在收购优质稻米进行快速分等定级中具有良好的应用前景。