豆浆制备过程中大豆脂肪氧化酶的抑制与豆腥味量的关系

探讨大豆加工制备豆浆的过程中,有效抑制大豆脂肪氧化酶对降低豆腥味量的影响,为生产低含量豆腥味的豆浆提供理论与技术支持.通过抑制大豆脂肪氧化酶实验,即热水研磨大豆、热处理或化学处理大豆原料后再沸水研磨、大豆脱皮后隔氧研磨,对得到的豆浆样品采用静态顶空气相色谱质谱法测定13种豆腥味物质,比较定量数据获得最佳抑制脂肪氧化酶的...     

Evaluation of Heat-Damage to Protein by Coomassie Blue G Dye-binding

A rapid, simple method is described which may be useful for determination of heat-damage to proteins in processed foods. It uses the Coomassie Blue dye-binding (DB) capacity of food proteins extract-able in 0.2% KOH, with lysozyme as reference standard. The presence of glucose or lactose was essential to reduce DB capacity of casein on autoclaving. The DB capacity, on dried basis, of fat-free milk, whole egg, egg white, or blood was reduced rapidly with autoclaving, but not that of gelatin and gluten. The DB capacity of extracted soybean flakes, mung beans and black-eyed pea beans was reduced gradually as the time of autoclaving was increased.     

去皮豆粕的生产与应用

在大豆浸出制油过程中,通过增加脱皮工艺,可得到高蛋白去皮豆粕.将豆粕与收集的豆皮分别粉碎后,把豆皮按需添加至去皮豆粕中,可得到不同粗蛋白(CP)含量的的等级豆粕.影响脱皮效果的因素主要有干燥温度、破碎辊间隙、吸风量、豆皮筛网规格等.高蛋白豆粕比普通豆粕具有较高的营养与使用价值,随着饲料工业的发展,我国高蛋白豆粕在饲料中所占比例将逐步增加.     

Residual Amounts of Proteinaceous Additives in Table Wine

Radioactive acetic anhydride was used to label casein, isinglass, egg white, and a pectic enzyme complex. The pectic enzyme was added to three different grape juices which were fermented, bentonite fined and filtered in an approximation of industrial practice. Three wines were fined using isinglass or egg white (red wines) or casein (white wines) applied at three rates each, and finished as above. Residual amounts of each additive were determined by scintillation counting of samples taken at each step. All of the pectic enzyme remained in the finished wines. Residual fining agents decreased with the application rate to levels showing much variation in the red wines and less in the whites.     

Collaborative Tests of ELISA Methods for the Determination of Egg White Protein and Caseins Used as Fining Agents in Red and White Wines

Methods are needed for detecting allergenic proteins in wine after fining processes, both for legal requirements and to estimate any risk for allergic individuals. Two of the critical allergens in this case are the protein fraction from egg white and caseins. Requirements for methods were set up both by the International Organisation of Vine and Wine (OIV) and the European Commission and included collaborative tests to determine repeatability, reproducibility, limit of detection (LOD), and recovery. Two collaborative tests with 18 participants from all over the world were conducted using commercial enzyme-linked immunosorbent assay kits to quantify egg white protein and casein. For each analyte, nine red and white wines (RW and WW, respectively) with different analyte concentrations were prepared and sent to the participants. Resulting sets of data were analyzed according to the AOAC by eliminating outliers and calculating the performance statistics for each assay. For wines with no or very low analyte concentrations, the values were extrapolated from the calibration curve and the resulting LODs are in accordance with the performance criteria set by the OIV method OIV-MA-AS315-23: R2012. For casein in WW and egg white protein in RW, all Horwitz ratio values for samples with concentrations above the required limit of quantification (0.5 mg/L) were below 2. While the recovery of egg white protein from RW is 90 % or more, the recovery of casein from WW is between 73 and 76 %, which is attributable to the instability/solubility of casein in wine.     

桂林罗汉果保健酒澄清稳定性研究

采用蛋清、明胶和酪蛋白3种单一澄清剂,以及明胶-单宁、蛋清-PVPP2种复合澄清剂为试材,对罗汉果保健酒进行下胶澄清实验。结果表明,60mg／L＋75mg／L蛋清＋PVPP的澄清剂澄清效果最好。     

Standardized Procedure for Measuring Foaming Properties of Three Proteins, A Collaborative Study

A collaborative study involving nine laboratories was conducted over four years to evaluate a rapid, simple and reliable whipping method for measuring overrun and foam stability. Effectiveness of the method was assessed by measuring the characteristics of foams formed by three protein solutions (5%): sodium caseinate, milk protein isolate, and egg white protein; identifying and systematically eliminating sources of variability. Major sources of variability were protein dispersing technique, the mixer, and the care exercised by the operator during sampling and weighing. The method detected differences in foam stability between egg white, casein and milk protein isolate (pooled SD = 4.5) using different mixers.     

Influence of double enzymic hydrolyses on gluten functionality

Functional properties of chemically deamidated and/or double enzymically‐treated gluten were studied. Performances of the modified glutens were compared to those of egg white proteins, casein, deamidated gluten and gluten submitted to deamidation plus single enzymic treatment. Higher nitrogen solubility index (>90%) was obtained after treatment of the gluten with the sequence pepsin + alcalase and deamidation + pepsin + papain. The sequence pepsin + papain has permitted the production of a gluten with foaming properties close to those of egg white. Deamidation + papain treatment leads to interesting emulsifying properties although different from those of casein. The results show that modified glutens present thresholds in the degree of enzymic hydrolysis (DH) for foaming and emulsifying properties (respectively 1.3% and 2.0%). For higher DH the stability decreases. © 1999 Society of Chemical Industry     

大豆蛋白、酪蛋白、卵清蛋白、浓缩乳清蛋白及转谷氨酰胺酶对鸡肉肠出品率和硬度的影响

本文采用两因素析因实验设计,研究了转谷氨酰胺酶和四种非肉蛋白(大豆蛋白、酪蛋白、卵清蛋白、浓缩乳清蛋白)对鸡肉肠出品率和硬度的影响。结果显示,随着浓度的增加,四种非肉蛋白均可显著增加鸡肉肠的出品率(p<0.01);转谷氨酰胺酶对出品率没有影响,与非肉蛋白之间亦无交互作用。转谷氨酰胺酶在提高鸡肉肠硬度的同时和非肉蛋白间有交互作用,其中酪蛋白和大豆蛋白能提高硬度,而卵清蛋白和浓缩乳清蛋白则显著降低了鸡肉肠的硬度(p<0.05)。     

大豆蛋白发泡粉的酶法提取工艺技术

以大豆粕为原料,选用优良的酶制剂,研发试制成可与碳酸钙、小苏打复合化学合成的固体发泡粉功能作用相同,能够代替动物性鸡蛋清液体发泡剂的大豆蛋白发泡粉。大豆蛋白发泡粉的使用可提高产品的蛋白含量,降低产品的生产成本,是食品、保健品和饮品加工业新辅料产品。     

Preparation of low-fat uptake frying batter composite by dry particle coating of microparticulated soybean hull

This study examined the influence of soybean hull-coated frying batter composite on fat uptake during deep fat frying. Soybean hull was microparticulated by impact mill at impact mill speed (IMS) of 6000, 10,000 and 14,000 rpm, and air-classified into coarse and fine fractions at Air Classifying Wheel Speed (ACWS) of 4000, 8000 and 12,000 rpm, respectively. Each soybean hull was dry-coated into wheat flour by dry particle coating system. As the difference in particle size between wheat flour and soybean hull got larger, the coating process became more effective, which indicates the size difference between wheat flour and soybean hull was important for coating effectiveness. When the ratios of wheat flour to soybean hull were 99:1 and 95:5, there were about 3.3 (g/100 g) and 24.4 (g/100 g) of fat content reduction, respectively. Inner crust structures showed slight reduction in cell size and improved cellular integrity with shrinkage in the cell membrane, with increase in soybean hull content. This means soybean hull can form a protective layer and can be applied to the food industry as a frying batter composite to reduce fat uptake.     

DHG-1015澄清剂下胶效果的研究

通过DHG-1015与膨润土、PVPP、蛋清、酪蛋白、明胶等几种下胶材料在干白、干红葡萄酒中下胶效果的比较；探索DHG-1015澄清剂对葡萄酒的下胶效果及对稳定性的影响。结果表明，DHG-1015澄清剂对葡萄酒有着良好的下胶效果，是一种干白、干红葡萄酒都可使用的安全、简易、高效的下胶材料。     

大豆皮利用的研究进展

大豆皮是大豆脱皮制油加工过程中的副产物。大豆皮富含纤维,除主要用作饲料外,可以经改性处理用作吸附剂,还可提取其中的有效成分,如膳食纤维、过氧化物酶等用于食品工业中。另外,大豆皮可以发酵生产燃料乙醇,还可以制作成锂离子电池的负极。大豆皮的利用途径很多,随着科技的发展,这一资源会得到充分的利用。     

改性大豆皮用于降低水硬度的研究

对大豆皮的改性方法及其处理水的过程进行了实验研究。对改性方法、改性剂和再生剂的选择进行了详细的实验，进而确定了改性剂、再生剂的最佳剂量及最佳反应时间。研究表明：大豆皮磺化改性后，对水中钙镁离子有很强的吸附作用，能够达到降低水硬度的目的；而大豆皮的再生实验也证明改性大豆皮可用作工业生产用水的软化处理。     

加工条件对全豆腐乳白坯品质的影响

以东北大豆为原料,通过对全豆磨浆粒度、凝固剂、凝固条件对全豆腐乳白坯的凝胶强度、硬度、弹性影响的单因素和正交试验,较系统地研究加工条件对全豆腐乳白坯品质的影响。结果表明：全豆豆浆经胶体磨磨浆3次,石膏与卤水以5:5的比例为混合凝固剂,凝固最佳工艺参数为点浆温度80℃、凝固剂用量(以干豆质量计)3.0%、豆浆可溶性固形物含量12%。此时,可使制得的全豆腐乳白坯质量与传统腐乳白坯接近。     

Chemical Characteristics of Low-Fat Soymilk Prepared by Low-Speed Centrifugal Fractionation of the Raw Soymilk

Abstract: Large oil–protein particles (2 to 60 μm) were found in raw soymilk (or water extract of soybean), which was prepared in specific conditions. The large particles could be separated by sedimentation by centrifuging raw soymilk for 5 to 30 min at a low gravitational force ranging from 96 to 2410 × g. Chemical analysis showed that 80% to 90% of the total lipids and 30% to 40% of the total proteins were located in the precipitated fraction. The supernatant fraction had a dramatically higher protein-to-lipid ratio than the whole soymilk. The ratio of 11S/7S proteins and the ratio of 11S acidic/basic subunits were significantly (P < 0.05) higher in the precipitate than that either in the whole soymilk or in the supernatant. Besides centrifuging conditions, other factors, including soymilk concentration, grinding method, soybean variety, and soybean storage, also significantly (P < 0.05) affected the centrifugal fractionation. This study showed that low-speed centrifugation facilitated the separation of oil-protein particles from raw soymilk, and can be used as an innovative method for preparing low-fat soymilk and 11S protein-enriched ingredients. The findings also increased our understanding of the association or aggregation between proteins and lipids in raw soymilk after grinding. Practical Application: Soymilk has become a popular beverage in the Western world due to its health benefits. Consumer demands for low-fat and organic foods have been increasing in the recent years. Currently, there are no alternative methods for manufacturing low-fat soymilk from whole soybeans. We found that most, if not all, of lipids in the raw soymilk were located in large particles, which could be separated by low-speed centrifugation. This centrifugal fractionation was investigated by varying processing parameters, soybean varieties, and soybean storage conditions. The approach has potential to be used for manufacturing low-fat soymilk. This study also has increased our understanding of the interactions between lipid and protein in raw soymilk.     

酶法制备豆皮低聚木糖的工艺研究

利用木聚糖酶酶解豆皮制备低聚木糖,通过单因素试验考察酶解温度、pH 值、时间、料液比以及酶添加量对酶解液中低聚木糖含量的影响,并在此基础上通过正交试验确立最佳酶解工艺条件：酶添加量0.3%、pH4.3、料液比1:15(g/mL)、温度40℃、酶解时间2h。该最佳工艺条件下,总还原还原糖含量为5.74mg/mL。通过离子色谱检测酶解液中的糖分组成,发现酶解液中的单糖以木糖为主,相对含量达到54.99%。     

豆酱中白色物质的分析研究

在传统豆酱的发酵过程中，会产生一些白色颗粒状或片状物质，人们通常认为是单一酪氨酸的结晶物。通过对白色物质的分析研究发现，这些白色物质的主要成分是酪氨酸和面筋蛋白，是由于面粉中的一些蛋白质未被彻底分解而与酱体中的部分游离氨基酸混合粘附于黄豆的表面，在盐水浸泡下形成较“硬”、难溶解的白点物。     

无脂人造奶油的制作

具有表面活性．一定分子量和亲水亲脂结构的食品物料,在高速搅拌时能形成泡沫。鸡蛋清蛋白、干酪素和大豆分离蛋白属于高起泡力的食品物料,可以取代食用油脂制作口溶性好、有一定可塑性和涂抹性的无脂人造奶油。加入稳泡剂是工艺的关键。     

国产大豆种皮中Fe(Ⅱ)稳定性的研究

本文采用离子色谱柱后衍生法,首先测定了大豆种皮中铁的存在状态及含量。又全面研究了在一般食品加工条件下二价铁的稳定性。同时也考察了二价铁在浸泡、发芽过程中的变化情况。结果表明,大豆种皮中的铁含量高达约400ppm,且90％为可被生物吸收的二价铁,同时具有良好的稳定性。