木材工业用大豆蛋白胶粘剂研究与应用现状

随着木材工业持续快速发展和化石资源的日益枯竭,寻找绿色环保、可再生的木材用胶粘剂已经成木材工业面临的重大课题。从大豆蛋白胶粘剂的产生、发展,大豆蛋白的结构、特性、耐水改性机理、改性方法等几个方面,综述了近年来木材用大豆蛋白胶粘剂的研究进展和发展趋势。     

甲醇联合改性大豆蛋白胶黏剂的研究

以甲醇、十二烷基磺酸钠、尿素为原料,研究了它们对大豆分离蛋白改性后胶黏性的改观作用。结果表明:随着甲醇含量的增加胶合强度先增后减,当甲醇含量占总体质量分数15%时胶合强度最好。取该条件下的大豆蛋白胶黏剂进行有关反应次序的对比试验。研究表明其部分干态胶合强度略有下降,湿态胶合强度有提升,且反应次序为SDS、甲醇、尿素所得的胶黏剂胶合强度达到最优。DSC、SEM图像和IR图像分析结果说明经此方法改性后的蛋白质展现出更多的二级结构从而大幅度的提升了其胶粘性,与此同时改性后的大豆蛋白玻璃化转化温度降低,从而降低了热压温度,说明经甲醇联合改性后的大豆蛋白胶黏剂不但能更加适应规模化的工业生产还可以节约资源。     

大豆蛋白活性肽在功能性食品中的应用及发展前景

本文对采用微生物发酵技术生产的大豆蛋白活性肽，在功能性食品中的应用及发展前景进行了研究。结合产品的功能特性及在功能性食品中的应用，总结了近年来国内外的应用情况及发展前景。     

木材粘接用交联大豆蛋白胶的研究

以氢氧化钠改性脱脂大豆蛋白粉为基础胶,选用六次甲基四胺(HMTA)作为交联剂,制备了聚乙烯醇(PVA)改性的大豆蛋白胶黏剂。通过正交试验方法研究了HMTA用量、PVA溶液用量(PVA质量百分比浓度为12%)、热压温度、热压时间对粘接性能的影响;并用红外和热失重分析仪探讨了大豆蛋白胶的粘接机理。结果表明:当HMTA质量百分比用量为6.5%,热压温度为140℃,热压时间为10 min,大豆蛋白胶黏剂粘接性能较优;120℃加热1 h后,酰胺Ⅰ带和酰胺Ⅱ带红外特征峰朝高波数方向移动,表明高温下蛋白质胶内部的氢键数目减少;而属于HMTA的C-N的红外响应峰(1 236和1 007 cm~(-1))减小。研究结果表明HMTA参与了化学交联反应,HMTA的加入能提高大豆蛋白胶黏剂的耐热性能。     

碱性蛋白酶改性大豆蛋白胶黏剂的研究

为解决大豆蛋白胶黏剂相对分子量高、黏度大以及改性剂用量多等问题,需要制备一种由碱性蛋白酶改性的新型大豆蛋白胶黏剂,使其满足室内使用胶合板及胶合制品的要求。本研究以脱脂大豆蛋白粉为主要研究对象,碱性蛋白酶作为改性剂,探究不同酶添加量、pH、酶解温度、酶解时间对大豆蛋白胶黏剂胶合强度的影响,并通过正交试验对其工艺条件进行优化。结果表明：大豆蛋白胶黏剂适宜反应条件为碱性蛋白酶添加量10 000 U·g^-1、pH9.5、酶解温度60℃、酶解时间100 min。改性胶黏剂与未改性的大豆蛋白胶黏剂相比,黏度由2 400 s降低为13 s,胶合强度由0.74 MPa提高为0.98 MPa,符合国家标准GB/T 9846—2004Ⅱ类胶合板要求。试验表明碱性蛋白酶改性大豆蛋白胶黏剂在胶合板生产领域中具有良好的应用前景。     

酒石酸酰化改性制备低固体含量大豆蛋白胶黏剂的研究

以L-酒石酸和乙酰氯在极少量磷酸做催化剂的条件下制备二乙酰基酒石酸,之后将二乙酰基酒石酸溶于乙醇中制备改性剂,加入到制备好的p H10.50~10.90低浓度大豆分离蛋白预处理液中,制备胶黏剂。测试胶黏剂的固体物含量、DSC、胶合强度以及胶黏剂横切面。结果表明:p H10.7~10.8时,200 m L大豆分离蛋白预处理液中加入0.4 g二乙酰基酒石酸和10 m L无水乙醇制备的改性剂,最终得到的胶黏剂有良好的耐水性,胶合强度2 MPa,远超过国家对Ⅱ类胶合板胶合强度的要求(≥0.7 MPa)。     

仙草胶-卡拉胶复合膜在枇杷保鲜中的应用

为了开发枇杷贮藏保鲜新技术,以福建地产枇杷为试材,研究仙草胶-卡拉胶复合膜对枇杷贮藏期间的果实品质及采后生理变化的影响。研究结果显示,复合涂膜处理可以保护细胞膜,降低呼吸强度,抑制枇杷的生理代谢,减少营养物质的损失,加入的尼辛、纳他霉素等抑菌配料可抑制金黄色葡萄球菌、青霉菌等微生物的生长,提高贮藏的保鲜效果。     

蛋白改性技术在大豆蛋白基木材胶粘剂制备中的应用

在建设环境友好型和资源节约型社会的今天,三醛胶面临的问题日益严峻,开发新型环保、绿色胶粘剂已成为趋势。而通过改性技术制备的大豆蛋白基木材胶粘剂具有很好的应用前景。本文综述了胶粘剂制备中大豆蛋白改性的原理及各种改性技术的研究现状,并分析了目前研究中存在的问题和今后的研究重点。     

陶瓷膜技术在微生物发酵法生产大豆蛋白活性肽中的应用研究

本文简单介绍了无机陶瓷膜的性能特点及大豆蛋白活性肽的功能及生产工艺，以陶瓷膜在微生物发酵法生产大豆蛋白活性肽中的应用为例，指出了无机陶瓷膜在微生物发酵法生产大豆蛋白活性肽分离纯化上使用的可行性。     

大豆蛋白在食品及纺织工业中的应用

大豆是唯一“完全蛋白质”的植物来源,其9种必需氨基酸的含量均能满足人体的需要。近几年,随着加工工艺的改进,添加大豆蛋白的营养食品开始在世界范围内受到消费者的青睐。简要介绍了大豆蛋白的应用现状、特点及在食品中的应用。     

储存条件对大豆分离蛋白凝胶性的影响

大豆分离蛋白的凝胶性在食品加工中得到了广泛应用。本文针对不同的环境温度、时间、包装方式等因素,对储存后大豆蛋白的凝胶性进行了研究。通过优化储存条件,使其在常温,通风的条件下,减少凝胶功能性的损失,达到最佳使用效果。     

Structural characteristics of corn starches extruded with soy protein isolate or wheat gluten

Commercially available corn starches containing 0, 25, 50 and 70% amylose were extruded with 10, 20 and 30% soy protein isolate (SPI) or wheat gluten (WG) at 22% moisture content (dry basis) in a C.W. Brabender single screw laboratory extruder using a 140°C barrel temperature and a 140 rpm screw speed. True, solid and bulk densities; percent total, closed and open pores; and shear strengths of the extrudates were determined. The microstructures of the extrudates were studied by scanning electron microscopy (SEM). The total pores of the extrudates were affected significantly (p < F=0.0001) by type of protein (SPI or WG) and starch amylose. The open or closed pores, were affected by protein type only. The interaction between amylose and protein contents was highly significant <(p < F=0.0001). In general, the total pores and bulk densities were higher for WG-starch extrudates compared to SPI-starch extrudates. These values decreased as amylose content increased from 0 to 25% and then increased thereafter. The open pores, on the other hand, increased with increasing protein content from 10 to 20% and then decreased. Extrudates containing WG had higher shear strengths than those containing SPI.     

Partial replacement of dietary casein with soy protein isolate can reduce the severity of retinoid-induced hypertriglyceridemia

Previous research carried out in an animal model of retinoid-induced hypertriglyceridemia – rats fet a 13-cis retinoic acid (13cRA)-containing diet having casein as the protein source – has demonstrated that the complete replacement of dietary casein with soy protein isolate (SPI) can decrease the severity of this condition. In this study, the effect of partially replacing dietary casein with SPI was investigated. Five groups of male Fischer 344 rats were used in a 14-day study, with two groups being fed diets having casein as the protein source, without or with 13cRA (groups A and B, respectively), and three groups being fed 13cRA-containing diets in which SPI was used to bring about the isonitrogenous replacement of 25, 50, or 100% of the casein in the formula for the diet used for group B (groups C-E, respectively). Serum triglyceride concentration for group B was significantly different ( p < 0.05) from that of groups A, D, and E (5.41 vs 2.62, 4.04, and 2.66 mmol/l, respectively). Serum cholesterol concentrations for groups D and E were significantly lower ( p < 0.05) than for groups A and B (1.63 and 1.60 vs 2.00 and 2.14 mmol/l, respectively). Thus, the isonitrogenous replacement of 50% of dietary casein with SPI can reduce the severity of retinoid-induced hypertriglyceridemia while decreasing the serum concentration of cholesterol.     

Physico-chemical properties and acceptability of yam flour substituted with soy flour

Yam flour was substituted 10, 20 and 40% with defatted and full fat soy flour. The effect of the substitution on the proximate composition, swelling power, solubility, water binding capacity and Brabender visco amylograph cooking properties of the yam flour and acceptability of the cooked paste (amala), were evaluated. Protein contents of the mixtures were 23.0 and 25.5% on substituting 40% full-and defated soy flours for yam flour; ash and crude fibre contents increased while carbohydrate content, swelling power, Brabender paste viscosities decreased with increase in soy flour substitution of yam flour. Colour, texture, taste and overall acceptability of pastes (amala) from the mixed flours were rated lower than that of yam flour. Up to 10% defated and 20% full fat soy flour substitution for yam flour was acceptable for amala.     

Changes in the nutritive value of soy protein concentrate during autoclaving

Soy protein concentrate (Promosoy R Plus) was mixed with water to form a thick paste and autoclaved at 121°C for 10 min, 30 min, 2 h, or 4 h. Unautoclaved SPC served as a control. Nitrogen solubility measurements and SDS-PAGE analysis indicated that autoclaving resulted in the formation of soy protein aggregates, with a MW of 1 million daltons, held together by non-covalent and disulfide bonds. The 10 min, 30 min, 2 h, and 4 h SPC samples contained 6, 20, 27 and 39% less cysteine, respectively, than the SPC control. No significant differences were found in the PERs, 2.6-2-7, of a casein control, unautoclaved SPC control and 10 min and 30 min autoclaved samples. PERs of the 2 h and 4 h autoclaved samples, 2.0 and 1.9 respectively, were significantly lower than the other four diets. No significant differences were found in the apparent digestibility of the 10 min, 30 min, and 2 h autoclaved samples; the 4 h autoclaved sample however was significantly less digestible. Decreased PERs of autoclaved SPC samples were likely due to (1) crysteine destruction, (2) decreased protein digestibility, and (3) decreased food intake.     

超声波对大豆蛋白增溶作用的研究

为了提高大豆深加工产品的得率和蛋白质含量，利用超声波处理大豆经湿磨后的浆潭混合液态物，产生超声空化效应，提高大豆蛋白的溶出率，减少大豆蛋白在豆渣中的残留，试验表明：超声提取技术能提高大豆蛋白的溶出率，从而使豆乳蛋白含量相对提高6.6%，豆乳干物质重量相对提高11.6%。该技术对于传统大豆制品及现代大豆加工新产品如豆奶、速溶豆粉及分离蛋白、农缩蛋白等产品的生产均具有提高蛋白含量、增加得率的效用。     

不同酶解程度的大豆分离蛋白在配制酱油中的应用

以大豆分离蛋白为原料,对不同酶解程度的大豆分离蛋白在配制酱油中的应用进行了研究。首先通过单因素试验确定了酶解大豆蛋白的工艺参数,然后对添加不同酶解程度的大豆分离蛋白配制酱油的质量进行了研究,研究结果表明:酶解温度为50℃、pH为7.0、酶解时间为5h条件下的大豆分离蛋白酶解产物最适合应用到配制酱油中。     

Long-term consumption of beef extended with soy protein by men,women and children: II. Effects on iron status

The iron status of men, women and children consuming beef extended with soy protein was evaluated by measuring serum ferritin and clinical parameters of iron status during a six-month study. Fifty-two families (245 participants) were randomly assigned to consume, for 180 days, 1 of 7 beef products: all beef, beef extended with either soy isolate, soy concentrate or soy flour (20% reconstituted soy product, 80% beef), or beef extended with each of the three soy products fortified with 60 mg Fe and 25 mg Zn/100 g protein. The beef product was consumed by the subjects as their principal source of protein for 1 meal a day (children 1–18 yr) or 1–2 meals a day (11 per week; adult men and women). A control group consumed their usual self-selected diets. No evidence was found that consumption of beef extended with soy protein deleteriously affected the iron status of men, women or children. Consumption of beef extended with soy protein, at the levels used in this study, by military men and women and by school lunch participants would not appear to impose a risk in these population groups.     

Intracerebroventricular Administration of Soy Protein Hydrolysates Reduces Body Weight without Affecting Food Intake in Rats

Some studies suggest that increased consumption of soy protein hydrolysates may cause body weight loss but the mechanism of action is unknown. The objective of this investigation was to determine whether intracerebroventricular (i.c.v.) infusion of soy protein hydrolysates decrease food intake and body weight. Adult male Sprague Dawley rats (n = 24) received i.c.v. injections of soy hydrolysate I (SH I) or soy hydrolysate II (SH II) three times weekly for 2 weeks. Krebs solution and leptin were used as negative and positive controls respectively. SH I (6.5–20 kDa with a strong band at 14 kDa) was produced by hydrolysis with alcalase, and SH II (∼2 kDa) was obtained by hydrolysis and ultrafiltration. Leptin successfully reduced body weight (−1.60 g) 24 h (p = 0.0093) after the third injection. SH I caused significant (p = 0.0009) decreases in body weight (−1.70 g) 24 h after the third injection but not after 48 h. SH II showed a tendency to prevent body weight gain but this effect was short of statistical significance (p < 0.40). Food intake was not affected by any of the soy hydrolysate treatments but leptin injection did cause significant decreases in food intake (p < 0.05). Data suggest that soy alcalase hydrolysate can decrease, in the short term, the rate of body weight gain independently of food consumption. This preliminary data show that soy peptides may play a role on body weight regulation, possibly by increasing energy utilization.     

The impact of protein characteristics on the protein network in and properties of fresh and cooked wheat-based noodles

The relation between protein characteristics, protein network formation and wheat noodle properties was studied. Bovine serum albumin (BSA), soy glycinin, ovalbumin, S-ovalbumin and lysozyme were included in the recipe of wheat-based noodles. The characteristics of these non-wheat proteins impacted the type, rate and extent of protein network formation during noodle dough preparation and cooking, and thereby the properties of fresh and cooked noodles. None of the added proteins enhanced the properties of fresh noodles. BSA and soy glycinin enhanced Kieffer-rig extensibility parameters of cooked noodles. Addition of ovalbumin or S-ovalbumin led to excessive protein polymerization in cooked noodles and lowered their quality. Inclusion of lysozyme lowered the rate and extent of polymerization during cooking. Experiments in which urea, olive oil or urea were added in the recipe showed that non-covalent interactions dominate the properties of fresh noodles while covalent cross-links and hydrogen bonds mainly impact the properties of cooked noodles.