降落数值测定中不同修正水分对结果的影响

GB/T10361-89谷物降落数值测定法采用的水分修正基础为15%,而ICC107/1,1995和AACC 56-81B,1992则以14%为水分修正基础,探讨了对同一份样品采用两种不同的修正标准所测得降落数值的差值.研究显示这种差值会在6～48s之间变化.     

不同实验条件对测定小麦降落数值的影响

论述了不同实验条件对小麦降落数值测定的影响,以及影响测定值的主要原因。加水温度以及水质、样品称量、样品含水量对降落值的测定有影响,但样品的细度影响不大。     

降落数值测定中的若干注意事项

对谷物降落数值测定过程的样品制备、实验条件和操作过程等方面进行了分析,探讨了影响降落数值测定的各种误差来源,为确保检验结果的准确性提供了指导.     

影响降落数值测定的几个因素及其在粮油检验中的应用

降落数值是反映面粉中α-淀粉酶活性的重要指标,在测定降落数值的具体操作过程中有许多因素都会影响测定结果,如:样品的制备、试验用水、加热池、样品与水的混合过程、黏度管和搅拌器、冷却水流速等。在生产实践中,正确运用降落数值来评定小麦发芽损伤程度、搭配小麦开发专用粉、预测小麦陈化程度、分类储存小麦及按质定价收购小麦。     

萌动小麦在常规储藏过程中降落数值变化趋势研究

选用采自河北、河南、山东、安徽及新疆5个省区不同年度生产的9个小麦样品为材料,对萌动小麦常规储藏过程中降落数值的变化情况进行了系统研究。结果表明:小麦发芽后降落数值比未发芽时平均降幅达31%,芽麦粉α-淀粉酶的活性明显增强;在常规储藏过程中,控制萌动小麦的水分含量在13.5%以内,其降落数值基本保持稳定,α-淀粉酶活性受到抑制。     

小麦降落数值与品质质量及储存时间相关联系的探讨

对小麦降落数值测定原理、试样制备、仪器调试等操作过程和技术要领进行阐述;分析探讨降落数值与小麦品质质量、储存时间的相关联系;提出入库加强降落数值测定,掌握麦粒发芽受损程度,按质分类分仓储存;科学保粮、及时推陈储新;合理搭配,满足需求.     

真菌降落数值与烘焙效果的关系

对添加不同剂量α-淀粉酶的小麦粉样品进行降落数值(FN)、真菌降落数值(FFN)、糊化和烘焙面包的分析检验,通过分析实验数据的对应关系,确定烘焙效果较好时的真菌降落数值范围。从而在面包粉生产的重要环节———添加剂添加过程中,能利用真菌降落数值来控制α-淀粉酶的添加量,避免添加不足影响面包粉质量,也避免过量添加增加生产成本,造成浪费。实验表明:FFN值的范围在91~158 s时,烘焙效果较好,FFN值91 s时,综合烘焙效果达到最佳。     

Amylab型降落数值仪的技术创新

α-淀粉酶活性对面粉制品质量影响很大,降落数值的大小反映了α-淀粉酶活性的高低.针对传统Hagberg降落数值仪在冷却、加热及粘度管等方面的存在不足,Amylab型降落数值仪对传统降落数值仪进行技术改进,并新增一种快速检测方法,使得降落数值的检测更加快速、准确、简便、安全.     

食品检验中称样量与检验结果的误差分析

通过在食品检验中的重量法和容量法和容量法中选取不同的称样量进行检验结果的相对偏差分析对比，讨论在食品检验中如何在标准规定的称样量范围内选取合适的称样量，以减小实际检验工作中检验结果的相对偏差。     

影响小麦粉灰分测定的因素综合性评价

根据国标GB5009.4—2016，研究评估标准应用于小麦粉灰分检测各影响因素对灰分含量变化的相对贡献，包括称样量、碳化时间、灰化时间、灰化温度。所有数据采用格鲁布斯检验法进行分析。分析结果显示，小麦粉灰分含量测定称样量推荐3 g范围内；控制碳化时间和过程非常重要，灰化温度和灰化时间分别为550 ℃和4 h；干基和湿基对于灰分含量平均值影响不显著。提出一种基于国标的小麦粉灰分含量分析方法。     

Factors influencing falling number in winter wheat

The Hagberg falling number (HFN) is one of the most important quality characteristics of wheat. Six winter wheat cultivars from three locations in Germany were analysed to assess the factors influencing the HFN. The cultivars and locations affected significantly the HFN of all the samples. The infection with Fusarium culmorum, determined in another cultivar, also led to an increase in HFN, which suggested that the HFN method is not adequate enough for the true determination of the alpha-amylase activity of fungus-infected, wheat flour. Furthermore, there was no clear correlation between HFN and thousand-kernel weight, starch content or pentosan content. The crude protein content was positively related to the HFN, while the total dietary fibre content depended on the cultivar and location.     

储粮扦样环节中扦样点数分析研究

为了监测粮仓中储藏小麦在分区后选取不同扦样点数时的质量指标状况,开展平房仓储粮分区分层扦样试验,确定扦样点数的选择及其布点方案,探索所扦取样品的代表性且能客观有效反映分区内储粮质量的可行性。方法:以平房仓中储藏小麦为研究对象,选取两个仓房中的3处区域作为平行实验单元,按标准进行分层分区后,依次选取3~9个扦样点数分别扦样,并对其容重和水分进行测定,采用SPSS进行单因素方差分析,依据不同扦样点数之间的质量指标差异,探讨储粮扦样时的扦样点数设置。 结果 小麦质量指标变化波动状况与扦样点数之间无明显联系;当选取的扦样点数不少于5个时,检测结果之间均无显著性差异;当选取扦样点数为5个时,能较好反映该分区内的小麦容重状况;选取扦样点数为5~8个时,能较好反映该分区内的小麦水分状况。结论 试验数据统计分析结果证明了每个分区选取 5 个扦样点（中心1个、四角各1个）,这样既可减少了样本量,又能扦取有代表性的样品,能合理有效反映该区域内小麦的质量状况。     

葡萄糖溶液板式外流降膜蒸发布液装置实验研究

以葡萄糖溶液为实验介质，比较了筛盘式布液装置和均流板式布液装置的布液性能，讨论了影响布液性能的主要因素。实验结果表明，均流板式布液装置优于筛盘式，其布液均匀，成膜稳定，适应性强。     

Nitrogen fertilizer and seed rate effects on Hagberg falling number of hybrid wheats and their parents are associated with α‐amylase activity,grain cavity size and dormancy

Field experiments were carried out to assess the effects of nitrogen fertilization and seed rate on the Hagberg falling number (HFN) of commercial wheat hybrids and their parents. Applying nitrogen (200 kg N ha^?1) increased HFN in two successive years. The HFN of the hybrid Hyno Esta was lower than either of its parents (Estica and Audace), particularly when nitrogen was not applied. Treatment effects on HFN were negatively associated with α‐amylase activity. Phadebas grain blotting suggested two populations of grains with different types of α‐amylase activity: Estica appeared to have a high proportion of grains with low levels of late maturity endosperm α‐amylase activity (LMEA); Audace had a few grains showing high levels of germination amylase; and the hybrid, Hyno Esta, combined the sources from both parents to show heterosis for α‐amylase activity. Applying nitrogen reduced both apparent LMEA and germination amylase. The effects on LMEA were associated with the size and disruption of the grain cavity, which was greater in Hyno Esta and Estica and in zero‐nitrogen treatments. External grain morphology failed to explain much of the variation in LMEA and cavity size, but there was a close negative correlation between cavity size and protein content. Applying nitrogen increased post‐harvest dormancy of the grain. Dormancy was greatest in Estica and least in Audace. It is proposed that effects of seed rate, genotype and nitrogen fertilizer on HFN are mediated through factors affecting the size and disruption of the grain cavity and therefore LMEA, and through factors affecting dormancy and therefore germination amylase. Copyright © 2004 Society of Chemical Industry     

The impact of cold temperatures during grain maturation on selected quality parameters of wheat

The influence of sudden cold spells during grain filling of wheat on the quality traits of three South African hard red wheat cultivars (Gariep, Elands and Tugela‐DN) was studied, with the emphasis on Hagberg falling number (HFN). Four treatments were used (?1 °C at soft dough stage, ? 1 °C at late milk stage, ? 4 °C at soft dough stage and ? 4 °C at late milk stage) and were administered for one night only. From the results it was concluded that, although limited in duration, such frost conditions did have an effect on the quality of the wheat cultivars. Cultivars differed in their response to the various treatments but also as to what quality traits were affected the most. The ? 4 °C at late milk stage resulted in significantly reduced HFN being measured for both Elands and Tugela‐DN. A similar effect was observed for Gariep, but was not statistically significant. Although the response was limited to the main tillers only, the conclusion was made that it is probable that the reduced HFN would be visible in the pooled sample of head and side tillers. A screening protocol was suggested that would allow classification of cultivars for frost tolerance. Copyright © 2007 Society of Chemical Industry     

微波辐照对发芽小麦理化特性影响的初步研究

在实验室条件下研究了微波辐照对不同品种、不同发芽时间的小麦样品其理化特性的影响.结果表明,随发芽时间延长,小麦及小麦粉的降落数值减小,表征小麦粉糊化及黏度特性的指标(面糊峰值黏度、峰值温度、崩解值、回生值)降低,面团的耐搅拌特性弱化,稳定时间缩短.微波辐照改善发芽小麦品质的作用非常明显,尤其对发芽时间短的小麦样品,可以显著增加其降落数值和峰值黏度,增强面团的搅拌稳定性.研究结果初步证实了微波辐照改善发芽小麦品质的可行性.     

通风过程中进风相对湿度对仓储粮堆温度和水分的影响研究

温度和水分含量是两个重要的物理变量,在研究谷物储存时品质变化起到很大作用。通风用于冷却粮堆并保持温度恒定,以防止水分迁移。良好的通风条件对粮仓内存储安全有显著影响。目前,通风空气相对湿度对粮堆水分影响的研究相对较少。采用数值模拟和实验研究相结合的方式,探索和比较因不同进风相对湿度而引起的通风过程中仓储的小麦温度和水分变化规律。结果表明:进风相对湿度较低时冷却干燥效率更高,小麦粮堆降温更快速,并将昆虫和霉菌的活动保持在较低水平。     

木棉花落花加工利用的研究

对木棉花落花进行干燥工艺试验,并以木棉花干花为原料进一步探讨花汁饮料的加工工艺。试验结果表明:木棉花落花后适宜干制加工的时间为16h之内,以3.0%的柠檬酸溶液护色20min、70℃恒温干燥可获得较好的干燥效果。干燥后的干花采用80～100℃热水3次提汁。花汁饮料的原料配方组成为1%干花、11%白糖、0.2%柠檬酸和1%蜂蜜。固酸比控制在50∶1～60∶1,制成的花汁饮料品质较好。