鱼糜在挤压过程中流变特性的初探

文章研究了鱼糜在挤压过程中的流变特性，建立了在不同压力下的流变模型，并分析了鱼糜表观粘度随压力而变化的原因     

花生籽仁中蔗糖含量近红外预测群体模型的建立及在突变体筛选中的应用

籽仁蔗糖含量是影响花生食味品质的重要因素。为了建立花生籽仁中蔗糖含量的高效检测技术,本研究采集了149份花生籽仁的近红外光谱,结合化学法测定籽仁蔗糖含量,采用偏最小二乘法 (PLS) 构建花生籽仁蔗糖含量近红外预测群体模型。结果显示,预测模型的决定系数(R²)为0.898,校正标准偏差(SEC)为0.253,20份外部验证材料的预测值和化学值的R²为0.873,预测模型具有较高的可信度,运用该模型筛选徐花17号诱变群体,从1 965份M₂单株籽仁中获得4份的突变体。本研究为优质食味花生种质资源的筛选和品种选育奠定了基础。     

花生机械收获中根、茎、果节点的力学试验与分析（英）

为了降低花生挖掘收获、摘果、脱壳作业,特别是花生联合收获中的掉果率、破碎率,该文利用CTM-4503型万能材料试验机及相关测试设备,对花生收获期前后近一个月(28 d)花生的秸秆、根茎节点、果根节点、果壳结合处分别做了拉伸与剪切力学性能试验与分析.通过试验,得到了花生的秸秆、根茎节点、果根节点、果壳结合处最大许用抗拉与抗剪应力;经力学性能理论分析,确定了花生最佳收获期(以鲁花14为例,最佳收获期为播种后的(122±1) d),给出了现行的花生联合收获采用的夹持收获中最大许用夹持力(49.71 N)和最大许用拉力(70.84 N);通过试验分析得出花生挖掘收获中主要机械损失为根茎节点断裂(95.7%),并根据农业部发布的花生收获机作业质量行业标准所给出的作业质量指标,给出了在花生挖掘收获时的最大拉力(9.51 N);通过花生果结合处的剪切试验,给出了不同时期花生果结合处最大抗剪强度.这为花生收获、摘果、脱壳装置,特别是联合收获装置的研制与优化设计提供了参考.     

土壤Cr(VI)在非线性Langmuir吸附条件下的径流流失试验与模拟

针对重金属铬(Cr)污染严重的现象,基于简单的二层非完全混合模型,将降雨时农田土壤与积水整个系统分为混合区及混合区以下两个部分,根据水量平衡原理和溶质质量守恒定律,研究土壤在非线性Langmuir吸附条件下,吸附性溶质Cr(VI)的径流流失规律。试验模拟的田间地表径流是由降雨引起的,根据降雨期间土壤与雨水相互作用情况,将降雨过程分为4个阶段分别求解进行研究。利用室内模拟降雨-径流试验所得数据进行模拟计算,并通过敏感性分析和模型参数对径流流失量的影响分析,阐明模型参数对土壤中吸附性溶质径流流失规律的影响。研究结果表明:此二层非完全混合模型能预测土壤在非线性Langmuir吸附条件下,吸附性溶质Cr(VI)的径流流失规律。该模型对入渗水溶质与土壤混合层溶质之间的非完全混合系数γ非常敏感,对土壤混合层溶质与地表积水-径流水溶质之间的非完全混合系数α不敏感,对Langmuir吸附方程中的参数B、C也不敏感。其中γ和α对模拟径流流失过程的影响主要作用于降雨前期,而Langmuir吸附方程中的参数B对模拟过程的影响作用于降雨前期,C也主要作用于降雨前期,但对后期的影响比其他参数更大。试验数据显示地表径流中溶质含量很低,说明该次试验中混合层溶质进入地表积水-径流层量很少,而模拟α值很小,与实际情况吻合,同时也说明,土壤中流失的污染物重金属Cr(VI)大多存在于地下排水中。     

岷江上游辽东栎与川榛在模拟降雨过程中蒸散特征研究

采用密封瓶称重的方法分圳在2006年6月下旬和8月下旬对灌从地的辽东栎和川榛两优势种进行了室内枝叶蒸腾模拟实验,分析了解岷江上游次生落叶阔叶灌丛存降雨过程中蒸散量,以了解这些次生灌从水文生态效益及涵养水源的能力.结果表明:6月辽东栎和川榛枝叶平均蒸腾速率均高于8月枝叶蒸腾速率,分别是8月的1.6倍和1.5倍.两个物种枝叶蒸腾速率均随枝叶含水率的增加而减小,但是辽东栎枝叶蒸腾速率小于相同含水率条件下的川榛的蒸腾速率.两物种枝叶蒸腾速率均与枝叶含水率呈幂函数趋势.枝叶蒸腾速率与周围环境因素和枝叶生物量等特征密切相关,枝叶蒸腾速率随风速的增大而增加;此外叶片数、叶面积、枝条粗细、长短均对枝叶蒸腾速率具有显著影响.     

堆肥过程中水溶性有机物的SUVA_(254)、SUVA_(280)值的变化及其与腐熟度进程的关系

在有机肥堆制过程中找到一个简单、灵活、准确和易于接受的判定腐熟程度的标准是研究者一直追寻的目标。本研究以鸡粪和稻壳作为原材料堆肥,研究堆腐过程中堆肥水溶性有机物(DOM)的SUVA_(254)和SUVA_(280)紫外光谱特征值的变化,对比传统的几种判定堆肥腐熟度的方法,对SUVA_(254)和SUVA_(280)值与堆肥腐熟度关系进行了量化研究。结果表明,按堆制过程中C/N判断,SUVA_(254)和SUVA_(280)的值分别为0.247和0.180时堆肥达到腐熟;按种子发芽指数(GI)判断,SUVA_(254)和SUVA_(280)值分别为0.192和0.153时堆肥基本腐熟,SUVA_(254)和SUVA_(280)值分别为0.247和0.180时堆肥完全腐熟。本研究结果可为判断堆肥腐熟度提供一个较为简便快捷的方法和新思路。     

冷榨工艺对芝麻油和芝麻饼品质的影响

为比较芝麻不同压榨工艺对芝麻油和芝麻饼品质的影响,分别以带皮和脱皮白芝麻为原料,采用液压榨油机进行冷榨,对所得芝麻油和芝麻饼进行品质分析,并与热榨芝麻油、芝麻饼以及芝麻油国家标准进行对比。结果表明：冷榨芝麻油的色泽、酸价、过氧化值等质量指标都明显优于热榨芝麻油和芝麻香油国家标准;脱皮冷榨芝麻油较整籽冷榨芝麻油的酸价降低,但过氧化值有所升高;冷榨芝麻油较热榨芝麻油的VE含量、芝麻酚含量明显降低,芝麻素含量有所升高,氧化诱导时间明显缩短;脱皮冷榨芝麻油较整籽冷榨芝麻油的生育酚含量降低,芝麻素和芝麻酚含量有所升高,氧化诱导时间稍有延长。脱皮冷榨芝麻饼粗脂肪含量16.63%、粗蛋白含量54.09%、蛋白质溶解度NSI为23.50%。芝麻冷榨不仅可以得到色浅清亮的清香芝麻油,还可以得到蛋白质含量高且功能性好的食用芝麻蛋白。     

Establishment of sesame germplasm core collection in China

A sesame core collection containing 453 accessions was established by assessing genetic diversity of 4251 accessions collected in China. The accessions in the whole collection were grouped based on their origin, varietal and agro-ecological type. A computer program was used to cluster the data of 14 traits from the random small sample. Ward's method was chosen as the desirable method for clustering sesame germplasm resources. A set of technical methods for establishing core collection has been developed through determining the number of selected accessions based on the diversity distribution. The agronomic traits of the pre-selected core collection were investigated and tested in three ecological locations in China for two years. Among six qualitative traits, including plant type and flower color in a total of 5304 accessions, 97.85% was completely the same as the original data, and three quantitative traits, including growth period and plant height, were significantly and positively related with the original data. The representativeness assessment of the final core collection indicated that 35 phenotypes of 10 qualitative traits in the core collection were basically similar to those of the pre-selected core collection. Six feature values such as mean, standard deviation etc. of four quantitative traits including oil content and 1000-seed weight were close to those of the pre-selected core collection. The final core collection possessed a fair representativeness of the pre-selected core collection.     

不同压榨工艺对芝麻油和芝麻饼品质的影响

为比较芝麻不同压榨工艺对芝麻油和芝麻饼品质的影响,分别以整籽带皮白芝麻和整籽脱皮白芝麻为原料,采用液压榨油机进行冷榨,对所得芝麻油和芝麻饼进行品质分析,并与热榨芝麻油、芝麻饼以及芝麻油国家标准进行对比.结果表明:冷榨芝麻油的色泽、酸价、过氧化值等质量指标都明显优于热榨芝麻油和芝麻香油国家标准;脱皮冷榨芝麻油较整籽冷榨芝...     

筒状固定床花生通风干燥性能指标模拟与分析

为了解筒状固定床花生干燥机理、作业性能,确定合理的结构和通风参数,根据干燥过程花生荚果和介质空气间的热质传递关系,以PDE模型为理论基础,建立了适用于筒状固定床花生通风干燥计算机模拟的离散模型,该模型可计算花生干燥实时状态及批次干燥耗时、不均匀度、生产率、单位质量能耗等干燥指标。经试验验证,模型模拟结果与试验结果基本相符,料层花生平均含水率和温度模拟值和试验值的相关系数r>0.975,模型模拟可用于筒状床花生干燥过程分析。在此基础上,分析了单位面积通风量、筒状固定床外径、内径变化对上述指标的影响。结果表明:受介质空气温度降低和相对湿度增加影响,内层物料干燥起始时间和干燥速率存在一定的滞后性,但单位面积通风量沿通风方向逐渐增大的特性对内层物料的干燥滞后有较好改善;随着单位面积通风量增加,干燥不均匀度明显降低,生产率亦有显著提高,但单位质量能耗增幅较大;筒状床外径增加或内径减小都可增加生产率,降低单位质量干燥能耗,但干燥不均匀问题很难解决。为进一步确定最优的结构和通风参数,采用均匀设计模拟试验和综合加权评分法,得出筒状固定床外径2.75 m,内径0.935 m,外进风面单位面积通风量0.36 m^3/(m^2·s)时干燥效果最优,此时干燥时耗39.2 h、生产率86.55 kg/h、单位质量能耗5.87×10~6 J/kg、干燥不均匀度1.54%。该研究可为筒状固定床干燥设备设计优化提供技术支撑。     

芝麻叶中总黄酮的最佳提取工艺研究

该文测定了芝麻叶中总黄酮的含量，并对芝麻叶黄酮的提取工艺进行了研究。重点探讨了采用乙醇提取法和微波处理与乙醇提取相结合的方法提取芝麻叶黄酮类化合物的最佳工艺条件。试验结果表明：芝麻叶中总黄酮的含量为0.98%；乙醇提取法的最适工艺参数是浸提剂乙醇浓度为80%、浸提温度为80℃、料液比为1∶25、浸提时间为2.5 h，如此条件可使黄酮提取率达95.6%；微波处理与乙醇提取相结合的方法的最适工艺参数是微波功率200 W、微波处理时间70s，乙醇浓度为80%、浸提温度为80℃、料液比为1∶25、浸提时间为30 min，这种工艺可使黄酮提取率达95.8%。     

花生种子颗粒离散元仿真参数标定与试验

由于花生排种装置在优化设计过程中缺乏准确的仿真模型参数,从而造成仿真与理论计算结果存在较大误差,一定程度上制约了花生排种装置的发展。该研究系统测定了花生种子的三轴尺寸、颗粒密度、弹性模量、泊松比等本征参数及其静摩擦因数、滚动摩擦因数、恢复系数。通过开展花生种子颗粒堆积试验,标定得到花生种间静摩擦因数为0.213,种间滚动摩擦因数为0.035。为检验标定参数的可靠性,开展了花生堆积角仿真与物理试验对比,结果表明花生物理堆积角和仿真堆积角相对误差为0.22%。通过开展机械式花生精量排种器的仿真与台架排种性能的对比试验,得到排种性能中漏播指数、重播指数相对误差分别为8.24%、5.12%,结果表明花生标定参数具有可靠性。该研究结果可为排种装置的优化设计与仿真研究提供理论参考。     

分步酶解制备花生短肽的研究

为了高效制备花生短肽,在花生蛋白Alcalase酶水解的研究基础上,进一步采用N120P酶水解花生蛋白并对各种影响因素进行了系统地研究;建立了短肽得率与各种影响因素的回归模型;确定出了N120P继续酶解花生蛋白Alcalase酶解物制备花生短肽的最佳工艺参数为pH值6.0,水解时间65 min,水解温度57℃,酶与底物比2061 U/g,。在此条件作用下,体系中短肽得率为89.01%,比Alcalase 单独酶解提高10.86个百分点;水解度为23.76%,平均肽链长度为4.21。经高效液相色谱测定,大部分水解产物的相对分子质量小于1000。     

Evaluation of water schemes for peanut,using CSM-CROPGRO-Peanut model

Drought stress is an important factor limiting the yield potential of peanut. In order to determine the effect of different irrigation scenarios on peanut production, field experiments were conducted in 2011 and 2012 growing seasons using factorial design with three replicates. On the other hand, the crop simulation models can be useful to predict crop yields and to investigate the impact of drought stress on plant growth and development. In this study, the Cropping System Model–Crop Growth (CSM-CROPGRO)-Peanut model was employed for the simulation of seed yield, pod yield, biomass, soil water balance components and water productivity for peanut in Astaneh-Ashrafiyeh, Iran. Results showed that the model was able to reasonably simulate seed yield, pod yield and final biomass for different irrigation scenarios (RMSEn < 20%, R² > 0.8 and d > 0.8). According to the results, irrigation depth and interval were important factors affecting yield and biomass. In general, model error increased as the amount of water applied decreased. The least amount of water applied (40 mm) resulted in yield reductions by 76%, 70% and 67% of the greatest amount of water applied (480 mm) for seed yield, pod yield and final biomass, respectively. For each irrigation interval, larger irrigation depth led to lower water productivity (WP) of irrigation (WP_I), but higher WP based on evapotranspiration (WP_ET) and transpiration (WP_T).The average amounts of WP_I, WP_ET, WP_T based on seed yield were 1.2, 0.63 and 1.01 kg m^?3, respectively.     

Diversity in Indian sesame collection and stratification of germplasm accessions in different diversity groups

Sesame (Sesamum indicum L.) is one of the ancient oil crops, grown in India since over 5,000 years ago. Diversity in the Indian sesame collection (3,129 accessions), representing all eco-geographical regions, for a range of morphological and agronomic characters was studied. Wide variation in plant habit (plant height and branching pattern), pubescence of various plant parts (stem, leaf, corolla and capsule), flower colour and number of flowers per leaf axil, capsule characteristics (shape, size, number in the axil of a leaf and number of locules in a capsule), number of capsules per plant, number of seeds per capsule, mean seed weight, and yield per plant was recorded. A detailed multivariate analysis was performed on a set of 100 selected accessions representing different agro-ecological zones. The accessions were classified into 7 discrete clusters. The principal components analysis described the spatial relationship among the entities and confirmed groupings obtained through clustering. Based on the clustering pattern of 100 accessions, the entire collection was allocated to different clusters. Representation of various zones in 7 clusters gives us the opportunity to form distinct diversity groups making combined use of passport and characterisation data. These diversity groups would subsequently be used for sampling the accessions for building up a core collection of sesame, a project already operative at the NBPGR.     

芝麻种子中内源性蛋白酶的热稳定性及其运用

近年来,芝麻的深加工偏重于制油,而忽略了对芝麻蛋白的高值利用。为了实现芝麻蛋白与油脂的高值综合利用,该研究将湿法脱皮芝麻进行干燥,经压榨制取芝麻油和压榨粕后,再利用内源性蛋白酶对芝麻压榨粕中的蛋白质进行水解,制取蛋白水解物。在此过程中,考察了干燥温度对湿法脱皮芝麻压榨出油率和内源性蛋白酶活性的影响。结果显示,在80～180 ℃干燥1 h时,脱皮芝麻出油率上升至88.55%～90.98%（带皮芝麻为81.76%）;对于内源性蛋白酶而言,在130 ℃时,仍可保留约57%的活性,表明芝麻种子中内源性蛋白酶具有良好的热稳定性。同时,通过将低变性芝麻粕（干燥条件为50 ℃、4 h）制浆,在pH 值为4.5、50 ℃下孵育6 h,经3 000 g离心5 min后,分离得到透明清液（蛋白水解物）,其清液中蛋白质的分布率为66%,且主要由38%小肽（< 1500 Da）和37%游离氨基酸组成,除此之外,还存在多种生物活性物质。该研究为芝麻内源性蛋白酶的实际应用以及芝麻蛋白新产品的开发提供了一种新思路。