甘薯品种干率与油炸薯片含油量和硬度间的相关性

选择20个干率18.72%～35.02%的甘薯品种,切成1.6～1.8 mm薄片,(135±10)℃常压油炸,测定薯片含油量和硬度.结果表明薯片含油量与干率成线性负相关,相关系数R=-0.827,薯片硬度与干率成非线性正相关,相关系数R=0.965,薯片硬度与含油量呈非线性负相关性,相关系数R=-0.890.显示油炸薯片含油量和硬度不可能同时达到最佳值.干率24%～26%的品种,薯片含油量在25%左右,硬度值650～700 g,具有较好的油炸品质,可以考虑作为油炸薯片专用品种选育的主要方向.     

Structure Oil-Absorption Relationships During Deep-Fat Frying

ABSTRACT Analysis of the oil-absorption process in deep-fat fried potato cylinders (frying temperatures of 155°C, 170°C, and 185°C) allowed to distinguish 3 oil fractions: structural oil (absorbed during frying), penetrated surface oil (suctioned during cooling), and surface oil. Results showed that a small amount of oil penetrates during frying because most of the oil was picked up at the end of the process, suggesting that oil uptake and water removal are not synchronous phenomena. After cooling, oil was located either on the surface of the chip or suctioned into the porous crust microstructure, with an inverse relationship between them for increasing frying times.     

马铃薯泥面条制作工艺优化及品质分析

为保留马铃薯的风味和营养成分,提高面条品质,加快马铃薯主食化进程,采用马铃薯泥和小麦面粉复配制作马铃薯泥面条。以感官评分为评价指标,结合单因素实验和正交试验,进而得到较优的马铃薯泥面条加工工艺。结果表明,在马铃薯泥占比50%的条件下,面条的较佳加工工艺参数为:面团醒发温度20 ℃、醒发时间30 min。复配改良剂最佳配方为:谷朊粉添加量3%、魔芋粉添加量1%、单甘酯添加量1%。该条件下制作的马铃薯泥面条品质较好,感官评分达90.1分。研究表明,在小麦面粉中加入马铃薯泥,所制备面条品质降低,但适当的添加改良剂可在一定程度上提升马铃薯泥面条品质。     

A different perspective to study the effect of freeze, air, and osmotic drying on oil absorption during potato frying

ABSTRACT:  The objective of this article is to assess the effect of different dehydration pretreatments on oil absorption and illustrate how the different ways results can be reported may even drive to opposite conclusions. To do so, potato cylinders were blanched in hot water and dried until a moisture content of 62% (w.b.) by either freeze-drying, air drying, and osmotic drying with a sucrose solution or osmotic drying with a NaCl solution. Control (blanched) and dried potatoes were deep-fat fried at 170 °C for time periods between 1 and 5 min. Water removal and total oil uptake were determined and 2 oil fractions were distinguished: superficial oil and penetrated oil. Compared to the control, freeze dried samples increased oil uptake in 15.4% (d.b.) whereas air-dried samples reduced it in 11.2% (d.b.). Similarly, osmotic dehydrated samples showed a high reduction in oil uptake compared to the control (up to 27%[d.b.] when using a sucrose solution). However, this high decrease in oil absorption was attributed to the increase in solids content occurring during the osmotic dehydration process rather than a reduction in the amount of oil taken up. In fact, when the amount of oil absorbed per cylinder was determined, it was verified that oil uptake of osmotically dehydrated samples was even higher than the control, as opposed to what has been previously reported in the literature. These results highlight the importance of selecting an adequate basis to carry out comparisons properly.     

高品质红薯渣在面条中应用的研究

采用单因素实验和正交实验相结合的方法,研究高品质红薯渣面条的加工工艺。结果显示,产品的最佳工艺为:纤维素酶处理红薯渣、红薯渣的添加量为11%、海藻酸钠的添加量为0.35%、食盐的添加量为0.25%,在此工艺条件下,产品的烹煮损失率为8.77%,断条率为0。     

膨化马铃薯片的生产工艺研究

本文以新鲜马铃薯和玉米淀粉的主要原料,从原料的配比,老化条件的测定等方面对一种即食马铃薯酥片的生产工艺进行了实验研究,通过实验研究初步确定了产品的生产工艺、主要工艺条件及配方。以本工艺生产的产品具有香酥脆的特点。该产品的开发与马铃薯资源的深加工利用提供了一条新途径。     

非晶颗粒态马铃薯淀粉改性研究

将非晶颗粒态淀粉和原淀粉在阴离子、阳离子、醋酸酯及羟丙基醚化剂条件下进行淀粉改性反应,取代度随醚化剂量的改变而改变,但由于整个颗粒处于非晶状态,导致非晶淀粉取代度和原淀粉相比有不同程度的提高,对羧甲基化,取代度平均提高9.15%,最高达10.72%,对阳离子化来说,取代度平均提高9.65%,最高达13.18%,对醋酸酯化,取代度平均提高47.49%,最高达64.82%,对羟丙基化,取代度平均提高22.78%,最高达27.48%.     

木糖醇紫薯海绵蛋糕的配方优化

研究了全蛋液、紫薯粉、木糖醇、护色剂、泡打粉、大豆油、蛋糕油添加量对木糖醇紫薯海绵蛋糕产品质量综合评分的影响,在单因素实验的基础上,通过Box-Behnken法设计实验,采用响应面分析法对产品配方进行优化。结果表明:产品最佳配方（烘焙百分比）为糕点粉100%、全蛋液157%、紫薯粉25%、木糖醇58%、白砂糖42%、护色剂0.8%（柠檬酸和抗坏血酸各0.4%）,无需添加泡打粉、植物油、蛋糕油,此条件下验证实验产品综合评分为92±0.5,与理论最优值92.39基本一致。      

马铃薯鲜薯酥脆饼干的配方优化

以马铃薯鲜薯为主要原料,采用二步焙烤工艺制备马铃薯酥脆饼干,研究马铃薯泥与低筋面粉比例、碳酸氢铵与小苏打比例、鸡蛋液与棕榈油比例等三个因素对饼干剪切力、色差和感官品质的影响。结果表明,马铃薯泥与低筋面粉比例为13:2、碳酸氢铵与小苏打比例为5:2、鸡蛋液与棕榈油比例为5:5时,马铃薯饼干的剪切力在2000～2500g、色泽适中、感官评分高于80分。在此基础上,通过三因素三水平响应面优化试验得到饼干的最优配方为:马铃薯泥55.00%、低筋面粉20.00%、碳酸氢铵0.50%、小苏打0.13%、鸡蛋液6.86%、棕榈油5.00%、糖霜6.82%、淡奶油5.69%。此配方下的马铃薯鲜薯酥脆饼干具有良好的马铃薯风味,口感酥脆,品质优良,感官评分为87.20,与响应面模型预测值符合。本研究可为马铃薯烘焙产品的发展提供理论依据。     

Gel-strength in Restructured Potato Products Affects Oil Uptake during Deep-fat frying

A controllable food system consisting of a restructured potato product was employed to study the effect of gel-strength on oil uptake. Water loss and oil uptake were affected markedly by gel-strength. Oil uptake decreased as gel-strength increased. The oil uptake ratio, U_R′ (weight ratio of the oil uptake to the water evaporated during frying) was utilized to assess the effectiveness of reducing oil absorption during frying. This criterion was useful for comparison of restructured potato products with different initial or final moisture contents.     

美国脱水马铃薯粉在月饼中的应用研究

马铃薯是世界上优质的粮食种类之一。主要是直接用于食用。而在美国有20％的马铃薯用于制备脱水的马铃薯产品。美国的脱水马铃薯制品是采用优质的品种、大规模的机械化生产、严格的科学管理所得的马铃薯为原材料，经过去皮、切片、清洗、蒸煮、研磨、干燥和粉碎等工艺生产各种各样的脱水马铃薯产品。该脱水产品由于具有增稠、膨胀和持水、粘合、增量、成壳、透明等特点；且具有优良的产品质量、保质期长、运输费用低等经济上的效益，越来越广泛地应用在休闲食品、烘焙、面制品、沙司、肉类加工、餐饮等行业上。本文就以美国马铃薯粉（flour）为原材料，研究在广式月饼上应用，旨在拓宽应用的品种范围。     

紫薯保健豆腐的工艺研究

以黄豆和紫薯为主要原料,通过传统豆腐工艺加工制作新型豆腐.通过单因素与多因素正交试验,确定紫薯豆腐的最佳配方工艺条件.结果表明:温度对产品感官品质的影响最大,其次是豆浆和紫薯汁比例、石膏量、黄豆和紫薯水的添加量;最后确定了最佳的工艺配方:黄豆500 g,紫薯250 g,分别加入水1000mL制备豆浆汁与紫薯汁,豆浆与紫薯汁比例为6:1,石膏量为3.5 g,温度为100℃.产品感官性状良好,不仅含有独特的紫薯营养功能,还为开发新品种豆腐提供了理论参考.     

Post-Frying Oil Drainage from Potato Chips and French Fries: A Comparative Study of Atmospheric and Vacuum Drainage

This paper represents a study of the transient changes occurring in temperature, and moisture and oil contents during the so called “post-frying drainage”—which is the duration for which a product is held in the head space of the fryer after it is removed from the oil. Since most of the oil adhering to the product penetrates into the structure during this period, this paper examines the effects of applying vacuum during drainage (1.33 kPa) to maintain the product temperature consistently above the water saturation temperature corresponding to the prevailing pressure (11 °C), which potentially eliminates water condensation and prevents the occluded surface oil from penetrating into the product structure. Draining under vacuum significantly lowers the oil content of potato chips by 38% compared to atmospheric drainage. This phenomenon can be further confirmed by confocal laser scanning microscopy (CLSM) images, which show that the boundary between the core and the crust regions is clearly visible in the case of vacuum drainage, whereas in the case of atmospheric drainage, the oil is distributed throughout the structure. Unfortunately, the same approach did not reduce the oil content of French fries—the oil content of vacuum-drained product was found similar to the product obtained by draining under atmospheric pressure. This is because the reduction in oil content only occurs when there is net moisture evaporation from the product and the evaporation rate is sufficient to force out the oil from the product; this was clearly not the case with French fries. The CLSM images show that the oil distribution in the products drained under atmospheric pressure and vacuum was similar.     

Reproducible Texture Analysis of Potato Chips

An Instron punch test with three point support of a potato chip was developed, and factors affecting the results were evaluated. Individual potato chips were fried in palm oil in a forced circulation glass container, and their moisture content and texture were determined. Sample handling parameters contributing most to variability of moisture and texture were the cutting device, and position of the sample within the tuber. For oil temperatures 140 and 180°C, and two potato specific gravities, moisture and texture changes were studied during frying. Maximum force of break was in the 2–4% moisture region. Individual chips showed highly variable room temperature adsorption/desorption.     

Towards potato protein utilisation: insights into separation,functionality and bioactivity of patatin

Potato fruit juice (PFJ) is a dilute industrial by-product of potato starch industry containing potato protein that is abundant in patatin, a major storage protein. From an economic standpoint, conversion of potato protein into a high value-added food ingredient has received considerable attention. In this review, the structural and physicochemical characteristics of patatin are introduced. The separation and purification methods of patatin are compared and summarised. The functional properties of patatin as food ingredients are comprehensively reviewed. The beneficial effects of patatin on health and food application are emphatically presented. In addition, the current challenges for development of patatin as a functional food ingredient are also discussed. This review offers a theoretical basis for further application of patain in the food industry.     

The possibility of lowering oil content of potato chips by combining atmospheric frying with postfrying vacuum application

Four protocols involving the application of low pressures, either toward the end of frying or after frying, were investigated with the aim of lowering the oil content of potato chips. Protocol 1 involving frying at atmospheric pressure followed by a 3 min draining time constituted the control. Protocol 2 involved lowering of pressure to 13.33 kPa, 40 s before the end of frying, followed by draining for 3 min at the same pressure. Protocol 3 was the same as protocol 2, except that the pressure was lowered 3 s before the end of frying. Protocol 4 involved lowering the pressure to 13.33 kPa after the product was lifted from the oil and holding it at this value over the draining time of 3 min. Protocol 4 gave a product having the lowest oil content (37.12 g oil/100 g defatted dry matter), while protocol 2 gave the product with highest oil content (71.10 g oil/100 g defatted dry matter), followed by those obtained using protocols 1 and 3 (68.48 g oil/100 g defatted dry matter and 52.50 g oil/100 g defatted dry matter, respectively). Protocol 4 was further evaluated to study the effects of draining times and vacuum applied, and compared with the control. It was noted that over the modest range of pressures investigated, there was no significant effect of the vacuum applied on the oil content of the product. This study demonstrates that the oil content of potato chips can be lowered significantly by combining atmospheric frying with draining under vacuum.     

果胶酶酶解预处理对马铃薯泥干燥特性及生粉加工特性的影响

为提高马铃薯生粉的干燥效率,考察了果胶酶酶解预处理不同时间(60~180min)对马铃薯泥热风干燥特性及制备的酶解马铃薯生粉(pectinase-treated native potato flour,PNPF)理化性质和加工特性的影响。结果表明:果胶酶酶解处理降低了马铃薯泥果胶含量和初始含水量,提高了薯泥干燥速率,干燥时间缩短了6.32%~7.81%;果胶酶酶解预处理制备的生粉中果胶、灰分、蛋白质含量显著降低,直链淀粉、支链淀粉和总淀粉含量显著提高,淀粉相对结晶度和生粉碘蓝值降低;同时酶解预处理制备的生粉与未处理生粉相比,具有较高的溶解度和溶胀度,持油性显著降低,持水性提高了40.49%~49.58%,冻融析水率降低了26.23%~62.11%,其中酶解预处理180min制备的生粉(PNPF180)冻融稳定性提升幅度最大;糊化特性分析结果表明,PNPF峰值温度降低,峰值时间缩短,崩解值上升,最终黏度和回生值下降。果胶酶酶解预处理可改善马铃薯泥热风干燥特性,缩短干燥时间,同时显著改善马铃薯生粉基本理化性质及加工特性。     

甘薯中去氢表雄酮的提纯工艺研究

利用超声波辅助法,对甘薯中的活性成分去氢表雄酮(DHEA)的提纯工艺进行了研究。结果表明,超声波提取DHEA的最佳条件为:60℃水浴下预发酵24h,预发酵液加入鲜甘薯质量2%的浓硫酸,90℃水浴下酸水解24h,水解液经20%的NaOH溶液中和,抽滤、离心去除水分,超声波辅助下石油醚浸提40min,过柱净化,HPLC定性、定量测定。该方法能有效地纯化分析甘薯功能因子DHEA,具有产物纯度高、方法简便、收率高等优点。     

氧化和湿热处理对马铃薯淀粉功能特性的影响

对原料淀粉进行改性处理可以改善其功能特性,使其更好的在食品中应用。利用氧化和湿热处理的方法改性马铃薯淀粉,并通过对其微观结构、膨润能力和溶解度、糊化特性和凝胶强度的测定,对改性马铃薯淀粉样品的功能特性进行了评价。偏光显微镜和扫描电镜结果显示,氧化作用主要发生在马铃薯淀粉颗粒的非结晶区域。氧化和湿热处理均使马铃薯淀粉的糊化温度升高、粘度降低,且两种处理方法均提高了马铃薯淀粉的热稳定性。凝胶强度测定结果显示,0.2%氧化剂浓度处理的马铃薯淀粉凝胶强度显著提高(p<0.05)。     

Combination of Moderate Vacuum Frying with High Vacuum Drainage—Relationship Between Process Conditions and Oil Uptake

This paper explores the possibility of combining moderate vacuum frying followed by post-frying high vacuum application during the oil drainage stage, with the aim to reduce oil content in potato chips. Potato slices were initially vacuum fried under two operating conditions (140 °C, 20 kPa and 162 °C, 50.67 kPa) until the moisture content reached 10 and 15 % (wet basis), prior to holding the samples in the head space under high vacuum level (1.33 kPa). This two-stage process was found to lower significantly the amount of oil taken up by potato chips by an amount as high as 48 %, compared to drainage at the same pressure as the frying pressure. Reducing the pressure value to 1.33 kPa reduced the water saturation temperature (11 °C), causing the product to continuously lose moisture during the course of drainage. Continuous release of water vapour prevented the occluded surface oil from penetrating into the product structure and released it from the surface of the product. When frying and drainage occurred at the same pressure, the temperature of the product fell below the water saturation temperature soon after it was lifted out of the oil, which resulted in the oil getting sucked into the product. Thus, lowering the pressure after frying to a value well below the frying pressure is a promising method to lower oil uptake by the product.