Mass transfer process of peanut protein extracted by bis(2-ethylhexyl)sodium sulfosuccinate reverse micelles

The liquid-liquid extraction method using reverse micelles can simultaneously extract lipid and protein of oilseeds,which have become increasingly popular in recent years.However,there are few studies on mass transfer processes and models,which are helpful to better control the extraction process of oils and proteins.In this paper,mass transfer process of peanut protein extracted by bis(2-ethylhexyl)sodium sulfosuccinate(AOT)/isooctane reverse micelles was investigated.The effects of stirring speed(0,70,140,and 210 r/min),temperature of extraction(30,35,40,45,and 50℃),peanut flour particle size(0.355,0.450,0.600,and 0.900 mm)and solidliquid ratio(0.010,0.0125,0.015,0.0175,and 0.020 g/mL)on extraction rate were examined.The results showed that extraction rate increased with temperature rising,particle size reduction as well as solid-liquid ratio increase respectively,while little effect of stirring speed(P>0.05)was observed.The apparent activation energy of extraction process was calculated as 10.02 kJ/mol and Arrhenius constant(A)was 1.91 by Arrhenius equation.There was a linear relationship between reaction rate constant and the square of the inverse of initial particle radius(1/r_(0)^(2))(P<0.05).This phenomenon and this shrinking core model were anastomosed.In brief,the extraction process was controlled by the diffusion of protein from the virgin zone interface of particle through the reacted zone and it was in line with the first order reaction.Mass transfer kinetics of peanut protein extracted by reverse micelles was established and it was verified by experimental results.The results provide an important theoretical guidance for industrial production of peanut protein separation and purification.

Peanut proteins:Extraction,modifications,and applications:A comprehensive review

As naturally sourced proteins,peanut proteins have garnered significant attention from the food industry,owing to their numerous advantages,such as easy extraction,non-pungency,and high bioavailability.Furthermore,peanut proteins are highly digestible in the gastrointestinal tract and boast a high net protein utilization rate,making them an appealing protein source in food products and a promising alternative to animal protein.In this paper,the recent works on the extraction method,modification method,and application of peanut proteins were reviewed.Both advantages and disadvantages of current extraction and modification were discussed.Recently updated information about peanut protein research was summarized.Based on these,the prospection of peanut proteins research was presented,which may be instructive for future research in this field.Future research is still needed for accessible modification methods to develop the functional properties of peanut proteins.

Impact of hot alkali modification conditions on secondary structure of peanut protein and embedding rate of curcumin

This study aimed to modify isolated and extracted peanut protein with hot alkali to study the impact of pH,heating temperature,processing time and other alkali liquor conditions on the molecular structure of the peanut.Curcumin was loaded in modified peanut protein.The results of the study are as follows:Within the alkaline range of 8<pH<12,the percentage of amino acid residue(AAR)and-turns first increased and then decreased with the increasing pH,and the percentage of AAR reached a maximum 5.21±0.33%when the pH was 11(p<0.01).The percentage of˛-helices andβ-sheets gradually decreased with increasing pH,while that of random coils gradually increased with increasing pH,reaching a maximum 11.24±0.87%when the pH was 11(p<0.05).Within the range of the heating temperature 75℃<T<95℃,the percentage of random coils andβ-sheets gradually increased with increasing heating temperature,while that of-helices and AAR gradually decreased with increasing heating temperature;they remained unchanged when the heating temperature was 90℃,and then decreased to(10.41±1.18%;p<0.01)and(4.02±2.12%;p<0.01),respectively.Within the range of 5 min<t<20 min,the percentage of random coils and AAR gradually increased with increasing heating time,while the percentage ofα-helices decreased from 11.83±1.04%to 10.75±2.34%with increased heating time(p<0.01).The optimum conditions for hot alkali modification of peanut protein as followed:heating temperature of 90℃,heating time of 20 min and a pH of alkali liquor of 11.Under these optimum conditions,the embedding rate of curcumin by the modified protein can reach 88.32±1.29%.

Size Changes of Reverse Micelles after Extraction of Peanut Protein and Their Forward Extraction Rates

The aim of this study was to detect the size changes of reverse micelles after extraction of peanut protein and their forward extraction rates. Factors that affect the size of reverse micelles and the extraction of peanut protein were also investigated. The size of reverse micelles and the size changes were measured according to the theory of dynamic light scattering under different conditions such as different sodium bis(2-ethylhexyl) sulfosuccinate(AOT) concentrations, p H values, ion concentrations, and salt species.With the increase of AOT surfactant concentrations in a certain range, the size of empty and full reverse micelles increased and the forward extraction rate decreased. The effect of pH on empty reverse micelles was not significant. However, the effect of pH on the full reverse micelle size and forward extraction rate were significant. Its forward extraction rate increased to the maximum39.6% at pH 7.5. The increase of the salt concentration of a buffer solution in a certain range decreased the size of empty and full reverse micelles and reduced the forward extraction rate of peanut protein. Ionic species had important effects on reverse micelles and peanut protein extraction. An increase in the amount of buffer solution enlarged the empty reverse micelle size in 0.03%-0.11%(V/V). However, it did not translate to a larger reverse micelle size. The size of the empty reverse micelles containing K_2SO_2 reached 24.1 nm with a 0.19%(V/V) buffer solution added. The sizes of the full reverse micelles were larger than those of the empty reverse micelles after forward extraction. However, maximum sizes were achieved with the addition of a 0.03%(V/V) buffer solution. The amount of 0.03%(V/V) buffer solution added was appropriate for extracting peanut protein.

Rheological properties and fractal-rheology analysis of peanut protein isolate suspension

This study focuses on the non-linear rheological property and microstructure of peanut protein isolate(PPI)aggregation suspension.The impact of higher harmonics(I3 and I5)on fundamental stress wave during large amplitude oscillatory shear test was studied.Rheological test show that storage modulus G′and loss modulus G″increased with increasing PPI concentration.The non-linear viscoelastic properties of PPI suspension with different concentration were investigated.Using confocal laser-scanning microscopy method,this research explored the microstructure of PPI suspension as well as the fractal dimensions.The new critical strain indirect method combined with Wu-Morbidelli model to calculate the fractal dimension(2.9225)is very close to the actual fractal dimension(2.9206).Fourier Transform Rheology was adopted to get the new critical strain for fractal dimension calculation,which was proved to be feasible.

Rheological properties of peanut protein isolate aggregation suspension and acid-induced gel

The dynamic rheological properties of peanut protein isolate(PPI)suspension and acid-induced PPI gels were studied.In frequency sweep test,the storage modulus(G′)and the loss modulus(G″)of PPI aggregation suspensions at different concentrations increased with the increase of frequency.The steady state shear flow test showed that PPI aggregation suspension had a thinning behavior of the shear,and the image of steady shear curve fitted the Carreau model.After gel formation,acid-induced PPI gels showed a typical Type I behavior(strain thinning)in strain sweep test,meaning that PPI gel got easily broken down,and there was a very small opportunity for the protein molecules to re-establish the network.Compared with the strain sweep of PPI aggregation suspensions and gels,the range of the storage modulus existed a dramatic difference,which could get about tenfold.As the frequency increased,both elasticity and viscosity increased in frequency sweep test,which indicated that the frequency dependence of the storage modulus increased with the increase of concentration.

Rapid and Non-destructive Prediction of Protein Content in Peanut Varieties Using Near-infrared Hyperspectral Imaging Method

This study was undertaken to investigate the feasibility of near-infrared(NIR) hyperspectral imaging(1 000–2 500 nm) for non-destructive and quantitative prediction of protein content in peanut kernels. Partial least squares regression(PLSR) calibration model was established between the spectral data extracted from the hyperspectral images and the reference measured protein content values, with the coefficient of determination of prediction(R_P^2) of 0.885 and root mean square error of prediction(RMSEP) of 0.465%.Regression coefficients(RC) from PLSR analysis were used to identify the most essential wavelengths that had the greatest influence on changes in the protein content. Eight optimal wavelengths were selected by RC and its corresponding simplified RC-PLSR prediction model was also obtained, showing better performance with a higher R_P^2 of 0.870 and a lower RMSEP of 0.494%. The results indicate that hyperspectral imaging with PLSR analysis can be used as a rapid and non-destructive method for predicting protein content in peanut.

不同植物蛋白肉坯料的香气和质地分析

为研究不同植物蛋白肉坯料的香气和质地,以花生、小麦、豌豆3种植物蛋白粉为原料,利用高温螺杆挤压技术,控制成型区温度制备植物蛋白肉坯料,采用气相色谱-串联质谱仪和质构分析仪对喜好度最佳的坯料进行香气和质构分析。结果显示,花生、小麦、豌豆蛋白肉坯料的最佳成型区温度分别为140、100、150℃,3种植物蛋白肉坯料均有较强的豆香、豆腥和油脂香气,其中豌豆蛋白肉坯料的豆香最强。香气分析结果显示,花生蛋白肉坯料的特征香气物质为庚醇、(2 E,4E)-癸二烯醛和苯甲醛,小麦蛋白肉坯料的特征香气物质为2-庚酮、庚醇和(E)-2-壬烯醛,豌豆蛋白肉坯料的特征香气物质为2-庚酮、甲基辛基甲酮、2-乙基-3,5-二甲基吡嗪和2-乙基-3,6-二甲基吡嗪。不同复水方法比较结果显示,花生蛋白肉坯料和豌豆蛋白肉坯料适合在50℃温度下复水,而小麦蛋白肉坯料适合在室温(25℃)下复水。小麦蛋白肉坯料复水后硬度、黏附性和咀嚼力最高,豌豆蛋白肉坯料的硬度、黏附性和咀嚼力最低。研究结果旨在为植物蛋白肉坯料风味品质提升和应用提供科学依据。

TG酶耦合糖基化改性花生饼蛋白质功能特性及其在面包中应用研究

采用谷氨酰胺转氨酶(TG酶)耦合糖基化改性花生饼蛋白质,并研究改性花生饼蛋白质的功能特性及其在面包中的应用。结果表明:B组(花生饼蛋白质与葡萄糖质量比4:1)与未改性花生饼蛋白质相比,面包感官评分最高。改性后花生饼蛋白质的乳化活性和起泡性显著提高。与空白组相比,B组制作的面包的比体积、含水量、弹性显著增加,硬度显著降低。B组面包室温储存10d的霉菌数量略高于A组(花生饼蛋白质与葡萄糖质量比3:2)。

近红外光谱法快速检测花生籽仁主要品质指标定量模型的研究

建立花生籽仁粗蛋白、粗脂肪、油酸、亚油酸含量的近红外光谱快速测定方法。利用波通DA7200型近红外分析仪采集近红外光谱,采用凯氏定氮法、索氏提取法分别测定粗蛋白、粗脂肪的含量,采用气相色谱法测定油酸、亚油酸的相对含量,采用偏最小二乘法,构建花生籽仁主要品质指标含量的近红外预测模型。结果表明,模型对花生籽仁粗蛋白、粗脂肪、油酸、亚油酸含量的决定系数分为0.9270、0.9647、0.9915、0.9915,均方根误差分别为0.8702、0.5631、1.6671、1.4040。经外部验证,独立测试集决定系数分别为0.9608、0.9460、0.9605、0.9492。该模型对花生籽仁粗蛋白、粗脂肪、油酸、亚油酸含量的预测准确,可实现花生籽仁主要品质指标的快速、无损测定,提升高品质花生新品种的育种效率。

近红外光谱技术对花生蛋白组分与亚基的高通量模型建立

花生是一种优质植物蛋白资源,花生蛋白组分与亚基含量显著影响其功能特性,决定了其在食品领域的应用范围,花生蛋白主要包括花生球蛋白和伴花生球蛋白,其中花生球蛋白包含4个亚基(40.5、37.5、35.5和23.5 kDa),伴花生球蛋白Ⅰ包含3个亚基(15.5、17和18 kDa),伴花生球蛋白Ⅱ只含有1个61 kDa亚基。为了实现花生蛋白主要组分及亚基的快速无损、高通量、高灵敏度检测,以全国145份优质花生样品为研究对象,首先采用便携式近红外花生品质速测仪,在900~1700 nm波长范围内对不同花生样品进行光谱采集,再采用聚丙烯酰胺凝胶电泳法测定了花生蛋白组分与亚基含量,花生球蛋白的亚基含量在44.3%~67.3%之间;伴花生球蛋白亚基含量在35.2%~55.7%之间;61 kDa亚基含量在13.5%~25.3%之间;40.5 kDa亚基含量在6.8%~16.0%之间;37.5 kDa亚基含量在6.9%~17.4%之间;35.5 kDa亚基含量在5.7%~19.2%之间;23.5 kDa亚基含量在18.7%~27.4%之间;18 kDa亚基含量在5.9%~11.7%之间;17 kDa亚基含量在6.9%~13.6%之间;15.5 kDa亚基含量在4.5%~11.9%之间,分别对比归一化(Normalize)、一阶导数(FD)和二阶导数处理(SD)、基线校准(Baseline)、去趋势(Detrend)、多元散射校正(MSC)和数据元素解析处理(Deresolve)这7种光谱预处理方法,结合主成分分析(PCA)和偏最小二乘法(PLSR),优化了2个蛋白组分和2个亚基(花生球蛋白、伴花生球蛋白、37.5和23.5 kDa)的近红外光谱模型,构建了6个亚基(61、40.5、35.5、18、17和15.5 kDa)的近红外光谱模型,实现了对上述10个指标的同步检测。结果表明,确定最优预处理方式后建立的模型校正集相关系数(R_(cal))为0.90~0.96,校正均方根误差(SEC)为0.25%~1.27%;预测集相关系数(R_(cp))为0.76~0.96,预测均方根误差(SEP)为0.50%~1.81%,具有很好的预测能力,可用于花生品种蛋白组分与亚基含量的快速检测,为花生蛋白品质的快速评价提供了新方法。

花生品种对水酶法制油水相体系中油脂和蛋白质分布的影响

为了明确花生品种对水酶法制油的影响,测定了不同品种花生(豫花23、豫花37、豫花9326)的基本成分,并研究了水酶法制油工艺条件对不同品种花生水相体系中油脂和蛋白质分布的影响。结果表明:3个花生品种中,豫花37的油脂、水分、灰分、可溶性糖、可溶性总酚含量均最高,豫花23的蛋白质含量最高(25.36%),豫花9326的粗纤维含量最高(6.59%);花生品种对水相体系中油脂和蛋白质的分布有显著影响;以水相体系中低油脂和高蛋白质分布为准则得到水酶法制油的最佳工艺条件为豫花37的粉碎时间90 s、豫花23和豫花9326的粉碎时间120 s,酶用量1.0%,酶解时间2 h,酶解温度50℃,此时豫花23、豫花37、豫花9326在水相体系中油脂分布分别为6.21%、4.19%、4.19%,蛋白质分布分别为50.99%、75.68%、63.84%。综上,豫花37能在更短的粉碎时间内使水酶法制油过程中花生水相体系中的油脂分布少,蛋白质分布多,更适用于水酶法制油。

红茶-花生蛋白复合饮品工艺优化及其营养特性研究

以红茶、花生为主要原料,脱脂奶粉、白砂糖为辅料,研制一款营养丰富、口感良好的红茶-花生蛋白复合饮品,并基于感官评分、蛋白质含量、脂肪含量、渗透压等指标研究该复合饮品的最佳工艺条件及营养特性。结果表明:红茶-花生蛋白复合饮品的最佳工艺条件为花生蛋白浆与红茶汁体积比1∶2、脱脂奶粉添加量10%、白砂糖添加量2%,在此条件下,所制备复合饮品的感官评分最高(86分),蛋白质含量为5.51 g/100 g,脂肪含量为5.90 g/100 g,总酚含量为139.04μg/mL,总黄酮含量为258.98μg/mL,脂肪液滴分布均匀且平均粒径(7.54μm)较小,渗透压(336.00 mmol/kg)接近人体血液渗透压,可满足消费者对感官品质和健康饮食的要求。

新型混炼单螺杆植物蛋白挤出机的仿真分析与参数优化

为了提高单螺杆挤出机中花生蛋白的挤出品质,基于拉伸应力的破碎效应,以传统单螺杆挤出机为参照,利用有限元软件CFX计算了花生蛋白在流场中的运动情况,通过压力场、速度流线场以及应变速率场,分析新型混炼单螺杆挤出机的特性,并以拉伸流变学理论对设计原理进行验证,同时采用响应面法对新型混炼单螺杆挤出机的工艺参数进行优化。结果表明:新型混炼单螺杆挤出机中混炼元件的分流作用使得沿挤出方向产生了压力降,物料发生回流,导致建压性能降低,从而延长了停留时间,此处因回流效果产生的局部高压也有利于压延,物料在流经抛物线曲面时既能经历周向拉伸,又能经历径向拉伸,分散混合效果更好;经模拟计算,发现新型混炼单螺杆挤出机的平均应变速率相较于传统单螺杆挤出机提高了16.5%,使得挤出产品质量更优;各因素对花生蛋白平均应变速率的影响顺序依次为螺杆转速、收敛比、分割棱厚度,新型混炼单螺杆挤出机最优工艺参数为螺杆转速128 r/min、收敛比6.6、分割棱厚度3.1 mm,在此条件下花生蛋白的理论平均应变速率为50.945 s^(-1)。综上,新型混炼单螺杆挤出机中由于拉伸流场的形成,有效提高了花生蛋白的挤出品质。

酸性pH偏移协同超声处理对花生蛋白结构与功能性质的影响

为进一步改善花生蛋白功能特性,以水剂法提取的花生蛋白为研究对象,考察了pH 1.5和2.5偏移或结合超声处理对花生蛋白结构与功能性质的影响。结果表明:与未处理蛋白相比,经不同方式处理后花生蛋白的亚基发生了一定程度的降解,粒径、绝对电位降低,而表面疏水性显著增加;与单独pH偏移处理相比,复合改性使蛋白的结构更加伸展;不同方式处理后的花生蛋白降低油水界面张力的能力增强,乳化活性和稳定性均增加,其中pH 1.5偏移结合超声处理使花生蛋白的乳化稳定性增加了2倍;pH 1.5偏移处理后的蛋白具有最高的弹性模量,可能与其暴露游离巯基含量最高以及绝对电位最低的结构性质有关。pH 1.5偏移或结合超声处理能够显著改善花生蛋白的功能性质。

超声改性对花生蛋白乳液凝胶荷载姜黄素性能的影响

为提高姜黄素的生物利用度,以花生蛋白为乳化剂制备荷载姜黄素的乳液凝胶,考察了蛋白超声改性对姜黄素的包埋率、稳定性和体外消化特性的影响。结果表明:花生蛋白质量浓度为4 g/100 mL时所制备的乳液姜黄素包埋率最佳;中强度(200 W,20 min)或高强度(600 W,20 min)超声改性使蛋白乳液粒径减小,姜黄素的包埋率增加至99.14%±0.05%,同时提高了姜黄素在乳液凝胶中的储藏稳定性和光稳定性;经中强度超声改性后,花生蛋白乳液凝胶中姜黄素的生物利用度(29.80%±0.83%)和脂肪酸释放率(83.24%±1.28%)均为最高;中或高强度超声改性显著提高了蛋白乳液凝胶的弹性模量(G′)。适当超声处理减小了花生蛋白乳液粒径,改善了乳液凝胶的质构特性,由此提升了乳液凝胶荷载姜黄素的性能。

酶解联合糖基化对花生蛋白结构及功能特性的影响

利用木瓜蛋白酶有限酶解花生分离蛋白,再与葡聚糖在80℃下进行湿法糖基化反应2~6 h,研究糖基化对花生分离蛋白酶解物结构及功能特性的影响。结果表明,糖基化反应后花生分离蛋白酶解物具有较高的接枝度,紫外光谱和内源荧光光谱表明其空间结构发生改变,傅里叶变换红外光谱结果证实花生分离蛋白酶解物与葡聚糖发生糖基化反应。通过对复合改性后花生分离蛋白功能特性进行评价,发现花生分离蛋白的溶解度在pH3~7内均有所改善,反应4 h的糖基化产物在pH7时溶解度达到最高,为91.56%,较相同pH值下的花生分离蛋白提高1.77倍。经过4 h的接枝反应后花生分离蛋白酶解物的乳化活性最高,达到61.08 m^(2)/g,较花生分离蛋白提高5.28倍。此外,有限酶解和糖基化反应能够明显降低花生分离蛋白的表面疏水性、提高花生分离蛋白的抗氧化活性。因此,通过酶解和糖基化复合改性能够有效改善花生蛋白的功能特性,扩大其应用范围。

227个花生品种(系)蛋白质及10种主要氨基酸遗传多样性分析

为深入了解花生籽仁蛋白质及主要氨基酸的遗传特性,为蛋白品质改良提供理论依据,本研究利用多功能近红外分析仪,测定227个花生品种(系)的蛋白质及10种主要氨基酸含量,并进行遗传多样性分析、相关性分析、聚类分析和主成分分析。结果表明,蛋白质及氨基酸含量共11个性状的变异系数以脯氨酸含量为最高,超过12%;赖氨酸含量次之,超过10%,其最小值与最大值相差一倍,改良潜力较大;其余性状的变异系数均小于6%。相关性分析结果表明,蛋白质含量与10种氨基酸含量均呈显著正相关,脯氨酸含量与蛋氨酸和苏氨酸含量间相关不显著,与缬氨酸含量显著负相关,其余氨基酸含量间均呈显著正相关。聚类分析将227个参试品种(系)分成三类,其中高蛋白及高氨基酸含量的10个品种(系)聚在第Ⅰ类。主成分分析结果表明,前3个主成分的累计贡献率达84.32%,其中第1主成分主要包括非极性氨基酸的异亮氨酸、亮氨酸、苯丙氨酸、精氨酸及蛋白质,贡献率接近60%;根据综合得分筛选出22个综合性状优良品种(系)。综上表明,参试品种(系)的蛋白质及氨基酸含量共11个性状具有不同程度差异,遗传多样性丰富。该结论可为花生品种蛋白品质改良和培育提供理论依据。

酪蛋白糖巨肽对花生过敏原免疫反应性的影响

目的 探究酪蛋白糖巨肽(casein glycomacropeptides,CGMP)与花生过敏原相互作用并降低其免疫反应性的潜力。方法 通过蛋白-蛋白分子对接技术探讨CGMP与Ara h1、Ara h2是否有相互作用的潜力。进一步通过混合水浴加热制备CGMP与花生蛋白的混合溶液(mixed solution of casein glycomacropeptides and peanut proteins,MCGP),建立MCGP致敏、花生蛋白激发的BALB/c小鼠模型,研究MCGP对花生过敏反应的影响。最后使用圆二色谱法研究酪蛋白糖巨肽与Ara h1、Ara h2的相互作用力及对其结构的影响。结果 CGMP与Ara h1、Ara h2间存在次级键(盐桥、氢键、范德华力),部分作用于过敏原表位;与花生蛋白过敏组相比, MCGP致敏组血清中的花生蛋白特异性免疫球蛋白E (specific immunoglobulin E, sIgE)、sIgG1、sIgG2a含量显著下降,白介素-4 (interleukin-4, IL-4)、IL-5、组胺水平显著下降,转化生长因子-β (transforming growth factor-β, TGF-β)、γ干扰素(interferon-gamma, IFN-γ)水平显著升高, MCGP中Ara h2的α-螺旋与β-折叠的比例改变。结论 CGMP能够改变Ara h2的结构,遮蔽花生过敏原表位,抑制sIgE、sIgG结合Ara h1、Ara h2,降低部分花生过敏原的免疫反应性。

微波预处理对花生压榨特性的影响

采用微波对花生进行预处理,研究处理前后花生水分、褐变程度、颗粒质构参量、水分状态分布、蛋白变性程度的变化趋势以及对压榨出油率的影响,并与真空烘箱处理作对比,经Pearson相关性分析,建立各指标与出油率之间的数学相关性,为花生的高效加工利用提供理论依据和数据参考。结果表明,花生在900 W条件下微波7 min,或者85℃真空烘箱烘制89 min,水分质量分数从5.25%降至2.27%,此时压榨出油率最高,分别为45.85%和45.76%;此条件下,花生与榨油机之间构成的切应力适中,花生受到充分挤压,发生形变,油脂大量流出,且花生可塑性最好,水分状态组成最为合理,蛋白变性程度适中,既可以使得油脂大量流出,又不会轻易破碎影响饼粕成形。