Effect of Germination on Phytic Acid, Protein and Fat Content of Rapeseed

Rapeseed was germinated over a 7-day period and the changes in phytic acid, protein and fat contents were monitored. Two-day germination period reduced the phytic acid by 13% and slightly increased the fat and protein by 6 and 4%, respectively. A 65% decrease in phytic acid, 10% increase in protein and 46% decrease in fat were observed after 7 days of germination. The free fatty acid values increased from 1 to 120. While reduction in phytic acid and increase in protein are desirable, the reduction in fat and its increased hydrolysis to free fatty acids after 7 days may be considered detrimental if rapeseed oil is to be extracted for commercial purposes.     

Effect of Acylation Upon Extractability of Nitrogen, Phytic Acid and Minerals in Rapeseed Flour Protein Concentrates

Rapeseed flour (RF) and protein concentrates (RPC) were acylated with various levels of succinic or acetic anhydride. Compared with the unmodified control, 63% succinylation or 87% acetylation resulted in up to 45% increase in nitrogen and 95% decrease in phytic acid extractabilities in the first RF extract. At 21% succinylation or 55% acetylation, the extractability of phytic acid was more than double that of the unmodified control whereas the extractability of nitrogen was increased by 22%. A second extraction of the residual acylated RF with deionized water increased the extractability of phytic acid. For both first and second extracts, the extractability pattern of the major minerals followed that of phytic acid. Acylation of heat treated protein concentrate was not effective in increasing the nitrogen and decreasing the phytic acid extractabilities.     

Study on Antioxidant Activity and Amino Acid Analysis of Rapeseed Protein Hydrolysates

Alkaline extraction followed by acid precipitation were employed to extract rapeseed protein and, Alcalase 2.4 L was used to obtain rapeseed protein hydrolysates. Three groups of rapeseed protein hydrolysates were obtained by purifying with membrane ultrafiltration and a Sephacryl S-100HR gel column. The antioxidant activities were then determined. Group 3 had the best antioxidant activities according to the oxygen radical absorbance capacity, peroxyl radical-scavenging capacity, and cellular antioxidant activity assays, with the following antioxidant values: an oxygen radical absorbance capacity value of 1610 ± 113 µmol TE/(g sample), a peroxyl radical-scavenging capacity value of 622 ± 30 mg VC/(100 g sample), and a cellular antioxidant activity value of 25 ± 2 µmol QE/(g sample) and corresponding EC₅₀ value of 58 ± 3 µg/mL. Six peaks of group 3 were collected and well separated by reversed phase–high-performance liquid chromatography. Peak 5 were identified to exhibit a higher antioxidant activity, the amino acid sequence of which was found to be Trp-Ile (Leu)-Tyr, as determined by liquid chromatography–mass spectrometry.     

油菜籽饼粕中植酸的提取技术研究

本文确立了简单有效的植酸测定方法，通过对油菜籽饼粕中植酸的提取量有影响的相关因素筛选，确定关键影响因素，并通过响应曲面法优化了植酸最佳提取工艺：在提取温度为44，11～55．23℃时，只需在pH为9．70～10．96，料液比为21，87～25．74g／mL的条件下，油菜籽饼粕植酸提取量即可达到62．367mg／g（本实验中心点预测值）以上的提取量。对二次多项式数学模型解逆矩阵得知：在pH、提取温度和料液比分别为10．96、56．07℃和23．96g／mL时，油莱籽饼粕植酸提取量可达到最大预测值为62．716mg／g。     

日粮纤维水平对鹅内源氨基酸排泄量和氨基酸真消化率的影响

30只42日龄鹅为试验动物,以砻糠和玉米秸秆为主要纤维源,在日粮等能量等蛋白的前提下,采用同位素示踪技术,研究了不同日粮粗纤维水平（3％、5％、7％、9％和11％）对鹅内源氨基酸排泄量和氨基酸真消化率的影响。结果表明,内源氨基酸排泄量指标,CF11组（最高）比CF3组（最低）升高了92．13％（P〈0．01）;氨基酸真消化率指标,CF11组（最低）比CF5组（最高）降低了39．88％（P〈0．01）;粗纤维水平在3％。7％范围内随粗纤维水平增加,鹅内源氨基酸排泄量有升高的趋势,但差异不显著（P〉0．05）,氨基酸真消化率较高且较稳定（P〉0．05）;粗纤维在7％-11％范围内随着粗纤维水平的增加,内源氨基酸排泄量极显著升高（P〈0．01）,氨基酸真消化率极显著降低（P〈0．01）。     

In-Vitro Protein Digestibility of Dehydrated Protein Extract from Poultry Bone Residue

In-vitro protein digestibility of freeze- or spray-dried protein obtained from poultry bone residue by alkali extraction was evaluated by a multienzyme procedure. Digestibility of the dehydrated extracts was significantly lower than chicken breast muscle or mechanically de-boned poultry. Digestibility of the spray-dried extracts was about 3% higher than freeze-dried extracts.     

Starch Digestibility as Affected by Polyphenols and Phytic Acid

The rate of wheat starch digestibility in the presence or absence of polyphenols (catechin or tannic acid) and/or phytic acid at concentrations found in legumes was determined in an in vitro dialysis system. Addition of tannic acid and phytic acid reduced the starch digestibility 13 and 60% respectively, at 5 hr. Combined tannic and phytic acid reduced the digestibility at a level (63%) which did not differ significantly from that with only phytic acid. Catechin had no significant effect on rate of starch digestibility.     

Effect of Lectins and the Mixing of Proteins on Rate of Protein Digestibility

The rate of digestibility of protein in raw bean extract (RBE), heat-treated bean extract (HBE), casein and bovine serum albumin (BSA) was determined. The pepsin and/or pancreatin hydrolysis of RBE which contains lectins or hemagglutinins was less than that of other proteins. Addition of lectins at the same concentration present in RBE decreased the rate of digestion of HBE, casein and BSA to levels close to that of RBE. In comparison with the respective single proteins, mixtures of RBE or HBE with casein have lower digestibilities while a mixture of casein and BSA, higher digestibilities. The results suggest that lectins can affect the activity of digestive enzymes and that mixing of proteins has an effect on digestibility which is unpredicted by amino acid composition.     

间接原子吸收法定量测定菜籽粕中植酸的研究

研究了间接原子吸收定量测定菜籽粕中植酸含量的方法。采用三氯乙酸提取植酸,添加三氯化铁,使其生成植酸铁沉淀,用原子吸收法测定上清液中剩余铁的含量,推算植酸沉淀铁的量,以定磷法得出的植酸含量为比较基准,结果表明植酸与铁离子（Fe^3 )以6．0：1的比例络合,根据这一比例关系,测出试样中植酸沉淀Fe^3 的含量,即可求算样品中植酸的含量。     

双低油菜饼粕中植酸的脱除技术研究

本文研究了利用小麦内源植酸酶（Myo-inositol hexaphosphate phosphohydrotase)来脱除菜籽饼粕中植酸的方法。研究表明，小麦在20℃下发芽24h,内源植酸酶的活力较高，以此发芽小麦与菜籽饼粕按1：10比例混合打浆，在pH5.2,55℃下保温6h酶解脱毒，抗营养物质植酸、单宁和硫代葡萄糖苷的脱除率分别为82％、23％和6．7％。粗蛋白的损失率仅为0．16％。饼粕色泽较好，蛋白质未受到破坏，完全符合饲料的要求。对猪、鱼的饲养试验获得较好的饲养效果。     

响应面法优化菜籽粕中植酸提取工艺研究

利用低浓度(体积分数)的醋酸溶液,在单因素试验的基础上选择了醋酸浓度、提取温度和提取时间进行响应面分析,以提取液中植酸含量(质量分数)为响应值,建立了植酸提取的二次多项式数学模型,确定了植酸提取的最佳工艺条件为:醋酸浓度4.4%,提取温度41℃,提取时间2h,得到提取液中植酸含量为1.64%。     

植酸及几种酚酸对牛奶蛋白体外消化率的影响

研究植酸和几种酚类物质(阿魏酸、单宁、水杨酸、对- 羟基苯甲酸)在常温和灭菌条件下(121℃,20min)对牛奶蛋白体外消化率的影响。结果表明：植酸和4 种酚类物质均降低蛋白质消化率,降幅为5%～27%;反应后延长静置时间可进一步降低蛋白质消化率;增加胃蛋白酶浓度可使蛋白体外消化率提高1%～9%。     

Enzyme Diafiltration Technique for In Vitro Determination of Protein Digestibility and Availability of Amino Acids of Legumes

In vitro protein digestibility determined by peptic hydrolysis in a diafiltration reactor gave values comparable to the published in vivo digestibility data in 16 samples from both animal and plant sources. The in vitro technique is easier to perform and the reproducibility is greater than that reported for in vivo rat assays. A high performance liquid chromatographic method was modified to determine the amino acids in the pepsin hydrolysates. The amino acid content of nine samples were compared to the FAO-WHO (1973) reference protein standard and the geometric mean of the essential amino acid content were compared with values for Protein Efficiency Ratio (PER), Net Protein Utilization (NPU), and Biological Value (BV). The geometric mean was most closely related to the NPU value with a correlation coefficient of 0.96.     

发酵法降解油菜籽废水中植酸的工艺研究

水酶法提取菜籽油工艺产生了大量废水,其中含有丰富的水溶性蛋白、碳水化合物和抗营养因子。为了降解水中的抗营养物质植酸,利用筛选出的酵母菌对其进行发酵,并通过正交试验优化培养条件,得出K酵母在32℃,pH 7条件下培养36 h,可将废水中植酸降解87%,从而为废水的循环利用或达标排放打下了基础。     

主要粮食饲料资源氨基酸消化利用率的研究

采用8头初始体重为(27．2±2．3)kg、在回肠末端装有简单T型瘘管的杜长大三元杂交公猪, 手术康复后随机分成2组,每组4头,每组采用同一豆粕-玉米淀粉基础日粮,按拉丁方设计,用于测定豆粕、棉粕、菜粕、稻谷、油糠、统糠和玉米7种饲料原料的回肠和粪氨基酸消化率。结果表明:所测氨基酸平均表观消化率回肠比粪低5—8个百分点(P<0．05);稻谷氨基酸表观消化率比玉米低5％;所测原料氨基酸表观消化率与中国饲料数据库等报道结果基本吻合。     

植酸对番茄保鲜效果的影响

以变色期番茄为材料,分别采用浓度为0.05%、0.10%、0.15%的植酸溶液浸泡30s,在室温下贮藏33d,研究不同浓度植酸溶液涂膜处理对番茄果实的保鲜效果。结果表明,植酸溶液处理能推迟番茄果实呼吸跃变时呼吸高峰的出现时间,降低呼吸强度峰值;对保持果实硬度、可溶性固形物、维生素C、可滴定酸有较好作用;能减少水分蒸发,降低果实失重率;其中浓度为0.10%的植酸溶液对番茄果实进行涂膜处理保鲜效果最好。     

菜籽粕脱毒液中植酸的提取及其抗氧化活性

采用碱沉淀法从菜籽粕脱毒液中回收提取植酸并对该制备植酸的抗氧化活性进行研究。以BHT为阳性对照,考察植酸对猪油的酸价和过氧化值的影响;采用流动化学发光法和可见分光光度法,以VC为阳性对照,考察植酸清除羟自由基( ·OH)、超氧阴离子自由基(O2 ·)、1, 1-二苯基-2-苦苯肼自由基(DPPH自由基)及H2O2的能力。结果表明：回收提取植酸以NaOH调节溶液pH8为优,得率达92.83%,植酸含量为45.96%;植酸对猪油的酸败和过氧化有一定的抑制作用且优于BHT;制备植酸(实验制备)清除各种自由基的能力依次为：O2 ·＞ ·OH＞H2O2＞DPPH自由基,且除DPPH自由基外对其他自由基清除效果均优于VC。表明植酸是一种较好的天然抗氧化剂。     

脱皮双低菜籽粕制取复合氨基酸工艺研究

该文研究以脱皮双低菜籽粕为原料制备复合氨基酸,通过正交试验确定双低菜籽粕水解最佳工艺是:硫酸浓度15％,固液比(W/V)1∶6,水解时间10 hr;适宜脱色条件为:活性炭浓度2％、脱色温度90℃,脱色时间30 min;复合氨基酸得率为46.65％,纯度为55.91％。     

超高温灭菌处理对再制干酪蛋白质和氨基酸含量的影响

通过测定不同热处理方式再制干酪的蛋白质和氨基酸含量,研究超高温灭菌对再制干酪蛋白质和氨基酸的影响。结果表明,不同热处理对再制干酪中蛋白质的含量没有显著影响(p>0.05)。但是相比于巴氏灭菌,超高温灭菌再制干酪的必需氨基酸含量显著降低了8.4%~9.0%,其中缬氨酸、蛋氨酸、异亮氨酸、亮氨酸和赖氨酸的含量显著降低(p<0.05)。而且超高温灭菌处理加强了氨基酸的脱氨反应,使再制干酪中氨的含量显著增加(p<0.05)。此次试验为再制干酪的工业化生产提供理论参考。     

Determination of True Ileal Amino Acid Digestibility in Feedstuffs for Pigs with the Linear Relationships between Distal Ileal Outputs and Dietary Inputs of Amino Acids

This study was carried out to investigate the methodological aspects of extrapolating the ileal losses of endogenous amino acids (AA) with linear relationships between the distal ileal outputs and dietary inputs of AA. Six barrows, average initial body weight 35 kg, were fitted with a simple T-cannula at the distal ileum and fed six diets according to a 6×6 Latin square design. Six maize starch-based diets containing six levels of crude protein (CP) and AA from soya bean meal (4, 8, 12, 16, 20 and 24% CP, respectively) were formulated. Chromic oxide (4 g kg^-1 diet) was included as the digestibility marker. Each experimental period consisted of 8 days. Ileal digesta were collected, at 2 h intervals, for a total of 24 h during days 7 and 8. There were strong linear relationships (P<0·01) between the ileal outputs and dietary inputs of AA. Differences in ranges of graded dietary levels of AA affected the linearity and caused large differences in the extrapolated levels of ileal endogenous AA. Therefore, the design of a suitable range of graded dietary levels of AA is the most important methodological consideration for the determination of endogenous AA losses and the true ileal digestibility values of AA with the linear relationship. For CP and the essential AA, the true ileal digestibility values (%) in soya bean meal and the ileal endogenous losses (g kg^-1 dry matter intake, in parentheses) were as follows: CP, 89·4 (16·4); arginine, 96·1 (0·68); histidine, 92·4 (0·24); isoleucine, 91·7 (0·45); leucine, 90·7 (0·69); lysine, 90·5 (0·48); methionine, 93·6 (0·13); phenyl-alanine, 92·5 (0·38); threonine, 86·5 (0·71) and valine, 90·3 (0·56). Furthermore, the levels of endogenous AA extrapolated with the linear relationships between the ileal outputs and dietary inputs of AA were very close to the values estimated with the linear relationships between the dietary contents of apparent ileal digestible and total AA, suggesting that both models of linear relationships can be used as the regression analysis technique for determination of ileal losses of endogenous AA and true ileal digestibility values of AA in feedstuffs for pigs. © 1997 SCI.