食用植物油中邻苯二甲酸酯类塑化剂来源和风险控制措施研究

对食用植物油中邻苯二甲酸酯类(PAEs)塑化剂的来源和风险控制进行了研究。针对植物油加工企业实际情况,分别从油料及其包装、加工,油脂接触的塑料制品进行全面排查和分析PAEs来源。结果表明:油料在种植过程中吸收了塑化剂导致其本身含有一定量的塑化剂;采用PP编织袋不会对油料造成塑化剂污染;油料在预榨之前有效地清理塑料杂质,可减少毛油中PAEs含量;油脂生产过程中接触的输油软管和垫片、垫圈等塑料制品的PAEs含量、温度、时间与PAEs在食用植物油中的迁移量成正比,是植物油中塑化剂污染的主要因素。脱臭工艺可脱除一定量的塑化剂。结合植物油中塑化剂来源和防治措施,可降低植物油中塑化剂风险。     

食用油脂鉴伪技术研究进展

近年来,地沟油事件多次引起人们对我国食品安全现状的担忧。由于缺乏有效的食用油脂中地沟油鉴别检测技术,制约着相关方面的食品安全监管和预警体系建设。由于地沟油通常是作为一种添加物掺入食用油脂中,更有甚者,地沟油渣直接冒充正常油脂流向餐桌,因此食用油脂鉴伪技术研究对地沟油的检测有较大借鉴作用。基于此,该文对近几年来食用油脂鉴伪技术研究进展进行综述。     

食用油掺入废食用油脂检测技术研究现状

该文综述目前食用油脂掺入废弃食用油脂现状及涉及食品安全问题;概述目前应用检测食用油掺入废弃食用油脂方法,主要是理化检测和仪器分析检测;最后对检测方法及我国食品安全问题进行展望。     

植物油料和食用油脂加工质量安全控制

食用油质量安全是食品安全的重要内容和组成部分。多环芳烃(PAHs)、真菌毒素(玉米赤霉烯酮ZEN、黄曲霉毒素AFB1)、塑化剂(PAEs)、反式脂肪酸(TFA)和3-氯丙醇酯(3-MCPDE)是食用植物油中的主要质量安全风险成分。课题深入系统研究了食用植物油中主要风险成分的成因、控制及脱除技术。毛油中PAHs成因是油料带入和油籽不当的高温焙炒,控制原料质量和适度炒籽是减少油脂中PAHs的关键,采用适度炒籽技术可使PAHs风险降低80%以上,优化的吸附技术能高效脱除油脂中的PAHs并减少油脂香味和营养成分损失(吸附剂用量为油重0.2%~0.5%,Ba P脱除率达到99%,油脂损耗降低90%);毛油中PAEs的成因主要是油料带入和加工助剂带入,采用优化的高温蒸馏脱除技术PAEs脱除率可达90%~95%,同时反式酸形成和维生素E损失降低50%以上;毛油中真菌毒素的成因主要是油料带入,不同真菌毒素向油脂中的迁移率不同,ZEN显著高于AFB1,根据毛油中真菌毒素含量不同,分别采用优化的碱炼脱除技术或碱炼-吸附-蒸馏三级深度脱除技术,可实现油脂中95%~99%真菌毒素的实质性脱除,同时明显减少油脂损耗和营养成分损失;毛油品质、毛油和加工助剂中的氯离子及长时间高温脱臭是3-MCPDE和GE形成的关键因素。     

油脂加工企业的食品安全风险

正本文提出了我国油脂加工企业在生产食用油脂产品时,在原料、加工、储运等各个环节所面临的食品安全风险,并就其中加工企业可以控制的部分工序提出控制对策,就其中涉及其他环节的工序提出改进建议,以期更好地控制食品安全风险,减少不当操作和违规操作造成的问题。油脂是生活必备品,也是油脂加工企业的主要原料,而在经济发展、生活水平提升的大背景下,人们对食用油脂品质的要求也愈来愈高。但当前食用油脂在加工储运中仍面临一些食品     

食用油中常见塑化剂的GC-MS法快速测定

为快速有效地检测食用油中的污染物邻苯二甲酸酯类物质,建立了GC-MS联用法对邻苯二甲酸酯类物质检测方法。PAEs在0.05~5.00 mg/L范围内线性关系良好,相关系数R2﹥0.997,仪器检出限大部分低于10μg/L;在0.5 mg/L和5.0mg/L的基质加标水平下,测得PAEs精密度的RSD在5.30%左右,精密度较好;在0、0.5、5.0mg/L三个基质加标水平下,PAEs的回收率在76.8%~118.0%之间,相对标准偏差(RSD)在3.86%~9.15%之间;与国标和其他方法相比,该实验方法样品前处理简单,分析时间少,实验成本低,检测效果好,准确度高,适用于质检和品控部门对食用植物油中的PAEs进行快速大量地检测。本论文还对PAEs的预防提出了一些措施,这在维护食品安全方面具有重要意义。     

食用油脂鉴别及掺假检测技术研究进展

食用油脂作为人们日常饮食中不可缺少的重要组成部分,可为人体产生热能,更是人们所需的脂溶性维生素、必需脂肪酸和磷脂等物质的重要来源。它们因种类、纯度、营养成分等指标的不同而在价格上差异悬殊,导致一些不法分子为牟取暴利而将低附加值食用油掺入到高附加值植物油中,更有甚者,将劣质、有毒油脂掺入食用植物油中,由此引发的食品安全问题也屡见不鲜。因此,本文对近年来国内外食用油脂鉴别及掺假检测技术进行了综述,介绍了色谱法（气相色谱法、液相色谱法）、光谱法（红外光谱法、荧光光谱法、拉曼光谱法、紫外-可见吸收光谱法、太赫兹光谱法、低场核磁共振法）、稳定同位素技术及其它方法（如电子鼻、电子舌）在食用油脂中的应用,并展望了食用油脂检测的未来发展方向,以期为我国油脂检测工作和食品安全提供理论参考。     

鉴别食用油脂中地沟油的方法探讨

地沟油是一种质量极差的非食用油脂,会导致身体诱发多种疾病,本文综述了目前鉴别食用油脂中地沟油的各种方法和原理,希望能找到较好的检测方法来作为判断的依据,从而保证食品安全。     

超声波萃取-气相色谱法测定塑料袋袋装食品中邻苯二甲酸酯

采用超声波萃取-气相色谱法测定经塑料食品袋盛装后食品中邻苯二甲酸酯(PAEs)含量。取烧饼、麻花和馒头样品用同种塑料食品袋与纸袋分别盛装30 min,进行检测。PAEs添加回收率在84．1％～107．8％之间,标准偏差在1．6％～6．7％之间。测定结果表明,经塑料袋盛装后食品PAEs含量均有不同程度提高:PAEs对温度高食品污染程度大;且PAEs对油脂含量高的食品污染程度比油脂含量低的污染程度大;PAEs对食品表面污染程度大于内部。     

食用油脂掺入异种油脂检测方法研究进展

目前我国食用油脂掺假现象仍很常见,严重影响人民身体健康,是油脂食品安全问题重中之重。该文就油脂掺假现象从感官检验、定性检验和定量检验三个方面,对目前国内外油脂掺假检测方法进展进行综述。     

Ovarian structures and circulating steroids in heifers and lactating cows in summer and lactating and dry cows in winter

Two experiments compared follicular and luteal development and circulating steroid concentrations from induced luteolysis to ovulation in lactating Holstein cows (n = 27; 40.0 +/- 1.5 kg milk/day) vs. nulliparous heifers (n = 28; 11 to 17 mo-old) during summer (Experiment 1), and in lactating (n = 27; 45.9 +/- 1.4 kg milk/d) vs. dry cows (n = 26) during winter (experiment 2). All females received PGF2,, 6 d after ovulation and were monitored until next ovulation by daily ultrasound and assay of serum progesterone (P4) and estradiol (E2). Every female was used two or three times. In Experiment 1, lactating cows had high incidence of multiple ovulation (63.5%) compared with heifers (1.3%). Among single ovulators, there was no difference in maximal size of ovulatory follicles between lactating cows and heifers (15.8 vs. 16.5 mm, respectively). However, lactating cows had lower peak serum E2 (8.6 vs. 12.1 pg/ml), took longer to ovulate after luteolysis (4.6 vs. 3.8 d), developed more luteal tissue volume (7,293.6 vs. 5,515.2 mm3), and had lower serum P4 on d 6 after ovulation (2.0 vs. 3.0 ng/ml) than heifers (data included multiple ovulators). In experiment 2, multiple ovulations were similar between lactating and dry cows (17.9 vs. 17.2%, respectively). Peak serum E2 was also similar between lactating and dry cows (7.6 vs. 8.5 pg/ml) although lactating cows had larger ovulatory follicles (18.6 vs. 16.2 +/- 0.4 mm). Lactating cows took longer to ovulate (4.8 vs. 4.2 d), developed more luteal tissue (7,599 vs. 5,139 +/- 468 mm3), but had similar serum P4 (2.2 vs. 1.9 ng/ ml) compared with dry cows. Therefore, lactating cows had similar or lower circulating steroid concentrations than dry cows or heifers, respectively, despite having larger ovarian structures.     

Fertilization and early embryonic development in heifers and lactating cows in summer and lactating and dry cows in winter

Two experiments in two seasons evaluated fertilization rate and embryonic development in dairy cattle. Experiment 1 (summer) compared lactating Holstein cows (n = 27; 97.3 +/- 4.1 d postpartum [dppl; 40.0 +/- 1.5 kg milk/d) to nulliparous heifers (n = 28; 11 to 17 mo old). Experiment 2 (winter) compared lactating cows (n = 27; 46.4 +/- 1.6 dpp; 45.9 +/- 1.4 kg milk/d) to dry cows (n = 26). Inseminations based on estrus included combined semen from four high-fertility bulls. Embryos and oocytes recovered 5 d after ovulation were evaluated for fertilization, embryo quality (1 = excellent to 5 = degenerate), nuclei/embryo, and accessory sperm. In experiment 1, 21 embryos and 17 unfertilized oocytes (UFO) were recovered from lactating cows versus 32 embryos and no UFO from heifers (55% vs. 100% fertilization). Embryos from lactating cows had inferior quality scores (3.8 +/- 0.4 vs. 2.2 +/- 0.3), fewer nuclei/embryo (19.3 +/- 3.7 vs. 36.8 +/- 3.0) but more accessory sperm (37.3 +/- 5.8 vs. 22.4 +/- 5.5/embryo) than embryos from heifers. Sperm were attached to 80% of UFO (17.8 +/- 12.1 sperm/UFO). In experiment 2, lactating cows yielded 36 embryos and 5 UFO versus 34 embryos and 4 UFO from dry cows (87.8 vs. 89.5% fertilization). Embryo quality from lactating cows was inferior to dry cows (3.1 +/- 0.3 vs. 2.2 +/- 0.3), but embryos had similar numbers of nuclei (27.2 +/- 2.7 vs. 30.6 +/- 2.1) and accessory sperm (42.0 +/- 9.4 vs. 36.5 +/- 6.3). From 53% of the flushings from lactating cows and 28% from dry cows, only nonviable embryos were collected. Thus, embryos of lactating dairy cows were detectably inferior to embryos from nonlactating females as early as 5 d after ovulation, with a surprisingly high percentage of nonviable embryos. In addition, fertilization rate was reduced only in summer, apparently due to an effect of heat stress on the oocyte.     

2018年深圳市售蔬菜和鸡蛋中氟虫腈及其代谢物的检测分析

目的 建立超高效液相色谱-串联质谱法同时测定蔬菜和鸡蛋中氟虫腈及其代谢物(氟甲腈、氟虫腈砜和氟虫腈亚砜), 并对深圳市售的蔬菜和鸡蛋中氟虫腈及其代谢物残留状况进行抽样检测。方法 采用QuEChERS前处理方法, 以C18色谱柱为分离柱, 以乙腈和10 mmol甲酸+6 mmol甲酸铵水溶液为流动相进行梯度洗脱, 用超高效液相色谱-串联质谱(ultra performance liquid chromatography-mass spectrometry/mass spectrometry, UPLC-MS/MS), 电喷雾电离(electrospray ionization, ESI), 多反应监测(multiple reaction monitoring, MRM)模式检测, 外标法同时定量测定氟虫腈及其代谢物。结果 方法的线性范围为0.1~2.0 μg/L, 线性相关系数均大于0.9994, 检出限0.0005 mg/kg, 定量限0.001 mg/kg; 蔬菜中3个水平的平均加标回收率88.0%~101.2%, 相对标准偏差(relative standard deviation, RSD)均小于8.5%; 鸡蛋中3个水平的平均加标回收率86.1%~104.8%, 相对标准偏差(RSD)均小于9.2%。结论 该方法具有操作简单、干扰少、快速、准确可靠等特点, 可适用于蔬菜鸡蛋中氟虫腈及其代谢物的检测。     

Zinc and iron contents and their bioaccessibility in cereals and pulses consumed in India

Several cereals and pulses commonly consumed in India were screened for zinc and iron contents and their bioaccessibility in the same was determined by equilibrium dialysis employing an in vitro simulated digestion procedure. Zinc content of cereals ranged from 1.08 mg/100 g in rice to 2.24 mg/100 g in sorghum. Zinc content of pulses was between 2.03 mg/100 g (whole chickpea) and 2.68 mg/ 100 g (decorticated chickpea). Iron content of cereals ranged from 1.32 mg% in rice to 6.51 mg% in sorghum, while that of pulses ranged from 3.85 mg% in decorticated green gram to 6.46 mg% in black gram. Dialyzability of zinc from pulses (27–56%) was generally higher than that from cereals (5.5–21.4%). Dialyzabilities of iron were almost similar from both cereals and pulses examined and were 4.13–8.05% in cereals and 1.77–10.2 % in pulses. A significant negative correlation between inherent phytate content and zinc dialyzability value was inferred in the case of pulses. Phytic acid content of the cereals had a significant negative influence on iron dialyzability. Inherent calcium had a negative influence on zinc dialyzability in cereals. Tannin did not have any significant influence on zinc or iron dialyzabilities from cereals and pulses. While both insoluble and soluble fractions of the dietary fibre generally interfered with zinc dialyzability, the insoluble fraction alone had this effect on iron dialyzability. The lower collective negative influence of the inherent factors on zinc dialyzability from pulses is consistent with their higher concentrations in these grains, relative to cereals. The negative correlation of inherent phytic acid with zinc and iron dialyzabilities was supported by enhanced dialyzabilities of these minerals upon partial removal of phytate from the grains by treatment with fungal phytase.     

果蔬及其制品中真菌毒素的污染与检测研究进展

果蔬在生长、贮存、运输及加工等一系列过程中,极易受到各种病原菌的侵染而发生腐烂,腐烂果蔬不仅造成巨大的经济损失,而且导致果蔬积累大量的真菌毒素。真菌毒素可通过食物链的传递对人或动物的健康带来巨大威胁。本文就果蔬中常见真菌毒素的种类、产毒菌株、侵染途径、产毒条件、毒性作用、检测方法和限量标准等方面进行详细的总结,旨在为果蔬中真菌毒素的控制提供参考。     

蛋白质组学技术及其在乳及乳制品中的应用研究进展

蛋白质组学技术是近年来生命科学研究的重要工具,在食品、医学及动植物研究领域具有独特优势。利用蛋白质组学技术研究乳及乳制品,深入阐明其中蛋白质的表达及动态变化已成为当前的研究热点。该文主要综述了蛋白质组学的概念、常用技术及应用领域,重点介绍蛋白质组学在乳及乳制品领域,特别是在乳脂肪球膜蛋白、乳清蛋白、乳及乳制品加工过程以及干酪制品中的研究应用,探讨了目前乳及乳制品蛋白质组学研究中存在的问题与局限,并对蛋白质组学及其在乳及乳制品中的应用前景进行了总结与展望,为应用蛋白质组学技术深入研究乳及乳制品提供了理论依据。     

冰酒中的毕赤属和汉逊属酵母菌的筛选及其在葡萄酒酿造中的应用

从冰葡萄酒自然发酵过程中分离、鉴定出10株毕赤属(Pichia)和汉逊属(Hanseniaspora)酵母,对其耐受性(酒精、糖、酸、SO2)进行研究,筛选得到4株耐受性能优良的酵母菌株,编号为"HO"和"HU"(Hanseniaspora属)、"PO"和"PK"(Pichia属)。再将此4个酵母菌株与商业酿酒酵母(Saccharomyces cerevisiae)按不同比例(1:1和10:1,1:1编号为1,10:1编号为2),先接种非酿酒酵母菌株,48 h后再接种酿酒酵母的顺序进行混合发酵。研究了发酵过程中菌群及乙醇的动态变化,又对发酵结束后冰葡萄酒的主要成分进行分析。结果显示:"HO"随接种量的增加菌落数受到抑制,"HU""PO"及"PK"随接种量的增大菌落数受到促进作用;HO1、HU1、HU2、PK1、PK2乙醇含量在发酵前期增长较少,在发酵中期迅速增大,HO2、PO1、PO2乙醇含量在发酵前期增长较多,在发酵中期显著增大,所有发酵乙醇含量皆于第21天稳定在9%左右;"HO""HU""PO"及"PK"不同比例混合发酵各理化指标(酒精度、总糖、总酸、有机酸)均符合国家葡萄酒标准,"HU"乙酸含量过高,葡萄酒品质中含有缺陷。以上结果表明4株酵母菌株均可应用于本土葡萄酒的酿造中,为生产具有本地特色的葡萄酒提供一定的参考。     

Fenvalerate residue level and dissipation in tea and in its infusion

Fenvalerate is a non-systemic insecticide/acaricide used in controlling a wide range of pests, including those resistant to organochlorine, organophosphorus and carbamate insecticides. The study investigated the dissipation behaviour (residue level) of fenvalerate in tea and its transfer during infusion. Fenvalerate was applied on tea crop at two dosages, 100 and 200 g a.i. ha^-1 (recommended and double the recommended) in the dry and wet seasons under field conditions. Samples (green tea shoots, made tea, its infusion and spent leaves) were analysed for fenvalerate by high-performance liquid chromatography using diode array detection. The residue dissipated faster in the wet season than in the dry season. Seven days after the treatment (normal round of plucking) the residues observed in the green shoots at the two dosages were 0.5 ± 0.01, 1.1 ± 0.01 and 0.4 ± 0.02, 0.9 ± 0.01 mg kg^-1 in the dry and wet seasons, respectively. During processing of green tea shoots to made tea a 30-40% loss of residue was observed. The transfer of residue from made tea to infusion was in the range 10-30% for both seasons, whereas 50-70% of the residues remained in the spent leaves. However, the degradation rate in both seasons followed first-order kinetics. The half-lives were in the range of 2-3 days for green shoots and made tea in both seasons.     

生物技术在制浆造纸中的应用与研究进展

介绍了生物技术在制浆造纸工业的应用与研究进展，包括生物制浆、生物漂白、生物脱墨及造纸过程中的生物技术等。     

Fenvalerate residue level and dissipation in tea and in its infusion

Fenvalerate is a non-systemic insecticide/acaricide used in controlling a wide range of pests, including those resistant to organochlorine, organophosphorus and carbamate insecticides. The study investigated the dissipation behaviour (residue level) of fenvalerate in tea and its transfer during infusion. Fenvalerate was applied on tea crop at two dosages, 100 and 200?g a.i.?ha^?1 (recommended and double the recommended) in the dry and wet seasons under field conditions. Samples (green tea shoots, made tea, its infusion and spent leaves) were analysed for fenvalerate by high-performance liquid chromatography using diode array detection. The residue dissipated faster in the wet season than in the dry season. Seven days after the treatment (normal round of plucking) the residues observed in the green shoots at the two dosages were 0.5?±?0.01, 1.1?±?0.01 and 0.4?±?0.02, 0.9?±?0.01?mg?kg^?1 in the dry and wet seasons, respectively. During processing of green tea shoots to made tea a 30–40% loss of residue was observed. The transfer of residue from made tea to infusion was in the range 10–30% for both seasons, whereas 50–70% of the residues remained in the spent leaves. However, the degradation rate in both seasons followed first-order kinetics. The half-lives were in the range of 2–3 days for green shoots and made tea in both seasons.