猪附红细胞体病继发猪瘟的诊断与治疗

根据临床症状和剖检变化,对病猪进行组织病理学和荧光抗体染色等实验室检查,并且做出诊断。     

常用食品改良剂对马铃薯米粉品质的影响

[目的]研究6种常用食品改良剂对马铃薯米粉品质的影响,为马铃薯米粉的加工应用提供参考依据.[方法]分别将0、0.02%、0.04%、0.06%和0.08%的焦磷酸钠、磷酸氢二钠、瓜尔豆胶和魔芋胶,以及0、2%、4%、6%和8%的绿豆淀粉和谷朊粉添加到马铃薯全粉含量为30%的米粉中,通过单因素试验,测定马铃薯米粉质构、蒸煮损失率和色差的变化.[结果]焦磷酸钠和磷酸氢二钠添加量分别为0.02%和0.08%时可显著提高马铃薯米粉硬度(P<0.05,下同),添加量分别为0.04%和0.06%时马铃薯米粉具有较高的拉伸特性,焦磷酸钠添加量为0.02%的马铃薯米粉蒸煮损失率低于10%;瓜尔豆胶和魔芋胶添加量为0.02%时可有效提高马铃薯米粉的硬度和拉伸性能、降低蒸煮损失率;绿豆淀粉添加量为2%时,马铃薯米粉的质构得到改善,蒸煮损失率低于4%,其添加量为4%时,马铃薯米粉的拉伸性能显著升高;谷朊粉添加量为2%时,马铃薯米粉的质构、拉伸特性及蒸煮性质均有显著改善.但6种食品改良剂在试验添加量范围内均对马铃薯米粉色泽无明显改善效果.[结论]在添加30%马铃薯全粉的条件下分别添加0.04%焦磷酸钠、0.06%磷酸氢二钠、0.02%瓜尔豆胶、0.02%魔芋胶、4%绿豆淀粉和2%谷朊粉,能够显著改善马铃薯米粉的质构和蒸煮特性,实际生产中可依此比例进行调配.     

直链淀粉含量与稻米品质主要性状及米饭质地关系的研究

以反义Wx基因的转化系及其受体亲本武运粳7号为材料,研究遗传背景相同仅直链淀粉含量不同的4个品系主要品质性状及米饭质地的变化。结果表明：直链淀粉含量不同的4个供试品系的主要品质性状指标与米饭质地指标之间有着明显的差异。直链淀粉含量的降低使得胶稠度变软,粗蛋白含量减少,过低的直链淀粉含量会导致米粒外观呈现蜡质。稻米RVA谱特征和米饭质地明显受到直链淀粉含量的控制,直链淀粉含量明显影响稻米糊化过程中黏度的变化,高直链淀粉品系具有较高的消减值、回复值、热浆黏度及最终黏度,米粉的回生性大,米粉难以糊化,其米饭质地过硬,咀嚼有渣感,无弹性;相反,低直链淀粉含量的品系具有较低的消减值、回复值、热浆黏度及最终黏度,冷却过程中米粉的回生性小,其米饭质地较黏,咀嚼无渣感,有弹性;直链淀粉含量与最高黏度值和崩解值间的关系并非是简单的线性关系,当直链淀粉含量较低时,随着直链淀粉含量的增加,最高黏度和崩解值随之升高,而当直链淀粉含量高于一定量时,直链淀粉的增加会降低最高黏度和崩解值。     

The Effect of Prior Frozen Storage (−20°C) on the Quality of Oven-Baked Sardines (Sardina pilchardus)

ABSTRACT

The effect of frozen storage for 3, 30, 60, 90, and 120 days on the quality of sardines baked for 15, 30, and 45 min was studied. The combination of frozen storage with the baking time in linear reduction of yield and moisture led to less juicy products, as well as significant changes in proteins and lipids. A linear increase of C16:0 followed by a linear reduction of C22:6ω-3 was detected due to frozen storage, indicating lipid oxidation. This was also confirmed by the C22:6ω-3/C16:0 and C20:5ω-3/ C16:0 ratios, which were reduced by 36.8 and 32.7%, respectively. The fatty acid profiles of sardine samples were not significantly altered due to oven-baking. A gradual reduction of eicosapentaenoic acid + docosahexaenoic acid (EPA + DHA) of the baked products was observed mainly due to frozen storage. Cholesterol and squalene content increased with increasing the time of baking. A gradual decrease of cholesterol and squalene was observed due to frozen storage.     

名优茶杀青叶冷冻存贮研究

对名优茶杀青叶进行冷冻存贮,研究其贮藏中主要生化成份、香气等的变化。结果表明:杀青叶在冻贮期间,其氨基酸总量、茶多酚含量的变化均达显著、极显著水平,与存贮的成品茶生化成份的变化基本一致,但其主要生化成份特别是茶多酚含量的变化滞后于成品茶,这说明杀青叶冻贮期间,其内部生化反应速度低于成品茶存贮。杀青叶冻贮6个月后,其香气成份的保留量高于成品茶26.86%,特别有利于香气成份的保存,这可能与杀青叶存贮中保存了大量的香气前体物有关。冷冻杀青叶的解冻等后加工过程对茶叶生化成份、香气等有较大影响,以微波方式快速解冻对茶叶品质最有利。     

Pins基因等位变异对磨粉品质和新疆拉面加工品质的影响

为了探讨新疆冬小麦品种Pins基因等位变异对小麦磨粉品质和新疆拉面加工品质的影响,对109份新疆冬小麦品种的籽粒硬度及其Pins基因等位变异、磨粉品质和新疆拉面加工品质进行测定,初步分析了新疆冬小麦品种资源籽粒硬度Pins基因的分布规律以及不同 Pins基因等位变异对籽粒硬度、磨粉品质和新疆拉面加工品质的影响。结果表明,新疆冬小麦品种属硬质麦类型,Pins基因型以 Pina-D1a、 Pinb-D1b和 Pina-D1a/ Pinb-D1b为主, Pins突变类型及Pins突变基因型组合类型小麦的籽粒硬度均显著高于野生型, Pinb-D1a基因型小麦的籽粒硬度最低,L^*值和a^*值最高,b^*值最低; Pinb-D1ab基因型小麦的吸水率最高。不同Pins基因型组合中,野生型小麦的籽粒硬度、b^*值和吸水率最低; Pina-D1a/ Pinb-D1aa的出粉率最高, Pina-D1a/ Pinb-D1ab的灰分含量最低,吸水率最高。Pins基因及其基因型组合对新疆拉面加工品质无直接影响,主要通过对灰分、面粉色泽和吸水率等磨粉品质的作用对新疆拉面产生间接影响。优质新疆拉面品种中,Pinb基因突变对新疆拉面加工品质的影响大于Pina基因突变,育种中应优先选择Pinb 基因突变型材料,其中 Pina-D1a/ Pinb-D1b可以作为重点选择的基因型组合。     

氮肥施用对米粉专用稻产量、米质及加工特性的影响

目的 为了探明氮肥施用量对不同米粉稻品种的产量、稻米品质和加工特性的影响,【方法】2018-2019连续两年以筛选出的适宜作米粉专用稻的3个品种(R0734, R2149, 嘉早66)、生产上常用作米粉加工的品种（珍贵矮）以及加工米粉未能成型的品种（R0711）作为供试材料,设置90、140、190kg/hm²三个纯氮水平。结果 1）各品种产量随着施氮量的增加而增大,但2019年R0734和R2149品种在中氮条件140 kg/hm²下产量达最高;其中米粉专用稻R2149和嘉早66极具产量优势,两者分别在140和190 kg/hm²施氮水平下达到最高。氮肥施用使有效穗数增大,而千粒重减小。2）随着施氮量的增加,米粉稻直链淀粉含量显著降低,在21.4%~26.5%波动,胶稠度增长,蛋白质含量增大;最高黏度、热浆黏度和最低黏度有减小趋势,崩解值显著减小,消减值显著增大。3）随着施氮量的增加,米粉稻断条率和蒸煮损失率显著增大,但均在10%以下;品种R2149和嘉早66较R0734来说,虽然对氮肥更敏感,但加工特性较佳。结论 米粉专用稻应选择直链淀粉含量在21%~27%范围的品种,24%左右则最佳,这样在实际生产中直链淀粉含量受氮肥影响不至于严重偏离适宜加工的范围;又由于施氮量的增加使米粉稻加工特性变差,因此,米粉专用稻栽培过程中,需在保证丰产同时,结合生产实际施用相对较低的氮肥;在米粉专用稻选育上,应选择直链淀粉含量适中、加工特性更佳的骨干亲本作为中间材料,培育高产米粉专用稻。     

Impact of guar and xanthan gums on proofing and calorimetric parameters of frozen bread dough

The influence of guar and xanthan gum and their combined use on dough proofing rate and its calorimetric properties was investigated. Fusion enthalpy, which is related to the amount of frozen water, was influenced by frozen dough formulation and storage time; specifically gum addition reduced the fusion enthalpy in comparison to control formulation, 76.9 J/g for formulation with both gums and 81.2 J/g for control, at 28th day. Other calorimetric parameters, such as T_g and freezable water amount, were also influenced by frozen storage time. For all formulations, proofing rate of dough after freezing, frozen storage time and thawing, decreased in comparison to non-frozen dough, indicating that the freezing process itself was more detrimental to the proofing rate than storage time. For all formulations, the mean value of proofing rate was 2.97 ± 0.24 cm³ min⁻¹ per 100 g of non-frozen dough and 2.22 ± 0.12 cm³ min⁻¹ per 100 g of frozen dough. Also the proofing rate of non-frozen dough with xanthan gum decreased significantly in relation to dough without gums and dough with only guar gum. Optical microscopy analyses showed that the gas cell production after frozen storage period was reduced, which is in agreement with the proofing rate results.     

Allelic variation of polyphenol oxidase genes impacts on Chinese raw noodle color

Polyphenol oxidase (PPO) activity is a factor in time-dependent discoloration of Asian noodles. At least two major genes Ppo-A1 and Ppo-D1 control kernel PPO activity in wheat. The goal was to determine the relative importance of allelic variation for Ppo-A1 and Ppo-D1 on Chinese raw noodle color profile and kernel and flour characteristics using a winter wheat recombinant inbred population segregating for Ppo-A1 and Ppo-D1. Ppo-A1 allelic variation explained 80% and Ppo-D1 allelic variation explained 2% of the variation in kernel PPO activity. The low PPO allele at each locus gave noodles that were brighter (greater L*), more yellow (greater b*) and more red (greater a*) at 24 h, and noodles with less change in L* but more change in a* and b* with time (0-24 h). The two loci combined explained 27, 35, and 17% of variation in L*, a*, and b* at 24 h, and 51, 55, and 58% of the variation in change in L*, a*, and b* with time, respectively. Allelic variation at Ppo-D1 explained a larger percentage of variation than did Ppo-A1 in each case except b* at 24 h where the two loci explained equal amounts.     

冻藏对牦牛肉蛋白质、脂质氧化和保水性的影响

通过测定蛋白质氧化产物(α-氨基己二酸半醛、γ-谷氨酸半醛、α-氨基己二酸、希夫碱)以及脂质氧化产物(硫代巴比妥酸、己醛)的含量,研究不同部位牦牛肉(腰肌、股四头肌、背最长肌)在冷冻贮藏期间(-18℃,0~140 d)蛋白质、脂质氧化规律及其对保水性的影响。结果表明:血红素铁和超氧化物歧化酶在背最长肌冻藏阶段的脂质氧化进程中发挥着重要作用,较低的血红素铁含量以及较高的超氧化物歧化酶是背最长肌脂质氧化程度较低的主要原因。冻藏显著影响腰肌和股四头肌蛋白质的氧化,血红素铁与超氧化物歧化酶、过氧化氢酶共同调控氧化反应的发生:冻藏140 d后,血红素铁的促氧化作用使腰肌和股四头肌中的α-氨基己二酸半醛、γ-谷氨酸半醛含量均显著增加(P0.05),尽管腰肌中的血红素铁显著高于股四头肌(P0.05),但腰肌中相对较高的超氧化物歧化酶和过氧化氢酶使腰肌与股四头肌的α-氨基己二酸半醛、γ-谷氨酸半醛含量并无显著性差异;血红素铁含量更高的腰肌容易使其产生更多的α-氨基己二酸,但腰肌中相对较高的超氧化物歧化酶与过氧化氢酶协同作用使腰肌中的α-氨基己二酸含量极显著低于股四头肌(P0.05)。此外,冻藏引起的蛋白质羰基化反应显著影响牦牛肉的保水性,抗氧化酶活力最低、血红素铁含量相对较高的股四头肌保水性最差,其解冻汁液流失率是背最长肌的3.55倍。