Reduction of acrylamide formation in potato slices during frying

Reduction of acrylamide formation in potato chips was investigated in relation to frying temperature and three treatments before frying. Potato slices (Tivoli variety, diameter: 37 mm, width: 2.2 mm) were fried at 150°C, 170°C and 190°C until reaching moisture contents of ∼1.7 g water/100 g (total basis). Prior to frying, potato slices were treated in one of the following ways: (i) soaked in distilled water for 0 min (control), 40 min and 90 min; (ii) blanched in hot water at six different time-temperature combinations (50°C for 30 and 70 min; 70°C for 8 and 40 min; 90°C for 2 and 9 min); (iii) immersed in citric acid solutions of different concentrations (10 and 20 g/l) for half an hour. Glucose and asparagine concentration was determined in potato slices before frying, whereas acrylamide content was determined in the resultant fried potato chips. Glucose content decreased in ∼32% in potato slices soaked 90 min in distilled water. Soaked slices showed on average a reduction of acrylamide formation of 27%, 38% and 20% at 150°C, 170°C and 190°C, respectively, when they were compared against the control. Blanching reduced on average 76% and 68% of the glucose and asparagine content compared to the control. Potato slices blanched at 50°C for 70 min surprisingly had a very low acrylamide content (28 μm/kg) even when they were fried at 190°C. Potato immersion in citric acid solutions of 10 and 20 g/l reduced acrylamide formation by almost 70% for slices fried at 150°C. For the three pre-treatments studied, acrylamide formation increased dramatically as the frying temperature increased from 150°C to 190°C.     

Reduction of acrylamide formation by vanadium salt in potato French fries and chips

The effects of vanadyl sulphate on the formation of acrylamide have been studied in fried potato products, such as French fries and chips. Acrylamide formation was inhibited by 30.3%, 53.3% and 89.3% when the sliced potato strips were soaked in 0.001, 0.01 and 0.1 M vanadyl sulphate (VOSO₄) solutions, respectively, for 60 min before frying. Moreover, 57.7%, 71.4% and 92.5% inhibition of acrylamide formation was observed when chips were soaked in the respective vanadyl sulphate solution before frying. In a separate model reaction, a solution containing an equimolar concentration of l-asparagine and d-glucose showed a significant inhibition of acrylamide formation when heated at 150 °C for 30 min in the presence of vanadyl sulphate (VOSO₄). The results indicate that the binding of VO²⁺ to asparagine and the decrease in the pH of the potato samples resulted in a significant reduction of acrylamide formation in fried potato products.     

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.     

Activities of hydrocolloids as inhibitors of acrylamide formation in model systems and fried potato strips

Effects of eight hydrocolloids on acrylamide (AA) formation were compared. At 2% (w/w), pectin, alginic acid (>50% reduction) and xanthan gum (∼20%) significantly (P < 0.05) reduced acrylamide formation in chemical models. In the fried snack model, effective inhibition of acrylamide formation (∼30%) by most of the hydrocolloids was observed only when the concentration was increased to 5%. Immersing potato strips for 1 h in a 1% alginic acid solution before frying produced inhibition of acrylamide formation similar to that in a 5% solution, and immersing for 5 h led to a significantly lower AA content (∼60% versus ∼30% reduction) compared with immersing for 1 h in a 1% or 5% immersion solution. Similar phenomena were also observed for pectin. The findings suggest alginic acid and pectin are promising inhibitors of acrylamide formation, and immersion time is an important determinant for their effects against acrylamide formation in fried potato products.     

Reduction of acrylamide formation by selected agents in fried potato crisps on industrial scale

Great interest and rapid research efforts on acrylamide in foods followed an announcement in April 2002 by the Swedish National Food Authority and the University of Stockholm. Reduction of acrylamide in high-temperature processing foods, including selection of the raw material and variation of processing parameters, etc. were extensive reported. In this research, effect of some agents on acrylamide formation was investigated. A glucose-asparagines reaction model system was used to test the effect of ferulic acid, catechin, CaCl₂, NaHSO₃, and l-cysteine on inhibition of acrylamide formation and three efficient inhibitors, NaHSO₃, CaCl₂ and l-cysteine were screened. The results showed that immersing of the fresh potato chips using different concentration of the agents greatly inhibited acrylamide formation in fried potato crisps, and the efficiency increased as their concentrations increased; among them, l-cysteine is the most efficient agent but CaCl₂ is most potential. Effects of these food additives on the texture of fried potato crisps were also studied. It was found that l-cysteine showed little effect on the texture of the crisps and CaCl₂ is regarded as the suitable choice because of its low price and the acceptable mouth feel of fried crisps treated by CaCl₂, although it increased the brittleness. Moreover, the application of CaCl₂ in industrial production of fried potato crisps was also studied. In the blanching process (deactivation process of enzymes at 85 °C), a computerized electrical conductivity detector was used to keep the concentration of CaCl₂ at constant and the result showed that immersion of potato slices in CaCl₂ solution at 5 g/L reduced acrylamide formation by more than 85% in fried crisps.Industrial relevanceThis research presents a technology to inhibit acrylamide formation in fried potato chips by immersion of fresh potato chips with some food additives. The approach suggested that cysteine and calcium chloride significantly decreased the content of acrylamide in fried potato chips and their concentrations could be kept constant by using a conductor as a detector.     

Inhibition of acrylamide formation by vitamins in model reactions and fried potato strips

The capacities of 15 vitamins in reducing the formation of acrylamide were examined. Inhibitory activities of the water-soluble vitamins were tested in both chemical models containing acrylamide precursors (asparagines and glucose) and a food model system (fried snack products), while activities of fat-soluble vitamins were examined only in the latter model. Biotin, pyridoxine, pyridoxamine, and l-ascorbic acid exerted a potent inhibitory effect (>50%) on acrylamide formation in the chemical model system. Using the food model, it was shown that water-soluble vitamins are good inhibitors of acrylamide formation. On the other hand, only weak inhibitory effects were observed with fat-soluble vitamins. Effects of pyridoxal, nicotinic acid, and l-ascorbic acid were further examined using fried potato strips. Nicotinic acid and pyridoxal inhibited acrylamide formation in fried potato strips by 51% and 34%, respectively. Thus, certain vitamins at reasonable concentrations can inhibit the formation of acrylamide.     

Reduction of acrylamide formation in French fries by microwave pre‐cooking of potato strips

In this study, the effect of microwave pre‐cooking of potato strips on the resultant acrylamide levels in French fries was investigated. Control and microwaved (10, 20, and 30 s at 850 W) samples were fried at 150, 170 and 190 °C for predetermined times. Surface and core temperatures of potato strips were acquired during frying, and acrylamide content in the surface and the core regions were determined separately. The results showed that microwave application prior to frying resulted in a marked reduction of acrylamide level in the surface region, whereas a slight increase was noted for the core region. When the potato strips were subjected to frying after a microwave pre‐cooking step, acrylamide content in the whole potato strip was reduced by 36%, 41%, and 60% for frying at 150, 170, and 190 °C, respectively, in comparison to the control. Copyright © 2006 Society of Chemical Industry     

Reactivity of acrylamide with coffee melanoidins in model systems

Coffee and its substitutes have been described as complex matrices for acrylamide (ACR) analysis due to both analytical interferences and ACR instability in the matrix. Melanoidins are multifunctional and biochemically active polymers which are formed in large extent during coffee roasting. Model systems composed of ACR (elimination studies) or glucose-asparagine (ACR formation/elimination studies) with/without melanoidins was heated at 180 °C. Washed sea sand and cellulose microcrystalline were used as matrix. Coffee melanoidins had a direct influence on the fate of ACR under heating, while the effect was not observed at room temperature. In addition, ACR decrease was also related to the reaction time and the initial amount of melanoidins in the media, where clearly a dose-response was observed. In contrast, pH (from 3.5 to 7.0) had no significant effect on ACR reactivity towards melanoidins. It is hypothesized that nucleophilic amino groups of amino acids from the proteinaceous backbone of melanoidins react via the Michael addition reaction with ACR, although the exact mechanism is unknown. Then, melanoidins could modulate the reaction pathways of ACR formation and elimination during coffee roasting and serve as acrylamide-mitigation substance.     

添加甘氨酸对天冬酰胺/葡萄糖模拟体系中丙烯酰胺形成的抑制作用

美拉德反应目前被认为是形成丙烯酰胺的重要途径,极探讨了甘氨酸在葡萄糖/天冬酰胺模拟体系中抑制丙烯酰胺形成的规律。模拟体系分别在90、100、110、120℃下反应4h,丙烯酰胺的生成、褐变度的增加、产物的减少以及对天冬酰胺和甘氨酸降解动力学的分析表明,甘氨酸的添加能够显著降低美拉德反应生成的丙烯酰胺,且在该反应体系中甘氨酸与天冬酰胺之间存在竞争关系。     

Lipid oxidation promotes acrylamide formation in fat-rich model systems

Lipid oxidation is one of the major chemical reactions occurring during food processing or storage and may have a strong impact on the final quality of foods. A significant role of carbonyl compounds derived from lipid oxidation in acrylamide formation has been recently proposed. In this work, the effect of lipid oxidation level on acrylamide formation was investigated by thermal treatment of differently formulated fat-rich model systems. Results showed that lipid oxidation positively influenced the formation of acrylamide. The effect was more evident in sugar-free system where lipid become the main sources of carbonyls. Catechins reduced acrylamide formation presumably by trapping carbohydrates and/or preventing lipid oxidation. More acrylamide was formed in model systems composed with sunflower oil than in those containing palm oil which is less susceptible to oxidation.In systems containing higher amount of water, acrylamide formation was delayed due to evaporative cooling. In these systems, the effect of catechin was more pronounced and the effect of lipid oxidation became detectable only after a prolonged reaction time.These findings suggested that lipid oxidation could become a relevant factor for acrylamide formation, particularly for dry foods with low carbohydrate content.     

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。     

Inhibition of acrylamide formation in potato strip by ultrasonic-treated methylcellulose batter

The ultrasonic (US)-treated batter mixtures of commercial methylcellulose (MC) as the fried potato strips' coating layer were demonstrated. The layer formed a rapid gel that absorbs the substrate's water content and related functional groups that contribute to acrylamide formation reduction. Different concentrations of MC (0.5-2.0 w/v %) mixtures were subjected to US at 20 W to evaluate coating layers' effect prior to the deep-frying process. At 1% w/v concentration batter mixture, the USMC layer reduced the highest acrylamide value. For comparison purposes, the differences in the acrylamide content of the USMC, the non-USMC and the uncoated samples were 64.7 ± 5.04, 156.4 ± 7.44 and 344.1 ± 5.39 ng g^-1, respectively. The results were supported with lower oil uptake and water retention of the USMC compared with the non-USMC with the values of 2.2 g/100g and 28.6 g/100g with 5.1 g/100g and 47 g/100g, respectively.     

Stability of acrylamide in model systems and its reactivity with selected nucleophiles

Since the discovery of relatively high amounts of the carcinogenic acrylamide in heat-processed food products, many studies have been devoted to the formation of acrylamide. However, as acrylamide is an α,β-unsaturated amide, subsequent reactions can provoke the desired removal of this compound. Therefore, the stability of acrylamide and its reactivity with various food-relevant nucleophiles were studied.The results showed that acrylamide was quite stable in aqueous solutions, but much less in dry reaction conditions. Buffer type and pH had a significant influence on the decrease of free acrylamide. The presence of amino acids with a nucleophilic side chain considerably decreased the free acrylamide, due to Michael-type addition reactions. The highest reactivity was noted for cysteine, leading to the formation of the mono-addition product cysteine-S-β-propionamide, as well as to the double addition product. Other nucleophiles, such as lysine, arginine, serine and ascorbic acid, were less reactive, but yielded comparable condensation products.     

牛磺酸对丙烯酰胺致SH-SY5Y细胞损伤的保护作用

用丙烯酰胺诱导SH-SY5Y神经细胞损伤建立细胞损伤模型,研究牛磺酸对SH-SY5Y细胞的保护作用。MTT法和LDH法测定结果显示:用100⁷00μg/m L丙烯酰胺对SH-SY5Y细胞孵育8 h,细胞存活率下降至52%⁸1%,表明丙烯酰胺对SH-SY5Y细胞有一定的损伤作用,导致细胞膜受损,LDH释放到细胞膜外。经牛磺酸（50、100、200μg/m L）预先孵育1 h后,再用300μg/m L丙烯酰胺对细胞孵育8 h,SH-SY5Y细胞的存活率分别升高至81.6%、92.7%、89.7%,显著高于丙烯酰胺损伤组的细胞存活率（67.6%）;且LDH释放程度呈现出下降趋势,LDH释放率分别为:150.7%、138.8%、113.3%,和丙烯酰胺损伤组的LDH释放率（188.5%）相比均显著降低。该研究结果表明牛磺酸对丙烯酰胺诱导的SHSY5Y细胞损伤具有保护作用。      

Dietary plant materials reduce acrylamide formation in cookie and starch-based model systems

BACKGROUND: Dietary plant materials have attracted much attention because of their health benefits to humans. Acrylamide is found in various heated carbohydrate‐rich foods. Our previous results showed that crude aqueous extracts from diverse dietary plants and some phenolic compounds could mitigate acrylamide formation in an asparagine–glucose model system. Based on our previous study, several plant materials were selected to further investigate their inhibitory effects on acrylamide formation in cookies and starch‐based model systems. RESULTS: Addition of raw powders from selected dietary plants and their crude aqueous extracts could considerably reduce acrylamide formation in both cookie and potato starch‐based models. Aqueous extracts of clove at 4% caused the largest reduction (50.9%) of acrylamide in cookies, whereas addition of 2% proanthocyanidins from grape seeds gave the greatest acrylamide reduction (62.2%) in a starch‐based model system. CONCLUSION: It may be feasible to use some of the tested dietary plant materials to reduce acrylamide formation in cookies and other starchy foods. Copyright © 2011 Society of Chemical Industry     

Color changes and acrylamide formation in fried potato slices

The objective of this work was to study the kinetics of browning during deep-fat frying of blanched and unblanched potato chips by using the dynamic method and to find a relationship between browning development and acrylamide formation. Prior to frying, potato slices were blanched in hot water at 85 °C for 3.5 min. Unblanched slices were used as the control. Control and blanched potato slices (Panda variety, diameter: 37 mm, width: 2.2 mm) were fried at 120, 150 and 180 °C until reaching moisture contents of ∼1.8% (total basis) and their acrylamide content and final color were measured. Color changes were recorded at different sampling times during frying at the three mentioned temperatures using the chromatic redness parameter a¹. Experimental data of surface temperature, moisture content and color change in potato chips during frying were fit to empirical relationships, with correlation coefficients greater than 90%. A first-order rate equation was used to model the kinetics of color change. In all cases, the Arrhenius activation energy decreases alongside with decreasing chip moisture content. Blanching reduced acrylamide formation in potato chips in ∼64% (average value) in comparison with control chips at the three oil temperatures tested. For the two pre-treatments studied, average acrylamide content increased ∼58 times as the frying temperature increased from 120 to 180 °C. There was a linear correlation between acrylamide content of potato chips and their color represented by the redness component a¹ in the range of the temperatures studied.