Overview on mitigation of acrylamide in starchy fried and baked foods

Acrylamide in fried and baked foods has the potential to cause toxic effects in animals and humans. A major challenge lies in developing an effective strategy for acrylamide mitigation in foods without altering its basic properties. Food scientists around the world have developed various methods to mitigate the presence of acrylamide in fried food products. Mitigation techniques using additives such as salts, amino acids, cations and organic acids along with blanching of foods have reduced the concentration of acrylamide. The use of secondary metabolites such as polyphenols also reduces acrylamide concentration in fried food products. Other mitigation techniques such as asparaginase pre‐treatment and low‐temperature air frying with chitosan have been effective in mitigating the concentration of acrylamide. The combined pre‐treatment process along with the use of additives is the latest trend in acrylamide mitigation. © 2018 Society of Chemical Industry     

原花青素抑制丙烯酰胺的动力学

对原花青素对丙烯酰胺形成-消除动力学的影响进行研究。在荔枝原花青素（litchi pericarp procyanidin, LPPC）和莲房原花青素（lotus seedpod procyanidin,LSPC）对丙烯酰胺最大抑制率添加条件的基础上,分别采用 Logistic-生长曲线模型、Logistic-Fermi动力学模型和Logistic-指数动力学模型描述丙烯酰胺的形成-消除动力学过 程,最终优化选择Logistic-指数动力学模型为描述对象。实验结果表明：两种原花青素对丙烯酰胺形成过程具有显 著性影响,且LSPC的作用大于LPPC,在反应后期,两种原花青素对丙烯酰胺抑制均无显著性影响。     

焙炒咖啡中丙烯酰胺的研究现状

咖啡在高温(200~250℃)焙炒加工过程中会产生一定量潜在的致癌物质丙烯酰胺。实验研究表明,短期接触大量丙烯酰胺会对人和动物的中枢神经造成损伤,人体长期小剂量接触丙烯酰胺会表现为四肢末端麻木、无力。咖啡焙炒加工过程中产生的丙烯酰胺除了通过天门冬酰胺途径生成以外,还可以由丙烯醛途径生成。其中影响咖啡中丙烯酰胺形成的主要因素有咖啡类型、咖啡的焙炒温度和时间。本文对控制丙烯酰胺形成途径的研究进展进行了相关阐述,并对焙炒咖啡中丙烯酰胺的进一步研究提出建议。     

美拉德反应对产品风味品质的影响及其衍生危害物研究进展

在食品加工过程中,美拉德反应虽然对提升食品的风味和品质具有重要作用,但也会衍生一些化学危害物。本文综述了美拉德反应对食品风味和色泽等品质的影响,以及美拉德反应产物的抗氧化和抗突变等特性,同时也探讨了美拉德反应产生的丙烯酰胺(acrylamide,AA)、杂环胺(heterocyclic amines,HAs)和晚期糖基化末端终产物(advanced glycation end products,AGEs)等化学危害物的生成机制、分析和抑制方法。由于3类危害物在食品中的含量较低(ng/g~μg/g)且基质非常复杂,因此其检测均需要采用固相萃取等方法进行分离富集,随后可采用超高效液相色谱串联质谱(ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS)等方法进行定性定量分析。危害物的抑制主要通过采用更加温和的加工方法、调整工艺参数和添加香辛料及酚类等天然抗氧化物质来实现。     

适用于“一步酸溶法”生产氧化铝工艺中稀释料浆的高分子絮凝剂的合成

为达到"一步酸溶法"生产氧化铝工艺中稀释料浆在高温、高酸度工况下进行固液高效分离的目的,以丙烯酰胺(AM)与阳离子(DMDAAC)为共聚单体,通过水溶液聚合法合成了阳离子聚丙烯酰胺(CPAM)絮凝剂。以转化率和相对分子质量为目标,通过单因素分析法确定了最优的合成工艺条件,即反应温度30℃,单体总质量分数为30%,阳离子度5%,K2S2O8和NaHSO3质量分数均为0.005%,2,2′-偶氮二(2-脒基丙烷盐酸盐)(V50)质量分数为0.0025%,乙二胺四乙酸(EDTA)质量分数为0.05%的条件下,反应时间为6 h,获得相对分子质量为1.2×107溶解性能较好的阳离子型聚丙烯酰胺(CPAM)。     

几种阳离子度PDA共聚物的合成

以丙烯酰胺(AM)和工业单体二甲基二烯丙基氯化铵(DMDAAC)为原料,过硫酸铵(APS)和亚硫酸氢钠(RH)复合物为引发体系,采取一次性加料方法,以特征黏度为考核指标,对几种阳离子度二甲基二烯丙基氯化铵与丙烯酰胺的共聚物PDA进行了制备工艺研究。通过正交优化等实验方法考察了单体起始质量分数、引发剂用量和聚合反应温度3个因素对选定的每一种阳离子度PDA共聚合反应结果的影响,得到了制备系列化具不同阳离子度PDA的各自最佳点的制备工艺条件,比较了在各阳离子度条件下,最佳制备工艺点时单体起始质量分数、引发剂用量和聚合反应温度的变化规律。结果表明,对于制备5%、10%、20%、30%和50%阳离子度的PDA产物,当单体起始质量分数分别为16%、18%、25%、35%和65%,引发剂用量占单体的质量分数分别为8.62×10-5、8.82×10-5、7.35×10-5、5.40×10-5和9.19×10-5,聚合反应温度分别为25、30、30、30℃和25℃时,特征黏度可分别达到17.0、15.0、11.6、9.0 dL/g和6.2 dL/g。此外还对共聚产物PDA进行了红外光谱结构表征。该工艺简单方便、清洁安全,适合于工业化生产。     

Synthesis and performance evaluation of a new drag reducer based on acrylamide/12-allyloxydodecyl acid sodium

Hydraulic fracturing with slickwater is a field-proven stimulation technology used in tight reservoirs. Because of the high pumping rate associated with slickwater fracturing, drag reduction (DR) is critical in minimizing pressure drop and the success of oilfield operations. In this paper, a new type of drag reducer (SPR) was synthesized with acrylamide and 12-allyloxydodecyl acid sodium, and its drag reduction performance was evaluated. The results showed that the new drag reducer features low molecular weight, fast-dissolving rate and low interfacial tension. The algorithm of estimating the drag reduction rate of non-Newtonian fluid SPR was proposed and validated. Empirical or semianalytical models for estimating the friction ratio (σ) or friction factor (λ or f) were used to simulate the turbulence behavior of the SPR drag reducer under different Reynolds numbers (Re). The modified Virk's correlation could accurately model the turbulent behavior of the SPR drag reducer. A unified calculation formula was established in this study for different pipe diameters.     

AM-ST共聚物乳液水解产物在再生浆纸张增强中的应用

用透射电镜及红外光谱表征了丙烯酰胺(AM)-苯乙烯(ST)无皂乳液共聚物的水解产物,并考察了水解产物对二次纤维纸张的增强效果。研究结果表明,所制得的几种聚丙烯酰胺乳液均能增强漂白再生浆和废纸箱再生浆纸张的干抗张强度和环压强度,并且对漂白再生浆的增强效果更佳;同时获得了在废纸箱再生浆、漂白再生浆应用中添加量少、效果好的聚丙烯酰胺乳液品种。     

Effect of Radio Frequency Postdrying of Partially Baked Cookies on Acrylamide Content,Texture, and Color of the Final Product

Abstract: Effect of radio frequency (RF) postdrying of partially baked cookies on acrylamide content, texture, and color of the final product was investigated in this study. Control cookies were prepared by baking in a conventional oven at 205 °C for 11 min. Cookies partially baked for 8 and 9 min were postdried in a 27.12 MHz RF tunnel oven until attainment of the moisture content of control cookies. Internal temperature of cookies was monitored during the experiments to better explain the results. Cookies were analyzed for acrylamide content using a liquid chromatography‐mass spectrometry (LC‐MS) method. Texture measurements were performed using a Texture Analyzer, while digital image analysis was used for color measurement. The results showed that RF postdrying of partially baked cookies resulted in lower acrylamide levels (107.3 ng/g for control cookies, 74.6 ng/g upon RF postdrying of cookies partially baked for 9 min, 51.1 ng/g upon RF postdrying of cookies partially baked for 8 min). Instrumental texture analysis showed no significant difference among the texture of cookies, whereas RF postdried samples had a lower degree of browning. According to sensory evaluation results, control had a more crumbly texture, and RF postdried sample that was conventionally baked for 8 min had a slightly uncooked flavor. Practical Application: Combining radio frequency and conventional baking may provide cookie manufacturers with ability to make cookies with lower levels of acrylamide.     

食品中丙烯酰胺分析方法研究进展

丙烯酰胺由于其神经毒性及其可能致癌性,引起了各国科学家的对其深入广泛的研究。文中介绍了食品中丙烯酰胺的分析方法及样品前处理方法的研究进展,包括提出了对食品中丙烯酰胺分析方法的新的需求。