葡萄糖氧化酶对油炸薯条中丙烯酰胺抑制作用研究

在单因素试验的基础上,采用响应面分析法研究了葡萄糖氧化酶的添加量、浸泡温度、浸泡时间对油炸薯条中丙烯酰胺形成的影响作用。结果表明:浸泡时间42min,浸泡温度70℃,葡萄糖氧化酶添加量1 700U/kg,丙烯酰胺最低生成量为240.62μg/kg。     

Variety and storage conditions affect the precursor content and amount of acrylamide in potato crisps

BACKGROUND: Acrylamide, a probable human carcinogen, is formed from the amino acid asparagine and reducing sugars when potato products are processed at high temperatures. This is a two‐year study on five Swedish‐grown potato clones, two of which are adapted to cold storage. The clones represented a wide range of precursor concentrations: asparagine, 3.7–15.3 mg g^?1; reducing sugars, 0.9–14.9 mg g^?1. Crisps were prepared in laboratory‐scale equipment mimicking industrial processing conditions. RESULTS: Potatoes stored at 4 °C had significantly higher levels of glucose and fructose than potatoes stored at 8 °C. Acrylamide levels were significantly higher in crisps made from potatoes stored at 4 °C. Two clones with a large difference in asparagine concentration but similar glucose and fructose concentrations gave crisps with significantly different acrylamide contents. The lowest levels of acrylamide were found in crisps made from the potato variety with the lowest asparagine concentration. CONCLUSION: The findings show that variety and storage conditions influence the levels of precursors. Acrylamide formation in crisps can be reduced by using potato varieties with low levels of both asparagine and reducing sugars. Mass transport of precursors during heating is suggested to be important for acrylamide formation in potato crisps. Copyright © 2007 Society of Chemical Industry     

Fracture properties of potato crisps

The Weibull modulus of potato crisps is about 4, comparable with ceramic materials, with a characteristic strength of about 1.5 MPa. This combination of brittleness and weakness gives crispness. The critical stress intensity factor (K_IC) and the energy of fracture (R) are around 0.12 MPa and 45 J m^–2, respectively. There was no significant difference between the material values obtained for the fracture properties of crisps of a range of subjective ‘crispness’ as measured by a trained organoleptic panel. Crispness is ranked by the structural bending strength. Centrally loaded plate tests give qualitative evaluation of crispness. Both these tests could be used in quality control, with advantage over organoleptic tests such as cost, the time required, objectivity, consistency of results, the relation of the measured parameters to standard materials tests and the relatively small amount of material that is needed by comparison.     

Study of acrylamide mitigation in model systems and potato crisps: effect of rosmarinic acid

In the current study, rosmarinic acid (RosA) played a critical role in inhibiting acrylamide (AA) formation in Maillard system and potato chips. Compared to the control group, AA formation was markedly inhibited by RosA of 10⁻⁴ and 10⁻¹ mm in asparagine (Asn)-glucose (Glc) system, and 10⁻⁵−1.0 mm in Asn-fructose (Fru) system. The kinetic study indicated that with heating time ranging from 30 to 60 min, RosA had a significant inhibition effect on AA formation. Mechanism study showed the addition reaction between RosA and AA was the primary pathway to inhibit AA formation. In potato crisps, response surface methodology showed that frying temperature of 140.11 °C, frying time of 6.02 min and RosA concentration of 0.012 μm had the lowest AA formation. In conclusion, RosA inhibited AA formation in both the model systems and potato crisps, and its application in food industry is well expected.     

油炸马铃薯片中丙烯酰胺形成的影响因素的研究

丙烯酰胺是富含碳水化合物和氨基酸的食品经高温加热发生美拉德反应而产生的,但有关影响丙烯酰胺形成因素的研究却较少。探讨了油炸温度、原料中还原糖和氨基酸含量、鲜薯切片浸泡液的柠檬酸浓度、油炸前薯片的水分含量及抗氧化剂和油的使用时间对丙烯酰胺形成的影响。结果表明:原料中还原糖和氨基酸含量越高,产品中生成的丙烯酰胺就越多;油炸温度越高,产品中丙烯酰胺含量也相应越高;浸泡液柠檬酸浓度越大,产品中丙烯酰胺含量越低;而随着半成品中含水量的降低,产品中的丙烯酰胺含量也逐渐减少;在油中添加不同浓度的BHT和TBHQ以及采用使用时间不同的油,对加工出来的薯片之间丙烯酰胺含量没有显著的影响。     

Kinetic modelling: A tool to predict the formation of acrylamide in potato crisps

Three empirical models were used to fit the formation of acrylamide in crisps of three different cold-sweetened potato genotypes, fried under the same experimental conditions. Statistical methods were used to compare the performance of the models, with the “Logistic-Exponential” model performing the best. The obtained model parameters for the formation of acrylamide showed improvement in precision compared to an earlier study, the precision of the parameter estimates for the degradation of acrylamide was still problematic. Nevertheless, the predictive capacity of the “Logistic-Exponential” model was tested, as this model showed a strong correlation between parameter a and the reducing sugar content of the raw potato. The predictions from this model for the formation of acrylamide in potato crisps were close to earlier reported experimental values. Therefore, the use of the “Logistic-Exponential” model as a tool to predict acrylamide in potato crisps seems promising and should be developed further.     

Impact of chemical pre-treatments on the acrylamide formation and sensorial quality of potato crisps

Several components were added to the blanching water of potato crisps. Calcium ions, sodium acid pyrophosphate, citric, acetic and l-lactic acid significantly reduced the final acrylamide content, as well as free glycine and l-lysine. The acids, NaCl and calcium-containing additives also lowered the oil absorption, which may have led to a reduced heat transfer and acrylamide contamination in the final product. Textural and compositional product changes may thus also influence acrylamide formation. By means of sensory analyses of these crisps, a successful combination was demonstrated between acrylamide mitigating treatments and crisps of acceptable or even superior product quality, compared to control crisps blanched in water. However, the applied components and concentration levels should be well chosen in order not to generate product-foreign flavours or undesired product colour.     

Dietary exposure to furan of the Austrian population

ABSTRACT

In the period from 2007 to 2017 furan levels of foods were analysed by the Austrian Agency for Health and Food Safety. Based on these analytical data and the Austrian consumption data the dietary exposure of children and adults to furan was estimated by using a deterministic approach. For the adult population the mean and 95^th percentile dietary exposures to furan were estimated at 0.31 µg/kg bodyweight per day and at 0.72 µg/kg bodyweight per day, respectively. The mean dietary exposure of children was estimated at 0.18 µg/kg bodyweight per day and is thus only about half as high as for Austrian adults. At the 95^th percentile the dietary exposure of children was estimated at 0.49 µg/kg bodyweight per day. The main contributor to the total dietary exposure for adults is coffee followed by convenience products and for children the main contributors are grain products as well as convenience products, bread and snacks. Based on the BMDL₁₀ of 0.064 mg/kg bodyweight per day for the development of cholangiofibrosis, the MOE-calculation revealed that the current levels of dietary exposure to furan are of concern for Austrian adult high consumers. The MOE-calculation, based on the BMDL₁₀ of 1.31 mg/kg bodyweight per day for the development of hepatocellular adenomas, indicated a health concern for Austrian children and adults.     

陕西省居民膳食中铝暴露风险评估

目的了解陕西省市售食品中铝污染状况,评估陕西省居民膳食中铝摄入水平及其潜在的健康风险。方法 2013—2015年在陕西省10个地市随机采集8类食品共计666份,按照食品中铝测定的标准操作程序进行检测,结合陕西省开展的居民膳食营养状况调查中各类食物的消费量数据,采用点评估方法,对陕西省不同性别-年龄组人群膳食中铝摄入水平及其潜在的风险进行评估。结果陕西省居民全人群膳食中铝平均每日摄入量为0.154 9 mg/kg BW,不同性别-年龄组人群以18~59岁女性摄入量最高,为0.178 5 mg/kg BW。当食物中铝含量取P97.5数值时,膳食中铝摄入量最高的人群是2~7岁儿童。各性别-年龄组人群膳食中铝平均暴露量(铝含量数据采用平均值)安全限值(MOS值)均1,偏高暴露量(铝含量数据采用P97.5数值)MOS值均1。2~7岁和8~12岁儿童膳食中铝摄入贡献率较高的食品是油炸食品和焙烤食品,其他组人群膳食中铝摄入贡献率前3位的食品均是油炸食品、凉皮和淀粉制品。结论陕西省居民不同性别-年龄组人群膳食中铝偏高暴露量已超过最新的健康指导值。女性和儿童是暴露量较高的人群,油炸食品是不同性别-年龄组人群膳食中铝摄入的最主要来源。     

Dietary exposure of Tunisian adult population aged from 19 to 65 years old to pesticides residues

ABSTRACT

Dietary exposure of the Tunisian adult population to pesticide residue was assessed using the Total Diet Study method. In the present study 170 pesticides were searched for in 42 aggregated foods characterised by 64 food samples representing the Tunisian diet. All the food samples were collected, prepared, and analysed for remains of pesticides including organochlorine, organophosphorous, carbamates and pyrethroids. The GC-MS analysis and the LC-MS/MS analysis and some other specific analytical methods were employed for the quantification of the pesticide residues in the food samples. Results revealed that21pesticides reached amounts greater than the LOQ(12.3%) and 149 pesticides reached amounts below the LOD (88%).For the 21 pesticides quantified, the ADI was not exceeded. For the 149 non-quantified pesticides, an interval defined by the lower and upper bounds was defined to assess the dietary exposure of the Tunisian adult population to those pesticides. We conclude that 8 pesticides theoretically exceed the ADI with the 95^th percentile of exposure, those are: Diféthialone, Brodifacoum, Bromadiolone, Glufosinate, Heptachlor, Dieldrin Aldrin Oxydemeton-methyl. This study concludes that there is a low dietary exposure to pesticide residue of the Tunisian adult population. In fact, all the cases where the ADI was exceeded were theoretical due to the lower ADI value used.     

A methodology for evaluating the formation and human exposure to acrylamide through fried potato crisps

Potato crisps are a popular snack food which have been implicated as a potential source of acrylamide. This study develops a farm-to-fork human exposure assessment model for acrylamide in fried potato crisps for Irish consumers. The model used Monte Carlo simulation techniques to model the various stages from on farm production of potatoes, storage, processing, crisp production and final human consumption of potato crisps. A baseline model is created and a number of scenarios are subsequently created to look at the impact of different model assumptions and input parameters. The baseline model found that the mean level of acrylamide in potato crisps in Ireland was 720 μg/kg. Irish consumer exposure to acrylamide in potato crisps was estimated to be 0.052 and 0.064 μg/kg bw/day for males and females, respectively. A sensitivity analysis revealed the important parameters influencing the model predictions. The initial level of reducing sugars was found to be the most important parameter (correlation coefficient 0.58 and 0.57 for glucose and fructose, respectively), highlighting the importance of selecting cultivars with low reducing sugar levels for crisp production. The cooking regime had a significant impact on model predictions, highlighting the need for further research into the impact of different time and temperature combinations. Blanching and soaking of potatoes were also identified as important risk reduction processes.     

油炸马铃薯片中丙烯酰胺形成的协同阻断研究

目的研究油炸温度、油炸时间对马铃薯片中丙烯酰胺生成的影响,进而探讨半胱氨酸(Cys)和热烫处理对丙烯酰胺生成的协同阻断作用。方法将试样马铃薯片分别在不同浓度的Cys(0~5 g/L)溶液中,进行热烫(25~85℃)前处理,在不同温度(140~220℃)以及油炸时间(0~35 min)条件下,油炸处理,利用衍生化气相色谱-质谱联用(GC-MS)法测定样品中的丙烯酰胺含量。结果无预处理下,油炸马铃薯片中丙烯酰胺的生成量,随油炸时间或油炸温度的增加,呈先升高后降低的变化趋势,油炸温度为180℃的条件下,油炸3 min时,达到最大值5.16 mg/kg;油炸时间为5 min的条件下,油炸温度为200℃时,达到最大值4.85 mg/kg。热烫前处理对丙烯酰胺生成具有显著抑制效果,抑制率随热烫温度的升高而增大,室温条件下Cys溶液浸泡对丙烯酰胺生成具有抑制效果,抑制率随Cys浓度增加未见明显变化,然而温度升高后,出现协同阻断效应,Cys浓度为5 g/L和热烫温度为85℃的条件下,丙烯酰胺抑制率达100%。结论 Cys和热烫处理对抑制丙烯酰胺的生成存在协同阻断效应,协同作用下的抑制率与两者单独作用相比显著增加。     

Acrylamide concentrations in potato crisps in Europe from 2002 to 2011

A dataset of manufacturers’ measurements of acrylamide levels in 40,455 samples of fresh sliced potato crisps from 20 European countries for years 2002 to 2011 was compiled. This dataset is by far the largest ever compiled relating to acrylamide levels in potato crisps. Analysis of variance was applied to the data and showed a clear, significant downward trend for mean levels of acrylamide, from 763 ± 91.1 ng g^?1 (parts per billion) in 2002 to 358 ± 2.5 ng g^?1 in 2011; this was a decrease of 53% ± 13.5%. The yearly 95th quantile values were also subject to a clear downward trend. The effect of seasonality arising from the influence of potato storage on acrylamide levels was evident, with acrylamide in the first 6 months of the year being significantly higher than in the second 6 months. The proportion of samples containing acrylamide at a level above the indicative value of 1000 ng g^?1 for potato crisps introduced by the European Commission in 2011 fell from 23.8% in 2002 to 3.2% in 2011. Nevertheless, even in 2011, a small proportion of samples still contained high levels of acrylamide, with 0.2% exceeding 2000 ng g^?1.     

低含量丙烯酰胺的油炸马铃薯片加工工艺研究

根据之前所做的单因素实验结果,确定以原料品种、浸泡液的柠檬酸浓度、预干燥时间以及油炸温度四个因素来做四因素四水平正交实验,并对实验结果进行数据分析。根据分析结果确定了生产低丙烯酰胺含量的油炸马铃薯片的最佳加工工艺条件为:以大西洋品种的马铃薯为原料,采用浓度为0.5%的柠檬酸水溶液浸泡,85℃鼓风干燥20min,最后在180℃的油温下恒温油炸至熟。     

Risk assessment of dietary exposure to perchlorate for the Austrian population

Perchlorate is frequently found as contaminant in a variety of food. Based on analytical data of perchlorate occurrence in food products from the Austrian market, this study calculated dietary perchlorate exposure of the Austrian population for the three age classes of adults, children and infants. Furthermore, a detailed risk assessment was conducted based on the tolerable daily intake (TDI) of 0.3 µg/kg body weight/day, established by the European Food Safety Authority in 2014. Calculations of a scenario of average food consumption did not indicate elevated health risks by dietary perchlorate uptake. Exposure estimates reached only 12%, 26% and 24% of the TDI for adults, children and infants, respectively. However, in a scenario of high consumption, the TDI was exceeded by all age classes with 132%, 161% and 156%. The major cause for this exceedance is the comparatively high perchlorate contamination of spinach, but also other leaf vegetables, legumes and pineapples, leading to elevated exposure of high consumers. Our calculations reveal that the current provisional intra-Union trade reference level for perchlorate in spinach of 0.2 mg/kg, advocated by the European Commission, is not sufficient to protect high consumers against possible health risks. In order to reduce health risks to a tolerable level for all consumers, lowering of the regulatory maximum perchlorate concentrations is indicated. Moreover, a generally diversified diet can also counteract excessive exposure to perchlorate as well as to other harmful food contaminants.     

Acrylamide levels in potato crisps in Europe from 2002 to 2016

ABSTRACT

European manufacturers’ data on acrylamide in potato crisps from 2002 to 2016 were analysed. A previous study showed a 53% reduction in mean acrylamide levels from 763 ng g^?1 in 2002 to 358 ng g^?1 in 2011. Analysis of data from the longer period showed that since 2011 there has been a levelling off, with the mean level for 2016 being 412 ng g^?1 (still a 46% reduction from 2002), suggesting that the most effective acrylamide reduction measures had been devised and implemented by 2011. There were similar trends in the 90^th and 95^th quantile values, with the 90^th quantile values being below 1000 ng g^?1 (the European Commission’s current ‘Indicative Value’ for acrylamide in potato crisps) since 2010. The proportion of samples with acrylamide above 2000 ng g^?1 fell from 4.8% in 2002 to 0.6% in 2016. Acrylamide levels showed marked seasonal variability, being highest in the first half of the year when potatoes were being used from storage, and lowest from July to September when potatoes were being harvested. Acrylamide levels were higher in thicker types of crisp in the early years of the study, but this difference disappeared in the later years, suggesting that manufacturers had acted to reduce acrylamide formation in these products. Higher values for acrylamide were recorded in north and east Europe than in the south and west up to 2013. Levels in the north and east declined in recent years, but remained higher in the north than in the other regions. The manufacturers’ data were compared with a much smaller dataset provided by the European Food Safety Authority (EFSA). Levels of acrylamide in the EFSA dataset were consistently higher than in the manufacturers’ data, possibly due to uneven sampling through the year and the seasonality of acrylamide levels.     

Dietary exposure to aluminium of urban residents from cities in South China

A dietary survey was conducted over three consecutive days by using 24-hour dietary recall in the Pearl River Delta of South China to investigate the dietary consumption status. A total of 1702 food samples, 22 food groups, were collected, and aluminium concentrations of foods were determined by using ICP-MS. Weekly dietary exposure to aluminium of the average urban residents of South China was estimated to be 1.5 mg kg^?1 body weight, which amounted to 76% of the provisional tolerable weekly intake. Wheat-made products (53.5%) contributed most to the dietary exposure, followed by vegetables (12.2%). The high-level consumers’ weekly exposure to aluminium was 11.1 mg kg^?1 body weight, which amounted to 407% of the provisional tolerable weekly intake. The results indicated that the general urban residents in South China might be safe from aluminium exposure, but the high-level consumers might be at some risk of aluminium exposure. The foods contributing to aluminium exposure were processed food with aluminium-containing food additives. It is necessary to take effective measures to control the overuse of aluminium-containing food additives.     

Effect of frying oil quality and TBHQ on the shelf-life of potato crisps

Three different systems were used for the evaluation of the effect of frying oil quality and tertiarybutyl hydroquinone (TBHQ) on the shelf-life of fried potato crisps. Batches of potato slices were fried for 4 min at 30 min intervals over a period of 5 h day^?1 for eight consecutive days in refined, bleached and deodorised palm olein (RBD olein) without antioxidant (system 1); RBD containing 200 μg g^?1 TBHQ at the start of the experiment (system 2) and RBD olein which had TBHQ topped up to a level of 200 μg g^?1 at the start of each frying day (system 3). Sensory evaluation of crisps showed that there is an initial rapid decrease in shelf-life with increase in fry number in all systems. There was only a comparatively smaller effect on shelf-life with increase in fry number in later fryings. When the shelf-life of crisps was related to the quality of oil in the frying medium, it was found that the shelf-life of the product is only slightly affected when the oil had deteriorated beyond the acceptable limit of quality of frying oil, where the acceptable limit was taken as 27-30% polar components and 1–2 mg potassium hydroxide g^?1 oil. TBHQ does have a protective carry-through effect. The protective effect is more pronounced when TBHQ is topped up to a level of 200 μg g^?1 at the beginning of each frying day.