Development of a long‐life vacuum‐packaged ready‐to‐eat meat product based on a traditional Portuguese seasoned meat

Carne do alguidar is a Portuguese traditional pork fried meat, usually manufactured for self‐consumption purposes. This study developed a ready‐to‐eat (RTE) meat product, to meet today's consumers’ convenience, manufactured at the industrial scale evaluating its quality and shelf life, assessing the effect of vacuum packaging and the use of an antioxidant (50 ppm BHT) to enhance oxidative stability. Physicochemical and microbiological parameters were assessed, and a sensory analysis was performed. Interestingly, no significant differences were recorded between control (non‐BHT) and antioxidant (BHT) samples. Microbiological counts remained at low levels throughout the storage period, ensuring the product's required microbiological quality. At later storage stages, higher values of thiobarbituric acid‐reactive substances arose and off flavours and aromas were perceived. Still, overall appreciation was not affected until 12 months of storage and a significant depreciation was perceived only after 15 months. Fibrousness and rising of off flavours were negatively correlated with overall appreciation.     

油炸食品中丙烯酰胺的检测方法研究

富含淀粉的食物在油炸过程中,极易产生一种有害的化学物质——丙烯酰胺。建立了油炸食品中丙烯酰胺的提取、纯化与高效液相色谱分析方法。油炸食品经水提后正己烷脱脂、Carrez试剂净化除蛋白、C18固相萃取柱纯化得到丙烯酰胺提取液,再经高效液相色谱法分析检测。研究了高效液相色谱不同流动相比例、柱温、流速、进样量对丙烯酰胺分离效果的影响,确立了最佳色谱分离条件:检测波长195 nm,流动相乙腈-水(体积比20∶80),柱温45℃,流速1. 0 m L/min,进样量20μL。该方法丙烯酰胺的检出限为5μg/kg,相对标准偏差在0. 5%范围内,薯片样品的加标回收率在88. 5%～90. 6%之间,该法能有效、快速测定油炸食品中丙烯酰胺的含量。     

抑制鲜切油炸薯片中丙烯酰胺产生的在线控制研究

前期研究表明,半胱氨酸、CaCl2等离子型物质能有效抑制油炸薯片中丙烯酰胺的产生。但在浸泡过程中其浓度会不断降低,因此如何在线监控抑制剂浓度并及时补充成为抑制剂能否成功用于工业化生产的关键。根据抑制剂浓度与电导率之间的线性关系,采用电导率仪监控浸泡液中抑制剂浓度,通过电导率仪获得的数据实时补充抑制剂。     

GC-MS测定薯类油炸食品及洋快餐中丙烯酰胺

利用中国疾病预防控制中心营养与食品安全所的样品前处理方法,采用气相色谱和四级杆一级质谱联用技术对薯类油炸食品及洋快餐两类8种食品中丙烯酰胺进行了测定,以相对保留时间和丙烯酰胺相应监测离子的丰度进行定性分析。结果表明,丙烯酰胺标准各浓度水平的相对响应因子RRF的相对标准偏差(RSD)小于20%,满足内标法计算要求,薯类油炸食品丙烯酰胺含量为456～5269μg/kg,洋快餐食品中丙烯酰胺含量为147～214μg/kg。     

油炸小食品中酚类抗氧剂的高效液相色谱法测定

采用反相高效液相色谱法测定油炸小食品中BHA、4HR、BHT、2,2-2甲基双(4-甲基6-叔丁基苯酚) (2246)的含量。采用V(甲醇):V(二氯甲烷)=9:1作提取剂,ODS-2HYPERSIL(250mm×4.6mm,5μm)色谱柱,体积分数80%的甲醇作流动相进行分离。结果表明:浓度在2.0～40μg/mL,4种物质均呈线性关系,相关系数为0.998 3～0.999 1,标准偏差为1.14%～5.90%,平均回收率均在80%以上,检出限2μg/g。因此,该方法可用于油炸食品中酚类抗氧剂的测定。     

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     

2015~2017年江苏省食品中多环芳烃污染状况的调查分析

目的 调查江苏省辖区内的食物中多环芳烃的污染水平现况。方法 收集2015~2017年江苏省13市区流通和餐饮环节的油炸食品、速食面、食用油类等样品, 采用高效液相色谱荧光检测器测定15种多环芳烃的含量。结果 采集5类食物共277份, 15种多环芳烃的检出率为18.8%, 各类食品中目标化合物检出含量范围: 油炸面类食品0.3~197.7 μg/kg; 速食面0.3~72.0 μg/kg; 食用油0.3~27.4 μg/kg; 果蔬类 0.1~2.56 μg/kg; 谷物0.1~6.92 μg/kg。苯并(a)芘(BaP)均未超标。结论 江苏省内食品中存在多环芳烃的污染状况, 15种多环芳烃的总含量的均值以油炸面类食品和食用油最高, 速食面次之, 谷物与果蔬类处于较低水平。     

淀粉和食用胶对油炸面制品油脂含量和油脂分布的影响

研究了淀粉种类及配比和食用胶种类及添加量对油炸面制品油脂含量和油脂分布的影响。采用索氏抽提法测定油炸面制品中的油脂含量,采用激光共聚焦扫描显微镜测定其断面的油脂分布。结果表明:以20%的木薯淀粉与80%的A4小麦淀粉为原料,加入0.5%酪朊酸钠、1%食用盐、0.5%Na HCO3、0.5%KHCO3、40%水,制作出的油炸面制品不仅油脂含量低而且油脂分布均匀。     

超声波提取炒王不留行总三萜的工艺优化及其抑菌活性研究

优化炒王不留行总三萜提取工艺,并分析其抑菌活性。在单因素实验的基础上,选取乙醇浓度、液料比、超声温度和超声时间为自变量,总三萜得率为响应值,采用4因素3水平的响应曲面分析法优化炒王不留行总三萜提取工艺;并采用倍比稀释法研究炒王不留行总三萜提取物对10种常见致病菌的抑菌作用。结果表明,超声波辅助提取炒王不留行总三萜最佳提取工艺条件为:乙醇浓度65%,料液比1:25(g/mL),超声温度63℃,超声时间40 min。在此工艺条件下,炒王不留行总三萜的得率为1.24%±0.003%,与模型预测值1.28%之间具有良好的拟合性。炒王不留行总三萜提取物对所选10种常见致病菌均有一定的抑制作用,尤其是对大肠杆菌、金黄色葡萄球菌、化脓性链球菌和肺炎链球菌抑制作用最强,其最小抑菌浓度(MIC)和最小杀菌浓度(MBC)均在1.25~5 mg/mL之间。该提取方法稳定、高效,可用于炒王不留行中总三萜的提取,同时提取物具有较强的广谱抗菌作用。     

山楂生、炒品果胶结构表征和体外降脂作用研究

目的 明确山楂生品果胶(raw hawthorn pectin, RHP)和炒品果胶(fried hawthorn pectin, FHP)的结构与其体外降脂作用的关系。方法 通过测定酯化度、半乳糖醛酸含量、分子量、特性黏度、黏均分子量、中性糖组成和比例,用扫描电镜观察微观形态,来表征RHP和FHP的结构。通过果胶对胆固醇胶束和胆酸盐的结合能力等体外实验评价其降脂作用。结果 RHP酯化度为52.19%,属于高酯果胶; FHP酯化度为31.95%,属于低酯果胶。RHP分子量有4个级分(217904、16907、8933、5104 Da),FHP分子量有4个级分(238813、16662、8770、5063 Da)。RHP特性黏度和黏均分子量分别为0.10 dL/g和2.75×10⁴ g/moL, FHP特性黏度和黏均分子量分别为0.16 dL/g和4.71×10⁴ g/moL。RHP、FHP均含有葡萄糖、鼠李糖、半乳糖、果糖和木糖等中性糖,但各糖的分子摩尔比不同。微观形态中, RHP分子间交联良好; FHP分子之间交联较少。在体外降脂实验中,R...