复配改良剂对马铃薯米线质构品质的影响

为探索马铃薯米线中品质改良剂应用的可行性,以质构品质为评价指标,研究不同品质改良剂(黄原胶、蔗糖酯和玉米淀粉)对马铃薯米线品质的改良效果,并在单因素实验基础上通过正交实验确定品质改良剂的最佳配比。实验结果表明:以原料质量为基准,当添加黄原胶0.4 g/100 g、蔗糖酯0.3 g/100 g和玉米淀粉6 g/100 g复配使用时,马铃薯米线的质构品质得到明显改良,弹性提高至0.988,硬度和咀嚼性分别为2271 g和2013 g。      

桃胶中多农药残留分析及风险评估

目的:研究桃胶中农药残留及风险。方法:基于液相色谱—串联质谱法(LC-MS/MS)建立桃胶中44种农药残留的定量分析方法,并对全国173份桃胶样品进行农药残留检测和风险评估分析。结果:基于LC-MS/MS农药残留检测方法的检出限(LOD)为0.05～1.80μg/kg,定量下限(LOQ)为0.20～2.42μg/kg,加标回收率为61.77%～119.48%。桃胶样品中共检出22种农药,农药总检出率为98.8%,平均每个样品检出农药次数为2.8次,苯醚甲环唑检出率最高(95%),其次是毒死蜱(54%)、多菌灵(34%)、呋虫胺(32%)、吡唑醚菌酯(19%)等。不同桃胶样品中苯醚甲环唑平均残留量最高为0.332 mg/kg,其次是呋虫胺(0.093 mg/kg)、多菌灵(0.061 mg/kg)、毒死蜱(0.033 mg/kg)。结论:桃胶中农药的残留与桃生产用药有关,其残留量总体处于低风险水平,推荐8—10月份采摘桃胶。     

不同黏度多糖阿拉伯胶和瓜尔胶对肌原纤维蛋白乳化性质的影响

选取两种分子质量相近、黏度相差较大的天然高分子多糖阿拉伯胶（arabic gum,AG）和瓜尔胶（guar gum,GG）分别与肌原纤维蛋白（myofibrillarprotein,MP）进行复合,研究不同多糖添加量（0.1%～0.5%）对MP-多糖复合物乳液性质的影响规律。结果表明,AG和GG均可以显著改善MP的乳化性质,其中AG对乳化活性的改善效果较好,而GG更有利于乳液的稳定性。随着多糖质量分数增加,乳化活性指数和稳定性指数均呈先升高后降低趋势,AG和GG添加量分别为0.3%和0.2%时,乳化活性指数和稳定性指数达到最大值。界面蛋白含量测定结果显示,AG和GG均会导致界面蛋白含量下降,尤其是GG的作用更明显。随着AG和GG添加量增加,乳液粒径逐渐减小,且尺寸分布更加均一,添加量超过0.3%后,GG组乳液出现少量絮凝现象。同一添加量下,GG组乳液粒径明显小于AG组。流变学分析证实,所有乳液均为假塑性流体,表现出弱凝胶性质。AG添加量较少（≤0.3%）时会降低乳液黏度,并明显提高乳液的储能模量,而GG的添加使乳液表观黏度和储能模量均显著提高,与AG相比,高黏度GG制备的乳液拥有更高的...     

阳离子田菁胶助染剂对纸浆纤维染色效果的影响

为实现无盐染色,本实验引入阳离子田菁胶作为助染剂,通过增强染料与纸浆纤维间的吸附作用,经济环保地提高了浆内染色效果。结果表明,阳离子田菁胶作为直接耐晒翠兰（GL）染料的助染剂效果良好。光学显微镜与扫描电子显微镜观察表明GL染料、纸浆纤维、阳离子田菁胶结合紧密。通过单因素实验探究阳离子田菁胶用量、染色温度、染液pH值对纸浆纤维染色效果的影响,确定了最佳助染工艺条件为：阳离子田菁胶用量0.2%,染色温度45 ℃,染液pH值3,该条件下上染率可达92.6%。建立染色吸附动力学模型和染色吸附等温线可知,染色时间对染色效果影响较小,适当提高染液初始浓度可有效提高染色效果。     

亲水胶体对海绵蛋糕中晚期糖基化终末产物的抑制作用

为探究亲水胶体对晚期糖基化终末产物（advanced glycation end products,AGEs）生成的抑制作用,首先采用牛血清白蛋白（bovine albumin,BSA）-果糖、BSA-葡萄糖、BSA-丙酮醛（methylglyoxal,MGO）、BSA-乙二醛4 个化学模型,考察9 种经典亲水胶体在化学模型中的抗糖基化能力,筛选出抑制效果最佳的海藻酸（alginic acid,ALA）和黄原胶（xanthan gum,XG）作为研究对象,探究不同亲水胶体添加量（0.25%、0.5%、1.0%、1.5%、2.0%）及烘焙温度、时间对海绵蛋糕品质属性、AGEs形成和蛋白氧化产物的影响。明确最佳烘焙温度和时间为180 ℃、40 min,在此条件下分别添加0.5% ALA或2.0% XG能够显著降低海绵蛋糕中的荧光AGEs、非荧光AGEs和蛋白氧化产物含量。同时,ALA和XG的添加能够改善蛋糕的质构,提高蛋糕的水分含量。ALA和XG是一类很有前途的天然AGEs抑制剂,可以在烘焙之前添加至原料中,以减少烘焙食品中AGEs的生成。     

海藻酸钠对O-羧甲基壳聚糖/阿拉伯胶复凝聚反应的影响

该文主要探讨海藻酸钠对O-羧甲基壳聚糖/阿拉伯胶复凝聚反应及复凝聚相性质的影响,以期获得具有新型功能性质的三元体系复合物.结果表明,与O-羧甲基壳聚糖/阿拉伯胶体系相比,添加海藻酸钠对其最适反应条件无显著影响,即在pH3.0、25℃下O-羧甲基壳聚糖与阿拉伯胶-海藻酸钠质量比为1∶4时反应1 h,复凝聚反应的程度最大....     

Improving the shelf life stability of vacuum-packed fresh-cut peaches (Prunus persica L.) by radio frequency heating in water

The present study aimed to investigate the influence of radio frequency (RF) heating at 70 and 80 °C, in comparison with the traditional conventional heating. The RF heating technology was applied for maintaining the colour and textural quality as well as inactivating the enzymatic activity of polyphenol oxidase (PPO) and reducing the Escherichia coli growth in packaged fresh-cut peach samples. To evaluate this, 120 g of freshly cut peach fruit was placed in heat-resistant plastic bags, and 50 mL of sugar solution (12°Brix) was added to each bag and vacuum-packed for conventional heating and radio frequency (RF) heating. Our results demonstrated that the RF heating process could reduce the heating time by up to 83% at 70 and 80 °C as compared to conventional heating. Moreover, RF heating at 70 and 80 °C reduced the PPO enzymatic activity, which caused enzymatic browning, up to 85.46% and 93.5%, respectively, as compared to 40.86% reduction only for conventional heating. Furthermore, RF heating completely inhibited E. coli growth. Collectively, we demonstrated that RF heating is an emerging and promising technology for improving the quality of fresh-cut fruits such as peach during various storage conditions. The present study provides relatively novel information on the effectiveness of RF heating in maintaining the quality of fresh-cut peaches. In the future, we would like to investigate the effectiveness of RF heating on other agricultural products.     

Encapsulation of protein hydrolysates by spray drying: feasibility of using buffalo whey proteins

This work aimed to produce and encapsulate protein hydrolysates of buffalo origin using spray drying with gum arabic and maltodextrin as encapsulating agents. The following core ratios were applied: encapsulating agent in the ratios of 1:10 and 1:15, with 50% gum arabic and 50% maltodextrin (50:50), and 70% gum arabic and 30% maltodextrin (70:30). The encapsulated particles were between 2.0 and 20.0 μm. The encapsulation efficiency of the samples was above 95% at the initial time. After 45 days of storage, encapsulation efficiency decreased to values below 60%. The 70:30 samples showed a significant decrease (P < 0.05) in hygroscopicity, moisture and water activity compared with free hydrolysates. The encapsulation process increased the values of oil retention, emulsifying activity and solubility of whey protein hydrolysates for all proportions evaluated, both at the initial time and after 45 days of storage. The branched-chain amino acid concentration was higher in samples encapsulated at the 1:10 ratio. The spray drying encapsulation of buffalo protein hydrolysates with suitable encapsulating agents improves the techno-functional characteristics of these hydrolysates, hence expanding their use in different food matrices and enabling the use of buffalo cheese whey.     

维药阿拉伯胶重金属含量测定及安全性评价

目的测定阿拉伯胶中常见重金属铅、镉、铜、砷、汞的含量,评价其安全性,为建立阿拉伯胶重金属检测限值提供参考。方法用原子吸收法测定铅、镉、铜、砷、汞的含量,以《药用植物及制剂外经贸绿色行业标准》为标准评价阿拉伯胶的安全性。结果所测各批次样品铅、镉、铜、砷、汞的含量相差较小,符合《药用植物及制剂外经贸绿色行业标准》。结论可安全用于临床,为保障临床用药安全提供依据。     

正交试验优选桃胶多糖超声波辅助提取工艺

优选并确定桃胶多糖的超声波辅助提取最佳工艺。以多糖含量为考察指标,以超声功率、料液比、超声时间为三因素,每个因素选择3个水平,采用L9(34)正交试验进行提取工艺的优化研究。影响桃胶多糖提取效果的主次因素依次为超声功率超声时间料液比。最佳提取工艺为超声功率70 W,料液比1∶100(g/m L),时间为10 min。