膨化米饼加工原料选择模型研究

选用湖北省广泛种植的21种稻米生产膨化米饼,研究稻米化学成分含量对膨化米饼感官品质的影响,确定生产膨化米饼的适宜的稻米品种.结果表明,膨化米饼的感官品质与稻米的直链淀粉含量和粗脂肪含量相关,用幂指数模型,以稻米的直链淀粉含量、粗脂肪含量或粗蛋白含量可较好地预测膨化米饼的感官品质.直链淀粉含量中低、粗脂肪含量高、蛋白质含量低的洪优1号和晚粳春103等适于加工膨化米饼.     

方便米粉加工原料的选择研究

采用湖北省广泛种植的21个品种稻米生产方便米粉,通过回归分析和聚类分析,探讨了稻米主要成分与方便米粉品质之间的关系,并建立方便米粉生产原料的选择模型,为方便米粉专用稻的生产和方便米粉加工原料的选择提供依据.结果表明,稻米的淀粉含量、直链淀粉含量等与方便米粉的滋味、口感、色泽等感官品质呈极显著或显著相关;用稻米的直链淀粉含量和蛋白质含量或脂肪含量的幂指数模型预测方便米粉的感官品质,可以达到极显著水平;直链淀粉含量中高(10%～17.5%),蛋白质含量中高等(7.1%以上)的稻米适于加工方便米粉.     

不同直链淀粉含量的稻米淀粉黏滞特性研究

用快速黏度分析仪分析了不同直链淀粉含量的稻米淀粉黏滞特性,结果表明不同品种具有不同特征性RVA谱。消减值和直链淀粉含量达极显著正相关,相关系数为0.93,根据消减值可以区分出直链淀粉含量高低的品种,低或中低直链淀粉含量的品种的消减值一般为负值或较小的正值,中高或高直链淀粉含量的品种的消减值是正值。消减值和崩解值与胶稠度相关系数分别为-0.91和0.81,由此可根据消减值和崩解值来判断稻米食用品质的优劣。     

近红外光谱技术在稻米品质快速检测中的应用

综述近红外技术在稻米品质的常规指标,如直链淀粉、蛋白质、脂肪酸、胶稠度中的研究与应用,总结不同样品形态和建模方法建立的近红外模型的检测精度,指出近红外技术在快速检测稻米品质中存在的问题,以及今后的研究方向。     

稻米直链淀粉与米饭物性及食味品质的关联特征研究

以同一产区、收获期一致,而淀粉含量有差异的26个品种大米为研究材料。通过相关分析,研究大米直链淀粉含量与米饭物性特征及感官品质之间的相关特性。结果表明:稻米的直链淀粉含量(Amylose content,AC)与长宽比成极显著正相关(P0.01)。蒸煮以后,直链淀粉含量与脂肪和蛋白质呈显著负相关关系。直链淀粉与黏性长度、硬度显著正相关(P0.05),与弹性、内聚性、胶黏性、咀嚼性成极显著正相关(P0.01),与黏性呈负相关关系(不显著)。而直链淀粉含量是影响大米食用品质的最主要因素,可作为衡量稻米食味品质的重要指标。因此,直链淀粉含量越高,稻米食味品质越差,感官食味值越低。     

直链淀粉含量与稻米的糊化温度及胶凝度的关系

测定了169个稻米样品的直链淀粉含量、糊化温度及胶凝度。结果表明：影响稻米蒸煮及食用品质的直链淀粉含量、糊化温度及胶凝度在一定程度上是相关的。一般直链淀粉含量低则糊化温度高而胶凝度较软。除直链淀粉含量外,其它一些因素也影响稻米的糊化温度及胶凝度。     

稻米淀粉RVA特性及食味评价技术研究进展

为全面客观评价稻米品质,提出在RVA指标与蒸煮食味品质之间建立评价体系.综述了稻米淀粉的RVA特性及食味评价研究概况,指出直链淀粉含量、胶稠度可以较好地反映稻米食味品质,与蒸煮食味品质关系密切,且与RVA谱的特征值存在显著或极显著相关性.阐述了稻米淀粉RVA谱与蒸煮食品品质的相关性.     

稻谷湿热处理对稻米和米粉性质影响的研究

通过对稻谷进行湿热处理,测定处理前后稻米膨胀率和直链淀粉含量变化,并对处理前后的米粉进行品质特性测定.研究发现:湿热处理前后,稻米蒸煮膨胀率由20.00%上升至34.00%;直链淀粉和不溶性直链淀粉含量变化显著,直链淀粉含量由21.26%上升到25.3%,不溶性直链淀粉含量由9.96%上升到13.09%;RVA测定米粉糊化峰值黏度由299RVU降为97RVU,物性分析仪测量黏度由70.62下降到35.74,凝胶的弹性、硬度都有显著变化,硬度由60.414 g上升到117.783 g,弹性由0.88上升到0.91.试验结果表明,处理后稻米的直链淀粉含量与淀粉质构性和黏滞性的相关性达显著水平,同时不溶性直链淀粉的含量增加也影响稻米的品质特性.     

大米淀粉特性与米线品质关系的研究

文章分析了14个稻米品种的淀粉特性,探讨了大米淀粉特性与米线品质的关系,并分别建立了米线品质各指标与直链淀粉含量、淀粉的溶解度、膨胀力和老化特性之间的回归模型。结果表明:直链淀粉含量对米线品质影响最大;直链淀粉含量、淀粉的溶解度、膨胀力和老化特性4个因素对米线煮沸损失、复水时间、断条率和口感都有显著影响;而对加工效果影响显著的只有直链淀粉含量。     

稻米品质直链淀粉测定仪研制成功

《科技日报》讯，由中国农业大学组织实施的农业部“948”计划，稻米品质直链淀粉测定仪研制项目已经完成并取得了显著成果。稻米的直链淀粉含量越高，发色后样品液的颜色越深。稻米品质直链淀粉测定仪就是根据这一规律结合色度学原理研制的，该仪器利用的数字色度学检测法比传统分光光度法的检测速度快100倍以上。仪器由计算机、自动进样器、蠕动泵、直链淀粉模块、自动气液分离器、光纤双光束自动光电比色计等部分组成，检测1个样品只需2分钟，仪器带有显示、打印功能，检测精度达到国际先进水平。     

Validation and Applicability of Single Kernel-Based Cut Grain Dip Method for Amylose Determination in Rice

Amylose content (AC) is an important parameter responsible for the cooking quality of rice. Different methods with varied principles are being employed to determine the AC on the basis of their capacity of detection. Recently, our group successfully developed a simple and rapid method for AC determination termed as cut grain dip (CGD) method. In spite of the fact that this method is proved to be user friendly, thorough validation is required for its routine application across laboratories working on rice grain quality. To verify the accuracy of the CGD method, we compared this method with routine Juliano and two pure starch-based methods namely colourimetric and high-performance size-exclusion chromatography. A total of 16 rice varieties with varied amylose contents were used for the estimation of AC using the aforementioned methods. The results indicated that the CGD method showed high correlation (r) value of 0.987 (p < 0.01) with Juliano’s method. This method also showed significant correlation values of 0.849 (p < 0.01) and 0.869 (p < 0.01) with pure starch colourimetric and high-performance size-exclusion chromatography (HPSEC) methods, respectively. While the CGD method was able to discriminate the genotypes of all the three amylose classes, the pure starch-based colourimetric method could only discriminate high and low amylose genotypes and failed to detect the intermediate class. The findings of the present investigation indicate that the CGD method is not only rapid enough to screen large germplasm samples, but it also works with acceptable accuracy for its application in rice quality breeding.     

Study on gelatinization property and edible quality mechanism of rice

The different quality of rice in simulated cooking process was investigated by using SEM, FT‐IR, XRD, and DSC methods. The result shows that the starch granules of rice of low amylose content (AC) have more pores and cavities, which directly led to the swelling of rice starch granule. With the change in temperature, the changes in intensity and width of the IR bands showed that the variation in proportion area of crystalline to non‐crystalline was related to AC of rice. According to the interpretative sensitivity of the data obtained, XRD method was suggested adequate for characterizing the pasting property of different quality of rice. Besides, DSC method showed the AC was not relevant to pasting temperature and enthalpy.     

Rice straw paper incorporated with activated carbon as an ethylene scavenger in a paper‐making process

Rice straw contains cellulose as its main carbohydrate component, which is the major constituent for making rice straw paper as an alternative use of the residue. The objectives of this study were to determine a rice straw paper‐making process incorporating activated carbon (AC) and the effect of AC and the glucomannan (GLU) content on the physical and mechanical properties, including the ethylene adsorption capacity of rice straw paper containing AC. The results showed that AC was an effective ethylene scavenger, and it was possible to incorporate it into the rice straw paper‐making process. Increasing the AC content increased the ethylene adsorption capacity but decreased the strength of the AC‐rice straw paper. GLU maintained the strength of the rice straw paper but did not affect the ethylene adsorption capacity. Incorporation of 30% AC content with 0.3% GLU in the AC‐rice straw paper produced the maximum level of ethylene scavenging (77%). Moreover, AC‐rice straw paper is an environmentally friendly material owing to its reusability, and it has the potential for applications in food and agricultural packaging because it can act as an ethylene scavenger and also provide protection against mechanical damage.     

A review on rice bran protein: its properties and extraction methods

Rice bran protein has been found to be of high quality and of importance for food and pharmaceutical applications. It is a plant protein that can be derived from rice bran, an abundant and cheap agricultural byproduct. The protein content in rice bran is about 10-15% and it consists of 37% water-soluble, 31% salt-soluble, 2% alcohol-soluble, and 27% alkali-soluble storage proteins. Its unique property as being hypoallergenic and having anti-cancer activity makes it a superior cereal protein that may find a wide range of applications. There were already reports on the extraction of rice bran protein several decades ago. However, as of now, commercial rice bran protein is still unavailable in the market. This review is aimed at providing valuable discussions on rice bran protein, that is, storage protein, its various properties, and extraction methods for the development of an effective processing scheme. Also, an update on the current processing methods is also included.     

Chemometric Formulas Based on Physical Properties of Single-cooked Milled Rice Grains for Determination of Amylose and Protein Contents

ABSTRACT: Chemometric formulas for predicting amylose content (AC) and protein content (PC) were developed based on the surface and overall physical properties of single-cooked milled rice grains as predictive variables. The formula with 8 predictors for AC determination exhibited the highest accuracy (coefficient of determination: R²= 0.952, standard error of calibration: SEC = 1.77) for calibration and the lowest standard error of prediction (SEP = 2.07) for unknown samples (AC: 0 to 30%). The formula with 7 predictors was effective in enhancing the prediction accuracy (SEP = 1.32) among non-waxy samples in a narrow range of AC (15 to 20%). The formula with 8 predictors for PC determination showed a higher accuracy (R²= 0.449 and 0.470) for both calibration and prediction than that of a conventional 3-grain method (R²= 0.168 and 0.124). It was possible to accurately determine AC using physical measurement of single grains instead of chemical analysis.     

Advances in Nondestructive Methods for Meat Quality and Safety Monitoring

ABSTRACT

Meat is highly perishable and poses health threats when its quality and safety is unmonitored. Chemical methods of quality and safety determination are expensive, time-consuming and lack real-time monitoring applicability. Nondestructive techniques have been reported as antidotes to these constraints. This paper assessed the potential of nondestructive techniques such as near-infrared spectroscopy, hyperspectral imaging, multispectral imaging, e-nose, and their data fusion, all combined with algorithms for quality monitoring of pork, beef, and chicken, the most consumed meat sources in the world. These techniques combined with data processing applications may offer a panacea for real-time industrial meat quality and safety monitoring.     

市场选择与优质食用稻米分级评价标准

从国内外大米市场的稻米价格比较角度,明确食用品质是优质食用稻米品质评价的关键质量指标。分析了我国稻米类标准评价结果与育种、生产和消费对稻米品质选择的符合程度,认为需要通过统一食用品质标准样品、实施评价员资格管理等措施,改进食用品质评价的可操作性,使优质稻米品质评价符合育种和生产现状,满足市场需求。企业可制订食用特性和等级标识引导分类消费,增加市场竞争力。     

基于GC-MS的大米挥发组分研究进展

大米的挥发组分是其香气的主要来源,虽然含量占比极低,却是决定大米品质的重要因素之一。目前,大米香气的评价方法包括感官评价法、电子舌/鼻法、以及气相色谱-质谱法(GC-MS)法等,其中,GC-MS法应用最为广泛。本文综述了近年来基于GC-MS技术研究大米挥发组分的进展,包括主要的前处理方法,分析了各种前处理方法的优势和不足,以及GC-MS技术在大米品种鉴别、加工机制和储藏机制研究领域的应用现状。其中,准确测定大米挥发组分的含量及阈值,以及从动态角度对大米香气成分的相互作用和形成机理进行研究是未来的研究方向。     

稻米品质检测技术研究进展及展望

大米现已成为国人的第一大主食粮种。随着人们生活水平的不断提高,对大米的食用品质和安全性要求也越来越高,其在储藏、流通过程中的品质变化状况亦备受关注。因此做好稻米在储藏、加工、市场流通等环节的品质检测及品质变化的预测工作已显得尤为重要。综述了无损检测技术(近红外光谱分析技术、电子鼻技术、计算机视觉技术)、色谱分析技术、扫描电镜技术、质构分析技术等在稻米品质分析检测中的研究进展,提出了这些技术存在的问题,展望了这些技术的应用前景。其中,无损检测技术在稻米品质分析中的作用将更加突出,开发性能稳定、精确度高、操作方便、小型化的稻米分析检测系统,建立标准化的测量方法及分析方法,将会成为今后的发展趋势。随着粮食物流过程品控追溯技术的研究,稻米物流环节的品质变化也将受到关注。     

Research advance in gas detection of volatile organic compounds released in rice quality deterioration process

Rice quality deterioration will cause grievous waste of stored grain and various food safety problems. Gas detection of volatile organic compounds (VOCs) produced by deterioration is a nondestructive detection method to judge rice quality and alleviate rice spoilage. This review discussed the research advance of VOCs detection in terms of nondestructive detection methods of rice quality deterioration, applications of VOCs in grain detection, inspection of characteristic gas produced during rice spoilage, rice deterioration prevention and control, and detection of VOCs released by rice mildew and insect attack. According to the main causes of rice quality deterioration and major sources of VOCs with off-odor generated during rice storage, deterioration can be divided into mold and insect infection. The results of literature manifested that researches mainly focused on the infection of Aspergillus in the mildew process and the attack of certain pests in recent years, thus the research scope was limited. In this paper, the gas detection methods combined with the chemometrics to qualitatively analyze the VOCs, as well as the correlation with the number of colonies and insects were further studied based on the common dominant strains during rice mildew, that is, Aspergillus and Penicillium fungi, and the common pests during storage, that is, Sitophilus oryzae and Rhyzopertha dominica. Furthermore, this paper pointed out that the quantitative determination of characteristic VOCs, the numeration relationship between VOCs and the degree of mildew and insect infestation, the further expansion of detection range, and the application of degraded rice should be the spotlight of future research.