发酵豆粕蛋白提取工艺及其品质的研究

采用单因素实验,考察不同碱溶p H、碱溶时间、碱溶温度和料液比对发酵豆粕乳中蛋白提取率的影响;通过响应面优化实验,建立了发酵豆粕乳中蛋白的最佳提取工艺;并测定了提取蛋白的主要品质指标。结果表明,不同因素对蛋白提取率的影响强弱顺序为:碱溶时间>碱溶p H>碱溶温度>料液比。优化后的最佳工艺为碱溶p H 9.4、碱溶时间56 min、碱溶温度41℃、料液比1∶12,在此条件下,蛋白的提取率达60.36%。经实验表明,植物乳杆菌发酵豆粕中提取的大豆分离蛋白(SPI)溶解性、体外消化率、酸溶蛋白含量较未发酵豆粕均有显著提高(p<0.05)。应用本文所得工艺参数提取发酵豆粕蛋白,方法经济易行,SPI品质良好,可为豆粕蛋白的开发利用提供参考。      

低温花生粕蛋白制备及其饮料稳定性分析

以低温花生粕为原料,利用碱溶酸沉法提取花生分离蛋白,继而制备花生蛋白饮料,考察自制花生蛋白饮料的稳定性,并研究其氮溶指数、乳化活性及乳化稳定性等功能特性。结果表明,最佳工艺条件为pH 9.5、碱提温度55℃、料液比1∶11(g/mL)、提取时间2.5 h,此条件下花生分离蛋白提取率可达90.25%。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析显示,其中包含花生蛋白所有特征条带。花生蛋白饮料的平均粒径(D[4,3])为4.31μm,稳定性分析仪测出粒子动态变化斜率(Slope)值为26.66%/h。低温花生粕制备的花生蛋白饮料具有良好的稳定性,这为花生粕高值化利用提供了新方向。     

反胶束溶液萃取杏仁蛋白前萃工艺的研究

对AOT/异辛烷反胶束溶液萃取杏仁蛋白的前萃工艺进行了研究。试验以AOT/异辛烷为反胶束溶液体系,以蛋白质萃取率为指标,分别对溶液的pH值、W0值、萃取时间和萃取温度进行了单因素试验以及四因素三水平的正交试验,以确定杏仁蛋白前萃的最佳工艺。正交试验结果方差分析表明,在各因素中,W0值对蛋白质提取率影响达到显著水平,其他三因素未达到显著水平,确定的最佳工艺条件为:W0值为40,溶液pH值7.0,前萃温度25℃,前萃时间90 min。     

苦杏仁蛋白的功能特性

采用稀盐溶液浸提及等电点盐析相结合的方法提取制备苦杏仁蛋白,研究pH值、NaCl浓度、蛋白质量浓度和温度等因素对苦杏仁蛋白功能特性(溶解性、持水性、吸油性、乳化性及乳化稳定性、起泡性及起泡稳定性)的影响。结果表明：在等电点pI附近时,苦杏仁蛋白的溶解性、持水性、乳化性及乳化稳定性、起泡性最差;在较低NaCl浓度范围内(0～0.8mol/L)提高NaCl浓度可促进蛋白溶解性、乳化性及乳化稳定性、起泡性及起泡稳定性的提高,而较高的NaCl浓度对蛋白功能特性提高具有抑制作用;当蛋白质量浓度达到一定水平时(3～4g/100mL),蛋白功能特性(乳化性及乳化稳定性、起泡性及起泡稳定性)提高趋于平缓;在适宜的温度范围内,提高温度可有效提高苦杏仁蛋白各项功能特性,但当温度继续上升,各项功能特性持续降低。     

Ultracentrifugal and polyacrylamide gel electrophoretic studies of extractability and stability of almond meal proteins

Solubility and stability properties of almond proteins were determined using ultracentrifugation and gel electrophoresis to gain a better insight into the complexity of these proteins. Ultracentrifugal analyses of the water-extractable proteins of defatted almond meal revealed four fractions of 2S, 9S, 14S and 19S. The 14S fraction corresponds to amandin, the classical globulin isolated earlier, and constitutes 65–70% of the extractable proteins. Variation of ionic strength from 0 to 1·0 at pH 6–8 showed no evidence of association–dissociation reactions that are typical of many oilseed and legume proteins. Polyacrylamide gel electrophoresis of the water-extractable proteins under reducing conditions separated two pairs of major polypeptides of 44 and 42 kDa and 27 and 25 kDa that appeared to be the respective acidic and basic polypeptides of amandin corresponding to the classical legumin model. Sodium chloride had no effect on total protein extractability but variation of extraction pH showed a broad minimum in extractability at pH 3–5. In contrast, when a pH 9 extract was lowered in pH, the minimum in protein solubility was narrower and shifted upward to pH 5 largely as a result of the precipitation of amandin. Interaction of amandin with phytate may explain the lower pH of minimum solubility when the meal was extracted directly as opposed to lowering the pH of an alkaline extract. Amandin is a cryoprotein and was obtained in 90% purity by cooling a water extract of defatted meal. Incubation of a water extract of meal in the presence of azide for about 12 days revealed proteolytic nicking of the acidic polypeptides of amandin apparently as a result of attack by endogenous proteinase(s). © 1998 Society of Chemical Industry.     

液压压榨澳洲坚果粕蛋白质提取工艺优化及其组成分析与功能性质

以液压压榨澳洲坚果粕为原料,采用碱溶酸沉法提取蛋白质,通过单因素与正交试验确定最佳提取条件,并对其组成与功能性质进行研究。结果表明:澳洲坚果粕蛋白质提取工艺各因素对提取率影响的主次顺序依次为料液比、碱溶p H值、提取时间、提取温度,且均达到了极显著水平(P0.01),最佳提取工艺条件为:料液比1∶50(g/m L)、碱溶p H 9、提取时间2 h、提取温度40℃。在此条件下提取率达到95.40%,纯度为65.46%。澳洲坚果粕蛋白质中清蛋白、球蛋白、醇溶蛋白、谷蛋白质量分数依次为:7.29%、14.58%、14.95%、63.18%。澳洲坚果粕蛋白质的等电点约为5.0。在适宜的p H值条件下,澳洲坚果粕蛋白质具有较好的溶解性、乳化性、乳化稳定性与泡沫稳定性,起泡性相对较差。在70℃温度条件下,吸油性达到最大值,为50.10%。     

沙棘籽粕蛋白的功能性质研究

以沙棘籽粕为原料,采用碱提酸沉法制备沙棘籽粕蛋白,并对其溶解性、水合能力、吸油能力、乳化性和乳化稳定性、起泡性和泡沫稳定性等功能性质进行研究.结果表明:沙棘籽粕蛋白的功能性质受pH、温度、盐离子浓度等环境因素影响大,在等电点pH 5.0附近时功能性质数据均最低.     

酶法制备巴旦杏蛋白工艺研究

以新疆巴旦杏为原料,采用酶法制备巴旦杏蛋白,通过比较纤维素酶、中性蛋白酶、酸性蛋白酶对巴旦杏蛋白的提取率,确定了最佳的酶为中性蛋白酶,同时考察了加酶量、料水比、时间、温度、pH等因素对巴旦杏蛋白提取率的影响。结果表明:中性蛋白酶提取巴旦杏蛋白的最佳工艺是:加酶量5%、料水比1:35、时间75min、温度50℃、pH为7.25。     

Chemical and functional characterization of Gum karaya (Sterculia urens L.) seed meal

Chemical and functional characterization of the meal of Gum karaya (Sterculia urens) whole and dehulled–defatted seed were investigated. Dehulled–defatted seed meal (DDSM) contained 40.7% of protein as compared to 20.4% in the whole seed meal (WSM). Essential minerals of Ca 39.5, Fe 4.4, K 9.6 and P 995 mg/100 g were found in DDSM. A solid to solvent ratio 1:40 and extraction time of 60 min was optimum. The highest protein solubility (93.97%) was observed at pH 12 and the lowest (26.41%) protein solubility at pH 6. The solubility of protein was enhanced in the presence of 0.1 M and 0.5 M NaCl between pH rang of 2–12. The protein precipitation from an alkaline extract of pH 10 was maximum (81%) at pH 6. Polyacrylamide gel electrophoresis shows that 14 bands of SDS soluble protein subunits were observed in WSM and DDSM. A higher buffer capacity of the meal was observed in the acid medium than in alkaline medium. The DDSM had an initial moisture content (IMC) of 5.16%, which equilibrated at 32% RH and moisture content increased sharply at higher humidity (70%) which, indicated that the non-hygroscopic in nature. Water holding capacity and oil holding capacity were 111 and 81, 67 and 114 g/100 g of WSM and DDSM respectively. DDSM showed very good foam capacity (32%) and stability (75%) even after 90 min at room temperature. The emulsification capacity of DDSM was found to be 20 mL/g sample.     

SOLUBILIZATION,ELECTROPHORETIC CHARACTERIZATION AND IN VITRO DIGESTIBILITY OF ALMOND (PRUNUS AMYGDALUS) PROTEINS1,2

ABSTRACT The major U.S. marketing varieties of almonds contained moisture, protein, fat, and ash in the range 4.35–5.86%, 16.42–22.17%, 53.59–56.05%, and 2.69–2.93%, respectively. Two fatty acids, oleic (range 52.44–67.07%) and linoleic (range 22.05–38.67%) accounted for up to 90% of the total fat. The majority of almond proteins (≥ 95%) are water soluble with a minimum solubility at pH ≤ 4.0. Sodium chloride (1.0 M) decreased the almond protein solubility in aqueous medium. Electrophoretic analyses indicated that one water soluble protein dominates the almond protein composition. This oligomeric major protein is made up of two kinds of polypeptides (molecular weight range 20,000–22,000 and 38,000–41,000) linked via disulfide bonds. Among the proteases tested, pepsin was the most efficient in hydrolyzing the almond proteins.     

微波辅助提取巴旦木蛋白工艺优化及其功能性质研究

本文采用微波辅助碱溶酸沉法提取巴旦木中的蛋白质,在单因素实验基础上,采用L₁₆（45）正交试验设计,研究微波预处理功率、微波预处理时间、提取液pH、提取温度和料液比对巴旦木蛋白提取率的影响。结果表明,微波辅助提取巴旦木蛋白的最佳工艺条件为:微波功率400 W、微波时间180 s、提取液pH 9.5、提取温度50 ℃和料液比1:25 g/mL,在此条件下测出的巴旦木蛋白提取率达到46.69%。相较于未经微波辅助提取的巴旦木蛋白,微波处理后蛋白的溶解性、持水性、持油性、乳化性和起泡性分别提升了15.35%、26.07%、26.22%、30.61%和20.53%,而乳化稳定性和泡沫稳定性分别降低了1.05%和13.29%,研究表明,微波处理有助于提高巴旦木蛋白的提取率并改善功能性质。     

Extractability and functional properties of some legume proteins isolated by three different methods

The extraction of protein from the flour of three grain legumes (faba beans, chick peas and fenugreek) was investigated using three different methods. Three protein preparations were made: by alkaline extraction and precipitation at isoelectric pH (protein isoelectric precipitate, PIP); extraction with 0.5 M sodium chloride solution and precipitation by ionic strength reduction (protein micellar mass, PMM); extraction in aqueous or saline solution in the presence of pepsin or pancreatin (partially hydrolysed protein preparation, PHP). Two of the protein isolates had higher values of water absorption and fat absorption compared to their corresponding parent flours, with fenugreek being the exception. Oil emulsification of the isolates was in the descending order: PMM, PHP and PIP. The PHP isolate had the highest nitrogen solubility index (NSI) values at pH 2.4 followed by PMM at pH 5.7–6.4 and finally PIP at pH 4.5–5.5.     

蒸汽爆破辅助提取高温豆粕中的蛋白质

研究了蒸汽爆破对高温豆粕中蛋白质溶解性的影响和后续蛋白质提取工艺。结果表明:当蒸汽压力较低时,高温豆粕的氮溶解指数随着蒸汽压力的升高而提高,但当超过2.1 MPa时,压力对爆破处理的效果的影响不明显;豆粕的粒度对蒸汽爆破效果有一定的影响,当豆粕颗粒的平均小于100目时效果不佳,在20～80目时效果较好。当高温豆粕颗粒大小为20～80目,爆破条件为1.8 MPa,180 s时,蒸汽爆破处理使高温豆粕的氮溶解指数提高了1.1倍。对经蒸汽爆破处理的高温豆粕中蛋白质的提取条件研究表明,pH值和温度对蛋白质的提取率有较大影响。在优化条件下,经蒸汽爆破处理的高温粕的蛋白质提取率达到76.04%。     

汉麻籽蛋白的提取及性质研究

以冷榨脱油后的汉麻籽粕为原料,通过料液比、pH、温度和提取时间等单因素实验和四因素三水平正交实验,研究了汉麻籽蛋白提取的最佳工艺条件。在pH8.0,料液比1∶20(g∶mL),温度40℃,提取时间70min条件下碱提汉麻籽蛋白,在pH4.5～5.0酸沉后进行喷雾干燥(进风温度120℃,出口温度70℃,固形物浓度200g/L),碱提提取率达到86.95%,蛋白质总得率达到70.56%,分离蛋白中蛋白质含量达到92.39%,氮溶指数为31.89%。同时,通过实验发现,汉麻籽蛋白的水合能力为3.59g/g(蛋白质),亲油能力为2.22mL/g(蛋白质)。DSC分析得到汉麻籽蛋白的变性温度为88.4℃,变性热为1.544J/g。     

Protein Extraction From Chicken Myofibrils Irrigated with Various Polyphosphate and NaCl Solutions

Physical changes in chicken gastrocnemius myofibrils incubated in 0.1 to 1.0 M NaCl solutions with or without 10 mM ortho-(P), pyro-(PP), tripoly-(TPP) or hexameta- (HMP) phosphate at pH 6.0 were examined by phase-contrast microscopy, electrophoresis, and solubility. PP and TPP performed similarly in promoting protein extraction, P had no apparent effect, and HMP exhibited an intermediate effect. PP, TPP, and HMP treatments markedly improved protein solubility in 0.3 and 0.4 M NaCl through the release of myosin, but the phosphate effect diminished in ≥ 0.6 M NaCl. Overall, phosphates influenced the ultrastructure of myofibrils and extraction of their constituents in the order: PP ∼ TPP > HMP > P ∼ nonphosphate control.     

玉米胚芽蛋白的碱法提取工艺及特性研究

对影响玉米胚芽蛋白提取量的因素进行了研究,通过单因素与正交实验法优化出最佳提取工艺;并对所得蛋白特性进行了探讨。结果表明:料液比、温度、pH等因素对蛋白提取率有明显影响,在pH9.5、料液比1∶12(g/mL)、温度50℃、时间4h时,玉米胚芽蛋白提取率最高,可达23.05%;玉米胚芽蛋白中氨基酸成分丰富,其中谷氨酸和精氨酸含量较高,分别为100g胚芽蛋白中含有6765.03mg和4265.81mg,且富含人体必需的八种氨基酸;此外,该蛋白具有良好的溶解性、起泡性、乳化性、持水性和持油性。      

Nitrogen extractability and buffer capacity of defatted linseed (Linum usitatissimum L.) flour

Defatted linseed flour was prepared from cold-pressed seed meal via hexane extraction of the residual oil, followed by removal of the major portion of the hulls through grinding and sieving (sieve size 0.25 mm). The resulting flour had 50% protein on a dry basis compared with 40% contained by the whole seed on an oil-free dry basis. Nitrogen extractability of the defatted flour in water was not influenced by the length of the extraction period but an increased extraction was observed at higher solid:liquid ratios up to the studied limit of 1:40. The smallest amount of nitrogen (20%) was extracted in the pH range 4.0–4.6 and the greatest (80%) at pH 12.0. Addition of NaCl (0.1–1.0 M) broadened the pH range of minimum nitrogen extractability and shifted it towards lower pH region. At higher concentrations (0.6 and 1.0 M) NaCl markedly increased nitrogen extractability in the pH range of 4.0 to 8.0. Precipitation of protein from an extract at pH 10.0 was maximum (77%) at pH 4.1. A higher buffer capacity of the flour was observed in the acidic medium (0.204 mmol HCl g^?1 flour) than in the alkaline medium (0.096 mmol NaOH g^?1 flour).     

巴旦木蛋白提取工艺

以巴旦木为原料,采用碱提酸沉法和超声波辅助碱液浸提法制备巴旦木蛋白,并对其理化性质进行研究。结果表明：碱提酸沉法提取巴旦木蛋白的最佳工艺条件是料液比1:25、pH10、60℃浸提40min;超声辅助碱液浸提法提取巴旦木蛋白的最佳工艺条件是pH9.0、料液比1:20、提取时间15min、超声功率125kW,在此条件下提取率为37.16%。与碱提酸沉法比较,超声波辅助碱液提取法时间短、得率高。     

火麻仁蛋白的提取分离及理化性质研究

以脱脂火麻仁粉(defatted hemp seed meal,HPM)为原料,采用两种方法进行火麻仁蛋白(hemp seed protein isolate,HPI)的提取分离,碱提/酸沉法制备得到碱提蛋白(hemp seed protein isolate-alkaline extraction,HPI-AE),盐...     

羽扇豆蛋白的提取及性质研究

采用碱溶酸沉法对羽扇豆蛋白进行提取,利用响应面法对羽扇豆蛋白的提取工艺进行优化,得到最佳提取工艺是:pH为9.9,液料比15.7,温度为55.5℃,提取时间为30.4min,蛋白最佳得率为13.2%。按照Osborne蛋白分级提取方法对羽扇豆蛋白进行了精细分类,分别得到了羽扇豆清蛋白、球蛋白、醇溶蛋白和谷蛋白,其中球蛋白含量最高。羽扇豆蛋白的功能性质,包括溶解性、持水持油性、乳化性质,也进行了测定。