Quality Characteristics of Wholemeal Flour and Bread from Durum Wheat (Triticum turgidum L subsp. durum Desf.) after Field Treatment with Plant Water Extracts

The use of selected plant water extracts to control pests and weeds is gaining growing attention in organic and sustainable agriculture, but the effects that such extracts may exert on the quality aspects of durum wheat are still unexplored. In 2014, 5 plant water extracts (Artemisia arborescens, Euphorbia characias, Rhus coriaria, Thymus vulgaris, Lantana camara) were prepared and distributed on durum wheat cv Valbelice to evaluate their potential herbicidal effects. After crop harvesting, the major physicochemical and technological parameters of wholemeal flours obtained from each treatment were measured and compared with those from chemical weeding and untreated controls. A baking test was also performed to evaluate the breadmaking quality. In wholemeal flours obtained after the treatment with plant extracts protein and dry gluten content were higher than in control and chemical weeding. Wholemeal flours obtained after chemical weeding reached the highest Mixograph parameters, and that from durum wheat treated with R. coriaria extract demonstrated a very high α‐amylase activity. We concluded that the treatments with plant water extracts may influence many quality traits of durum wheat. This occurrence must be taken into account in overall decisions concerning the use of plant extracts in pest and weed management practice.     

马铃薯全粉对比萨饼底加工工艺及品质的影响

研究马铃薯全粉对比萨面团流变学特性、发酵能力和比萨饼底质构特征、感官品质的影响。结果表明:马铃薯全粉能提高小麦粉的吸水率,缩短面团的形成时间,但会导致比萨面团的稳定时间缩短,弱化度增加;马铃薯全粉的添加量与面团的拉伸阻力、延伸度、最大拉伸比例和拉伸面积呈极显著负相关;马铃薯全粉能够提高面团的发酵能力和弹性,但会导致比萨饼底的硬度增加,感官品质略有下降,因此综合考虑确定马铃薯全粉的最佳添加量为15%;并进一步通过单因素和正交试验确定马铃薯比萨饼底的最佳原料配方为马铃薯全粉添加量15%、加水量60%、酵母添加量1.2%;在最佳原料配方的基础上确定马铃薯比萨的最佳工艺条件为醒发温度38℃、醒发湿度75%、醒发时间30 min、烘烤温度200℃、烘烤时间15 min,所得比萨的硬度为4 166.493 g,感官品质最佳。     

发酵型半干米粉加工工艺参数的研究

以大米粉蛋白质含量、米粉断条率、感官评分为指标,研究发酵温度、发酵时间、菌液添加量、磨粉粒度、加水量、糊化温度和糊化时间对发酵型半干米粉品质的影响,确定发酵型半干米粉的加工工艺参数为：发酵温度35 ℃、发酵时间18 h、菌液添加量4%、粒度120目、加水量60%、糊化温度95 ℃、糊化时间4 min。在此条件下,发酵大米粉的蛋白质质量分数为6.37%,发酵型半干米粉断条率为4.94%,感官评分为86.43。大米发酵后基本成分发生改变,蛋白质和脂肪含量下降,淀粉含量增加。糊化特性和热特性分析结果表明：大米发酵后最低粘度、最终黏度、回生值、糊化温度显著降低,说明发酵处理有利于大米粉的糊化,并能延缓米粉制品的老化。     

超声波酸浸法提取米糠中植酸钙的研究

以米糠为原料在超声波作用下用酸浸泡提取植酸钙，研究了酸的种类，浸提时间，溶液的pH值及液料比对提取效率的影响，并与无超声波作用的酸浸提取进行了比较。结果表明：所试三种酸的种类对植酸钙提取效果影响不大；与传统的酸浸法相比，用超声波酸浸法可将浸提时间从3h左右缩短至15min，酸浸所需的酸度也有所降低，且所得粗植酸钙产率和其含量均明显提高。     

木糖醇对小麦淀粉和复配面粉糊化性质及回生特性影响的研究

本文以小麦淀粉为原料,把谷朊粉按10%、12%、15%质量浓度添加到小麦淀粉中配成三种复配面粉,研究不同添加量木糖醇对小麦淀粉、复配面粉糊化性质和回生特性的影响。结果表明：添加木糖醇后,小麦淀粉糊化温度升高;峰值黏度随着木糖醇添加量的增加呈上升趋势;添加15%、20%、25%木糖醇时,小麦淀粉的衰减值、回生值增加。添加木糖醇后,复配面粉的峰值黏度、低谷黏度和最终黏度增加。随复配面粉中谷朊粉含量的增加,添加相同含量木糖醇的复配面粉的峰值黏度、低谷黏度、最终黏度呈下降趋势。在不同天数添加木糖醇的小麦淀粉硬度增加,且随添加浓度的增加,硬度呈上升趋势;而添加木糖醇的复配面粉硬度降低,且随添加浓度的增加,硬度呈下降趋势。     

多重PCR法检测转Bar、Bt基因双抗稻米

旨在建立一种快速、有效的检测转基因双抗稻米的方法,以转Bar、Bt基因双抗稻米为原料,针对其水稻内源基因SPS和外源基因(包括Bar基因、Bt基因、CaMV35S启动子、Ubiquitin启动子和NOS终止子)设计多重PCR检测体系。结果表明,应用该多重PCR检测体系可快速检测出原料中的全部6条目标基因,检测灵敏度可达0.9%。     

中性条件下大米蛋白的酶法增溶工艺研究

为改善大米蛋白(RP)溶解性,对中性条件下RP酶法增溶工艺进行研究。在对中性蛋白酶、碱性蛋白酶、酸性蛋白酶、菠萝蛋白酶和木瓜蛋白酶5种酶单因素实验基础上,研究RP的复合酶解。结果表明:单酶水解以中性蛋白酶效果最好,在底物质量分数20%、酶用量1%、酶解温度50℃、酶解时间4 h条件下,所得速溶大米蛋白(IRP)溶解度为79. 01%,水解度为6. 79%。复合酶解以中性蛋白酶和木瓜蛋白酶复配效果最好。综合考虑溶解度、水解度和功能性质等要求,RP适宜的酶解条件为:底物质量分数20%,中性蛋白酶和木瓜蛋白酶复合酶解,酶用量各0. 5%,酶解温度50℃,酶解时间4 h。复合酶解所得IRP具有较好的溶解度(63. 58%)、乳化活性(27. 60 m~2/g)和乳化稳定性(29. 61 min),在pH 5～8范围内具有良好的溶解性(溶解度54. 39%～68. 34%)。此外,IRP中游离氨基酸和肽含量显著增加,其营养价值明显改善,更易于消化吸收。研究表明,复合酶解是RP增溶改性的有效途径,所得IRP的溶解性、乳化性均有明显改善。     

不同地区黄酒挥发性物质差异性分析

比较不同地区黄酒中主要挥发性物质种类及其含量的差异,采用顶空固相微萃取和气相色谱-质谱联用技术对不同地区的12 个品牌黄酒的挥发性物质进行测定,并分别对黄酒中的挥发性物质进行主成分分析、对不同地区黄酒进行聚类分析。结果表明：从不同地区的12 种黄酒中共检测出142 种挥发性物质,其中酯类、醇类、醛类、酮类、酸类、酚类、烃类占挥发性物质总量的比例分别为33.04%、39.26%、24.64%、0.37%、0.63%、0.28%、1.36%,其中13 种物质为12 种黄酒所共有;通过主成分分析发现黄酒中对整体风味以及口感的形成影响较大的挥发性物质为异丁醇、苯乙酸乙酯、乳酸乙酯、乙酸乙酯、苯乙醇和糠醛;此外,通过聚类分析可将所研究的不同地区12 种黄酒分为3 类,各类黄酒的挥发性物质均有其显著特征,客观地反映了样品的真实信息。     

Effects of using eolic exhausters as a complement to conventional aeration on the quality of rice stored in metal silos

The aim of this study was to evaluate the effects of utilizing an eolic exhauster on reducing the qualitative losses of rice stored in silos. Paddy rice was stored for a nine-month period, in triplicate, in metal silos with a 550-ton capacity that were or were not equipped with an exhauster system and were analyzed every three months. To evaluate the effects of complementary eolic aeration, the energy consumed for aeration and the physical properties of the grain, as well as the thermal and pasting properties of rice, were analyzed. Using the exhauster system in the rice storage silo reduced the loss of dry matter, the energy required for aeration maintenance over a 9-month period, grain hardening, the development of grain staining defects and the darkening of the grain, while preserving the conclusion temperature of gelatinization and the enthalpy, the final viscosity and the head rice yield and not affecting the onset temperature or the peak temperature of gelatinization. Increasing the duration of storage reduced the aeration maintenance requirement, changed the cooking time, the hardness of the grains, the conclusion temperature and the enthalpy, the peak viscosity and final viscosity, the head rice yield, the development of grain staining and the darkening of rice grains, but with less intensity when the rice was stored in silos that used an exhauster system, without affecting the onset and peak temperatures of gelatinization.