固相萃取-高效液相色谱法检测油炸薯条中丙烯酰胺

目的 建立了一种采用固相萃取-高效液相色谱(SPE-HPLC)测定油炸薯条中丙烯酰胺的方法.方法 样品用2.0 mol/L氯化钠溶液进行提取,使用Styre Screen H2P固相萃取柱(200 mg/3 ml)净化,然后用Sapphire C18反相色谱柱进行分析,流动相为甲醇/水(5∶95),流速为1.0 ml/min,检测波长为200 nm.结果 在1.0 ～ 10.0 μg/g的添加水平范围内,样品中丙烯酰胺的平均回收率为66.2％ ～80.9％,相对标准偏差为1.6％ ～2.1％,最低检测限和最低定量限分别为0.025和0.080 μg/g.结论 该方法操作简单、快速、准确,可用于油炸薯条中丙烯酰胺的快速测定.     

外源添加剂对油炸薯条中丙烯酰胺抑制作用研究

采用不同种类、不同浓度的添加剂对油炸薯条进行前处理,探索控制油炸薯条中丙烯酰胺的方法。用绿茶、大蒜浸提液等四种添加剂浸泡薯条后高温油炸,用气相色谱—电子捕获检测器(GC-ECD)方法进行定性定量分析。结果表明:四种添加剂均能有效抑制丙烯酰胺的产生;当绿茶浸提液添加量为5 g/100 m L,浸泡时间为60 min,对丙烯酰胺抑制率达到49.53%。     

不同食物在油炸过程中吸油量的研究

为研究不同食物在油炸过程中吸油量的规律,选用茶油、棕榈油、调和油在不同温度下对不同水分和结构的食物(薯条、馒头、面饼)进行油炸。结果表明:温度对吸油量有较大的影响,170℃时食物吸油量最快达到最高点(薯条12 min),油炸结束时食物含油量最低(p<0.05);馒头疏松多孔的结构可大大提高食物的吸油量(45%~60%),远高于薯条(15%~45%)和面饼(15%~35%)(p<0.05);食物水分越高,需要油炸的时间越长。棕榈油油炸时食物的吸油曲线最平稳,吸油量也最低,可能比茶油和调和油更适合油炸。      

亲水性胶体降低油炸裹浆薯条含油量的研究

以冷冻薯条为原料,通过在天妇罗预拌粉中添加亲水性胶体甲基纤维素(Methylcellulose,MC),羟丙基甲基纤维素(Methylhydroxypropylcellulose,HPMC)及羧甲基纤维素钠(Carboxymethylcellulose sodium,CMC),配成面糊裹在冷冻薯条表面,使薯条在油炸过程中减少油脂摄入,进而降低样品中的油脂含量。结果显示:3种亲水胶体与对照组相比均有显著的减油效果,其中甲基纤维素(MC)效果最好,羧甲基纤维素钠(CMC)效果次之,羟丙基甲基纤维素(HPMC)效果最小,在质量分数为0.4%时减油率分别达到19.54%,14.58%,9.88%;选取减油效果较好的MC和CMC按照总质量分数0.4%进行不同比例(1∶9、2∶8、3∶7、4∶6、5∶5、6∶4、7∶3、8∶2、9∶1)的混合,研究二者混合后添加到裹浆层中对裹浆薯条油炸后含油量的影响。结果显示MC与CMC按照3∶7的比例复配后减油效果最好,0.4%的质量分数下减油率可达到31.24%。     

油脂对油炸食品中反式脂肪酸含量的影响

目的:研究花生油、大豆油、菜籽油、24°棕榈油以及42°棕榈油5种油脂连续油炸薯条、油条和鸡块后,对油炸食品中反式脂肪酸含量的影响,从而为油炸食品工艺的选择提供实验依据。方法:采用5种油脂连续油炸薯条(176℃、2 min、45 s)、油条(176℃、2 min、30 s)和鸡块(176℃,3 min)5 d,并采用气相色谱法分析不同油脂对油炸食品中反式脂肪酸含量的影响。结果:使用不同种类油脂油炸的薯条、油条和鸡块均产生反式脂肪酸,其中,菜籽油煎炸的薯条和油条中反式脂肪酸最多,为38.74 mg/100 g和37.51 mg/100 g,棕榈油煎炸的油炸食品中反式脂肪酸含量最少,薯条为4.98 mg/100 g、油条为6.01 mg/100 g、鸡块为4.36 mg/100 g。结论:为使食品加工所产生的反式脂肪酸最少,应选用稳定性较好的42°棕榈油。     

三种多羟基醇协同海藻酸钠处理对油炸薯条吸油量和品质的影响

为了减少油炸薯条吸油量,探讨不同浓度多羟基醇协同1%海藻酸钠溶液预处理薯条对油炸薯条脂肪含量的影响,利用不同浓度的多羟基醇(木糖醇、山梨醇及丙三醇)溶液协同1%海藻酸钠溶液预处理自制薯条与商业冷冻薯条,研究薯条吸油量、质构、色差的变化。结果表明:在自制薯条中,经木糖醇、山梨醇与丙三醇协同1%海藻酸钠溶液分别处理的薯条,与不做任何处理的油炸薯条相比,脂肪含量分别减少了20.45%(1%海+0.5%木)、53.00%(1%海+0.25%山)、48.72%(1%海+0.75%丙),而与仅仅涂抹1%的海藻酸钠溶液的油炸薯条相比,脂肪含量分别减少了18.35%(1%海+0.5%木)、51.75%(1%海+0.25%山)、47.37%(1%海+0.75%丙)。而商业冷冻薯条,与不做任何预处理的油炸鲜样和仅涂抹1%海藻酸钠溶液组相比,脂肪含量反而分别增加了12.29%和29.11%(1%海+1%木)。同时,木糖醇处理还能显著提高薯条L^*(p<0.05)和咀嚼性(p<0.05)。木糖醇对自制薯条具有减油效果,且作用效果是山梨醇 > 丙三醇 > 木糖醇,三种多羟基醇能改善自制薯条的色差与质构。     

中式油炸食品中丙烯酰胺测定及降低方法初探

研究高效液相色谱法分析测定中式油炸食品中丙烯酰胺方法。样品预处理条件:油炸样品粉碎后用0.1%甲酸水溶液(料液比1:5)进行三次重复提取,提取液经高速离心、冷冻、C_(18)固相萃取小柱纯化,最后采用高效液相色谱仪进行测定。测定色谱条件:流动相为甲醇—0.02 mol/L乙酸胺溶液(5:95,v/v)、流速为0.9 ml/min、进样量为20μl、保留时间约4.887 min,检测器为紫外检测器,波长为210 nm、柱温25℃±0.5℃;试验结果表明,丙烯酰胺色谱图峰面积与其浓度在0.5～5.0μg/mL范围内呈良好线性关系,其最低检出限为10 ng/mL,回收率为94.5%～106.5%,相对标准偏差3.2%～4.5%;该法回收率高、精密度好,重复性好。利用该法测定几类市售中式油炸食品和自制油炸食品中丙烯酰胺含量,结果表明,市售中式油炸食品丙烯酰胺检出率为100%,仅含量水平有较大差异;试验也表明,通过优化工艺技术条件和配方如调节pH值或添加抗氧化剂等可降低油炸食品中丙烯酰胺含量。     

不同油脂对油炸食品中苯并(a)芘含量的影响

以薯条、油条和鸡块为研究对象,探究花生油、大豆油、菜籽油、24°棕榈油、42°棕榈油5种煎炸油对油炸食品中苯并(a)芘含量的影响,以期在今后的油炸烹饪过程中控制油炸食品中苯并(a)芘的含量。采用5种煎炸油176℃油炸薯条(165 s)、油条(150 s)和鸡块(210 s),并用液相色谱法分析不同油脂对油炸食品中苯并(a)芘含量的影响。结果表明:随煎炸批次的增加,不同油脂煎炸食品中苯并(a)芘含量也逐渐增加。花生油煎炸的食品中苯并(a)芘含量最高,薯条为1.64μg/kg,油条为1.73μg/kg,鸡块为1.15μg/kg;42°棕榈油煎炸的食品中苯并(a)芘含量最低,薯条为0.04μg/kg,油条为0.10μg/kg,鸡块为0.05μg/kg。综上所述,42°棕榈油煎炸的食品中苯并(a)芘含量较低,煎炸稳定性较好。     

油炸食品中丙烯酰胺的检测方法研究

富含淀粉的食物在油炸过程中,极易产生一种有害的化学物质——丙烯酰胺。建立了油炸食品中丙烯酰胺的提取、纯化与高效液相色谱分析方法。油炸食品经水提后正己烷脱脂、Carrez试剂净化除蛋白、C18固相萃取柱纯化得到丙烯酰胺提取液,再经高效液相色谱法分析检测。研究了高效液相色谱不同流动相比例、柱温、流速、进样量对丙烯酰胺分离效果的影响,确立了最佳色谱分离条件:检测波长195 nm,流动相乙腈-水(体积比20∶80),柱温45℃,流速1. 0 m L/min,进样量20μL。该方法丙烯酰胺的检出限为5μg/kg,相对标准偏差在0. 5%范围内,薯片样品的加标回收率在88. 5%～90. 6%之间,该法能有效、快速测定油炸食品中丙烯酰胺的含量。     

油炸薯条中酚类抗氧化剂的高效液相色谱法测定

采用反相高效液相色谱法测定油炸薯条中PG、TBHQ、BHA、4HR、BHT、2246.其中PG、TBHQ用50%甲醇(体积分数1%的冰醋酸)作流动相,BHA、4HR、BHT、2246用80%的甲醇作流动相,检测波长为280nm,用纯甲醇提取样品中的PG、TBHQ;用甲醇∶二氯甲烷=9∶ 1(V/V)提取BHA、4HR、BHT、2246.相关系数在0.9983～0.9996之间,检出限为1.0～2.0μg/g ,标准偏差在0.21%～5.30%之间,平均回收率均在85%以上.     

Combined Effects of Gamma Irradiation and Blanching Process on Acrylamide Content in Fried Potato Strips

Potato tubers were irradiated in ⁶⁰Co gamma station at different doses in order to investigate the effect of gamma irradiation on acrylamide formation in fried potato strips. Acrylamide content due to the irradiation treatment was reduced by 20–54% compared to a control after frying the irradiated tubers. While apply a blanching process, using warm tap water, to potato strips before frying has decreased acrylamide by 61%. A combination of gamma irradiation and a blanching process, which was applied in this work, showed a maximum decrease in acrylamide formation to reach 78% in fried potatoes.     

The effect of asparaginase on acrylamide formation in French fries

Acrylamide formation in French fries was investigated in relation to blanching and asparaginase soaking treatments before final frying. Par-fried potatoes of Bintje variety were prepared by cutting strips (0.8 × 0.8 × 5 cm) which were blanched at 75 °C for 10 min. Unblanched strips were used as the control. Control or blanched strips were then dried at 85 °C for 10 min and immediately partially fried at 175 °C for 1 min. Finally, frozen par-fried potatoes were fried at 175 °C for 3 min to obtain French fries. Pre-drying of raw or blanched potato strips did not generate acrylamide formation as expected. Partial frying of pre-dried control potato strips generated 370 μg/kg of acrylamide and the final frying determined French fries with 2075 μg/kg of acrylamide. When control potato strips were treated with a 10000 ASNU/l asparaginase solution at 40 °C for 20 min, the acrylamide formation in French fries was reduced by 30%. When blanched potato strips were treated in the same way, the produced French fries have 60% less acrylamide content than blanched strips without the enzyme treatment. Soaking of blanched potato strips (75 °C, 10 min) in an 10000 ASNU/l asparaginase solution at 40 °C for 20 min is an effective way to reduce acrylamide formation after frying by reducing the amount of one of its important precursors such as asparagine.     

Effect of osmotic pretreatment and microwave frying on acrylamide formation in potato strips

BACKGROUND: The presence of acrylamide, a probable carcinogen, is currently a major concern relating to the consumption of fried products. Therefore, recent frying studies have focused on ways of reducing the acrylamide content. The main objective of the present study was to determine the effects of microwave frying and osmotic treatment prior to frying on acrylamide formation in potato strips. RESULTS: Potatoes fried using 400 W microwave power for 1.0 min had an 87.85% lower acrylamide content than potatoes fried conventionally for 4.5 min (i.e. an 81.82% reduction in frying time) but a comparable moisture content. The acrylamide content of fried potatoes treated osmotically prior to both microwave and conventional frying was found to be lower than that of fried potatoes not pretreated osmotically. However, the reduction in acrylamide content was lower when osmotic treatment was applied before microwave frying. CONCLUSION: As a result of this study, it was concluded that microwave frying can be an alternative to conventional frying. Copyright © 2007 Society of Chemical Industry     

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     

Reduction of Acrylamide Formation in Potato Chips by Low-temperature Vacuum Frying

ABSTRACT: Potatoes and other foods that have a high content of the amino acid asparagine and a high accumulation of reducing sugars are subject to the formation of acrylamide upon frying. The objectives of this research were (1) to analyze the level of acrylamide formed during deep-fat frying of potato chips and (2) to evaluate means of reducing acrylamide in potato chips by using different potato cultivars and vacuum frying. Several potato cultivars were used in this research, including Innovator (I), NDTX 4930–5W (N), ATX 854 04–8W (ATw), Atlantic (A), Shepody (S), ATX847806–2Ru (ATr), and White-Rose (W). An electric bench-top (atmospheric conditions)-type fryer was used to fry the potatoes. Three temperatures were used: 150 °C, 165 °C, and 180 °C. The vacuum frying experiments were performed at 118 °C, 125 °C, and 140 °C and a vacuum pressure of 10 Torr. The potatoes were sliced (1.5-mm thick) and fried for different lengths of times. For potatoes fried at 165 °C (for 4 min) at atmospheric conditions, the acrylamide contents were 5021 ± 55 ppb (W), 552 ± 25 ppb (I), 358 ± 50 ppb (N), 397 ± 25 ppb (ATw), 646 ± 55 ppb (A), 466 ± 15 ppb(S), and 537 ± 14 ppb (ATr). Vacuum frying reduced acrylamide formation by 94%. Results showed that both cultivar and modified frying systems can play an important role in reducing acrylamide formation in fried potatoes. As the frying temperature decreased from 180 °C to 165 °C, acrylamide content in potato chips reduced by 51% during traditional frying and by 63% as the temperature decreased from 140 °C to 125 °C in vacuum frying. Increased frying time increased acrylamide formation during traditional frying for all temperatures and frying methods analyzed. However, the effect on acrylamide concentration was greater for the traditional frying than the vacuum frying. Keywords: acrylamide, vacuum, frying, potato, temperature     

KINETICS OF ACRYLAMIDE FORMATION DURING TRADITIONAL AND VACUUM FRYING OF POTATO CHIPS

Acrylamide is considered a carcinogen in animals and a possible carcinogen in humans. It has been found in starch‐rich foods cooked at high temperatures. Vacuum frying (10 Torr) was investigated as a possible alternative to reduce acrylamide formation in potato chips. The cultivar Atlantic was used to determine the kinetics of acrylamide formation during traditional and vacuum frying at different temperatures. There was a 94% decrease in acrylamide content when potatoes were fried to the same final moisture content (1.5% ± 0.3% w.b.) under vacuum compared to those fried under atmospheric conditions. Acrylamide accumulation under vacuum frying was modeled using first‐order kinetics (during traditional frying, the logistic kinetic model was used). The behavior of the kinetics of acrylamide content in potato chips fried under the two processes was different mainly because of the different temperatures used. During traditional frying, higher temperatures are used (150 to 180C) and acrylamide after some time is produced but starts degrading, producing a constant level of acrylamide content at longer times. During vacuum frying (10 Torr), acrylamide increased exponentially (but at lower levels) for all frying times.     

Effect of Microwave Frying on Acrylamide Generation,Mass Transfer,Color, and Texture in French Fries

The objective of this work was to evaluate the effect of microwave power on acrylamide generation, as well as moisture and oil fluxes and quality attributes of microwave-fried potatoes. Concretely, 25 g of potato strips, in 250 mL of fresh oil (at room temperature), were subjected to three different microwave powers (315, 430, and 600 W) in a conventional microwave oven. Microwave frying resulted in an acrylamide reduction ranged from 37 to 83% compared to deep-oil frying. Microwave-fried French fries presented lower moisture and higher fat content than deep-oil fried potatoes. Concretely, microwave-fried potatoes presented values of moisture and texture more similar to potato chips than French fries, nonetheless with lower fat levels (less than 20 g/100 g wb) and acrylamide content (lower than 100 μg/kg wb) at the reference time. This study presents an alternative way of frying to address the production of healthier potato chips.     

Effect of microwave pre-thawing of frozen potato strips on acrylamide level and quality of French fries

The objective of this study was to reduce frying time, and hence acrylamide level of French fries by microwave pre-thawing of frozen potato strips. Effect of this pre-treatment on acrylamide content and quality attributes of French fries was determined. Frozen par-fried potato strips (8.5 × 8.5 × 70 mm) were thawed in a microwave oven prior to final frying in sunflower oil at 170, 180, and 190 °C. Potato strips that were final fried without pre-thawing were considered as the control. Acrylamide analysis was performed by liquid chromatography–mass spectrometry (LC–MS) method. Microwave pre-thawing of frozen strips reduced the acrylamide level of French fries by 10% (from 17.7 to 15.9 ng/g), 89% (from 72.1 to 8.0 ng/g), and 64% (from 50.5 to 18.4 ng/g) for frying at 170, 180, and 190 °C, respectively, in comparison to the control samples. Quality attributes (texture, color, and oil content) of pre-treated strips were found to be comparable to those of the control.     

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.     

A novel strategy of acrylamide mitigation in fried potatoes using asparaginase and high pressure technology

The potentiality of high pressure processing (HPP) to possibly enhance diffusion of asparaginase into raw potato sticks, and consequently on reduction of acrylamide levels in fried potatoes was evaluated. Raw potato sticks were immersed in asparaginase (10,000 ASNU/L) and immediately subjected to 0.1, 100, 200 and 400 MPa for 5 min, with total enzymatic reaction times of 5, 10 and 20 min and room temperature. Pressurized raw potato sticks became softer, more flexible, and required lower energy for cutting (up to 47% less); the roughness of potato surface and moisture content were slightly reduced; and the concentration of soluble solids in the exterior solutions increased, indicative of a leaching effect. Due to changes induced by asparaginase and/or HPP on raw potatoes, fried potatoes exhibited higher weight loss after frying, and higher hardness (crispness). The combined treatment with asparaginase and HPP showed to reduce acrylamide levels by 26–47%, while with asparaginase or HPP alone there was no significant reduction.Industrial relevanceHPP is a non-thermal technology that may be used as a pre-treatment for the production of fried potatoes with different/better textural and nutritional properties, as well as to reduce energetic costs of some industrial steps of the production of fried potatoes (for instance, the cutting process and frying time). Also, a combined pre-treatment with HPP and asparaginase may be used as a strategy of acrylamide mitigation in fried potatoes.