Aluminium contents in baked meats wrapped in aluminium foil

In this investigation, the effect of cooking treatments (60 min at 150 °C, 40 min at 200 °C, and 20 min at 250 °C) on aluminium contents of meats (beef, water buffalo, mutton, chicken and turkey) baked in aluminium foil were evaluated. Cooking increased the aluminium concentration of both the white and red meats. The increase was 89–378% in red meats and 76–215% in poultry. The least increase (76–115%) was observed in the samples baked for 60 min at 150 °C, while the highest increase (153–378%) was in samples baked for 20 min at 250 °C. It was determined that the fat content of meat in addition to the cooking process affected the migration of aluminium (r² = 0.83; P < 0.01). It was also found that raw chicken and turkey breast meat contained higher amounts of aluminium than the raw chicken and turkey leg meat, respectively. Regarding the suggested provisional tolerable daily intake of 1 mg Al/kg body weight per day of the FAO/WHO Expert Committee on Food Additives, there are no evident risks to the health of the consumer from using aluminium foil to cook meats. However, eating meals prepared in aluminium foil may carry a risk to the health by adding to other aluminium sources.     

Aluminium in foodstuff and the influence of aluminium foil used for food preparation or short time storage

Aluminium is an omnipresent part of everyday life. It is widely used in industry and furthermore in products like cosmetics, sun creams or it can be applied for instance as aluminium foil by consumers during food preparation in households. However, over the last decades the toxicity of aluminium for humans has been heavily discussed and is still not completely clarified. Therefore, food aluminium concentrations were investigated in different untreated foodstuff as well as a possible aluminium transfer from aluminium foil to food. The results show that untreated food is not significantly contaminated. Furthermore, short time contact to aluminium foil increases the food aluminium concentration only marginally. Nevertheless, as soon as the food is in contact to aluminium foil and at the same time in contact with metals (alloys) with a higher standard electrode potential than aluminium (?1.66 V) high aluminium contaminations were observed.     

Quality assessment of gutted wild sea bass (Dicentrarchus Labrax) stored in ice, cling film and aluminium foil

The effects of aluminium foil and cling film on microbiological, chemical and sensory changes in wild sea bass (Dicentrarchus labrax) stored at chill temperature (4 °C) were studied. A quality assessment of wild sea bass stored in ice, in boxes without ice, wrapped in aluminium foil (WAF) and wrapped in cling film (WCF) at 4 °C was performed by monitoring sensory quality, nucleotide breakdown products, total volatile base nitrogen (TVB-N), and total viable counts (TVCs). The observed organoleptic shelf-life of sea bass was found to be 16 days in ice, 4 days in boxes without ice, 8 days in aluminium foil and 8 days in cling film. Demerit points did not differ significantly (P>0.05) between WCF fish and WAF fish. The nucleotide degradation pattern was found to be similar for all storage conditions except for inosine and hypoxanthine contents, which decreased after 12 days of storage for WAF and WCF. The content of TVB-N for all storage conditions showed similar tendencies until 12 days storage but reached the highest level (41.6 mg TVB-N 100 g^–1 flesh) for fish stored in WAF and WCF. No significant differences (P>0.05) were found in TVB-N concentrations within the treatments during the early stages of the storage period. Bacteria grew most quickly in the sea bass kept in boxes without ice, followed by those kept WAF, WCF and in ice. Significant differences (P<0.05) in TVC were observed amongst the treatments, especially between fish stored in boxes without ice and fish stored in ice     

Migration of antimony from PET containers into regulated EU food simulants

Antimony migration from polyethylene terephthalate (PET) containers into aqueous (distilled water, 3% acetic acid, 10% and 20% ethanol) and fatty food simulants (vegetable oil), as well as into vinegar, was studied. Test conditions were according to the recent European Regulation 10/2011 (EU, 2011). Sb migration was assayed by ICP-MS and HG-AFS. The results showed that Sb migration values ranged from 0.5 to 1.2 μg Sb/l, which are far below the maximum permissible migration value for Sb, 40 μg Sb/kg, (EU, Regulation 10/2011). Parameters as temperature and bottle re-use influence were studied. To assess toxicity, antimony speciation was performed by HPLC-ICP-MS and HG-AFS. While Sb(V) was the only species detected in aqueous simulants, an additional species (Sb–acetate complex) was measured in wine vinegar. Unlike most of the studies reported in the literature, migration tests were based on the application of the EU directive, which enables comparison and harmonisation of results.     

不锈钢餐具中镍含量的测定

研究了以非离子型微乳液乳化剂-OP/n-C4H9OH/n-C7H16/H2O为介质,Ni(Ⅱ)与1-(2-吡啶偶氮)-2-萘酚(PAN)的显色反应,在pH值8.58～10.70范围内,配合物的最大吸收波长为570nm,回归方程:A=0.0313c-0.0066(c/μg·25mL-1),相关系数r=0.9996,表观摩尔吸光系数为4.56×104L/mol·cm,Ni(Ⅱ)浓度在0.2μg/25mL～25μg/25mL范围内服从比尔定律,检出限0.2μg/25mL,相对标准偏差(RSD%)在0.014%～0.64%之间,加标回收率在95.00%～110.9%之间。该法用于合成样和不锈钢餐具浸泡液中镍的测定,结果令人满意。     

热流道技术在塑料容器注塑加工中的应用

介绍了热流道系统的组成和与冷流道的比较,国内外热流道注塑模具的差距及热流道系统的发展方向。     

Availability of aluminium from tea and coffee

 The amount of aluminium in different kinds of tea and ground coffee was analysed, the transfer of aluminium into the infusion was determined and aluminium intake via tea and coffee was calculated within the framework of our investigations. Aluminium concentrations amounted to (in μg/g dry matter): black tea, 899; flavoured black tea, 763; peppermint tea, 477; mountain herbal tea, 419; fruit tea, 292; ground coffee, 19. About 30% of the aluminium stored in black tea’s dry matter was transferred into the infusion, which contained 4.2 mg Al/l. In contrast, the availability of aluminium from peppermint and fruit tea as well as from ground coffee was very low (about 5%). The calculated aluminium intake via tea and coffee was 0.2 to 0.3 mg/day and contributed about 5% to the total aluminium intake. Only black tea infusions are a significant source of aluminium intake via beverages. Received: 9 January 1997     

一次性餐饮具中微量甲醛的溶出实验研究

一次性餐饮具中甲醛的残留量倍受关注,实验采用乙酰丙酮法测定在不同浸泡溶液(25℃水、95℃水和60℃4%乙酸)和不同浸泡条件(恒温静置、超声波作用、紫外照射和微波炉加热)下一次性餐饮具中甲醛的溶出情况。结果表明,用60℃4%乙酸浸泡纸质餐饮具2h,甲醛的溶出量最高可达0.102mg/L;而用95℃水浸泡并经紫外照射后,甲醛溶出量达到0.131mg/L;当用60℃4%乙酸浸泡同时经紫外照射后,甲醛的溶出量可增至0.213mg/L,是95℃水恒温浸泡时的2倍。此外,实验发现:外表有印刷图案的纸质餐饮具在相同的浸泡溶液和浸泡条件下,甲醛的溶出量均高于无印刷图案的餐饮具,且溶出量随着浸泡时间的延长而增加。     

端视ICP-AES法测定食品用塑料包装容器在四种食品模拟物中有害元素迁移量

建立了端视电感耦合等离子体原子发射光谱(ICP-AES)法测定食品用塑料包装容器在4种食品模拟物中有害元素铅、镉、铬、砷、锑和锗迁移量的分析方法。研究了不同食品模拟物试液的处理方法以及仪器工作参数对铅、镉、铬、砷、锑和锗测定信号的影响,消除了乙醇基质的严重抑制干扰,并优化了ICP-AES测定条件。铅、镉、铬、砷、锑和锗的检出限分别为0.0025、0.00023、0.00016、0.0033、0.0032、0.0030mg/L,测定低限:以蒸馏水、3%乙酸、10%乙醇作食品模拟物时分别为0.010、0.0010、0.0010、0.010、0.010、0.010mg/L;以精制橄榄油作食品模拟物时分别为0.020、0.0020、0.0020、0.020、0.020、0.020mg/L。加标回收率在92.0%～98.8%,相对标准偏差在1.69%～7.64%(n=8)。方法灵敏、简便、快速、准确,适用于进出口食品用塑料包装容器中有害元素迁移量的快速测定。     

Hybrid of multi-signal processing methods for detection of small objects in containers filled with beverages using ultrasound

Ultrasound backscattered signals for object detection could be too weak to be perceived when superposed to strong reflection signals, and could also be complicated either in time or frequency domain. These peculiarities raise a challenge for signal processing methods. In this paper four signal processing methods were studied to detect objects in containers. Root mean squares (RMS) method was better in object detection but needed to combine other methods to increase detection success rate. Variance, center frequency pressure ratio (CFPR) and backscattered amplitude integral (BAI) methods have similar overall detection ratings. The optimal signal size, to increase the detection ability, corresponded approximately to the length of reverberation signals before it was dissipated.     

Corrosion of aluminium in soft drinks

The corrosion of aluminium (A1) in several brands of soft drinks (cola- and citrate-based drinks) has been studied, using an electrochemical method, namely potentiodynamic polarization. The results show that the corrosion of A1 in soft drinks is a very slow, time-dependent and complex process, strongly influenced by the passivation, complexation and adsorption processes. The corrosion of A1 in these drinks occurs principally due to the presence of acids: citric acid in citrate-based drinks and orthophosphoric acid in cola-based drinks. The corrosion rate of A1 rose with an increase in the acidity of soft drinks, i.e. with increase of the content of total acids. The corrosion rates are much higher in the cola-based drinks than those in citrate-based drinks, due to the facts that: (1) orthophosphoric acid is more corrosive to A1 than is citric acid, (2) a quite different passive oxide layer (with different properties) is formed on A1, depending on whether the drink is cola or citrate based. The method of potentiodynamic polarization was shown as being very suitable for the study of corrosion of A1 in soft drinks, especially if it is combined with some non-electrochemical method, e.g. graphite furnace atomic absorption spectrometry (GFAAS).     

Total content and speciation of aluminium in tea leaves and tea infusions

A total of 29 tea samples of different origin, 13 green tea samples, 13 black tea samples, two semi-fermented and one white tea, imported to the Czech Republic, were collected and analysed for total content of aluminium (Al) in tea leaves and tea infusions, as well as for Al compounds in these infusions. The total content of metals in tea leaves differs according to the type of tea (green or black) and is probably influenced by many factors, e.g., soil properties. The HPLC/IC speciation of Al in tea infusions was performed for all samples. The addition of Al³⁺ to the tea infusion proved that Al³⁺, Al(Y)²⁺ and Al(X)¹⁺ species can be determined in tea infusions. Increased extraction time did not show any affect on Al speciation, neither did the addition of sugar. After the addition of lemon juice, the speciation changed in one sample of black tea and five samples of green tea. These findings suggest that lemon juice as an additive can significantly influence Al speciation in tea infusions.     

Comparison of treatment records and inventory of empty drug containers to quantify antimicrobial usage in dairy herds

Assessment of antimicrobial use (AMU) is vital for interpreting the origin of changes in antimicrobial resistance (AMR). The objectives of the present study were to estimate the association between AMU determined using on-farm treatment records (TR) and inventory of empty drug containers (INV). Herds were selected to represent Canadian dairy farms. Producers were asked to record animal health events and treatments on a standard General Health Event form. For inventory data, 40-L receptacles were placed at various locations considered convenient to deposit all empty drug containers. Antimicrobial defined-daily dosages (ADD) were calculated for 51 Canadian herds using the 2 methods. Estimation of AMU was 31,840 ADD using the INV and 14,487 ADD using the TR, indicating that for every TR entry, 2.20 times more treatments were observed using the INV. Mastitis, reproductive conditions, and dry cow therapy were the most frequent reasons for antimicrobial therapy when assessing TR. For all antimicrobials evaluated, mean ADD was higher using the INV versus TR. Regardless, a strong positive correlation (0.80) was observed between the 2 methods, indicating that herds with increased number of ADD recorded using the INV also had increased number of ADD recorded using TR. Furthermore, a positive association was observed for the 6 most commonly used antimicrobials. In comparison to methods used in surveillance programs on AMU in livestock that assume a constant use in all herds (i.e., sales data), INV provided a herd-level specific quantity of AMU positively correlated with AMU recorded at the animal level in general. The INV was easy to implement and provided a measure of total AMU in the herd. Availability of such information would be valuable for interpreting changes in AMR at the herd level and enabling evaluation of interventions for decreasing AMR.     

Identification of print-related contaminants in food packaging

Since the UV ink photoinitiator (PI) isopropylthioxanthone (ITX) was discovered in packaged milk, studies of print contamination have focused primarily on PIs but have also included amine synergists. Many other substances are used or formed during the print process, yet their identity and set-off properties have yet to be catalogued in food packaging. Three different techniques: direct analysis in real-time high-resolution mass spectrometry (DART-HRMS), gas chromatography-mass spectrometry (GC-MS) and ultra-high-pressure liquid chromatography electrospray ionisation/HRMS (UHPLC/ESI-HRMS) were used to detect and identify print-related molecules from the food-contact and print surfaces of three different packages with under-cured prints. This approach tentatively identified or confirmed 110 compounds, including 35 print-related molecules. The majority of compounds identified on food-contact surfaces were packaging monomers/byproducts, solvents/plasticisers, antioxidants/degradants or slip agents/lubricants. Of these, 28 showed evidence of set-off. The identities of 16 PIs, seven known scission products and five probable PI degradants were confirmed, most showing signs of set-off. Of the print-related molecules, at least five are novel print contaminants such as 4-morpholin-4-yl-benzaldehyde or 3-phenyl-2-benzofuran-1(3H)-one.     

Identification of objectionable flavors in purported spontaneous oxidized flavor bovine milk

Spontaneous oxidized flavor (SOF) has been reported over the past 5 decades as a sporadic objectionable flavor problem in bovine milk. Parameters previously reported to influence SOF development in milk have been contradictory, limiting the ability to monitor and develop mitigation strategies. The current paper investigates the causative compounds associated with milk identified as SOF milk in the Midwest dairy region of the United States. Based on GC/MS-olfactometry analysis, endo-borneol, 2-methylisoborneol, and α-terpineol were identified as the off-flavor compounds. Sensory recombination studies further confirmed the sensory contribution of these compounds to the noted off-flavor attributes in the original milk, which were described as “green,” “musty,” and “unclean.” These compounds are known microbial-derived flavor taints, indicating oxidation was not the origin of the objectionable flavor in the milk. This noted misclassification of the milk as SOF indicates the challenge of defining flavor defects without the identification of the active compounds.     

Assessment of dietary exposure of young Chinese children to aluminium residues

The aim of this study was to assess the Al dietary exposure of young Chinese children aged 0–3 years via formulae, complementary foods and wheat-based foods. Al residue data were obtained from the national food contamination monitoring programme from 2013 to 2016, encompassing 13,833 samples of 12 food items with a detection rate of 76.0%. Food consumption data were gathered from the China National Food Consumption Survey conducted in 2015, comprising 20,172 children aged 0–3 years old. The mean dietary exposure to Al for the general population of young Chinese children was estimated at 0.76 mg/kg bw/week, which does not exceed the PTWI. The 97.5th percentile intakes of Al reached 3.42 mg/kg bw/week, more than 1.7 times the PTWI. Wheat-based foods contributed 80.5% of the Al intake for the general population of young Chinese children, while formulae and complementary foods accounted for 19.5% of the total intake. The dietary intake of Al from formulae and complementary foods accounted for 6.0% and 1.6% of PTWI, respectively. These findings suggested that dietary exposure to Al among the general population of young Chinese children was lower than the PTWI and that there are no health concerns related to this level of Al intake. However, more attention should be placed on the health risks associated with Al exposure from wheat-based foods for young consumers with high food consumption in China (97.5th percentile)     

FOCKE350包装机组双铝包内衬纸折叠并包装置的设计

为实现加热不燃烧卷烟双铝包包装自动化生产,基于FOCKE350包装机组设计了一种双铝包内衬纸折叠并包装置。该装置主要由内衬纸折叠机构、内衬纸并包机构、内框纸插入机构、内折角器组件等部件组成,通过将单路直包改为双路直包,实现双铝包包装自动化生产,满足了加热不燃烧卷烟保香保润的功能要求。以玉溪卷烟厂生产的"MC(美西)"牌加热不燃烧卷烟为对象进行测试,结果表明:改进后FOCKE350包装机组运行稳定可靠,生产加热不燃烧卷烟的外观质量合格率达97.4%,感官质量评价良好。该技术可为卷烟包装形式多样化生产提供支持。     

Roles of acetone-conditioning and lipid in sorption of organic contaminants

Sorption of phenanthrene and 1-naphthol by a peat soil (PS) and its humic acid fractions (HAs) and humin (HM) was examined. Both phenanthrene and 1-naphthol consistently had decreased isotherm nonlinearity in the order PS > HA1 (first fraction) > HA7 (seventh fraction), due to decreased heterogeneity of soil organic matter (SOM). High isotherm nonlinearity of HM was attributed to the condensed structure of SOM in it. Acetone-conditioning increased sorption affinity and isotherm nonlinearity of HAs and HM for phenanthrene, and the conditioning effect was more pronounced at low solute concentrations. However, sorption of 1-naphthol by PS, HAs, and HM was insignificantly affected by acetone-conditioning, suggesting that 1-naphthol could have disparate distribution of sorbed sites from phenanthrene due to their structure and hydrophobicity difference. Lipid removal further increased sorption of phenanthrene and 1-naphthol by acetone-conditioned PS, HAs, and HM, due to increased accessibility of high-energy sites in SOM. Nonlinearity of phenanthrene and 1-naphthol also increased after lipid removal from the acetone-conditioned sorbents. In 1-naphthol- and phenanthrene-lipid competitive sorption systems, lipid had strong competition with phenanthrene, whereas 1-naphthol exhibited cooperative sorption with lipid on lipid-free PS, HAs, and HM, again showing the different sorption characteristics between phenanthrene and 1-naphthol.