利用固定化酶改善酸法大豆浓缩蛋白持水性和吸油性的研究

利用固定化谷氨酰胺转胺酶(MTG)对酸法大豆浓缩蛋白(SPC)进行改性,并对改性SPC进行红外光谱分析。通过单因素和正交实验研究了MTG改性对SPC持水性和吸油性的影响。结果表明,当固定化MTG添加量1U/g,pH6.0,50℃下反应2h时,改性后大豆浓缩蛋白的持水性和吸油性分别比对照提高了24.8%和64.5%;与大豆分离蛋白相比,其凝胶性和吸油性分别高出58.3%和27.0%,持水性则低8.0%。     

改性大豆分离蛋白产品功能性及机理的研究

利用氮气和谷氨酰胺转胺酶(MTG)对大豆分离蛋白(SPI)进行复合改性.复合改性SPI的吸水性、保水性和吸油性分别比对照提高了121%、222%和150%;溶解性比对照降低了36%.经MTG改性后SPI可在分子间生成共价键,形成相对分子量较大的聚合物.复合改性可在MTG改性的基础上进一步增加SPI分子间的交联程度.     

储藏时间对大豆蛋白和谷朊粉的结构及功能特性的影响

为了探究储藏过程中组织化植物蛋白原料性质的变化，本研究对大豆分离蛋白（SPI）、大豆浓缩蛋白（SPC）和谷朊粉（WG）三种主要蛋白原料进行加速储藏实验，测定储藏过程中原料的羰基含量、巯基及二硫键含量、表面疏水性、溶解度、持水性、持油性和吸水率的变化。结果表明：到储藏期结束，SPI和SPC羰基含量大约分别增加144%和130%，游离巯基含量则在加速储藏15天显著降低，大约分别减少62%和67%；WG的羰基含量大约增加45%，游离巯基含量在储藏过程中缓慢下降，大约减少15%。随着储藏的进行，三种蛋白的二硫键含量和表面疏水性均先增加后降低，功能特性上SPI和SPC的溶解度分别从88.67%、78.69%降低到42.36%、25.22%，而WG溶解度却从6.78%增大到8.48%；三种蛋白质持水性均降低，其中SPC持水性下降程度大，达30%，WG吸水率没有显著性变化；SPI和WG的持油性先升高后降低，SPC的持油性则在加速储藏75天时出现显著性下降。这说明储藏期内蛋白质发生氧化反应，导致蛋白结构和功能特性发生变化，最终将影响组织化蛋白的品质特性。     

酸法去酰胺提高大豆分离蛋白持水性的研究

为了提高大豆分离蛋白(SPI)的持水性,采用HCl对SPI进行去酰胺改性。采用响应面分析法,以持水性为响应值,研究了HCl浓度、反应温度、反应时间对SPI持水性的影响。并对去酰胺改性前后的蛋白样品进行疏水性和电镜扫描(SEM)的测定与分析,结果表明:HCl对SPI能够发挥去酰胺作用,其酸法提高SPI持水性优化的工艺条件为HCl浓度0.21 mol/L、反应温度66℃、反应时间3 h。该条件下生产的SPI样品与未改性的SPI样品相比,持水性由5.60 mL/g提高到7.82 mL/g,提高了39.6%,其脱酰胺程度为24.5%。     

酶复合改性大豆分离蛋白相关功能性研究

利用微生物中性蛋白酶、微生物谷氨酰转氨酶(MTG)二者复合改性大豆分离蛋白(SPI),结果发现,双酶复合改性SPI的溶解性、吸水性、保水性和吸油性相关功能性显著增加,分别比对照提高了26.5%、48%、173%、35%,并经电镜观察改性SPI微观结构,探讨了SPI改性机理。     

桃仁清蛋白与大豆分离蛋白功能特性比较研究

为提高桃仁清蛋白(PKA)在食品工业中的应用,将其与大豆分离蛋白(SPI)对照,研究了PKA的溶解性、持水性、持油性、起泡性及泡沫稳定性、乳化性及乳化稳定性和凝胶性等功能特性.结果表明:与SPI相比,PKA具有很好的溶解性、泡沫稳定性、乳化稳定性及较低的凝胶质量浓度,持油性略高于SPI,但起泡性、乳化性及持水性较差;PKA溶解性受溶解条件影响较小.PKA具有良好的功能性质,适合作为食品添加剂或配料.     

热处理对葵花分离蛋白功能性质的影响

葵花分离蛋白(SPI)通过盐溶酸沉法从葵花籽中提取。将SPI配成8%的溶液(pH 7.0),分别在92℃,102℃和112℃下热处理20 min,分析热处理对SPI的溶解性、持水性、持油性、乳化性和起泡性的影响。结果表明,与SPI进行对比,热处理蛋白除了溶解性和泡沫稳定性,其他功能性质都有所改善;持水性和持油性随着热处理温度的升高而升高;在92℃和102℃热处理温度下起泡性提高;乳化性在92℃热处理温度下得到改善,而热处理后SPI乳化稳定性显著提高。     

不同制备方法桑叶蛋白功能性质的比较

以广东桑大10为原料,采用水提法制备叶蛋白浓缩液,用加热法、酸沉法、酸热法、盐析法沉淀叶蛋白,分别得到蛋白样品RC、SC、SR、LC。对所得样品进行功能性质测定,与大豆分离蛋白对比,得出不同样品的功能特点。结果表明,异亮氨酸、赖氨酸分别为桑叶粉的第一、第二限制性氨基酸。不同沉淀方法对叶蛋白的功能性质有显著影响:LC的溶解性、起泡性、乳化性、吸油性最好,均优于SC、SR及RC;SR的持水性优于SC及RC,但乳化性、起泡性较差;RC、LC的胶凝性最好。与SPI相比,4个样品的吸油性均优于SPI,持水性、胶凝性则显著低于SPI(p0.05);LC的乳化稳定性(68.57%)及SC的起泡性(40%)最好,显著优于SPI(54.86%、37.67%),RC与SPI相当,SR最差,显著低于SPI(p0.05)。LC电镜扫描结果显示其具有典型的蜂巢结构。     

功能性大豆浓缩蛋白性能测定及其应用研究

实验研究功能性(物理和酶法改性)大豆浓缩蛋白(FSPC)的NSI值、乳化能力、凝胶性、持水性及吸油性等变化。结果表明,功能性大豆浓缩蛋白NSI值明显提高,大豆蛋白功能特性有不同程度提高和改善;FSPC应用试验,即乳化体凝胶强度试验表明,FSPCI(物理改性)大豆浓缩蛋白有较好凝胶、乳化、持油和持水性;而FSPC2(酶法改性)大豆浓缩蛋白有较好溶解、乳化性。     

超声波-酶法联合改性提高酸性条件下大豆分离蛋白的乳化性能

为了研究超声波联合酶技术提高大豆分离蛋白(Soybean Protein Isolated,SPI)在酸性条件下(pH 4)乳化性能的效果,本文以大豆分离蛋白为原料,以乳化性能和乳状液粒径为衡量指标,确定超声波联合植酸酶-酸性蛋白酶(Ultrasound combined with phytase-acidic protease,Uphy-aci)改性方法的最适宜条件。研究发现,当SPI浓度6%,植酸酶添加量4 U/g,酸性蛋白酶添加量1500U/g,植酸酶与酸性蛋白酶的酶解时间分别为50 min和30 min时,改性后的SPI(pH 4)乳化性能明显增加,乳状液粒度减小;通过表面疏水性(H0)和扫描电镜(SEM)分析了超声波-酶复合改性处理的SPI,发现在酸性条件下,SPI表面疏水性含量为487.78,比未改性提高了71.2%,并呈现破碎均一、多孔的微观结构。因此,超声波与植酸酶-酸性蛋白酶联合改性提高酸性条件下SPI的乳化特性等功能性质,并且拓宽了大豆分离蛋白的应用领域。     

PARTICLE SIZE AND NONMEAT ADJUNCT EFFECTS ON THE PROTEIN FUNCTIONALITY OF BONELESS CURED PORK FORMULATED WITH PSE AND RFN RAW MATERIAL

A randomized complete block design with six replications was utilized to test the treatment effects of adjuncts (no adjuncts (C), 2% soy protein concentrate (SPC), and 2% SPC + 1.5% modified food starch (SPC + MFS)) and raw material size (2.54 ± 2.54 cm (CF) and 10 ± 10 cm (SF)) on the protein functionality in boneless cured pork produced from a combination of 25% PSE and 75% red, firm, and nonexudative (RFN) semimembranosus muscle. Utilization of the smaller raw material size, CF decreased (P < 0.05) expressible moisture, CIE L *, and CIE b* values and also decreased (P < 0.001) protein-protein bind. SPC and SPC + MFS were effective in decreasing (P < 0.05) cooking loss in the CF product. Formulations utilizing smaller particle size in a chunked and formed product demonstrate the potential to improve the water holding capacity and cooked color in deli ham rolls formulated from a combination of 25% PSE and 75% RFN pork.     

Utilization of response surface modeling to evaluate the effects of non-meat adjuncts and combinations of PSE and RFN pork on water holding capacity and cooked color in the production of boneless cured pork

Boneless cured pork was produced from combinations of pale, soft, and exudative (PSE) and red, firm, and non-exudative (RFN) semimembranosus muscle. Response Surface Methodology was utilized to determine the effects of soy protein concentrate (SPC), sodium caseinate (SC), and modified food starch (MFS) on the water holding capacity and cooked color in a chunked and formed product. Fifteen ingredient combinations were replicated three times for each PSE and RFN combination giving 75 treatments per replication. Utilization of SPC decreased (P<0.01) cooking loss and redness while increasing (P<0.01) yellowness. MFS decreased (P<0.01) expressible moisture, and both MFS and SC increased (P<0.05) cooked redness while decreasing (P<0.01) cooked lightness. Product formulations using these adjuncts demonstrate potential to improve the water-holding capacity and cooked color in PSE as well as RFN pork. This research also demonstrated that diluting RFN pork with no more than 25% PSE pork permits the formation of a high quality boneless deli ham roll.     

Effect of extra virgin olive oil substitution for fat on quality of pork patty

BACKGROUND: Extra virgin olive oil (EVOO) is well known for its beneficial effects on human health. Thus, the purpose of this study was to investigate the effect of EVOO substitution for backfat on qualities of pork patty to avoid high consumption of animal‐originated fat, because it is closely related to development of cardiovascular disease and obesity. RESULT: Water‐holding capacity was higher in control (lean pork + 10% backfat) and T3 (lean pork + 5% backfat + 5% EVOO + 0.5% isolated soy protein + 0.5% carrageenan + 0.5% maltodextrin) than T1 (lean pork + 5% backfat + 5% EVOO + 0.5% isolated soy protein) and T2 (lean pork + 5% backfat + 5% EVOO + 0.5% isolated soy protein + 0.5% carrageenan). Hardness was higher in EVOO substitution for backfat patty samples than control. In sensory evaluation, the control was significantly higher in overall acceptability compared with EVOO substitution for backfat pork patty samples. CONCLUSION: The physical properties of pork patty made by EVOO substitution for backfat were stable as a commercial pork patty (control). However, sensory evaluation scores were higher in control compared to EVOO‐substituted pork patty samples. Copyright © 2008 Society of Chemical Industry     

复乳凝胶作为脂肪替代物 对鸡肉肠理化性质的影响

本实验将海带水提多糖以0%、0.25%、0.5%、0.75%、1.00%、1.25%的浓度添加到复乳凝胶中,以改善其持水性和热稳定性。并将1.00%多糖复乳凝胶以0%、15%、30%、45%、60%、75%替代度替代猪背脂,分析其对鸡肉肠持水持油性、乳化稳定性、质构与感官的影响。随着海带多糖浓度的增加,复乳凝胶的持水性和热稳定性增加(P<0.05),当添加量大于1.00%时,硬度、粘聚性、咀嚼性显著降低(P<0.05)。随着复乳凝胶替代猪背脂比例增大,鸡肉肠的持油性、乳化稳定性、硬度和咀嚼性显著提高(P<0.05),L*值、b*值逐渐增大,a*值逐渐降低(P<0.05),当替代度为30%时,脂肪含量为9.29%;替代度为75%时,脂肪含量仅2.68%。感官评定结果显示,当替代度达到60%时,感官评分与对照组相似。由以上结果说明,复乳凝胶可替代鸡肉肠中60%的猪背脂,且保证了产品性质和质量。     

醇法大豆浓缩蛋白改性及在肉制品中的应用

采用醇法提取大豆浓缩蛋白具有明显优势,但此方法提取的大豆浓缩蛋白功能性不好,应用受限。本文介绍了通过物理、化学、酶法、基因工程等方法对醇法大豆浓缩蛋白进行改性,改性后醇法大豆浓缩蛋白的功能性明显提高。改性后的醇法大豆浓缩蛋白应用于肉制品中具有优良的持水持油性、乳化性以及凝胶性,可以提高肉制品的组织结构特性,并降低生产成本,且价格低廉,是一种性价比很高的大豆蛋白产品。     

7S球蛋白水解产物的功能特性及其对猪肉肠质构的影响

以中豆36为原料,提取7S球蛋白,用菠萝蛋白酶水解对其水解。研究了不同水解度酶解产物的、持水性、吸油性、乳化性、乳化稳定性及疏水性等功能特性,结果表明水解度为7%时7S球蛋白酶解产物的吸油性、持水性、疏水性最高。并将不同水解度的酶解蛋白添加到猪肉肠中,水解度为7%的酶解蛋白可以明显的改善猪肉肠的质构特性。     

11S球蛋白水解产物功能特性及其对猪肉肠质构影响

以中豆36为原料,提取11S球蛋白,用菠萝蛋白酶对其水解,研究不同水解度酶解产物的持水性、吸油性、乳化性、乳化稳定性及疏水性等功能特性;结果表明,水解度为5%时11S球蛋白酶解产物吸油性、持水性、乳化活性最高;并将不同水解度酶解蛋白添加到猪肉肠中,水解度5%酶解蛋白可明显改善猪肉肠质构特性。     

Chemical composition of alkaline-pretreated sugarcane bagasse and its effects on the physicochemical characteristics of fat-replaced sausage

The potential of cellulose from sugarcane bagasse used for pork sausage was investigated. The purity level of cellulose fibre from sugarcane bagasse and the functional characteristics in pork sausage were studied. The differences in the sugarcane fibre and sausage characteristics were strongly related to the cellulose/lignin content of the extracted cellulose under different amounts of bleaching. Bleached sugarcane fibres showed better water (3.55) and oil (2.34) holding capacity in comparison with untreated fibre (2.92 and 2.38, respectively). The sugarcane fibres in each treatment stage showed different effects on sausage properties. Sausages with 1% cellulose fibres added had an improved texture profile, but the addition of 3% cellulose fibres to sausages resulted in a higher cooking yield. Consumers considered the sensory characteristics of all sausages as acceptable. These results indicated that low levels of cellulose extracted from sugarcane bagasse could be added and maintain the inherent characteristics of meat products.     

海藻酸钠添加对大豆浓缩蛋白植物肉特性的影响

以大豆浓缩蛋白为原料，添加不同比例海藻酸钠并改变模头温度，利用双螺杆高水分挤压技术制备植物肉。通过组织化度、咀嚼度、颜色、扫描电子显微镜等指标表征植物肉的宏观结构和微观结构。通过比机械能、蒸煮特性、吸水率评价植物肉的结构性能。结果表明，海藻酸钠的添加可以提高植物肉的组织化度，增强咀嚼性。并且在模头温度为150 ℃时，所有挤压样品具有较好的组织化特性。比机械能和吸水率表明，海藻酸钠增强了蛋白质-蛋白质、蛋白质-水之间的相互作用，得到的植物肉持水性升高。扫描电子显微镜表明，过量的海藻酸钠会使产品形成致密的层状而非纤维状结构。因此，海藻酸钠添加量为6%时，通过高水分挤压技术可制备组织化程度高，蒸煮效果较好的大豆浓缩蛋白挤压植物肉产品。     

复合保水剂及异抗坏血酸钠对乳化肠乳化性的影响

研究复合保水剂芋头、卡拉胶、大豆分离蛋白和异抗坏血酸钠对乳化肠保水性与保油性的影响,以总压出汁液率、蒸煮损失、保油性和感官评定为指标,通过单因素试验和中心组合试验,运用响应面法优化工艺参数,建立多元二次回归方程,优选出乳化肠的保水性与保油性的最佳工艺参数。结果表明芋头添加量7.02%、卡拉胶添加量0.51%、大豆分离蛋白添加量5.13%、异抗坏血酸钠添加量0.06%时,与预测值基本一致。