热烫预处理降低鲜切油炸薯片中丙烯酰胺的工艺优化研究

研究热烫预处理对鲜切油炸薯片中丙烯酰胺的影响和薯片油炸工艺优化。在相同条件下,分别对原料进行热烫和非热烫处理,在不同油炸温度和时间条件下进行油炸试验,采用DNS法测还原糖,液质联用法检测薯片中丙烯酰胺含量。结果表明,通过对切片的马铃薯进行热烫处理,即75℃热烫150s,能明显降低还原糖含量,160℃油炸120s,可降低丙烯酰胺含量至67.18μg/kg。     

温州蜜柑热烫过程中营养成分和感官品质变化的研究

研究柑橘罐头加工中热烫对产品品质的影响,温州蜜柑在75~100℃的热水中处理30~180s,考察热烫温度和时间对温州蜜柑营养成分及感官品质的影响。结果表明:随着热烫温度和时间的增加,橘肉中总酚、总黄酮、可溶性固形物的含量及对DPPH·的清除能力升高;橘肉中类胡萝卜素、V C、总糖、还原糖的含量,橘皮硬度及褐变指数降低;橘肉亮度变浅,颜色由橘红向橘黄转变。热烫会导致部分热敏性成分损失,但是可提高果品酚类物质含量和抗氧化性能,抑制果品酶促褐变。在100℃以下,3min内热烫对温州蜜柑果肉色泽的影响不显著。     

低温果浆酶处理对黑莓出汁率和几个理化指标的影响

用低温果浆酶处理黑莓浆液,探讨酶处理对黑莓出汁率、还原糖含量和色泽等的变化规律。在pH、酶作用时间、加酶量和反应温度单因素实验的基础上进行正交实验。结果表明,pH为3.5、低温果浆酶用量为0.2%,反应温度为30℃,作用时间为1.5h时,黑莓的出汁率最高。     

预处理对云南脆皮薯条中丙烯酰胺形成的抑制效果研究

目的探究预处理对云南脆皮薯条中丙烯酰胺形成的抑制效果。方法通过选取油炸温度、油炸时间和淀粉水溶液浓度的3个梯度设计单因素实验,对其品质变化进行测定以及感官综合评分法评定,建立云南脆皮薯条的最佳加工工艺。为有效控制丙烯酰胺,在热加工前,将马铃薯分别进行热烫(85℃下热烫10 min)、半胱氨酸浸泡(常温下于3 g/L的半胱氨酸溶液中浸泡10 min)、热烫+半胱氨酸浸泡(在85℃下浸泡于3g/L半胱氨酸溶液中10min)预处理,以未处理为对照组。热加工后,分别对云南脆皮薯条样品的风味品质指标:水分含量、水分活度、质量、颜色、还原糖含量、天冬酰胺、半胱氨酸等进行测定,分析不同预处理方式对云南脆皮薯条风味品质的影响,并对丙烯酰胺含量进行测定,比较3种预处理方式对云南脆皮薯条中丙烯酰胺的抑制情况。结果用热烫+半胱氨酸浸泡的预处理方式处理马铃薯后制作云南脆皮薯条,水分含量、颜色、还原糖、天冬酰胺与未处理组相比没有统计学差异(P0.05);半胱氨酸含量与其他预处理组对比显著增加;丙烯酰胺含量与单独热烫、未处理组相比明显减少(P0.05)。结论运用半胱氨酸溶液浸泡并联热烫预处理云南脆皮薯条能有效降低食物中的丙烯酰胺同时保留食物风味品质。     

速冻山药热烫工艺研究

对山药的速冻预处理工艺进行了研究。在实验中,以清水为热烫液,通过测定Vc的含量、可溶性固形物的含量、过氧化物酶和多酚氧化酶的活性这四个指标来确定最佳的热烫时间和温度。同时对经热烫和不经热烫两种不同处理的山药在冻藏过程中的色泽变化进行了评价。研究表明,速冻山药必须进行热烫处理以使酶失活。最佳的热烫时间和温度为60s和90±1℃。     

不同加工温度对蜂蜜中糖类含量及淀粉酶值的影响

对经不同温度处理过的蜂蜜中的还原糖、蔗糖含量及淀粉酶值进行了测定。结果表明:随着温度的升高,蜂蜜中的还原糖、蔗糖含量逐渐降低,淀粉酶值减小。蜂蜜加工的适宜温度为60～65℃、时间为10～15 min。     

紫薯麦芽复合饮料加工工艺的研究

以紫薯和麦芽为原料制备复合饮料,利用麦芽里含有的淀粉酶水解原料中的淀粉,采用单因素实验和正交实验研究酶解温度、酶解时间、紫薯和麦芽质量比对饮料中还原糖含量和感官评分的影响,探讨还原糖含量和感官评分的相关性。结果表明,在不同加工条件下,还原糖含量的变化趋势并不总是与感官评分一致。优化的工艺条件是:酶解温度为75℃,酶解时间为1h,薯麦质量比为5:7,制得的复合饮料还原糖含量为10.45%,感官评分为21分。     

不同预加工方式对马铃薯片中丙烯酰胺的影响

研究不同预加工方式对油炸马铃薯片中丙烯酰胺生成的影响,进而探讨一种可有效抑制马铃薯片中丙烯酰胺含量的方法。将马铃薯片在不同温度（120℃ ～200℃）及不同时间（0 ～30 min）下进行油炸处理,通过品质指标及丙烯酰胺含量的变化趋势确定最佳油炸时间及温度,利用高效液相色谱法测定经热烫和添加剂浸泡后马铃薯片中丙烯酰胺的含量,并计算丙烯酰胺抑制率。在未进行预处理条件下,随着油炸时间及油炸温度的增大,质量损失率、色差呈整体上升趋势,水分活度、水分含量及还原糖含量呈整体下降的趋势,丙烯酰胺含量呈先上升后下降的趋势;在油炸前进行不同预处理对马铃薯片中的丙烯酰胺具有显著抑制作用,90℃热烫处理协同5 g/L半胱氨酸溶液浸泡处理10 min对马铃薯片中丙烯酰胺的抑制率达到了100%。因此,热烫协同半胱氨酸溶液浸泡处理是一种可有效抑制马铃薯片中丙烯酰胺含量的方法。     

湿热处理对马铃薯全粉品质的影响

湿热处理马铃薯全粉,研究水分含量、时间和温度对马铃薯全粉微观结构、还原糖、结晶度、溶胀度、吸油性、冻融稳定性和糊化等品质指标的影响。结果表明:湿热处理使得马铃薯全粉的结晶度和溶解度升高;冻融稳定性、吸油性、膨胀度、峰值黏度、谷值黏度、最终黏度、崩解值、回生值和还原糖含量降低。当温度和时间一定,水分含量为30%时,溶解度和还原糖含量最高,峰值黏度、谷值黏度和最终黏度最低。当水分含量和温度一定时,不同时间对马铃薯全粉各品质指标的影响之间没有明显差异。当水分含量和时间一定,温度为110℃时,还原糖含量和溶解度最高。温度为120℃时,冻融稳定性、峰值黏度、谷值黏度、最终黏度、回生值和崩解值均最低。说明,湿热处理对马铃薯全粉的品质有显著影响(p0.05)。     

Box-Behnken优化富硒豆芽处理条件

以有机富硒液体肥为硒源,对豆芽的富硒培育条件进行优化研究。选择热烫温度、热烫时间、有机富硒浓度和浸泡时间作为优化因素,研究各因素的不同水平对富硒豆芽发芽率和硒含量的影响。通过单因素试验和box-behnken设计得出了豆芽富硒处理的最佳条件。结果表明:最佳处理条件为热烫温度49℃、热烫时间为10min,有机富硒浓度为3.5×10-4mg/m L,浸泡时间为6 h,在此条件下富硒豆芽的实测发芽率达到最大值为97.96%,相应地硒含量为14.893μg/g。     

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.     

Heat and Mass Transfer During the Warm Water Blanching of Potatoes

A model of heat and mass transfer with simultaneous chemical reaction is proposed for analyzing the influence of operating variables on the reducing sugar content at the surface of blanched potatoes. This content is partially responsible for the color of the finished product. The involved parameters (potato thermal conductivity, heat transfer coefficient of the system and kinetic constants for overall reaction of reducing sugar generation) were evaluated in separate experiments. The apparent diffusion coefficient of reducing sugars in potatoes was the only parameter obtained from blanching experiments. Temperature and concentration profiles and effect of blanching temperature on surface reducing sugar content are analyzed using the developed model. The possible underestimation of the diffusion coefficient when simultaneous starch hydrolysis is not taken into account is also considered.     

两种干燥方式对马铃薯全粉营养品质和加工特性的影响

以新鲜"云薯304"切片后,采用漂烫冻干、不漂烫冻干、漂烫烘干和不漂烫烘干四种工艺条件制备干片,再经研磨粉碎制成半生的马铃薯全粉,研究不同工艺条件下全粉的营养品质和加工特性。结果表明:采用漂烫冻干工艺,马铃薯全粉的颜色与鲜马铃薯颜色最接近,制备的马铃薯全粉还原糖含量最低,为0.15%;蛋白质含量(9.01%)、总淀粉含量(69.12%)、直链淀粉含量(31.60%)与其他三种工艺处理无显著差异;从加工特性上看马铃薯全粉的持水力(5.27 g水/g全粉)和持油力(1.55 g油/g全粉)、透光率(83.43%)和各个温度下的膨胀度(50℃:9.32 g/g;60℃:11.98 g/g;70℃:13.11 g/g;80℃:15.35 g/g;90℃:12.50 g/g)均最高,都显著高于其他三种工艺(P<0.05);且凝胶流程最短,为10.96 mm。因此,可认为漂烫冻干是制备马铃薯全粉的最优工艺。     

Acrylamide in potato crisp—the effect of raw material and processing

Reducing sugars and free amino acids were analysed in slices from three potato cultivars before and after blanching (0-3 min). The potato crisps were deep fried at 185 °C for different times (3-8.5 min), and analysed for the concentration of acrylamide (AA) and moisture. Potato cultivar and the temperature during processing were important parameters for AA formation in potato crisps. The amount increased with an increase in the processing time. Blanching before deep-frying reduced the concentration of free asparagine and reducing sugar in the raw material. We found no effect of blanching as pretreatment on the concentration of AA in the potato crisps. Any relationship was not detected between the levels of asparagine in the different cultivars, before and after blanching, and the formation of AA in the crisp products. However, it was shown that the content of reducing sugars determined the level of AA after frying.     

Improvement of color and limpness of fried potatoes by in situ pectinesterase activation

 Low-temperature, long-time blanching (LT–LT blanching) was performed on potato strips prior to frying. Application of this treatment actived the pectinesterase enzyme in situ resulting in a decrease in the limpness of the fried potatoes; likewise, an improvement in color was obtained as the result of a decrease in reducing sugar content. LT–LT blanching at 65  °C for 45 min gave the greatest improvement in the color and limpness of french fries. Received: 1 December 1998     

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。     

Quality of French Fried Potatoes as Affected by Surface Freezing and Specific Gravity of Raw Potatoes

Russett Burbank potatoes were stored at 7.2°C for 9 months and processed into French fries. Some of the potato strips were subjected to partial freezing at – 20°C for 25 min before water blanching for surface leaching. The samples treated by partial (surface) freezing generally absorbed more oil during par-flying but less oil during finish-frying compared to the untreated samples (control). French fries made from partially frozen potato strips contained less reducing sugar and ascorbic acid and were lighter in color than the control. Darker fries were produced from potatoes of lower specific gravity because of the higher reducing sugar content. The surface freezing treatment was an effective means of decreasing oil absorption and improving color of French fries.     

酶法制备紫马铃薯汁及其乳酸菌发酵特性

本文以紫马铃薯为原料,通过酶法制备富含花色苷的紫马铃薯汁,分别使用干酪乳杆菌、保加利亚乳杆菌及植物乳杆菌三种乳酸菌对其进行发酵,研究烫漂时间、酶用量对紫马铃薯汁出汁率、花色苷、还原糖含量的影响及发酵过程中pH、花色苷、总酚含量、糖组分、有机酸、DPPH·清除能力等变化。结果表明:紫马铃薯经烫漂护色2.5 min时出汁率最高。烫漂时间对紫马铃薯汁的花色苷含量影响极为显著,烫漂2.5 min时花色苷含量比未经烫漂处理的提升了7.7倍。经高温α-淀粉酶(20 U/g)、糖化酶(200 U/g)酶解处理后的紫马铃薯汁出汁率为69.80%±3.85%,总酚含量1136.7±33.76 mg/L,花色苷含量为218.25±1.89 mg/L。紫马铃薯汁经乳酸菌发酵后pH逐渐下降,并产生大量的乳酸,产酸能力大小依次为保加利亚乳杆菌 > 植物乳杆菌 > 干酪乳杆菌,蔗糖、葡萄糖和果糖在发酵过程中均作为底物被乳酸菌消耗,发酵48 h后花色苷、总酚、DPPH·清除能力分别下降了11.33%~17.82%、6.22%~7.73%、24.23%~27.62%。抗氧化活性下降与花色苷和总酚含量的减少有关。     

马铃薯块茎干物质、淀粉及还原糖含量的检测及相关性分析

本文以来自全国13个省(14个地区)46个品种的马铃薯为实验材料,采用国家标准方法或国标方法稍有改动,检测马铃薯的干物质、还原糖和淀粉含量。再通过SPSS 20.0对不同样品中还原糖和淀粉含量差异的显著性进行了分析,并采用矩阵散点图、一元线性回归研究了干物质、还原糖和淀粉含量之间相关性。结果表明:马铃薯中干物质含量为15.43%~29.67%,还原糖含量为0.09%~1.84%,淀粉含量为9.11%~22.30%(均为湿基);大部分样品的还原糖含量差异都很显著(p0.05),淀粉含量差异也很显著(p0.05);通过矩阵散点图发现马铃薯中还原糖含量与干物质含量无相关性,与淀粉含量也无相关性;马铃薯中干物质含量和淀粉含量呈正相关,服从一元线性方程:y=9.626+0.708x,即马铃薯中干物质含量越高,淀粉含量也就越高。