Analysis and simulation of an industrial vegetable oil refining process

This work focuses on the performance analysis of an industrial vegetable oil refinery. Using a commercial process simulator, a process model was developed and validated against actual vegetable oil refinery field data. The simulator allowed investigating both energy and safety aspects related to the presence of residual extraction solvent (extraction grade hexane) in the processed crude vegetable oil. The critical nodes for hexane accumulation in the process were evaluated, both considering ordinary operative conditions and undesired process deviations due to increase of the hexane content. In this latter case, the control actions able to restore the normal operation were simulated, in terms of increased utility consumption (e.g., motive steam for ejectors and cooling water) or by modifying and optimizing equipment operating conditions. Finally, the possibility of flammable mixtures formation inside process vent pipes, caused by the entrainment of air due strong vacuum conditions, was also investigated.     

大豆油生产中生物及化学性危害的分析和控制

通过对原料大豆及其加工、储运过程中的生物及化学危害分析,找出了危害大豆油食用安全的主要原因。在原料大豆储运过程中,应严格控制大豆在安全水分(13.5%)以下;在大豆油的加工过程中,应严格控制溶剂残留和防止大豆油的氧化酸败,这样可有效地消除安全隐患,保证食用安全。     

Oxidative stability of water/oil mixtures as influenced by the addition of free Cu or Cu–alginate gel beads

The formation of Cu–alginate complexes and the impact of free or bound copper on the oxidative stability of model water/oil mixtures containing edible sunflower or corn oil were examined. Equilibrium dialysis showed that copper binding capacity of alginate increased proportionally with copper concentration and the binding was rapid. The results indicated that 25 mM CuCl₂ was necessary in obtaining beads of spherical shape and adequate mechanical strength (0.45 N at 80% compression) to avoid rupture during mixing, whereas lower CuCl₂ concentrations resulted in weak gel beads (0.34 N) of irregular shape. When Cu–alginate beads were dispersed in the aqueous phase to give 0.5 mM copper, the peroxide value of water/corn oil mixtures was 3.7 mEq peroxide/kg oil after 7 days. Corn oil-containing mixtures with 0.5 mM free Cu²⁺ in the aqueous phase had a peroxide value ∼3 times higher (P < 0.001) after the same storage time. However, copper binding by alginate did not significantly reduce the peroxide values of the water/sunflower oil mixtures. Results indicated that the binding of pro-oxidant minerals, such as copper, in alginate beads can reduce the levels of oxidation in water/oil mixtures.     

一种食用油锁养保鲜生产工艺

为了解决食用油在储存过程中因发生各种变化而造成的品质下降问题,介绍了一种食用油的锁养保鲜生产工艺,包括全工段恒温灌装、充氮灌装和抗紫外瓶包装。实践证明,全工段恒温灌装有效避免了灌装油温过高产生负压造成的瓶内缩吸瘪,减少了标签不平整情况的发生;充氮灌装使食用油包装瓶内顶空残氧量低于6%,产品残氧量指标稳定;以色母为抗紫外助剂,制成的食品级食用油包装瓶可防止紫外线对食用油品质的影响。采用此生产工艺,可以有效提高食用油的品质并延长储存期。     

食用油包装成品仓库设计输入与库容理论计算模型研究

随着我国食用油消费方式由散装向包装油的转变和物流业的发展,食用油中小包装厂建设飞速发展,由于包装厂的地域、加工规模、产品种类、货物周转率及物流状况等各不相同,设计出的仓储方案也各有差异。通过分析影响库容的所有相关因素,结合建筑厂房设计固有特点,探讨设计参数输入条件,揭示能够指导设计应用的一般性规律,构建特定条件下的最小库容理论计算模型,基于模型叠加实际生产运营中不断变化的常见变量,通过引入周转率来修正真实状态对理论模型的偏差,进而推导出一个简便的公式,以期为设计提供参考。     

The role of some antioxidants in the HPMC film properties and lipid protection in coated toasted almonds

Hydroxypropylmethylcellulose based edible films with and without antioxidant additives were characterised as to their microstructure, water vapour and oxygen permeability, mechanical behaviour, optical properties and protective ability against lipid oxidation. The corresponding film-forming dispersions were also used to coat toasted almonds in order to test their effectiveness at protecting against rancidity development. The efficiency of three additives (ascorbic acid, citric acid or ginger essential oil) was tested and compared with antioxidant-free coatings. A cross-linking effect in the film matrices containing ascorbic or citric acid was detected through the analysis of the film microstructure, mechanical behaviour and barrier properties to oxygen and water vapour. These films were the most effective protectors against oxidation of almonds, due to both their antioxidant effect and the tighter structure which leads to lower oxygen permeability. In films with ginger oil, the hydrophobic effect markedly reduced water vapour permeability at low temperatures, but protection against lipid oxidation was less effective at long storage times.     

三标度模糊层次评判模型在食品安全风险 评估中的应用

目的采用国家食品标准与三标度层次分析法(TAHP)对新疆小麦粉和食用植物油进行风险评估。方法层次构建中采用三标度(0,1,2)定量确定各个有害物的危害程度,并建立相应的比较和判断矩阵。通过矩阵运算获得各个危害物的权重并进行一致性检验。结果采用TAHP在MATLAB软件的辅助下计算各有害物的权重并检验其一致性。一致性检验结果为小麦粉为0.089,4种植物油为0.085,均低于0.1。利用各危害物权重因子构建的风险模型分别运用于新疆小麦粉和食用植物油2010、2014和2015年的风险评估,结果与实际情况较为吻合。结论该风险模型不仅可应用于上述食品质量风险评估,而且还可推广应用于其他食品的安全评价模型的构建,以及对食品质量安全的调查、评估和监督提供参考。     

现代植物油储运工艺设计探讨

随着植物油生产、流通领域市场的全面开放,大型现代化植物油加工厂和植物油库的油脂储运能力快速提高。现代化的植物油储运工艺设计成为大型植物油加工厂和植物油库建设中的重要内容。介绍了植物油储运工艺设计的主要内容,并对现代化的植物油储运工艺、输油管道清扫、储运过程伴热、计量及储存保鲜等技术进行了探讨。     

Effects of methyl cellulose-based coating on physiochemical properties and chemical hazards of Chinese fried dough cake during storage

Coating has been used as a practical method to ensure the physiochemical properties and reduce the chemical hazard of fried foods. Methyl cellulose (MC) was used as a coating material to pretreat Chinese fried dough cake (CFDC) before frying. The results showed that the water content, hardness and L* value of the 1% MC coated sample were 31.67%, 848.54 g and 51.62, respectively, at the seventh day at 25 °C. Coating contents 1% MC could reduce the oil content, hardness, and extent of browning and improve the physiochemical properties of CFDC on 7 days of storage. Coating contents 1% MC also reduced the acid value, peroxide value, p-anisidine value, malondialdehyde content, 4-hydroxy-2-(E)-hexenal content, 4-hydroxy-2-(E)-nonenal content, acrylamide content and glycidyl ester content in CFDC on 7 days of storage. Our work contributes to the control of the oil content and chemical hazards for fried food during storage by applying an edible coating.     

The effect of long-term frozen storage on the quality of frozen and thawed mashed potatoes with added cryoprotectant mixtures

Cryoprotectant mixtures were added to frozen/thawed (F/T) mashed potatoes in the form of amidated low-methoxyl (ALM) pectin and xanthan gum (XG), kappa-carrageenan (κ-C) and XG and sodium caseinate (SC) and XG, and the effect of frozen storage was examined. F/T mashed potatoes without added biopolymers had higher storage modulus G ' after freezing and frozen storage, associated with sponge formation due to amylose retrogradation. Oscillatory measurements indicated weakening of the structure of mashed potatoes without biopolymers and with added κ-C/XG and SC/XG mixtures at the end of storage due to ice recrystallisation, whereas the structure of samples with added ALM/XG mixtures was reinforced by increasing time in storage. Mashed potatoes with added mixtures exhibited water-holding capacity for 1 year. Samples with added κ-C/XG mixtures were more structured, although when both κ-C/XG and SC/XG mixtures were included in mashed potato, very acceptable sensory quality was maintained in usual frozen storage conditions.     

食用油中多环芳烃检测的前处理方法研究进展

近年来，食用油中多环芳烃的检出多有报道，其安全问题备受社会关注。多环芳烃作为一类复杂的高亲脂性有机污染物，具有致畸致癌性，易在食用油的生产加工贮存过程中残留，对人体健康造成危害。因此，开发快速准确的分析方法检测食用油中的多环芳烃对于认识和应对食用油中多环芳烃的危害有着重要的理论和实践价值，其中分析检测过程的关键环节是选择合适的前处理方法。本文首先对食用油脂中多环芳烃进行概述，同时重点综述了近年来检测食用油中多环芳烃的常用样品前处理方法，并比较了不同前处理方法的优缺点，最后对未来多环芳烃检测方法的发展方向进行了展望，以期为开发更高效的油脂中多环芳烃检测的前处理方法提供参考。     

?植物油料热处理影响油脂氧化稳定性机理的研究进展

植物油料的热处理是我国植物油脂制备工艺中必不可少的一个加工环节。在追求安全营养的前提下,适度的植物油料热处理,在降低水分含量、提高出油率的同时,更赋予油脂特征风味、最大限度保留营养素、去除危害物和避免其形成,从而提高油脂的食用价值和商品价值。针对植物油料热处理影响油脂品质的问题,本文综述了植物油料热处理影响油脂氧化稳定性机理的研究进展,同时对植物油料热处理影响油脂氧化稳定性机理尚未研究清楚的困难点进行了总结和分析。旨在对植物食用油脂的适度加工提供一定的参考,对我国植物食用油脂产业的发展提供一定的帮助。     

食用油中邻苯二甲酸酯检测方法研究进展

邻苯二甲酸酯类物质(phthalate esters,PAEs)具有脂溶性并且容易从塑料制品中迁移出来。在生产或储存过程中食用油与塑料制品接触是无可避免的,因此食用油容易遭受PAEs污染。食用油是人体每日摄入的食品,检测食用油中的PAEs,对PAEs人体膳食暴露相关的食品安全评估有重要意义。由于食用油基体复杂,大量脂肪色素干扰检测,同时因分析系统中广泛分布的PAEs导致难以获得稳定系统空白值,影响检测。本文综述了近年来食用油中PAEs检测的研究进展,从前处理净化技术、仪器分析技术和定量方式等3个方面进行了归纳和总结,并对存在的问题进行了探讨和展望,以期为食用油中PAEs的检测提供理论参考。     

食用油储存期品质变化的太赫兹光谱无损识别

为研究食用油在储存期间的品质变化情况，利用太赫兹衰减全反射技术对不同氧化程度的食用油进行无损识别。首先探究储存条件对食用油品质的影响情况，进一步根据国家定义食用油品质的标准将样品分为新鲜油、可食用油和不宜食用油，采集各类油品的太赫兹时域光谱，经数据预处理后采用欧氏距离匹配法进行聚类分析，并采用线性判别分析法进行样本分类，其中欧氏距离匹配法识别食用油折射率谱，准确率为95.65%；线性判别分析法识别吸收系数谱数据，准确率为91.00%，经比较两模型识别准确率理想，分析效果良好。该研究首先得出储存条件对食用油品质的影响规律，以论证太赫兹衰减全反射技术在分析食用油储存期品质变化方面的可行性，实现了食用油品质的快速无损检测；也可为太赫兹光谱技术深入应用于食用油多种属性的研究提供一定参考依据。     

Amounts of malondialdehyde do not accurately represent the real oxidative level of all vegetable oils: a kinetic study of malondialdehyde formation

Malondialdehyde (MDA), a widely used oxidation indicator for both lipid and edible oil, has been suggested to be genotoxic and cytotoxic, thus attracting increasing attentions about its formation and exposure assessment. In this study, kinetics of MDA formation in vegetable oils and model oils were investigated by high-performance liquid chromatography. Results showed MDA contents firstly increased rapidly then kept to a plateau over time in both reaction systems at 100, 140 and 180 °C, significant temperature-dependent of MDA formation was observed. The rate constant and activation energy (E_a) were calculated from the fitted pseudo-first-order model and Arrhenius equation. E_a of MDA-formation was much lower in linseed oil, corn oil and rapeseed oil, indicating the higher degree of unsaturation resulted in the greater susceptibility to MDA formation. Besides, MDA content was inappropriate to assess the oxidation of palm oil and camellia oil possessing high level of saturated and/or monounsaturated fatty acid.     

基于近红外光谱技术的食用油酸值和过氧化值定量分析研究

目的 建立基于傅里叶近红外光谱技术的定量分析模型, 实现快速测定食用油中酸值和过氧化值含量, 保证食用油的品质安全以及跟踪食用油储藏期间的品质变化。方法 首先采用傅里叶近红外光谱仪采集食用油样品漫反射光谱, 接着采用归一化(Normalize)和标准正态变换(standard normal variate, SNV)对光谱数据进行预处理, 降低原始光谱中噪声的影响; 其次通过随机森林(random forest, RF)和引导软收缩(bootstrapping soft shrinkage, BOSS)算法提取特征波长; 最后结合径向基函数(radial basis function, RBF)神经网络和极限学习机(extreme learning machine, ELM)建立食用油酸值和过氧化值的预测模型, 并与全波段的模型进行对比分析。结果 经过BOSS算法所提取的特征波段建立的模型预测效果优于RF算法以及全波段模型, 酸值模型的决定系数(determination coefficient, R2)达到0.98, 均方根误差(root mean square error, RMSE)达到0.08; 过氧化值模型的R2达到0.96, RMSE达到0.63。结论 BOSS算法有效的提取了食用油酸值和过氧化值的特征波段, BOSS-RBF模型能够适用于食用油中酸值和过氧化值含量的快速、无损检测。利用近红外光谱技术对食用油酸值和过氧化值进行定量分析是可行的, 可通过该方法实现对食用油品质的分析研究。     

食用植物油中矿物油污染物的分析进展

矿物油是C_(10)~C_(50)烃类化合物的总称,包括直链、支链和环状烷烃以及烷基取代芳烃两大类,化学成分复杂。食用植物油中普遍存在矿物油污染,含量达到1~1 000 mg/kg,矿物油污染来源广泛,涉及原料的采收、运输、加工和油脂的精炼、包装与储存等过程。植物油中干扰矿物油分析的成分较多,如甘油三酯、奇数碳正构烷烃、角鲨烯、甾烯、胡萝卜素等,需要采用适当方法排除。由于矿物油组成复杂,目前常用具有等碳响应的氢火焰离子化检测器分析含量,其中液相色谱-气相色谱联用是测定矿物油的理想技术。考虑到普及性问题,一些实验室开发了固相萃取结合大体积进样气相色谱法。综述了国内外近十年来食用植物油中矿物油的分析方法,以期为我国油脂及其相关产品中矿物油的检测工作提供参考。     

体外生物测定法在食品接触材料安全性评价中的应用研究进展

体外生物测定法是利用酵母、细菌、细胞等进行的生物体外短期毒性实验,可以有效针对生物体某一特异性效应,评价测试物的危害性以及探索其毒性作用机制。由于体外生物测定法可以提供食品接触材料迁移物（混合物）整体实际危害的综合信息,因此,近年来被越来越多地应用于食品接触材料的危害评估,尤其集中在细胞毒性、遗传毒性和内分泌干扰这3 类毒理学终点。本文重点综述了这3 类体外生物测定方法的基本原理,以及近20年来其在食品接触材料提取物危害评价中的应用研究进展,以期为今后食品接触材料生物学安全性评价的相关研究提供理论参考。     

食用油中增塑剂溶出的原因分析及风险预测

通过对市场上销售的食用油样品中邻苯二甲酸酯类(PAEs)物质的检测,发现塑料桶装的食用油均有不同程度的PAEs检出,从而对增塑剂溶出的原因进行了分析和验证,并对可能存在的质量安全风险进行分析预测.     

A review on grain and nut deterioration and design of the dryers for safe storage with special reference to Turkish hazelnuts

Turkey produces about 80% of the total hazelnut crop of the world. About 75% of the production are exported. In Turkey hazelnuts are traditionally sun dried, and may be subject to mold growth and subsequent mycotoxin formation due to prolonged drying time under humid and rainy weather conditions. Drying hazelnuts in a reasonable time after harvest is necessary for mycotoxin-free, high-quality products. In general, nuts and cereals contaminated by the toxins pose a potential hazard not only to the people of the producer countries, but also to people of the importing countries, if they should be regarded as safe by inefficient sampling plans, therefore preventing toxin formation actually benefits very large populations. Deterioration and health hazards associated with toxin contaminated hazelnuts and other nuts and cereals have similar causes and consequences; therefore, deterioration of the nuts and cereals in storage has been reviewed by considering as many grains and nuts as possible, then special reference was made to hazelnuts. Proper preharvest practices followed by proper drying and safe storage reduces the hazards associated with contamination by the toxins. This article reviews the pre- and post-harvest practices, and the grain- and nut-drying systems required for toxin-free products. Because drying is the major unit operation involving this process, the drying systems and the mathematical models required for their design is also discussed.