The application of wheat fibre and soy isolate impregnated with iodine salts to fortify processed meats

The aim was to use wheat dietary fibre and soy protein isolate as carriers of KI and KIO₃ for fortification of processed meat with iodine. Products from minced pork were prepared with addition of iodised wheat fibre and soy isolate, and iodised table salt for comparison and the effects of thermal processing and storage on changes in iodine content were determined. It was shown that both alternative carriers limited the iodine changes in meat products compared with iodised table salt. However, wheat fibre was more effective in limiting iodine losses during thermal processing and soy protein during storage of the products. The greatest effect of the carriers was found in meat products fortified with the less stable KI.     

The effect of iodine salts on lipid oxidation and changes in nutritive value of protein in stored processed meats

The aim was to assess the effect of iodine salts (KI or KIO(3)) on lipid oxidation as well as changes in the availability of lysine and methionine and protein digestibility in frozen-stored processed meats. Three types of iodine salt carriers were used: table salt, wheat fiber and soy protein isolate. The results showed no catalytic effect of iodine salts on lipid oxidation in stored processed meats. The application of a protein isolate and wheat fiber resulted in the inhibition of lipid oxidation in meatballs. During storage of meat products the contents of available lysine and methionine as well as protein digestibility were decreased. The utilization of wheat fiber as an iodine salt carrier had a significant effect on the reduction of lysine losses. No protective properties were found for the wheat fiber or soy protein isolate towards methionine.     

大豆分离蛋白对涂抹型再制干酪质构的影响

添加大豆蛋白可降低涂抹型再制干酪的成本，但也会对再制干酪的质构产生一定的影响。设计4因素3水平正交实验．应用TA—XT2i型物性分析仪考察添加了大豆蛋白后的再制干酪产品的质构变化，使用Statistix 8.0统计分析软件对实验结果进行统计分析并作出比较和对正交试验作极差分析。结果表明，4个因素在水平不同的9组正交实验的结果的差异性显著（p〈0.05），在极差分析中，4个因素对硬度的影响排序为D〉C〉A〉B；4个因素对剪切功的影响排序为D〉A〉B〉C；4个因素对粘着性的影响排序为A〉B〉D〉C；4个因素对感官评价的影响排序为A〉D〉C〉B。最后重做不同的最优组并再次测定各项指标，得到最好的组合为大豆蛋白添加量6％．黄油添加量10％，乳化盐添加量1、5％，加水量50％（均为质量分数，下同）。     

盐对可食性大豆分离蛋白膜亲水性影响的研究

在大豆分离蛋白(SPI)膜中添加NaCl、Na2CO3、Na2S2O3、Na3PO4、Na4P2O7、ZnCl2和FeCl3,通过研究膜的水分含量(WC)、可溶性干物质(TSM)、水蒸气透过系数(WVP)及其动态接触角(DCA)系统考察盐对SPI膜亲水性的影响。结果表明:NaCl和FeCl3使得SPI膜的WC分别增加7.4%和15.5%,Na4P2O7、Na2S2O3、Na3PO4、Na2CO3和ZnCl2分别使WC减少18.8%、18.9%、3.8%、7.6%和16.1%;NaCl和Na2S2O3使SPI膜的TSM略有增加,但Na3PO4、Na2CO3、Na4P2O7、ZnCl2和FeCl3使TSM分别降低32.3%、13.7%、7.1%、12.7%和23.9%;Na3PO4、Na4P2O7、Na2CO3和Na2S2O3及ZnCl2分别使WVP增加88.9%、51.4%、36.5%、28.7%和21.0%,NaCl不改变膜的WVP,而FeCl3使膜的WVP值略有下降;NaCl、Na2CO3、Na2S2O3和FeCl3使SPI膜在极性和非极性溶剂中的DCA均降低,而Na3PO4、Na4P2O7和ZnCl2使得SPI膜在极性和非极性溶剂中的DCA均提高。     

大豆分离蛋白与谷朊粉可食性复合膜研究

该文报道影响大豆分离蛋白与谷朊粉复合膜成膜因素,分析各种因素对复合膜性能影响,并对正交试验结果采用极差分析和综合评分法进行评定,得到制备综合性能良好的可食性膜最佳条件为:谷朊粉与大豆分离蛋白比例为1∶5,甘油量为20%,pH为11,预热处理温度和时间分别为80℃和40min;此时,膜的透光率、拉伸强度、撕裂强度、水分含量和水蒸汽透过率依次为60.5%、38.38MPa、198.02N/mm、13.87%和0.507g·mm/kPa·h·m2。     

Functional properties of films based on soy protein isolate and gelatin processed by compression molding

Soy protein isolate (SPI) based films, blended with gelatin and plasticized with glycerol at pH 10, were prepared by compression molding with the aim to obtain environmentally friendly materials for packaging applications. Different contents and types of gelatin were incorporated into SPI-based mixtures to improve mechanical properties. All films obtained were flexible and transparent. Films with 15% of bovine gelatin showed higher tensile strength and similar elongation at break compared with the ones without gelatin. Moreover, contact angle measurements showed that the addition of gelatin decreased the hidrophilicity of the films, while UV barrier properties were maintained. The effect of gelatin addition has been explained using Fourier transform infrared (FTIR) and the changes observed in the intensity of the bands corresponding to the amide group showed that gelatin interacts with SPI, which was confirmed by the decrease of total soluble matter.     

大豆分离蛋白凝胶的制备

以大豆蛋白粉为基质,添加油脂、单甘脂,采取热凝胶法制备凝胶。以凝胶持水性为评价指标,在单因素试验的基础上,采用Box-Behnken试验设计方法优化试验条件。结果可知:在油脂添加量8%、单甘脂添加量1%、超声波功率200 W的条件下,大豆分离蛋白凝胶持水率最高为90.85%。     

Inhibition of surface spoilage bacteria in processed meats by application of antimicrobial films prepared with chitosan

A study was undertaken to evaluate the feasibility of using antimicrobial films, designed to slowly release bacterial inhibitors, to improve the preservation of vacuum-packaged processed meats during refrigerated storage. The antimicrobial films were prepared by incorporating acetic or propionic acid into a chitosan matrix, with or without addition of lauric acid or cinnamaldehyde, and were applied onto bologna, regular cooked ham, or pastrami. At various times during storage, packages were opened and the amounts of antimicrobial agents remaining in the chitosan matrix were measured. Regardless of film composition or meat product type, propionic acid was nearly completely released from the chitosan matrix within 48 h of application, whereas release of acetic acid was more limited, with 2-22% of the acid remaining in chitosan after 168 h of storage. Addition of lauric acid, but not cinnamaldehyde, to the chitosan matrix generally reduced the release of acetic acid significantly (P < or = 0.05) and the release was more limited onto bologna than onto ham or pastrami. In addition, the efficacies of the various films for inhibiting bacterial growth were tested against indigenous lactic acid bacteria and Enterobacteriaceae, and against Lactobacillus sakei or Serratia liqueficiens, surface-inoculated onto the meat products. Whereas lactic acid bacteria were not affected by the antimicrobial films under study, the growth of Enterobacteriaceae and S. liquefaciens was delayed or completely inhibited as a result of film application. Strongest inhibition was observed on drier surfaces (bologna), onto which acid release was slower, and with films containing cinnamaldehyde, as a result of its greater antimicrobial activity under these conditions.     

Ohmic heating of meats: Electrical conductivities of whole meats and processed meat ingredients

The ohmic heating rate of a food is highly influenced by its electrical conductivity (σ). A survey of σ values of commonly used meat ingredients when dispersed as 5% (w/w) aqueous solutions/suspensions was undertaken. A subset was further investigated at typical usage levels in solution/suspension, and/or when incorporated into beef blends, while σ of selected cuts from five meat species (beef, pork, lamb, chicken and turkey) was also measured. Measurements were made from 5 to 85 °C and showed a linear increase in σ values with increasing temperature. In processed beef, addition of sodium chloride and phosphate (P22) caused a significant increase in σ which in turn would lead to an increase in ohmic heating rates. Furthermore, whole meats with lower endogenous fat or processed meats with the least added fat displayed higher σ and reduced ohmic heating times. In beef maximum σ was observed when fibres were aligned with the current flow.     

功能性强化大豆膳食纤维的生理功效及其在食品上的应用

叙述了功能性强化大豆膳食纤维的物化特性、生理功效及其在食品上的应用。大豆膳食纤维不能为人体提供任何营养物质,但对人体具有多种重要的生理活性作用。改性纤维在保留膳食纤维的全部性质和生理作用的基础上,增加了更多的功能,应用范围进一步拓展,在食品、医药等行业有着更为重要的应用价值。      

酶聚合结合超滤技术分离豆腐废水乳清蛋白的工艺研究

为改善豆腐乳清蛋白及低聚糖的回收率、提高膜通量,研究采用转谷氨酰胺酶在豆腐黄浆水自然条件下(温度50℃、pH值6.0)对乳清原液预处理,使蛋白质聚合,方便后续分离工艺选用截留分子量大的超滤膜分离大豆乳清蛋白。数据显示转谷氨酰胺酶Ⅰ可有效催化大豆乳清蛋白聚合,1%的酶添加量50℃反应30min即可催化95%以上的大豆乳清蛋白聚合,酶添加量3‰,聚合时间延长至5h。与对照组相比,乳清采用酶法预处理然后超滤分离,蛋白截留率及膜通量分别提高了2倍和1.3倍,而低聚糖的透过率没有明显影响。试验结果表明,相对于单纯的超滤工艺酶聚合预处理乳清然后超滤的分离效果是显著的。     

影响大豆分离蛋白提取率因素及实际解决方法

该文结合原料和生产过程中各个环节,分析影响大豆分离蛋白得率因素,并提出相应解决方法或工艺条件控制。     

小麦蛋白对TGase酶交联改性大豆蛋白凝胶特性的影响及机制

为探讨TGase酶对大豆与小麦混合蛋白凝胶性质的影响,本文研究了小麦蛋白的加入前后混合蛋白凝胶功能性质的变化规律。通过研究TGase酶添加量、反应温度、反应pH对混合蛋白凝胶特性的影响可知:蛋白浓度为11%（11 g/100 mL）保持不变,TGase酶添加量为30 U/g,反应温度为40℃,反应pH为7.0时,TGase酶对混合蛋白凝胶特性改善效果最强。对比小麦蛋白加入前后蛋白凝胶的性质,发现小麦蛋白的添加使得蛋白结构的β-折叠含量升高,游离巯基含量减少,凝胶弹性模量（G’）增强,形成了更为多空且紧密有序的三维网络结构,使得混合蛋白的凝胶性能显著增强（p<0.05）。      

麦胚保健豆奶的研制

<正> 小麦胚芽富含蛋白质、亚油酸、维生素E、B族维生素和各种矿物质,以及微量生理活性组分,被营养学家誉为“人类天然的营养宝库”和“人类的生命之源”。若将麦胚营养液添加到豆奶中,便可制成美容健康饮料——麦胚保健豆奶。     

大豆分离蛋白中蛋白质含量的快速测定

采用基于经典凯氏定氮法原理设计的KDN-08A半自动定氮仪对大豆分离蛋白中蛋白质含量进行快速测定.结果经t检验,与经典凯氏定氮法测得结果无显著性差异,且回收率在99.53%～100.19%之间.表明该方法测定结果准确可靠、操作简单快速,适用于大豆分离蛋白中蛋白质含量的测定.     

碱性蛋白酶和木瓜蛋白酶对热变性大豆分离蛋白的酶解研究

采用碱性蛋白酶和木瓜蛋白酶对热变性大豆分离蛋白进行酶解,研究两种蛋白酶酶解温度对大豆分离蛋白酶解效果的影响。结果表明:碱性蛋白酶在60℃时比在70℃时对大豆分离蛋白的酶解更彻底,得到的相对分子质量小的肽段更多,大豆分离蛋白的水解度较高(14.73%);酶解温度对木瓜蛋白酶酶解大豆分离蛋白的效果影响不明显;与木瓜蛋白酶相比,碱性蛋白酶酶解大豆分离蛋白可以得到更多的小分子肽段。     

淀粉代替乳化盐在再制干酪中的应用

采用感官评定、TPA试验和应力松弛实验方法,对淀粉作为乳化盐替代物对再制干酪进行感官和质地的研究.结果表明,交联马铃薯淀粉和对照组在感官、TPA性能、应力松弛性能都比较接近,可以代替乳化盐在再制干酪中的应用.     

Glycation of soy protein isolate with two ketoses: d-Allulose and fructose

Modification of food proteins to have improved functional properties is of great importance. In this study, modification of soy protein isolate (SPI) was achieved through glycation. SPI was glycated in a spray dryer (SD) and an incubator followed by freeze drying (FD). d -Allulose, an important rare sugar, was used in SPI glycation as the carbohydrate source, and results were compared with fructose. In addition to the sugar type, two different SPI powder: sugar ratios (1:1 and 5:1) were investigated. For the glycated samples, emulsification activity, free amino groups, protein solubility, Fourier-transform infrared spectroscopy analysis, antioxidant activity experiments and time-domain NMR relaxometry measurements for hydration were conducted. According to the results, the solubility of SPI that is limited in native form has shown a significant improvement after glycation through both FD and SD methods. Besides, glycation through the FD method was found to be more favourable due to its milder conditions than the SD method. Considering the physicochemical properties, the best combination for the highest glycation degree was found to be the samples prepared at the 1:1 ratio with d -Allulose in the FD method. Overall, it was concluded that glycation of SPI enhanced its functional properties such as antioxidant and emulsification activities.     

Use of histidine dipeptides to estimate the proportion of pig meat in processed meats

High performance liquid chromatography on a Partisil-10 SCX column was examined as an alternative to conventional ion exchange chromatography as a means of quantitating the histidine dipeptides, anserine, carnosine and balenine in processed pig meats. Because the ratio of these dipeptides in skeletal muscle of the pig is different from that in other species commonly used for meat, it is possible to estimate the proportion of pig meat in processed meats. Several Australian pork products were found to contain a low proportion of lean pig meat.