汉麻籽在压缩干粮中的应用

分析汉麻籽的主要营养成分,包括必需脂肪酸和必需氨基酸组成,运用数学建模的方法,进行优化设计,得到汉麻籽蛋白和汉麻籽油脂在压缩干粮中应用的最佳营养配方,即汉麻籽蛋白质粉与小麦粉、全脂奶粉的优化比例为:15.6∶153∶10.8,汉麻籽油与棕榈油的优化比例为:38.2∶63.8,获得营养构成合理的汉麻籽压缩干粮。汉麻籽蛋白和汉麻籽油脂能提高压缩干粮的品质,经大鼠饲养实验验证表明,汉麻籽压缩干粮配方能明显促进大鼠生长,并且无毒副作用。     

硬段含量对水基聚氨酯性能的影响

以聚四氢呋喃醚二元醇(PTMG)作为软段、以异氟尔酮二异氰酸酯(IPDI)、1,4-丁二醇(1,4-BDO)作为硬段、以2,2-二羟甲基丙酸(DMPA)为亲水扩链剂,合成一系列硬段含量不同的水性聚氨酯,并研究了硬段含量对合成革用水性聚氨酯性能的影响。结果显示:在R(—NCO/—OH)值,DMPA含量不变的情况下,硬段含量在40%时,聚氨酯膜的拉伸强度、断裂伸长率、吸水率、玻璃化转变温度等综合性能优良,适合合成革的制造。     

不同打浆度胶原纤维形态及抄片性质

采用机械方法分离制革废弃物的胶原纤维,并对其进行打浆处理,对不同打浆度的胶原纤维形态和抄片性能进行了研究。实验表明:打浆度在80°SR以上时,胶原纤维才能较好地分散;采用扫描电子显微镜及粒径统计法测定不同打浆度下(80°SR、85°SR、92°SR)胶原纤维的直径,发现纤维直径多分布在0.1μm左右,且随着打浆度的提高,纤维粗细更加均匀;通过湿重法间接表示纤维长度,实验表明在85°SR时纤维长度达到最大,后逐渐降低;随着打浆度的提高,抄片紧度、抗张强度和撕裂强度均增加,92°SR抄片的抗张和撕裂强度可分别达到14.60N.m.g-1、5.553N.mm-1;但抄片透气性及透水汽性降低。     

水解胶原蛋白的溶解性和乳化性研究

采用复合酶从皮边角余料中提取得到分子量分布在 4.2× 10 4 ～ 8.5× 10 4 的水解胶原蛋白样品 ,对其溶解性和乳化性进行了系统研究。结果发现 ,水解胶原蛋白的溶解度随 pH值与等电点的差值的绝对值增加而增加 ,但即使等电点时 ,也高达 91.4%;在低于 2 0℃时 ,其溶解度随温度的升高而增大 ,在 2 0～ 6 0℃内 ,其溶解度高达 10 0 %,故水解胶原蛋白水溶性好 ,使用酸度和温度范围宽。水解胶原蛋白的乳化能力和乳化稳定性都随其浓度增加而增大 ,但浓度越大 ,乳化能力和乳化稳定性增大幅度越小 ;酸、碱性溶液中水解胶原蛋白都有较高乳化能力和乳化稳定性 ,碱性环境的乳化能力略高于酸性环境 ,而乳化稳定性却在酸性环境中更高。在等电点附近 ,乳化能力和乳化稳定性最差 ;水解胶原蛋白的乳化能力和乳化稳定性先随NaCl浓度升高而增大 ,但当NaCl浓度达到一定值时 ,胶原蛋白的乳化能力和乳化稳定性又随NaCl浓度升高而减小。实验还发现浓度达 5 %以上时 ,溶液 pH值 ,外加电解质的量对其乳化能力和乳化稳定性几乎无影响。     

几种新型无铬鞣剂的鞣性研究

主要研究了几种新型无铬鞣剂的鞣性及其在无铬、少铬鞣中的应用。实验结果表明这几种鞣剂具有较好的鞣性，用于无铬鞣能明显地提高革坯的湿热稳定性，15％荆树皮栲胶与6％无铬鞣剂(I)可使革的收缩温度达到100℃以上，并赋予革坯较好的柔软性和丰满性。用于少铬鞣除了能提高革坯的湿热稳定性之外还可增加铬的吸收，降低废铬液中铬含量，4％的KMC与3％的无铬鞣剂结合鞣能使革的收缩温度达到110℃以上，废铬液中铬含量≤0．2g／L。     

Determination of strongly reducing substances in sediment

Reducing substances in sediments play an important role in regulating the chemical and biological status of the sediment. Strongly reducing substances are the most active part of them, and are difficult to measure directly. In this work, we have developed a method for their determination based on the oxidation by Fe(III). Then, the produced Fe(II) was determined by colorimetry, using 2,2'-bipyridine as the chelating agent. Prior to determination, these substances were extracted from the sediment by M acetic acid. The whole process was carried out in a closed system, so that oxidation of Fe(II) and reducing substances by atmospheric oxygen could be avoided. The calibration curve between absorbance and Fe(II)-chelate concentration in extract was linear. When ascorbic acid was added to the extract, the recovery was larger than 94.0%. The effect of surplus Fe(III) on the result was discussed. With the proposed method, the concentration of strongly reducing substances in sediment samples from Dianchi Lake of China was measured with good reproducibility.     

超声波对生皮的作用

研究了超声波对生皮的作用.试验选取了20kHz和40 kHz 2种频率的超声波,对猪皮和羊皮进行了研究.结果表明超声波作用于生皮,有助于生皮中的可溶性蛋白、脂肪及纤维间质的溶解去除,而不会导致胶原纤维的明显变化.     

茉莉酸对烤烟烟苗生长的影响

本文研究了茉莉酸对烤烟烟苗生长的影响,结果表明,在5至7叶期喷施茉莉酸(2.8×10-4~4.2×10-4 mol/L)能促使幼苗健壮,提高叶片中过氧化物酶和超歧化物氧化酶活性,从而提高抗逆力。喷施茉莉酸,叶片中细胞分裂素、生长素和赤霉素含量水平有所提高。      

蟠桃品种用于加工鲜榨汁的适宜性评价

为研究不同蟠桃品种的鲜榨汁加工适宜性,本实验对北京平谷地区的7 个蟠桃品种的理化与营养指标（pH值、总酚含量、抗坏血酸含量、蛋白质含量、可滴定酸含量、可溶性固形物含量（soluble solids content,SSC）、固酸比、果胶含量）和加工品质指标（单果质量、L*、a*、b*值、褐变度、出汁率、黏度）进行了测定,并从色泽、气味和风味三方面进行感官评价。通过相关性分析、主成分分析和聚类分析法筛选出了SSC、出汁率、果胶含量、a*值和蛋白质含量5 个核心品质评价指标。通过层次分析法得出：SSC和出汁率的权重值为0.32,果胶的权重值为0.18,a*值和蛋白质的权重值分别为0.11和0.07。对7 个蟠桃品种的鲜榨汁品质综合评价表明：瑞蟠21的鲜榨汁品质最好,其次为瑞蟠20、瑞蟠4和瑞蟠19,而巨蟠、瑞蟠2和瑞蟠3的鲜榨汁品质较差。     

Anthocyanins,but not Anthocyanidins,from Bilberry (Vaccinium myrtillus L.) Alleviate Pruritus via Inhibition of Mast Cell Degranulation

Abstract: We have previously reported that bilberry anthocyanins exhibit an anti‐pruritic effect in a mouse model of allergic contact dermatitis. It has been reported that anthocyanins are particularly sensitive to thermal treatment and are easily hydrolyzed to anthocyanidins when exposed to high temperatures. The objective of this study was to compare the anti‐pruritic effect of anthocyanin‐rich quality‐controlled bilberry extract and anthocyanidin‐rich degraded extract using a mouse model of allergic contact dermatitis. BALB/c mice with allergic contact dermatitis induced by 4 weeks of repeated application of 2,4,6‐trinitro‐1‐chlorobenzene (TNCB) were administered Bilberon‐25 orally for 4 weeks after sensitization with TNCB. The effect of Bilberon‐25 on pruritus was evaluated by measurement of scratching behavior. RBL‐2H3 mast cells were used to investigate the effect of Bilberon‐25 on degranulation in 48/80‐stimulated mast cells. Compared with nonheated Bilberon‐25, the proportion of anthocyanins in heated Bilberon‐25 decreased, and the proportion of anthocyanidins was increased in heated‐time dependent manner. Treatment with non‐heated Bilberon‐25 significantly attenuated the TNCB‐induced increase in scratching behavior, whereas treatment with 2 h‐heated Bilberon‐25 did not. Moreover, 300 μg/mL nonheated Bilberon‐25 showed significant inhibition of degranulation in RBL‐2H3 mast cells, whereas 2 h‐heated Bilberon‐25 had no effect at any concentration studied. It is assumed that the inhibitory effect of bilberry anthocyanins on pruritus might be mediated, at least in part, by its inhibitory effect on mast cell degranulation. In conclusion, the anthocyanin‐rich but not anthocyanidin‐rich bilberry extract may be a useful dietary supplement for skin diseases involving pruritic symptoms, such as chronic allergic contact dermatitis, atopic dermatitis, and rhinitis.