豌豆蛋白质起泡、乳化功能特性研究初探

为了更好的利用豌豆蛋白质和提高产品副加值,研究了豌豆蛋白质的起泡性与乳化性.在FAI单因素试验中发现,在3%蛋白质浓度、1.75 mmol/LNaCl、50℃和pH值9.0时FAI较高.在3%蛋白质浓度、0.75 mmol/LNaCl、45℃和pH值8.0时FAI较高.运用统计学原理对FAI条件进行优化,发现在3%豌豆蛋白、pH值10.0、1.00 mmol/L NaCl和40℃时,FAI最好(375%).EAI单因素研究发现,在3%蛋白质浓度、0.75 mmol/LNaCl、45℃和pH值8.0条件下EAI较好,正交试验表明,在2%蛋白质浓度、pH值8.0、0.75 mmol/LNaCl和45℃条件下EAI最好.     

豌豆蛋白质起泡、乳化功能特性研究初探

试验研究了豌豆蛋白质的起泡性伊AD与乳化性（EAI）。在FAI单因素试验中发现,在3％蛋白质浓度、1．75mmol／LNaCl、50℃和pH9．0时FAI较高。运用统计学原理对FAI条件进行优化,发现在3％豌豆蛋白、pH10．0、1．00mmol／LNaCl和40℃时,FAI最好（375％）。EAI单因素研究发现,在3％蛋白质浓度、0．75mmol/NaCl、45℃和pH8．0条件下EAI较好,正交试验表明,在2％蛋白质浓度、pH8．0、0．75mmol／LNaCl和45℃条件下EAI最好。     

豌豆蛋白质起泡性与乳化性研究初探

研究了豌豆蛋白质的起泡性与乳化性.在起泡性(FAI)单因素试验中发现,在3%蛋白质浓度、1.75mmol/L NaCl、50℃和pH9.0时FAI较高.在3%蛋白质浓度、0.75mmol/L NaCl、45℃和pH8.0时FAI起泡性较高.运用统计学原理对FAI条件进行优化,发现在3%豌豆蛋白、pH10.0、1.00mmol/L NaCl和40℃时,FAI最好(375%).乳化性(EAI)单因素研究发现,在3%蛋白质浓度、0.75mmol/L NaCl、45℃和pH8.0条件下EAI较好,正交试验表明,在2%蛋白质浓度、pH8.0、0.75mmol/L NaCl和45℃条件下EAI最好.     

豌豆蛋白酶法水解及产物特性研究

为研究豌豆蛋白质酶解前后功能特性变化,利用Alcasase2.4L碱性蛋白酶对其限制性酶解,对酶解水解度动态变化、蛋白质回收率及酶解产物功能特性等方面进行研究。试验结果表明,Alcasase2.4L碱性蛋白酶能够有效酶解豌豆蛋白,蛋白质回收率可达84%,与豌豆原蛋白相比,在pH 2～12范围内,不同水解度的酶解产物溶解性均有明显改善,最高可达95%左右。5%水解度的酶解产物乳化性、乳化稳定性、起泡性和泡沫稳定性相比豌豆蛋白均较好,但随着酶解的进一步进行,其乳化和起泡特性均呈下降趋势。     

牛血清白蛋白的乳化和起泡特性

研究蛋白质量浓度、pH 值、CaCl2 质量浓度和温度对牛血清白蛋白(BSA)的乳化性、乳化稳定性、起泡性和起泡稳定性的影响。结果表明：蛋白质量浓度为0.1g/100mL 时乳化性和乳化稳定性最大,pH 值为5 时乳化性和乳化稳定性最小,乳化性随着CaCl2 质量浓度的增加而缓慢增大,乳化稳定性随着CaCl2 质量浓度的增加而减小,60℃时乳化性较好,乳化稳定性在60℃后显著下降;随着蛋白质质量浓度的增加,起泡性呈上升趋势,起泡稳定性先上升后下降,在质量浓度为1.5g/100mL 时起泡稳定性最好;pH 值为5 时起泡性最小,而此时起泡稳定性最好;CaCl2 质量浓度对起泡性和起泡稳定性没有影响。     

豌豆蛋白的起泡性和稳定性的研究

植物源蛋白如豌豆蛋白是一种很有前途的动物蛋白替代品,近年来因其高营养价值和潜在的环境友好性而受到欢迎。通过加深对豌豆蛋白以及其泡沫的知识了解,可以建立对植物源性蛋白溶液的泡沫特性认知,拓宽豌豆蛋白在食品工业中的应用。因此,文章综述了国内外对于豌豆蛋白溶液发泡特性的一些研究和目前进展,包含泡沫的发泡性、泡沫稳定性、发泡剂、与泡沫实验有关的检测方式及影响因素。这篇综述将为豌豆蛋白的泡沫特性的控制和优化提供参考。     

黑龙江省主栽红小豆品种蛋白质功能性质分析

黑龙江省是红小豆的主要产区之一,为深入了解黑龙江省主栽红小豆蛋白质功能特性,本研究利用荧光及紫外分光光度法对农安红、状元红、农垦红二号、品鉴红、宝清红等五种红小豆蛋白质功能性质进行了测定分析。结果表明：五种红小豆蛋白质含量为19.32%-24.36%;在pH 4.0左右时,蛋白质溶解性最低;宝清红红小豆蛋白质游离巯基及总巯基含量均最高,分别为33.4±5.6 μmol/g和61.6±3.2 μmol/g;农垦红二号蛋白质疏水性最强,为425.5±0.5;五种红小豆蛋白质起泡性随质量浓度增大呈现先升高后降低的趋势,当质量浓度为6 g/100 mL时达到最大值;五种红小豆蛋白质起泡稳定性、乳化性、乳化稳定性、吸水性均随蛋白质浓度的增加而增大,吸油能力随着蛋白质所占比例的减小而增强;宝清红和农垦红二号凝胶点较低,在蛋白质浓度为11 g/100 mL就可以形成凝胶,当蛋白质质量浓度为13 g/100 mL时,五种红小豆蛋白质均产生凝胶现象。     

燕麦胶的乳化性和起泡性研究

以裸燕麦麸皮为原料,提取得到富含β-葡聚糖的燕麦胶。研究了燕麦胶的乳化性和起泡性,结果显示,燕麦胶具有一定的乳化性和起泡性能,其乳化性和起泡性及其乳化和起泡稳定性与浓度、温度和pH值有关。燕麦胶还具有较低的表面张力和界面张力,随着浓度的增加表面张力和界面张力下降。燕麦胶的黏性和界面张力是影响乳化性和起泡性的主要因素。这些特性都表明了燕麦胶在食品中的潜在应用价值。     

大豆蛋白质的构造和功能特性(中)

介绍了大豆蛋白质的组成、氨基酸成分、分子结构、溶解性，着重分析了大豆蛋白的食品功能特性中的乳化性、起泡性、水化性、凝胶性的相互关系以及这些特性与组成结构的关系，对大豆蛋白产品的生产提供了一定的理论依据和参考。     

籽粒苋蛋白质功能特性的研究(I)——籽粒苋蛋白质乳化性、持水力的研究

采用碱性提取和等电点法分离出籽粒苋蛋白质,测定了不同浓度、pH值、离子强度、蔗糖浓度条件下的蛋白质乳化能力、乳化稳定性、持水力,探讨了籽粒苋蛋白质在不同条件下乳化性和持水力的变化规律,为籽粒苋蛋白质在食品加工中的应用提供了一定的理论依据。     

酶法水解对罗非鱼下脚料蛋白功能特性的影响

以罗非鱼下脚料为原料,采用Alcalase蛋白酶、中性蛋白酶、风味蛋白酶对其进行控制酶解,通过pH-stat法控制水解程度,制备不同水解度(1.0%～15.0%)的罗非鱼下脚料酶解蛋白,探讨酶的种类和水解度对其乳化性和发泡性的影响。结果表明:在水解度较低(3.0%～5.0%)时,酶解蛋白的乳化性和发泡性较好,随着水解度进一步增大,酶解蛋白的乳化性和发泡性均降低;比较而言,由中性蛋白酶水解得到的酶解蛋白乳化性较好,而风味蛋白酶水解得到的酶解蛋白发泡性较好;此外,pH值(2～10)对轻度酶解蛋白的乳化性和发泡性影响较大,在pH 4.0～5.0范围内,酶解蛋白的乳化性和发泡性最差。     

干热处理对大豆分离蛋白乳化与起泡性能的影响

研究了60℃、80℃和90℃下干热处理对大豆分离蛋白乳化和起泡性能的影响.研究发现,干热处理4 d使大豆分离蛋白的乳化活性增加到最大值,其乳化稳定性也增加到接近最大值的水平,长时间的热处理降低大豆分离蛋白的乳化活性;60℃干热处理1 d使大豆蛋白的膨胀率增加到最大值880%,此后随热处理时间的延长而持续下降,80℃和90℃热处理降低了大豆分离蛋白的泡沫稳定性;干热处理使大豆分离蛋白7S亚基各组分和部分11S酸挂亚基发生共价聚合形成高分子量的聚合物.     

Effects of Phosphorylation on Emulsifying and Foaming Properties and Digestibility of Yeast Protein

Phosphorylated yeast protein (PYP) (73% protein, < 3% nucleic acid) was prepared from yeast nucleoprotein by chemical phosphorylation using phosphorus oxychloride. The emulsifying activity index (EAI) of PYP was low at pH 5 but exceeded that of BSA at pH 7.0. The emulsions were stable after heating to 90°C for 60 min. The stability of foams made with PYP increased from t_1/2 1.5 to 13 min as pH was increased from 5 to 8. Foams made from PYP were weak but increased with protein from 0.1 to 0.5 mg/100 mL. The PYP were easily digested by pepsin and pancreatin indicating negligible inhibition by phosphorylation.     

Solubility, Emulsifying, and Foaming Properties of Rice Bran Protein Concentrates

Rice bran protein concentrates were prepared from full-fat and defatted raw rice bran. Selected functional properties, viz. nitrogen solubility, emulsification properties, and foaming properties were measured over the pH range 2.0 to 10.5 and in three dispersion media including water, 0.1M NaCl (low salt) and 1.0M NaCl (high salt). Below and above the isoelectric pH (4.5) the nitrogen solubility increased. Higher pH enhanced the nitrogen solubility and, thereby, considerably improved the functional properties. In higher salt concentration, nitrogen solubility was reduced which also altered the properties of emulsification and foaming. Multiple regression analysis showed that pH was the primary determinant of nitrogen solubility, emulsification and foaming properties. Multiple regression models including pH, salt concentration and nitrogen solubility as independent variables were found to be more accurate in predicting other functional properties.     

Predicting Protein Functionality with Artificial Neural Networks: Foaming and Emulsifying Properties

Using physicochemical properties of 11 food-related proteins, artificial neural networks (ANN) were developed for predicting foam capacity and stability and the emulsion activity index. The prediction accuracy of ANN was compared to that of principal component regression (PCR) models. ANN had better prediction ability than PCR, especially after cross-validation. For foam stability, PCR did not generate a significant model. ANN and PCR models indicated that fluorescence probe hydrophobicity (measured using cispsrinaric acid) and other properties, such as viscosity, surface tension and net charge were important in predicting foam capacity and stability.     

Foaming and Emulsifying Properties of Whey Protein Concentrates As Affected by Lipid Composition

Freeze-dried WPC, containing 35 and 75% protein were manufactured by pretreating whey with calcium chloride and heat. These and commercial WPC were subjected to proximate analysis and lipid classes, phospholipid classes, free fatty acids (FFA), and monoacylglycerols (MAG) composition were determined. Solubility, thermal, foaming, and emulsifying properties of the WPC were studied. Pretreatment increased calcium and phosphorus contents and decreased the contents of all other minerals. The pretreatment had no effect on solubility, denaturation enthalpy, and onset temperature of denaturation of WPC. These values were comparable to those of commercial WPC. Foaming capacity and emulsion stability were unaffected, but foam stability increased and emulsifying capacity decreased due to pretreatment. Overall, total lipids and lipid class contents of experimental WPC were too low to affect surface properties of WPC.     

Compositional Factors That Affect the Emulsifying and Foaming Properties of Whey Protein Concentrates

An emulsion containing 30% fat was used to study emulsifying and foaming properties of commercial whey protein concentrates. Residual lipids, both total and phospholipids, inhibited foaming of dilute aqueous solutions of whey protein concentrates, whereas in aerated emulsions residual lipids were positively correlated with foaming. Under both test conditions the ash content was positively correlated with good and moderate foaming properties. Among the compositional factors which best predicted foaming of emulsions were sulfhydryls. Emulsions which contained insoluble whey proteins were highly stable but air incorporation was poor. When soluble whey proteins were utilized to stabilize emulsions, serum separation occurred more readily but did not correlate with good foaming properties.     

干热处理下焦磷酸钠改性大豆蛋白乳化和起泡性质研究

研究了在80℃干热条件下焦磷酸钠改性大豆蛋白的乳化和起泡性质。研究发现:改性大豆蛋白的乳化性质和起泡性质得到明显的改善,蛋白质结合磷的量随干热处理时间的延长而增加。在干热处理前对大豆蛋白进行适度的预热处理大大提高了蛋白质结合磷的量,80℃预热处理10min使改性大豆蛋白表现出最好的乳化性质,而预热处理20min的改性蛋白质却表现出最好的起泡性质。红外光谱分析发现,焦磷酸钠以磷酸根的形式与蛋白质分子的游离羟基缩合。SDS-凝胶电泳表明,焦磷酸钠能抑制干热处理时大豆蛋白各亚基之间的聚合作用,从而提高其功能性质。该研究为大豆蛋白的改性提供了新的思路。     

Emulsifying and Foaming Properties of Protein Concentrates Prepared from Cowpea and Bambara Bean Using Different Drying Methods

Effect of cabinet-drying, vacuum-drying, and freeze-drying methods on the surface hydrophobicity, secondary structure, emulsifying, and foaming properties of protein concentrates prepared from different cultivars of cowpea and Bambara bean was investigated. The vacuum-drying method reduced hydrophobicity, while freeze-dried concentrates presented high hydrophobicity. The concentrates prepared by freeze drying presented more β-sheet (40–43%) and less β-turn (19–24%) structures. Bambara bean protein concentrates prepared by freeze-drying presented higher emulsifying activity (56–59%) compared to those by vacuum-drying and cabinet-drying, while emulsifying activity varied significantly among cultivars of cowpea (46–61%). Protein concentrates prepared by cabinet-drying showed the highest foaming ability.