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关键词： DPPH radical scavenging activity   Food additive   FRAP   Purslane (Portulaca oleracea L   )   Total flavonoids   Total phenols   PORTULACA-OLERACEA L.   FLAVONOIDS   EXTRACTS  

摘要： Purpose This paper aims to study the effect of cooking and food additives, such as lemon juice and vinegar, on phenols and flavonoids contents and antioxidant activity of purslane. Design/methodology/approach The Folin-Ciocalteu method was used to determine total phenols content (TP), while total flavonoid content (TF) was determined by the aluminum chloride method. Two methods were used for determination of antioxidant activity: DPPH (1, 1-diphenyl-2-picrylhydrazyl) assay to determine radical scavenging activity, and ferric-reducing antioxidant power (FRAP) to measure the reducing power. Findings According to the results, leafs had higher values of TP, TF and antioxidant activity than aerial parts. Both lemon juice and vinegar retracted antioxidant properties of leafs. TP and TF of leaves showed deterioration after treatment with lemon by 58% and 21.8%, respectively, and FRAP and radical scavenging activity decreased by 75.8% and 74.5%, respectively (p < 0.001). Also, TP, TF, FRAP and DPPH radical scavenging activity decreased in leaves by 82.2%, 30.5%, 87.8% and 90.9%, respectively, after treatment of leaves with vinegar. TF increased after cooking in studied parts, where no significant statistical difference was observed in TP and antioxidant activity (DPPH assay and FRAP) of cooked aerial parts. Adding lemon juice after cooking increased antioxidant properties of purslane (p < 0.001). Originality/value Purslane has antioxidant activity because it is rich in polyphenols and flavonoids. Effects of food additives and cooking were studied using different measurements. According to the authors' knowledge, this is the first work that studied the effect of food additives on antioxidant properties of purslane.

关键词： 食品添加剂  

摘要： “吃的健康”越来越深入人心,食品添加剂成了很多人担心的焦点:有食品添加剂的食品可以放心吃吗?“无添加”的食品才是最好的?

关键词： 食品分析   谷物   铝   质谱法  

摘要： 目的调查中国未加工粮谷类食品的铝含量情况。方法2013年6月至2014年12月,采用分层随机抽样选取吉林、山东、湖北、湖南、广东、广西、河南、安徽、江苏等9个省份作为采样地区,每个采样地区以单纯随机法选取3个市、县或乡作为采样点,通过立意抽样选择粮站、粮库、种植地或农贸市场采集本地自产的粮谷类食品,并要求采样点周围无铝矿区或含铝工业污染源。共采集粮谷类食品样品470份,每份样品500 g,以电感耦合等离子体质谱法检测干制粮谷类样品铝含量;基于Bootstrap再抽样方法计算各类食品铝含量P99的95%CI值,以上限值作为该类食品铝含量的关注水平。结果剔除检测结果中异常值后,可用于统计分析的各类样品数分别为小麦109份、大米111份、玉米78份、小米69份、大豆87份,共计454份。检出铝的阳性样品420份(92.5%)。小麦和大豆的铝含量较高,M分别为9.59和7.12 mg/kg,最大值分别为31.55和28.80 mg/kg;其次为玉米,M为4.65 mg/kg,最大值为26.79 mg/kg;大米和小米的铝含量相对较低,M分别为1.49和2.21 mg/kg,最大值分别为7.56和8.07 mg/kg。基于Bootstrap再抽样法得到小麦、大豆、玉米、大米和小米铝含量P99的95%CI上限值分别为29.86、28.80、26.79、7.56和8.07 mg/kg,可以此作为相应粮谷类食品铝含量的关注水平。结论铝在未加工的粮谷类中普遍存在,不同类别粮谷类对铝的富集能力不同。

关键词： 食品安全问题   质量管理工作   风险分析   安全管理工作   食品市场   健康生活   食品质量   政府部门  

摘要： 随着社会经济的高速发展,人们的生活水平在不断地提升,食品质量与安全问题受到了广泛的关注,对于食品安全问题需要更高的标准去解决。基于此,本文就以食品安全风险分析为基础,科学分析食品安全风险分析对于食品质量管理的作用,并提出相关措施,以期能够为食品安全管理工作提供参考依据,构建良好的食品安全环境。随着我国食品市场安全问题的频发,食品安全成为了社会广泛关注的问题,面对如此复杂的食品市场,政府部门开始提升对于食品安全问题的关注度,将食品安全风险分析有效地运用到食品质量管理工作中,为社会大众构建安全的食品环境,降低食品安全问题的发生,为人们的健康生活提供有力的保障。