方便蕨菜加工中几种前处理对矿质元素、氨基酸保存率的影响

以野生蕨菜为原料，采用自然脱水与盐腌脱水和烫漂与不烫漂等前处理进行方便蕨菜加工的对比试验，研究其对矿质元素、氨基酸保存率的影响。结果以不烫漂的自然脱水处理保存率较高。     

不同工艺条件对肌肉蛋白质氨基酸的影响

测定在不同工艺条件下加工的肉制品中粗蛋白质和17种氨基酸的含量。结果表明加工温度和加热时间对肌肉蛋白质和氨基酸含量有显著性的影响(P<0.05);在原料肉预处理时,腌液的 pH 值对蛋白质和氨基酸含量无显著性影响(P>0.05);腌液中的硝盐对氨基酸含量有显著性的影响(P<0.05)。     

不同蛋白源日粮对绵羊瘤胃氨基酸和肽释放影响的研究

选择 3只绵羊 ,采用 3× 3拉丁方设计研究不同蛋白源 (豆粕、鱼粉 ,玉米蛋白粉 )日粮对绵羊瘤胃肽和氨基酸释放影响 ,结果表明 :采食后 1h是氨基酸和肽释放的高峰。各处理组瘤胃内游离氨基酸组成 (采食后 6h内的平均值 )与饲料蛋白源蛋白质氨基酸组成相比 ,组氨酸 ,半胱氨酸 ,丙氨酸具有增加的趋势。鱼粉组、玉米蛋白粉组的肽氨基酸氮平均释放量 (采食后 6h内平均数据 )高于豆粕组 ,分别为 11.7mg氮 L ,9.0 1mg氮 L ,1.80mg氮 L。各处理组释放肽的氨基酸残基组成有一定的相似性 ,各组含量相对比例较高的有天冬氨酸 ,谷氨酸 ,酪氨酸和组氨酸     

化肥与盐土盐分对土壤溶质势影响的比较研究

化肥与盐土盐分以０．０５％与１．００％浓度施入土壤,使同一浓度的溶质势相近;而１．００％浓度比０．０５％浓度的溶质势可增高约３倍。表明化肥与盐土主要含盐成分的化学性质虽有不同,但对溶质势的影响一致。在化肥采用全层施、穴施、底施、表施等不同施肥方法时,溶质势有差异,结果为全层施〉穴施〉底施〉表施,似可说明全层施在土壤中分布均匀,溶质势增强快,化肥穴施时,愈近施肥点则溶质势愈高,影响范围可及１５～２０     

几种有机酸和氨基酸对乙醇酸氧化酶活性的影响

本文研究苹果酸、甘油酸、丝氨酸、谷氨酸对菜心(Brassica parachinensis Bailey)叶片乙醇酸氧化酶活性的影响。结果表明,苹果酸、丝氨酸和谷氨酸均对乙醇酸氧化酶起竞争性抑制作用,其中以苹果酸和丝氨酸的抑制作用较强而谷氨酸的抑制作用较弱;测定菜心乙醇酸氧化酶对乙醇酸的Km值为0.36m mol/L,丝氨酸、苹果酸、谷氨酸对乙醇酸氧化酶的Ki值分别为5.5,7.0,13.5m mol/L,甘油酸对乙醇酸氧化酶活性没有明显的影响,讨论了上述几种有机酸和氨基酸在乙醇酸途径代谢调节中的作用。     

灌注和日粮添喂挥发性脂肪酸及其盐类对山羊瘤胃代谢及自由采食量的影响

用装有永久性瘤胃痿管的5头小型土种山羊和3头奶山羊(均为干乳期,空怀),通过瘤胃灌注和日粮添喂挥发性脂肪酸(VFA)及其盐类,观察了VFA对瘤胃代谢及自由采食量的影响。第一系列试验研究瘤胃灌注高浓度VFA及其盐类对采食量的影响。在精料 青干草和青草二种日粮时瘤胃灌注丙酸使青干草和青草采食量分别下降61.81％和61.92％;而在青草日粮时瘤胃灌注丙酸钠、丙酸、乙酸钠、乙酸使青草采食量分别下降30.40％,57.28％、37.73％和45.56％,第二系列试验研究瘤胃灌注生理剂量VFA盐类,可改变瘤胃发酵类型,并促进采食。土种山羊瘤胃灌注丙酸钠、乙酸钠、混合酸钠、乙酸铵溶液时,青干草采食量分别增加22.86％、23.33％、28.57％和17.97％;奶山羊瘤胃灌注丙酸钠、乙酸钠、乙酸铵溶液时,稻草采食量分别增加41.67％,28.68％和38.78％;灌注丙酸钠期采食量一般高于灌注乙酸钠期采食量,粗饲料采食动态与C_2/C_3动态基本上呈负相关趋势变化,说明发酵类型对采食有一定影响。第三系列试验研究在精料 青草日粮中添加乙酸钠和乙酸铵,可使瘤胃发酵类型改变。添喂乙酸钠时青草采食量增加5.05％,添喂乙酸铵时青草采食量降低20.33％。     

有机酸对鲜猪肉的保鲜作用研究

将鲜猪肉用１％过氧乙酸表面杀菌后，浸入２％焦磷酸钠、３％柠檬酸、２％抗坏血酸和３％葡萄糖保鲜液中３０－６０ｓ，在常温下（２０－２５℃）可保存４－５天。本文还对有机酸的保鲜机制作了探讨。     

ON THE X-RAY DIFFRACTION EFFECTS FROM SOLID FATTY ACIDS

Powder reflections, as well as single face reflections of large spacing, have been obtained from palmitic and other fatty acids. Single specimens with all the optical properties of a crystal and giving the same large spacing X-ray reflections as solidified films on glass have been grown from solution of palmitic acid in acetone. This acid, at least, therefore appears to be truly crystalline under these conditions and not in a "smectic" or other sub-crystalline state. Since the X-ray data from this acid are strictly analogous to those from other typical "smectic" substances, it seems necessary further to conclude that no definite X-ray evidence yet exists for this "smectic" state. The symmetry of palmitic acid is either monoclinic or triclinic and the long carbon chains are not normal to the face producing the large spacing reflections. Such spacings are therefore not direct measures of the lengths of these chains. By growing single plates of the acid from solution more intense reflections from the long spacings have been obtained than from films made by solidifying the acid on glass or mica. Such single crystals may prove especially useful as gratings in long wave length X-ray spectrography.     

ON THE "RAWNESS" OF SUBSOILS

1. Suboils of arid regions are certainly no less "raw" than those of semi-arid regions, and probably only slightly less so than those of humid regions. 2. If, as seems as yet unproved, inoculated legume seeds fail to develop on humid subsoil material, such failure can not justifiably be attributed as is done by Alway, McDole and Rost, to a lack of available phosphoric acid and potash. 3. A lack of available nitrogen probably is sufficient to account for rawness of subsoils. 4. The poor aeration of subsoils which indirectly results in their rawness, may be accounted for more simply than by Hilgard's explanation of the washing down of fine particles into the subsoil, which prevents proper aeration.