丙烯酰胺抑制剂对曲奇面团流变学和烘焙特性的影响

通过引入天冬酰胺酶和/或甜菊苷到曲奇配方中替代部分糖以抑制其生产过程中丙烯酰胺的生成,分析单独或同时添加这两种配料时曲奇面团的动态流变学特性、硬度和曲奇饼干的烘焙感官特性。结果表明：当单独添加天冬酰胺酶(1000 ASNU)时可降低曲奇样品中天冬酰胺含量(0.045mg/g)的67%,从而抑制95%丙烯酰胺的生成,且不会影响曲奇产品的烘焙特性。而天冬酰胺酶和甜菊苷同时添加时可抑制样品中96%丙烯酰胺的生成。动态流变学结果表明：引入天冬酰胺酶不会影响曲奇面团的流变学性质,而甜菊苷的加入会增加面团的弹性模量G＇和黏性模量G〃,这是因为甜菊苷替代面团中糖成分后促进曲奇面团面筋网络的形成。但是,部分糖被取代后会改变曲奇的一些烘焙特性,如：水分含量增加,曲奇饼干颜色变淡,延展率和破碎力降低。感官分析结果表明：感官评定者不能接受45%和60%糖取代量的曲奇,但可以接受15%或30%糖取代量的曲奇。     

Effect of Pretreatments and Air‐Frying,a Novel Technology,on Acrylamide Generation in Fried Potatoes

This paper investigated the effect of air‐frying technology, in combination with a pretreatment based of soaking the samples in different chemical agent solutions (citric acid, glycine, calcium lactate, sodium chloride, or nicotinic acid [vitamin B3]), on the generation of acrylamide in fried potatoes. The influence of reducing sugars on the development of surface's color was also analyzed. The experiments were conducted at 180 °C by means of air‐frying and deep‐oil‐frying, as a reference technology. Based on the evolution of color crust with frying time, it could be concluded that the rate of Maillard reaction decreased as the initial reducing sugars content increased in the raw material, and was also lower for deep‐oil‐frying than for air‐frying regardless of pretreatments applied. Air‐frying reduced acrylamide content by about 90% compared with conventional deep‐oil‐frying without being necessary the application of a pretreatment. However, deep‐oil fried potatoes pretreated with solutions of nicotinic acid, citric acid, glycine at 1%, and NaCl at 2% presented much lower acrylamide levels (up to 80% to 90% reduction) than nonpretreated samples.     

Effects of dough formula and baking conditions on acrylamide and hydroxymethylfurfural formation in cookies

The effects of dough formula and baking conditions on the formations of acrylamide and hydroxymethylfurfural (HMF) were studied in a cookie model system. Increasing the sugar concentration in the dough formula increased acrylamide formation during baking at 205 °C for 11 min. The effect of sugar on acrylamide formation was more pronounced for glucose than for sucrose, expectedly. Addition of citric acid into dough formula comprising sucrose increased the susceptibility of acrylamide formation, while it decreased acrylamide formation in the dough formula comprising glucose. Decreasing the pH of dough formula increased the tendency to surface browning and the formation of hydroxymethylfurfural in cookies during baking. The results suggest that a cookie with acceptable texture and colour, but having less than 150 ng/g of acrylamide, can be manufactured by lowering the baking temperature and avoiding reducing sugars in the recipe.     

焙烤食品中生成丙烯酰胺的影响因素

人类可能致癌物丙烯酰胺在富含碳水化合物的热加工食品中含量较高。本文结合近年来的研究结果.综合分析了影响焙烤食品中丙烯酰胺形成的因素(前体物质、水分、酸碱环境、油脂氧化、阳离子、抗氧化剂和加工工艺)。并探索将糠氨酸和羟甲基糠醛作为预洲焙烤食品中丙烯酰胺含量的指示物。     

Effect of Cooking Method (Baking Compared with Frying) on Acrylamide Level of Potato Chips

ABSTRACT:  The effect of cooking method (baking compared with frying) on acrylamide level of potato chips was investigated in this study. Baking and frying experiments were conducted at 170, 180, and 190 °C using potato slices with a thickness of 1.4 mm. Raw potatoes were analyzed for reducing sugars and asparagine. Surface and internal temperatures of potato slices were monitored during the experiments to better explain the results. Fried and baked chips were analyzed for acrylamide content using an LC-MS method. The results showed that acrylamide level of potato chips prepared by frying increased with frying temperature (19.6 ng/g at 170 °C, 39 ng/g at 180 °C, and 95 ng/g at 190 °C). In baking, however, the highest acrylamide level was observed in potato chips prepared at 170 °C (47.8 ng/g at 170 °C, 19.3 ng/g at 180 °C, and 29.7 ng/g at 190 °C). The results showed that baking at 170 °C more than doubled the acrylamide amount that formed upon frying at the same temperature, whereas at 180 and 190 °C, the acrylamide levels of chips prepared by baking were lower than their fried counterparts.     

Acrylamide in Baking Products: A Review Article

Acrylamide or 2-propenamide is a chemical compound, with chemical formula CH₂=CH–CO–NH₂, that can be produced at high levels in high-carbohydrate heat-treated foods. The risks of acrylamide to health and its toxic properties (neurotoxicity, genotoxicity, carcinogenicity and reproductive toxicity) were demonstrated by the Scientific Committee on Toxicity, Ecotoxicity and the Environment in 2001. Potato and bakery products account for around 50% and 20% of human exposure to acrylamide, respectively. Factors affecting acrylamide formation and degradation in foods are acrylamide precursors such as free amino acids (mainly asparagine), reducing sugars and processing conditions (i.e. baking time and temperature, moisture content and matrix of product). The aim of this review was to present some results from recent investigations of the effects of different factors affecting acrylamide formation in bakery products. Finally, recommendations are proposed as guidelines for baking manufacturers to reduce the level of acrylamide in their products.     

The influence of tuber mineral element composition as a function of geographical location on acrylamide formation in different Italian potato genotypes

BACKGROUND: The present study was aimed at examining the effect of tuber mineral composition, distinctive for geographical location, on the expression of acrylamide precursors in three potato genotypes (Arinda, Rossa di Cetica and Sieglinde) in three Italian potato cultivation regions (Puglia, Sicily and Tuscany). RESULTS: Sucrose and amino acids were not correlated with acrylamide formation. In contrast, reducing sugars, limiting with respect to the principal amino acid precursor asparagine, were positively correlated with acrylamide. From analysis of variance, both acrylamide and reducing sugars were not significant for variety but highly significant for location, with higher levels occurring in all three varieties cultivated in Tuscany, followed by Sicily and Puglia respectively. Reducing sugars were negatively correlated with K and Ca and positively correlated with Zn and Cu. Neither N nor P was correlated with reducing sugar content. Path analysis, a statistical technique distinguishing causation and correlation between variables, was implemented to provide additional insight on the interactions between mineral elements and reducing sugars under open field conditions. The variation in reducing sugars in all three varieties was shown to be attributable to Zn. CONCLUSION: Cultivation location has a significant impact on the composition of tuber mineral elements and, as a result, on genotype in the expression of reducing sugars. The negative correlation between Zn and K and the variation in reducing sugar content attributed to the element Zn, which is particularly available in acid soils, are important factors warranting future research aimed at reducing acrylamide formation from an agronomic perspective. Copyright © 2010 Society of Chemical Industry     

天然抗氧化剂抑制曲奇中丙烯酰胺含量的研究

采用天然抗氧化剂荞麦、孜然和黑种草籽抑制曲奇中丙烯酰胺的生成。研究这3种配料对面粉中丙烯酰胺前体的含量、面粉和曲奇抗氧化的特性、曲奇烘焙特性和丙烯酰胺含量的影响,结果表明：这3种配料组合都可以增加面粉中还原糖和天门冬酰胺的含量,也可以增加面粉和曲奇的抗氧化特性(包括总酚类物质、DPPH自由基清除能力和ABTS+·的抑制能力)。当所添加的天然抗氧化剂含量增加时,曲奇颜色变深,表现为更低的L*,a*和b*值;荞麦和孜然的引入会增加曲奇中的水分含量,而黑种草籽则相反。所有天然抗氧化剂组合都可以增加曲奇的延展率。未添加天然抗氧化剂的曲奇中丙烯酰胺的含量为361.2μg/kg,而单独添加15%荞麦、15%孜然和15%黑种草籽使得曲奇中丙烯酰胺的含量分别降低了20.2%、67.6%和75.9%。感官分析结果表明：富含天然抗氧化剂的曲奇都可以被人们所喜欢。     

减少高温加工食品中丙烯酰胺含量的几种方法

原料中还原糖、天冬酰胺含量及加工温度是影响食品中丙烯酰胺形成的主要因素。减少原料中的还原糖或天冬酰胺含量及降低加工温度能显著降低食品中丙烯酰胺的含量。本文概述了几种减少高温加工食品中丙烯酰胺含量方法的研究进展。     

Optimization of the blanching process to reduce acrylamide in fried potatoes

A central composite design was used to study the effect of blanching time and temperature on the extraction of reducing sugars from potato strips and slices. After frying, the impact of both factors on the acrylamide content in French fries and potato crisps was evaluated. Acrylamide could be lowered more efficiently in potato crisps compared to French fries, due to a more pronounced extraction of sugars from potato slices upon blanching. In both products, blanching temperature was the main influencing factor for sugar extraction and subsequent acrylamide mitigation. Blanching at temperatures of about 70 °C for a short period of time (about 10 min) was more efficient compared to blanching at lower temperatures, which appeared more time-consuming. However, the extraction efficiency of reducing sugars was over 10% lower when the potato cuts were blanched in water which was previously used for blanching, leading to over 10% less reduction in the final acrylamide content.     

Effect of crust temperature and water content on acrylamide formation during baking of white bread: Steam and falling temperature baking

The effect of crust temperature and water content on acrylamide formation was studied during the baking of white bread. To assess the effect of over-baking, we used a full factorial experimental design in which the baking time was increased by 5 and 10 min at each baking temperature. Additional experiments were performed with steam baking and falling temperature baking. Immediately after baking, the crust was divided into the outer and inner crust fractions, and the water content and acrylamide concentration of each fraction was measured. The outer crust had a significantly lower water content and higher acrylamide concentration than the inner crust did. Crust temperature in combination with water content had a significant effect on acrylamide formation, higher temperatures resulting in higher acrylamide concentrations. However, at very high temperatures and lower water contents, acrylamide concentration was observed to decrease, though the bread colour was then unacceptable for consumption. Steam and falling temperature baking, on the other hand, decreased the acrylamide content while producing bread crust with an acceptable colour. The lowest acrylamide values and an acceptable crust colour were produced by steam baking.     

Acrylamide monitoring in Switzerland, 2007–2009: results and conclusions

Parallel to the European Union acrylamide monitoring for the years 2007–2009, Switzerland performed its own monitoring, covering the whole range of products that significantly contain acrylamide (almost 300 samples per year), but focusing on those products that may result in high exposure. As reducing sugars are critical for potato products, these were included. No significant change, particularly improvement, was noticed, especially regarding those products for which substantial potential for improvement is known. ‘Western-style’ French fries continued to contain some four times more reducing sugars than ‘traditional’ fries, with correspondingly higher acrylamide in the finished product. The supply of raw potatoes low in reducing sugars by retail shops needs improvement, but there seemed to be insufficient willingness on a voluntary basis. A foreign producer was successful in penetrating the Swiss market with special potato chips containing up to 7000 µg kg^?1 acrylamide and only harsh measures could stop this. Three of about 61 products in the group of bakery ware showed a marked improvement. But there was also a store brand cracker that competed with a leading brand which contained 15 times more acrylamide (845 µg kg^?1). Cereals contained 1080 µg kg^?1 acrylamide and even a warning did not prompt the producer to sell substantially better products one year later. It seems that only measures by the authorities will achieve improvements. The following seem promising: a limit for reducing sugars in prefabricates for French fries; the improved supply of raw potatoes low in sugars for roasting and frying; a legal limit for acrylamide content in potato chips; a general provision that products must not contain substantially more acrylamide than achievable by good manufacturing practice; and fryers with a temperature profile from an initial high to a lower final value.     

Effect of Raw Potato Composition on Acrylamide Formation in Potato Chips

ABSTRACT: Recent studies have shown that subjecting foods to high temperatures during cooking processes such as frying gives rise to the formation of acrylamide. Several factors including product composition and processing conditions affect the rate of formation of this chemical in starch-rich foods. Low reducing sugar and the amino acid asparagine content is desired when cooking because the formation of acrylamide is attributed to the Maillard reaction that occurs between these food components. The cultivar 'Atlantic' was used to determine the effect of potato components (reducing sugars and asparagine) on acrylamide content during frying in a traditional fryer. A model system was developed by infusing leached potato slices with predetermined amounts of glucose and asparagine. Increasing glucose and asparagine content in the slices increased the acrylamide content in the potato chips. Color could not be used as an indication of acrylamide content because potato chips with similar color had very different acrylamide concentrations.     

Acrylamide in almond products

Acrylamide was determined in 86 different almond products, such as roasted almonds, almond-containing bakery products, raw almonds, and marzipan. The highest acrylamide concentrations were found in dark roasted almonds, while only moderate acrylamide contents were determined in bakery products. Roasting experiments under different process conditions showed that acrylamide increases with time and that temperature has a much stronger effect on acrylamide formation than time. During roasting reducing sugars are consumed faster and to a larger extent than free asparagine, suggesting that the content of reducing sugars may be a critical factor for acrylamide formation in roasted almonds. Acrylamide was found to decrease in roasted almonds during storage at room temperature.     

馍干中丙烯酰胺的抑制工艺及添加剂配方

研究降低馍干中丙烯酰胺含量的方法,包括馍干加工工艺和食品添加剂两方面。结果表明,采用高温（230 ℃）烘烤馍干,与低温（190 ℃）烘烤相比,馍干中丙烯酰胺含量下降10.9%;降低馍干坯水分（从41.7%降到9.6%）,馍干中丙烯酰胺含量下降31.7%;添加复合食品添加剂（硫酸钙添加量为1.0%,茶多酚添加量为0.04%）,馍干中丙烯酰胺含量下降56.5%。通过优化工艺条件和添加复合添加剂,馍干中的丙烯酰胺含量从177.2 μg/g下降到46.8 μg/g,总共下降了73.5%。因此,采用高温短时烘烤、降低馍干坯烘烤前水分含量和添加复合添加剂,能有效降低馍干中丙烯酰胺含量。     

Legal limit for reducing sugars in prefabricates targeting 50 μg/kg acrylamide in French fries

A legal limit for the reducing sugars in the prefabricates for French fries is a simple and efficient measure to reduce the exposure to acrylamide from the predominant source for many consumers. The acrylamide content of French fries of comparable crispiness is approximately proportional to the concentration of the reducing sugars glucose and fructose in the potato sticks. On average, optimally prepared French fries from prefabricates with a (moderately low) sugar content of 0.3 g/kg contained 32 g/kg acrylamide. With 0.15 g/kg reducing sugar even severe overfrying at 170 °C only resulted in 90 g/kg acrylamide, i.e. a low sugar content keeps acrylamide low even under inappropriate frying conditions. In the prefabricates, the sugar content is about 10% lower than in the raw potato (resulting from the effects of blanching and prefrying). It is similar to that in the finished French fries, which enables one to distinguish whether a high acrylamide content in French fries results from high sugars in the raw material or unsuitable frying conditions. An average concentration of 50 g/kg acrylamide in French fries could be targeted by limiting the reducing sugars in the prefabricates to 0.7 g/kg and the frying temperature to 170 °C. Even considerable overfrying in terms of duration can be tolerated then.     

Potential for acrylamide formation in potatoes: data from the 2003 harvest

Reducing sugars, free amino acids, and the potential for acrylamide formation were determined in more than 50 potato samples from the 2003 harvest in Switzerland. The reducing sugar content strongly correlated with acrylamide, whereas no correlation was found between acrylamide and free asparagine or the pool of free amino acids. The reducing sugar contents and the acrylamide potentials were higher in most of the cultivars tested than in the samples from 2002. This was probably due to the hot and dry summer of 2003. Monitoring sugars and amino acids during heating at 120 °C and 180 °C showed that glucose and fructose reacted much faster than sucrose and the amino acids. Glutamine was consumed to a larger extent than any of the other amino acids. During prolonged storage, the reducing sugars decreased considerably while only moderate changes in the free amino acids were observed. Altogether, glucose and fructose remain the critical factors for acrylamide formation in potatoes and represent the most feasible way of reducing the formation of acrylamide in potato products.     

Acrylamide and 5-hydroxymethylfurfural formation during baking of biscuits: NaCl and temperature–time profile effects and kinetics

The present study aimed to investigate the effect of recipe and temperature–time on the formation of acrylamide and 5-hydroxymethylfurfural (HMF) during biscuit baking. Baking experiments were performed with biscuits of two different recipes, with and without NaCl, at 180 °C, 190 °C and 200 °C. Acrylamide and HMF reached highest concentrations at 200 °C for both recipes. The presence of NaCl in the biscuit formulation lowered acrylamide concentrations at 180 °C and 190 °C but not at 200 °C, and led to higher concentrations of HMF at all the tested temperatures. Sucrose hydrolysis was a key step in acrylamide and HMF formation during biscuit baking, even though a significant amount of acrylamide already had formed before the onset of sucrose hydrolysis. A lag phase was observed before sucrose hydrolysis occurred, which might depend on the melting of crystalline sucrose occurring at approximately 180 °C.A mathematical model based on the chemical reaction pathways was developed for the recipe with NaCl baked at 200 °C. The model described the chemical evolution during the last part of biscuit baking, and accurately predicted acrylamide and HMF content at the end of baking. The model showed the significant contribution of the reducing sugars to the formation of both acrylamide and HMF. The model could not be extended to the entire baking period because it was not possible to incorporate the lag phase observed before sucrose hydrolysis. The results reported in this study confirm that the kinetics of acrylamide and HMF formation in real food and dry systems may depend on the physical state of their precursors.     

Acrylamide formation and antioxidant level in biscuits related to recipe and baking

Heated plant foods may contain compounds with adverse health effects (e.g. acrylamide). On the other hand, health-promoting compounds (e.g. antioxidants) have also been identified in such foods. Therefore, a baking experiment with biscuits was carried out to study the potential impact of both acrylamide and antioxidants in that food. Two different wheat flour types - wholemeal (WMF) and white flour type 550 (T550; 0.55% mineral content) - as well as recipe (fat and leavening agent) and thermal input (temperature?×?time) were changed. Furthermore, the effect of an enzymatic asparagine hydrolysation was tested. Antioxidants were determined with two independent procedures ABTS - (2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate)) and FRAP-assay (ferric reducing ability of plasma). WMF samples resulted in an unchanged acrylamide level, but in a significantly higher antioxidant concentration when compared with T550 samples (149 and 141?μg?kg(-1) acrylamide and 9.1 and 5.1?mmol?TE?kg(-1) FW ABTS for WMF and T550, respectively). A reduced fat content yielded in an increased volume. Raising agents had no effect on acrylamide levels, but antioxidants were higher in samples with sodium bicarbonate (SBC) than with ammonium bicarbonate (ABC). Thermal input (temperature?×?time; 150°C?×?25?min to 240°C?×?9?min) indicated an exponential acrylamide increase especially at higher temperatures (from 75 to 236?μg?kg(-1)), whereas antioxidant increase was linear (from 7.0 to 7.7?mmol?TE?kg(-1) FW, ABTS). FRAP and ABTS values were correlated on a low level, whereas acrylamide content of biscuits was correlated with FRAP and lightness (R (2?)=?0.62 and 0.47, and 0.71 and 0.85 for WMF and T550, respectively). The enzyme asparaginase reduced acrylamide formation by about 50% for both raising agents (SBC and ABC, respectively), whereas antioxidant levels were not affected. An evaluation of recipe variants with low acrylamide and high antioxidants indicated the advantage of wholemeal biscuits.     

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