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1.
Acrylamide is formed from reducing sugars and asparagine during the preparation of French fries. The commercial preparation of French fries is a multistage process involving the preparation of frozen, par-fried potato strips for distribution to catering outlets, where they are finish-fried. The initial blanching, treatment in glucose solution, and par-frying steps are crucial because they determine the levels of precursors present at the beginning of the finish-frying process. To minimize the quantities of acrylamide in cooked fries, it is important to understand the impact of each stage on the formation of acrylamide. Acrylamide, amino acids, sugars, moisture, fat, and color were monitored at time intervals during the frying of potato strips that had been dipped in various concentrations of glucose and fructose during a typical pretreatment. A mathematical model based on the fundamental chemical reaction pathways of the finish-frying was developed, incorporating moisture and temperature gradients in the fries. This showed the contribution of both glucose and fructose to the generation of acrylamide and accurately predicted the acrylamide content of the final fries.  相似文献   

2.
This study evaluated various additives or process aids on the industrial production of French fries, based on their acrylamide mitigation potential and other quality parameters. The application of acetic and citric acid, calcium lactate and asparaginase was investigated on the production of frozen par-fried French fries at the beginning and end of the 2008 and 2009 potato storage season. Despite the fact that some of these treatments significantly reduced acrylamide content of the final product in preliminary laboratory experiments, their application on the industrial production of French fries did not result in additional acrylamide reductions compared to the standard product. Asparaginase was additionally tested in a production line of chilled French fries (not par-fried). Since for this product a longer enzyme-substrate contact time is allowed, a total asparagine depletion was observed for the enzyme treated fries after four days of cold storage. French fries upon final frying presented acrylamide contents below the limit of detection (12.5 μg kg?1) with no effects on the sensorial properties of the final product.  相似文献   

3.
Acrylamide in French fries: influence of free amino acids and sugars   总被引：8，自引：0，他引：8  
The free amino acid profile and sugar (fructose, glucose, and sucrose) composition were determined in potato samples selected to give a large range of variation (a total of 66 samples). From these samples French fries were produced in a laboratory-scale simulation of an industrial process followed by a finish fry at 180 degrees C for 3.5 min using a restaurant fryer. The final product was blast frozen and analyzed for acrylamide. Acrylamide was detected in all samples, but its concentration varied significantly from 50 to 1800 ng/g. For isotope dilution (13C3) acrylamide analysis, samples were extracted with water, cleaned up on HLB Oasis polymeric and Accucat mixed mode anion and cation exchange SPE columns, and analyzed by LC-MS/MS. Statistical analysis of the data indicates that the effect of sugars and asparagine on the concentration of acrylamide in French fries is positive and significant (p < 0.001). It appears that one of the ways acrylamide formation in French fries can be effectively controlled is by the use of raw products with low sugar (and to a lesser degree, asparagine) content.  相似文献   

4.
A number of parameters linked to storage of potatoes were evaluated with regard to their potential to influence the acrylamide formation in French fries. Acrylamide, which is a potential human carcinogen, is reported to be formed during the frying of potatoes as a result of the reactions between asparagine and reducing sugars. This study was conducted using three potato varieties (Bintje, Ramos, and Saturna) typically used in Belgium, The Netherlands, and the northern part of France for French fry and crisp production. Saturna, mainly used in crisp production, appeared to be the least susceptible for acrylamide formation during frying. Especially storage at low temperatures (4 degrees C) compared to storage at 8 degrees C seemed to enhance acrylamide formation due to a strong increase in reducing sugars caused by low-temperature storage. Because of the reversible nature of this physiological reaction, it was possible to achieve a significant reduction of the reducing sugars after a reconditioning of the cold-stored potatoes for 3 weeks at 15 degrees C. All changes in acrylamide concentrations could mainly be explained by the reducing sugar content of the potato (R2 = 0.84, n = 160). This means that, by ensuring a low reducing sugar content of the potato tuber, the risk for acrylamide formation will largely be reduced. Finally the use of a sprout inhibitor did not influence the composition of the potato, and thus acrylamide formation was not susceptible to this treatment.  相似文献   

5.
Fried potato products such as French fries and chips may contain substantial amounts of acrylamide. Numerous efforts are undertaken to minimize the acrylamide content of these products while sensory properties such as color and flavor have to be respected as well. An optimization of the frying process can be achieved if the basic kinetic data of the browning and acrylamide formation are known. Therefore, heating experiments with potato powder were performed under controlled conditions (moisture, temperature, and time). Browning and acrylamide content both increased with heating time at all temperatures and moisture contents tested. The moisture content had a strong influence on the activation energy of browning and acrylamide formation. The activation energy strongly increased at moisture contents below 20%. At higher moisture contents, it was very similar for both parameters. At low moisture contents, the activation energy of acrylamide formation was larger as compared to the one for browning. This explains why the end of the frying process is very critical. Therefore, a lower temperature toward the end of frying reduces the acrylamide content of the product while color development is still good.  相似文献   

6.
A number of parameters linked to the selection of potato tubers were evaluated with regard to their potential to influence acrylamide formation in French fries. The formation of acrylamide, which is a potential human carcinogen, can be minimized for a big extent by the selection of an appropriate tuber. This study focused on the following selection criteria: variety as influenced by storage time and soil type, underwater weight, and tuber size. A total of 16 varieties were compared, concerning their potential for acrylamide formation. From that survey, certain varieties, such as Tebina and Quincy, could be appointed as unsuitable for frying. The differences in the potential of acrylamide formation between the varieties could mainly be explained by the reducing sugar content of the potato (R2 = 0.82, n = 96). The investigated type of soil and storage time at 8 degrees C appeared to have a minor influence on the acrylamide formation during frying. On the other hand, the tuber size of the potato did contribute in a significant manner to the acrylamide formation. Smaller tubers were more susceptible to acrylamide formation and should be avoided in the frying process. The last selection parameter, the underwater weight, appeared to be of minor importance in the acrylamide formation. On the basis of these simple selection criteria, it is possible to make a first screening of potatoes to reduce the acrylamide formation during frying.  相似文献   

7.
The aim of this work was to examine the effect of blanching or soaking in different acid solutions on the acrylamide content in potato crisps. Furthermore, the effects of a shorter frying time and a lower frying temperature combined with a postdrying were investigated. Soaking or blanching of potato slices in acidic solutions decreased the pH of potato juice and increased the extraction of amino acids and sugars. Potato crisps obtained after such pretreatments were characterized by lower acrylamide content. The most effective extraction of free amino acids and sugars as well as the largest decrease of acrylamide content (90%) in crisps was obtained when potato slices were soaked in acetic acid solution for 60 min at 20 degrees C. Shorter frying time followed by postdrying resulted in low-moisture potato crisps. Furthermore, the postdrying treatment gave a decreases in acrylamide content of approximately 70% when potato slices were fried at 185 degrees C and approximately 80% when potato slices were fried at 160 degrees C. Effective ways of decreasing acrylamide content in crisps production have been found. Crisps with low acrylamide content and good sensory quality can be obtained either by blanching in acetic acid as pretreatment or by a short frying followed by postdrying.  相似文献   

8.
The quality of the potato has been found to vary, when grown under different agricultural and environmental conditions, such as the level of fertilization. Consequently these factors may influence the acrylamide formation during the preparation of French fries. These assumptions were studied on three varieties: Bintje, Ramos, and Saturna from the harvest of 2003. Decreasing N fertilization caused increases in the reducing sugar concentration from 60% up to 100% on DM for all varieties studied. Due to a high correlation between the reducing sugar content and the generation of acrylamide during frying, this resulted in a parallel increase in the acrylamide concentration of the French fries. Thus by lowering the amount of N fertilizer, an increase of 30-65% of the acrylamide generation during frying could be observed. It seems of extreme importance to find an appropriate balance between the level of N fertilizer in order to diminish acrylamide formation but on the other hand to obtain an acceptable tuber and to consider the environmental impact. All results reported should be seen in the perspective of the warm growing season of 2003.  相似文献   

9.
In this paper the relationship between virgin olive oil (VOO) phenol compounds and the formation of acrylamide in potato crisps was investigated. The phenol compositions of 20 VOO samples were screened by LC-MS, and 4 oils, characterized by different phenol compound patterns, were selected for frying experiments. Slices of potatoes were fried at 180 degrees C for 5, 10, and 15 min, and acrylamide content was determined by LC-MS. Results demonstrated that VOO phenolic compounds are not degraded during frying, and crisp color was not significantly different among the four VOOs. Acrylamide concentration in crisps increased during frying time, but the formation was faster in the oil having the lowest concentration of phenolic compounds. Moreover, the VOO having the highest concentration of ortho-diphenolic compounds is able to efficiently inhibit acrylamide formation in crisps from mild to moderate frying conditions. It was concluded that the use of ortho-diphenolic-rich VOOs can be proposed as a reliable mitigation strategy to reduce acrylamide formation in domestic deep-frying.  相似文献   

10.
The present study was to demonstrate the efficiency of antioxidant of bamboo leaves (AOB) on the reduction of acrylamide during thermal processing and to summarize the optimal level of AOB applied in potato-based products. Potato crisps and French fries were immersed into different contents of AOB solution, and the frying processing parameters were optimized. The acrylamide content was determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The sensory evaluation was performed in double blind manner. Our results showed that nearly 74.1% and 76.1% of acrylamide in potato crisps and French fries was reduced when the AOB addition ratio was 0.1% and 0.01% (w/w), respectively. The maximum inhibitory rate was achieved when the immersion time was designed as 60 s. Sensory evaluation results showed that the crispness and flavor of potato crisps and French fries processed by AOB solution had no significant difference compared to normal potato matrixes (P > 0.05) when the AOB addition ratio was <0.5% (w/w). These results suggested that AOB could significantly reduce acrylamide formation in potato-based foods and keep original crispness and flavor of potato matrixes. This study could be regarded as a pioneer contribution on the reduction of acrylamide in various foods by natural antioxidants.  相似文献   

11.
The relations between the formation of acrylamide and color, pyrazines, or antioxidants in an asparagine/d-glucose browning model system under various conditions were investigated. The highest level of acrylamide was produced in the asparagine/glucose (1:3) system heated at 170 degrees C for 30 min (2629 microg/g asparagine). Color intensity increased with temperature and heating time. The formation of pyrazines increased steadily with an increase of temperature (140-170 degrees C) and heating time (15-60 min). Antioxidant formation varied among the samples heated under different conditions. A clear correlation between formation of acrylamide and browning color was obtained. The formation of acrylamide was linearly correlated with the formation of total pyrazines during the initial stages of the Maillard reaction. No obvious correlation between formation of acrylamide and antioxidants was observed. However, excess amounts of asparagine increased the formation of antioxidants, whereas excess amounts of glucose reduced its formation.  相似文献   

12.
The concentration of hydroxytyrosol (3,4-DHPEA) and its secoiridoid derivatives (3,4-DHPEA-EDA and 3,4-DHPEA-EA) in virgin olive oil decreased rapidly when the oil was repeatedly used for preparing french fries in deep-fat frying operations. At the end of the first frying process (10 min at 180 degrees C), the concentration of the dihydroxyphenol components was reduced to 50-60% of the original value, and after six frying operations only about 10% of the initial components remained. However, tyrosol (p-HPEA) and its derivatives (p-HPEA-EDA and p-HPEA-EA) in the oil were much more stable during 12 frying operations. The reduction in their original concentration was much smaller than that for hydroxytyrosol and its derivatives and showed a roughly linear relationship with the number of frying operations. The antioxidant activity of the phenolic extract measured using the DPPH test rapidly diminished during the first six frying processes, from a total antioxidant activity higher than 740 micromol of Trolox/kg down to less than 250 micromol/kg. On the other hand, the concentration of polar compounds, oxidized triacylglycerol monomers (oxTGs), dimeric TGs, and polymerized TGs rapidly increased from the sixth frying operation onward, when the antioxidant activity of the phenolic extract was very low, and as a consequence the oil was much more susceptible to oxidation. The loss of antioxidant activity in the phenolic fraction due to deep-fat frying was confirmed by the storage oil and oil-in-water emulsions containing added extracts from olive oil used for 12 frying operations.  相似文献   

13.
The addition of spinach (Spinacia oleracea) powder in flour dough as a natural antioxidant was investigated, and oxidation of frying oil and the lipid in fried products during frying was also studied. Flour dough with spinach powder was rolled into sheets of 0.1 cm thickness and then cut into squares to be fried. Each frying was performed in 160 degrees C soybean oil for 1 min, repeated every 20 min for 20 h. Fried samples were analyzed immediately or after being stored at 60 degrees C for 12 days under dark. The lipid content of fried dough was lower in samples with the addition of spinach powder. Spinach in the dough decreased accumulation of the polar compounds in soybean oil during frying but had little effect on the fried dough. It also reduced conjugated diene and aldehyde formation in the lipid of fried dough during storage. Improvement in lipid oxidative stability, presumably due to pigments in spinach, was more noticeable in the fried products during storage than in the frying oil.  相似文献   

14.
Acrylamide formation was studied by use of a new heating methodology, based on a closed stainless steel tubular reactor. Different artificial potato powder mixtures were homogenized and subsequently heated in the reactor. This procedure was first tested for its repeatability. By use of this experimental setup, it was possible to study the acrylamide formation mechanism in the different mixtures, eliminating some variable physical and chemical factors during the frying process, such as heat flux and water evaporation from and oil ingress into the food. As a first application of this optimized heating concept, the influence on acrylamide formation of the type of deep-frying oil was investigated. The results obtained from the experiments with the tubular reactor were compared with standardized French fry preparation tests. In both cases, no significant difference in acrylamide formation could be found between the various heating oils applied. Consequently, the origin of the deep-frying vegetable oils did not seem to affect the acrylamide formation in potatoes during frying. Surprisingly however, when artificial mixtures did not contain vegetable oil, significantly lower concentrations of acrylamide were detected, compared to oil-containing mixtures.  相似文献   

15.
Fried potato products may accumulate substantial amounts of acrylamide due to high precursor contents, namely reducing sugars and asparagine. In a two-factorial experiment increasing N supply, increased the contents of reducing sugars in most cases, and resulted in higher contents of free amino acids. α -amino-N, which was tightly correlated with the contents of free amino acids, can be regarded a suitable rapid test for free asparagine for a given variety. Increasing K addition always raised the citrate contents, but lessened the contents of reducing sugars. Selected treatments were processed into French fries. Highest acrylamide contents were observed in tubers grown with high N and inadequate K supply, which also contained the highest contents of precursors. The experiment clearly demonstrates that nutrient supply has significant impact on the contents of acrylamide precursors and thus for the acrylamide formation during frying.  相似文献   

16.
The effects of adding amino acids on the content of acrylamide in potato crisps, French fries, flat breads, and bread crusts were investigated. Addition of glycine or glutamine during blanching of crisps reduced the amount of acrylamide by approximately 30% compared to no addition. No effect was found in French fries. Addition of glycine during doughmaking significantly reduced acrylamide in both flat breads and bread crusts. In bread crusts the reduction of acrylamide ranged from 50 to >90% depending on the baking condition. In flat breads the reduction varied between 60 and >95%.  相似文献   

17.
The influence of water activity on the formation and elimination reactions of acrylamide was examined by means of multiresponse modeling on two different levels of complexity: basic equimolar asparagine-glucose systems and equimolar potato-based asparagine-glucose systems. To this end, model systems were first equilibrated to initial water activities in the range of 0.88-0.99 (corresponding roughly to the moisture gradient observed in French fries) and then heated at temperatures between 120 and 200 degrees C during different reaction times. For each sample, the concentration of acrylamide, glucose, asparagine, and aspartic acid was measured, as well as the extent of browning. A mechanistic model was proposed to model the five measured responses simultaneously. For both types of model systems, the model prediction was quite adequate, with the exception of the extent of browning, especially in the case of the potato-based model system. Moreover, the corresponding estimated kinetic parameters for acrylamide formation and elimination did not change significantly (based on a 95% confidence level) within the range of water activities tested, nor between the systems in the absence or presence of the potato matrix. The only remarkable difference was observed for the activation energy of acrylamide elimination, which was lower in the presence of the potato matrix, although not always significant. In general, these results confirm the generic nature of the model proposed and show that the influence of different moisture levels on acrylamide formation and elimination is minimal and that the addition of a potato matrix has little or no influence on the kinetic model and corresponding kinetic parameters.  相似文献   

18.
On the basis of a stable isotope dilution assay and derivatization with 2-mercaptobenzoic acid, the presence of the carcinogenic glycidamide ( 2) in processed foods was verified for the first time. Using (13)C-labeled 2 as the internal standard and the formation of the thioether derivatives, a new stable isotope dilution assay for the quantitation of 2 was developed. Application of the method on several potato samples revealed amounts between 0.3 and 1.5 mug/kg depending on the processing conditions. In a model experiment, the formation of 2 by an epoxidation of the double bond in acrylamide, that is, by a reaction with linoleic acid hydroperoxides, was established. This result was in good agreement with data showing that French fries processed in sunflower oil, which is high in linoleic acid, contained more 2 as compared to fries prepared in coconut oil. The derivatization procedure allows the simultaneous quantitation of acrylamide and glycidamide in foods.  相似文献   

19.
不同油炸时间的马铃薯片油脂吸收规律   总被引：2，自引：2，他引：0  
为了表征不同油炸时间下马铃薯片的油脂吸收规律,该文结合索氏抽提、染色法、激光共聚焦扫描镜观察、低场核磁共振成像技术等方法对马铃薯片的油脂吸收规律进行描述和解释,获得了油炸温度180℃、油料比10:1时不同油炸时间下马铃薯片油脂含量、油脂类型以及油脂分布的变化规律,并结合其孔隙特征解释油脂的吸收行为。结果表明:油炸时间(0~12 min)显著影响马铃薯片的总油脂质量分数、表面油脂、结构油脂和表面渗透油脂质量分数(P0.05);随着油炸时间的延长,马铃薯片的总油脂质量分数逐渐上升,当油炸10 min后,总油脂质量分数达到47.09%,之后逐渐趋于稳定;马铃薯片的表面油脂质量分数最低,约1.30%~2.06%;随油炸时间的延长,结构油脂质量分数逐渐上升,而油炸6 min后马铃薯片的表面渗透油脂质量分数呈下降趋势;激光共聚焦扫描镜观察显示,油炸过程中,随着油炸时间的延长,马铃薯片红色区域面积增大,表明油脂质量分数增加,且油脂从表面逐渐向中心渗透,黏附于细胞壁上,充盈细胞间质;当油炸时间为0~8 min时,马铃薯片的孔体积和孔隙率随油炸时间而增大,对应的油脂质量分数也逐渐提高,研究结果可为油脂吸收的表征,以及低油马铃薯片的开发提供参考。  相似文献   

20.
N-Nitrosothiazolidine-4-carboxylic acid (NTHZC) was recently identified in a variety of smoked fish and cured meat products. While the toxicological properties of NTHZC are currently unknown, it has been speculated that N-nitrosothiazolidine (NTHZ) in fried bacon may be caused in part by decarboxylation of NTHZC. A limited survey of uncooked cured meat products failed to demonstrate any correlation between levels of NTHZC and NTHZ. However, NTHZC levels were significantly higher, ranging from 8 to 1400 ppb, than the corresponding NTHZ levels, which ranged from less than 2 to 18 ppb. Decarboxylation of NTHZC to NTHZ in a model system occurs at 110 degrees C, which is significantly higher than the average bacon processing temperature of 54 degrees C, but lower than the normal frying temperature of 177 degrees C recommended for bacon. Results from both model system and frying experiments with NTHZC and its precursors suggest that NTHZC decarboxylation to NTHZ is not the principal pathway to NTHZ formation in uncooked bacon.  相似文献   

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