改进的国标方法测定炒货类食品的可食部分与果壳中铝元素含量及其食用风险性探讨

目的 研究炒货食品可食部分与果壳中铝元素含量对人体摄入铝水平的影响,评估人体的食品安全风险暴露水平。方法采用HNO_3+H_2O_2+HF的酸消解体系进行微波消解前处理,运用电感耦合等离子体质谱法对炒货食品中可食部分与果壳的铝元素进行检测。通过对比每个样品的2部分数据,得出风险评估结果。结果 本方法在铝浓度为0～100μg/L范围内线性良好(r=0.9998),国家标准物质小麦、辽宁大米、茶叶的检测值都位于定值区间内,实际样品6次测定的相对标准偏差为3.45%,检出限为0.1 mg/kg,定量限为0.3 mg/kg。瓜子、花生、榛子样品的果壳部分铝含量高于可食部分,松子的果壳部分铝含量要低于可食部分,开心果的检测结果未収现明显觃律性。结论 为避克铝暴露量过高的风险,在炒货食用方式上,应注意减少与果壳的过多接触。     

Determination of the country of origin of pistachio nuts by DSC and HPLC

The laboratories of the U.S. Customs Service frequently encounter the major analytical problem of determining the country of origin of imported commodities. This is particularly challenging with natural products. This paper will describe the process for one such commodity —pistachio nuts. Two approaches were taken, high performance liquid chromatography (HPLC) and Differential Scanning Calorimetry (DSC). It was found that the results of these two techniques were complimentary and confirmatory. The HPLC data was obtained on the petroleum ether soluble fraction of the pistachio nuts while the DSC runs evaluated both this fraction and the whole nut. The HPLC results were further investigated by collecting fractions from the eluting peaks, derivatizing them to form the methyl ester of the fatty acids, and profiling by gas chromatography to confirm the triglycerides originally present. The U.S. Customs Service is currently using DSC area ratios to screen imported pistachio nuts for country of origin.     

Optimization of the Acceptance of Prebiotic Beverage Made from Cashew Nut Kernels and Passion Fruit Juice

The aim of this research was to develop a prebiotic beverage from a hydrosoluble extract of broken cashew nut kernels and passion fruit juice using response surface methodology in order to optimize acceptance of its sensory attributes. A 2² central composite rotatable design was used, which produced 9 formulations, which were then evaluated using different concentrations of hydrosoluble cashew nut kernel, passion fruit juice, oligofructose, and 3% sugar. The use of response surface methodology to interpret the sensory data made it possible to obtain a formulation with satisfactory acceptance which met the criteria of bifidogenic action and use of hydrosoluble cashew nut kernels by using 14% oligofructose and 33% passion fruit juice.     

2010—2011年泰州市部分食品中甜蜜素检测

目的 了解泰州市部分食品中甜蜜素的使用情况,为今后开展监管工作提供依据.方法 2010-2011年泰州市区范围的9个大型超级商场及30多个个体小卖店采集5类甜味食品共110份,按照国家标准GB/T5009.97-2003《食品中环已基氨基磺酸钠的测定》方法检测甜味食品中甜蜜素的含量.结果 共检测110份样品,其中80份检出有甜蜜素,检出率为72.7％.蜜饯类合格率最低,仅为52.9％.坚果类合格率最高,为100％.结论 泰州市售甜味食品添加甜蜜素现象普遍,蜜饯类超标较严重,应加强此类食品的监督管理,以保护消费者身体健康.     

18种市售坚果脂肪酸组成的比较分析及营养评价

为研究市售坚果脂肪酸的组成和营养价值,以18种市售坚果为原料,采用干柱法对其油脂含量进行测定,并通过气相色谱-质谱法对坚果油脂的脂肪酸组成进行分析和营养评价.结果 表明:18种市售坚果种仁富含油脂,油脂质量分数为43.15％ ～ 63.70％;脂肪酸以油酸(8.05％ ～ 84.60％)和亚油酸(1.27％ ～76.2...     

坚果类过敏原的分离及免疫印迹分析

本文采用传统的丙酮、乙醚溶剂去脂方法,选用不同品种和不同种类的坚果食品对其进行过敏蛋白的初步分离,应用BCA蛋白试剂盒测定各蛋白浓度,通过SDS-PAGE电泳分离坚果过敏蛋白各组份,采用免疫印迹(Western-blotting)方法鉴定坚果蛋白的过敏性。结果表明,各坚果蛋白提取浓度为白芝麻:14 mg/mL,黑芝麻:4 mg/mL,核桃:8 mg/mL,腰果:28 mg/mL,开心果:21 mg/mL。SDS-PAGE电泳显示15 ku是白芝麻的主要蛋白,34 ku是黑芝麻的主要蛋白,19和37 ku是腰果的主要蛋白,13 ku是核桃的主要蛋白,13和21 ku是开心果的主要蛋白。Western-Blotting显示对过敏患者的阳性混合血清均有过敏反应,坚果过敏具有同源性,白芝麻与黑芝麻的主要过敏原分子量均在22 ku,腰果的主要过敏原分子量在20 ku,核桃的主要过敏原分子量在54 ku,开心果的主要过敏原分子量在23 ku。     

隔膜室盖螺母液压拆装工具在隔膜泵中的应用

越来越多的用户需要高压大流量的隔膜泵,隔膜泵结构中的承压件大多是螺栓连接,螺栓的拧紧和拆卸已成为一个重要的问题.我公司也曾经出现过螺栓断裂造成设备停机,影响生产的情况,所以我们分析了原因,借鉴外国的先进技术.研制了隔膜室盖螺母液压拆装工具.本文介绍了螺栓的预紧力,拉伸的胡克定律和隔膜室盖螺母液压拆装工具的结构原理,及使用方法.     

银杏冰淇淋的研制

银杏中含有黄酮类物质和品质较好的蛋白质。银杏冰淇淋的研制增添了冰淇淋的花色品种,是健康人和心脑血管病患者等食用的保健食品。     

GH2036螺母开裂原因分析

某批GH2036螺母在使用过程中,有8件的表面出现了开裂现象。通过宏观观察、金相检验、硬度测试、断口分析等方法,确定了螺母开裂的原因。结果表明:该批零件局部区域存在大量呈带状分布的球型夹杂物,球型夹杂物的类型为含锰、硅和氧的硅酸盐型夹杂物,由于夹杂物的存在,破坏了材料的连续性,降低了材料的强度,同时由于夹杂物与基体之间变形速率的差异,导致了裂纹在棒材成型过程中的扩展,最后在外力的作用下发生了开裂。     

Postharvest processing of tree nuts: Current status and future prospects—A comprehensive review

Tree nuts are important economic crops and are consumed as healthy snacks worldwide. In recent years, the increasing needs for more efficient and effective postharvest processing technologies have been driven by the growing production, higher quality standards, stricter food safety requirements, development of new harvesting methods, and demand to achieve energy saving and carbon neutralization. Among all, the technologies related to drying, disinfection, and disinfestation and downstream processes, such as blanching, kernel peeling, and roasting, are the most important processes influencing the quality and safety of the products. These processes make up the largest contribution to the energy consumptions and environmental impacts stemming from tree nut production. Although many studies have been conducted to improve the processing efficiency and sustainability, and preserve the product quality and safety, information from these studies is fragmented and a centralized review highlighting the important technology advancements of postharvest processing of tree nuts would benefit the industry. In this comprehensive review, almonds, walnuts, and pistachios are selected as the representative crops of tree nuts. Current statuses, recent advances, and ongoing challenges in the scientific research as well as in the industrial processing practices of these tree nuts are summarized. Some new perspectives and applications of tree nut processing waste and by-products (such as the hulls and shells) are also discussed. In addition, future trends and research needs are highlighted. The material presented here will help both stakeholders and scientists to better understand postharvest tree nut processing and provide technological recommendations to improve the efficiency and sustainability, product quality and safety, and competitiveness of the industry.