EFFECTS OF GAMMA RADIATION ON NUTRITIVE AND SENSORY QUALITIES OF SWEET POTATO STORAGE ROOTS

Jewel and Georgia Jet sweet potato storage roots were treated with gamma radiation doses of 0.1, 0.5, 0.8, 1.5 and 2.0 kGy and compared to the untreated control. Analyses showed that ascorbic acid and starch decreased at 1.5 and 2.0 kGy. Total carotenoids in both cultivars were unaffected by radiation treatment. Gamma radiation caused softening of Jewel and Georgia Jet sweet potato roots and the texture score decreased at 1.5 and 2.0 kGy. Color was not affected by radiation in either cultivar and differences in L, a and b values were not observed. The total sugar content of the Jewel sweet potato was higher at 0.8 kGy than at other doses but for Georgia Jet it tended to increase as the radiation dose increased. The sensory evaluation test indicated that acceptability of baked sweet potatoes was severly affected by gamma radiation at doses of 0.5 kGy and above.     

Effects of heat treatment on the quality and storage life of sweet potato

The effects of heat treatment (50 °C) on the sprouting inhibition and spoilage of sweet potato roots (curing temperature: 29 °C) stored in wrapper‐type cold store (WTCS) were determined during year‐long storage. The quality attributes of sweet potato were also evaluated. The results indicated that hot water treatment significantly inhibited sprouting and decay of sweet potato for the storage period. It also showed that there were no significant differences in starch properties in terms of pasting properties, enthalpy and temperatures onset (T_O), peak (T_P) and endset (T_E) of gelatinisation of sweet potato starches among all the treatments, especially between heat‐treated and without‐heat‐treated samples. Also, hot water treatment did not have any significant impact on the internal components' quality of the roots: less than 4% of the year‐long stored roots were discarded due to spoilage. Heat treatment supplied a lethal dose of heat to surface pathogens and cauterised the eyes without damaging the nutritional and processing qualities of sweet potato. The success of storage experiments in prolonging sweet potato stored in WTCS by heat treatment was obtained from the effective control of weight loss, sprouting and decay without influence on quality characteristics. This new technique opens a new avenue to prolonging the storage life of sweet potato with good quality and minimal loss. Copyright © 2006 Society of Chemical Industry     

Method of Preparation and Sensory Evaluation of Sweet Potato Patties

Sweet potato patties were prepared from Jewel and Centennial cultivars which were freshly harvested or cured and stored. The patties were prepared with additions of sugar, starch and other minor ingredients to peeled, cooked sweet potatoes. The resulting mixture was comminuted, heated by steam injection; vacuum cooled and molded into patties. The patties were cooked in peanut oil and evaluated by a sensory panel. The evaluations indicated that patties of acceptable quality could be prepared from either freshly harvested sweet potatoes or from roots that had been cured and stored for up to 6 months.     

基于模糊数学综合感官评价的甘薯淀粉面包的工艺优化

为了提高面包营养价值,改善滋味,降低面包老化速度,延长保质期,将甘薯淀粉添加到面包当中,采用单因素和正交实验,考察配方(甘薯淀粉、黄油、干酵母的添加量)及加工工艺(一次醒发时间、醒发温度和烘焙时间)对面包感官性状和质构的影响。基于模糊数学的评价方法评价甘薯淀粉面包的品质,对甘薯淀粉面包的形状、色泽、松软度、香味、滋味进行感官性质的分析。结果表明:最佳配方为混合粉(小麦粉+甘薯淀粉)150 g,甘薯淀粉的含量为15 g、黄油15 g、干酵母5.5 g;最优加工工艺为一次醒发时间为60 min、醒发温度为25 ℃、烘焙时间为9 min;最优条件下其硬度为27.95 N,弹性为15.18 mm,咀嚼性为228.30 mJ,胶粘性为15.05 N。按此条件制作的甘薯淀粉面包色泽金黄,外形饱满,柔软适口具有甘薯淀粉面包特有的风味,为甘薯淀粉面包工业化生产提供理论指导,同时丰富面包种类,拓宽甘薯淀粉用途。     

淀粉种类对鲜湿面色泽及品质影响的研究

将小麦淀粉、马铃薯淀粉、红薯淀粉、豌豆淀粉及玉米淀粉添加到面粉中制作面条,从鲜湿面色泽、质构及感官三方面,研究淀粉种类对面条的影响规律。结果表明：不同淀粉均能改善鲜湿面的色泽,玉米淀粉效果最佳;质构影响方面,除红薯淀粉外,其他淀粉的添加使得面条的硬度下降,黏附性、回复性、粘聚性升高,坚实度和拉断力随添加量的增加呈先升后降的趋势;感官评价方面,玉米淀粉、小麦淀粉、马铃薯淀粉显著增大了面条的色泽得分,豌豆淀粉和红薯淀粉显著影响了韧性和粘性得分。     

不同淀粉对饼干口感润滑质地的影响

为了掌握淀粉对饼干口感润滑质地的影响规律,本研究采用质构仪、流变仪、模拟口腔摩擦、及感官差异检验等手段,通过添加六种淀粉考察其对饼干质地、口腔润滑及感官属性的影响。结果显示,添加淀粉后,不同淀粉饼干的明度(L^*),黄蓝色(b*),硬度、酥脆性、弹性、咀嚼性和回复性,均存在显著性差异(P＜0.05)。动态流变学结果显示绿豆、小麦、玉米淀粉的添加可以一定程度上增强了面团中淀粉分子之间发生交联,形成稳定的凝胶网络结构。口腔摩擦学结果显示,添加淀粉可以改善饼干的润滑特性,绿豆、红薯、豌豆、马铃薯淀粉对饼干润滑度的提升具有显著性(P＜0.05)。不同淀粉饼干的润滑性结果为：马铃薯淀粉饼干＞豌豆淀粉、红薯淀粉饼干＞绿豆淀粉饼干,其结果与感官差异分析结果一致。淀粉作为润滑质地调节剂,可以提高饼干产品口腔润滑性能,同时该研究也为口腔摩擦学用于主观感官分析的提供参考。     

紫薯全粉面条的制备及其品质影响研究

为了研究高占比紫薯全粉面条的最佳制作条件,在单因素实验的基础上,选择紫薯全粉添加量、谷朊粉添加量、食盐添加量为自变量,紫薯全粉面条的熟断条率、感官评分为评价指标,利用Box-Behnken中心组合原理设计3因素3水平实验,研究各自变量交互作用及其对紫薯全粉面条品质的影响。实验结果表明,高占比紫薯全粉面条的最佳工艺条件为:紫薯全粉与小麦粉的比例为44:56、谷朊粉添加量为7.0%、食盐添加量1.6%。在此条件下紫薯全粉面条的熟断条率为0.42%,感官评分为84.08。经中试验证,此工艺可规模化生产。     

不同品种甘薯与小麦配粉对粉质及馒头品质的影响

研究5个高胡萝卜素甘薯品种(秦薯8、普薯32、南薯010、徐渝薯34、泰中14)的甘薯全粉不同添加量对配粉面团特性及配粉馒头品质的影响。结果表明,随着甘薯全粉质量分数的增加,5种甘薯配粉面团的形成时间、稳定时间及粉质指数均逐渐下降,弱化度均升高。添加甘薯全粉后,5种甘薯全粉制作的馒头亮度均降低、色泽均变暗,馒头感官评价得分随甘薯全粉质量分数的增加逐渐降低。同一质量分数下,5种甘薯配粉的面团特性及配粉馒头品质存在品种差异,南薯010配粉馒头感官评价得分最高。制作配粉馒头时,南薯010、普薯32、秦薯8号甘薯粉的添加量可以添加到15%,徐渝薯34和泰中14甘薯粉的添加量不能高于10%。     

紫甘薯全粉流变学特性的研究

以紫甘薯全粉为原料,研究其在不同加工条件如剪切速度、加热、pH值、盐浓度、蔗糖浓度等影响下的流变学特性.结果表明:紫甘薯全粉溶液的黏度随加热时间的延长和溶液浓度的增加而增大;随温度的升高与剪切速率的增加而减小;pH值、盐浓度等对其黏度也有很大影响.     

红薯浊汁饮料生产工艺的研究

研究红薯浊汁饮料的生产工艺,以红心红薯为原料制作混浊汁饮料,采用色差分析和感官评价分析原料预处理方式、主要加工工艺、VC及预热方式对浊汁饮料色泽的影响;采用正交试验和感官评价确定了红薯浊汁饮料稳定剂和配方的最优水平。结果表明,分别采用预处理方式4、预热方式1和0.015%VC制作出的红薯浊汁饮料具有良好的色泽,浊汁浆液经过胶体磨后色泽变暗,之后色泽逐渐变亮;稳定剂用量为0.04%黄原胶+0.2%分子蒸馏单甘酯+0.08%海藻酸钠+0.08%CMC-Na时,浊汁饮料具有很好的组织状态和口感;配方为0.008%红薯香精,0.3%食盐,3%蔗糖,0.02%柠檬酸时,浊汁饮料具有很好的香气和滋味。     

薯类淀粉种类对黄冈鱼面品质的影响

为研究薯类淀粉种类对黄冈鱼面品质的影响,测定了红薯淀粉（SPS1、SPS2、SPS3）、马铃薯淀粉（PS）、木薯淀粉（CS）的理化性质、糊化特性、粒径、溶解度及膨胀度,分析了这些性质与鱼面品质之间的关系。结果表明:不同薯类淀粉的理化性质、糊化特性、粒径、溶解度及膨胀度均存在显著差异（P<0.05）,红薯淀粉的糊化温度（78.37~79.97 ℃）最高,马铃薯淀粉的粒径、溶解度及膨胀度最大。不同薯类淀粉加工鱼面的质构特性、煮制品质、感官评价及色泽均存在显著差异（P<0.05）。红薯淀粉加工鱼面的硬度显著大于马铃薯淀粉、木薯淀粉（P<0.05）,红薯淀粉中SPS3加工鱼面的硬度最大。马铃薯淀粉加工鱼面的拉伸强度、吸水率及煮制损失率最大。SPS2加工鱼面的感官评价最高,CS加工鱼面的最低。不同薯类淀粉加工鱼面干燥前的色泽在亮度、红绿值和白度上差异显著（P<0.05）,但对鱼面干燥后的色泽影响并不明显。根据综合评分的大小对鱼面的品质进行排序为:SPS2>SPS1>SPS3>PS>CS。淀粉的糊化特性、直链淀粉含量、粒径与鱼面的品质具有显著的相关性（P<0.05）。     

基于因子分析和Box-Behnken响应面提高冷冻淮山紫薯球品质

本研究基于TPA质构测定和感官评定,单因素探讨冷冻淮山紫薯球外表皮的生产工艺配方,并通过因子分析与响应面法优化其关键工艺配比,以提高冷冻淮山紫薯球的冻藏品质。结果显示,冷冻淮山紫薯球外表皮的主要工艺配比的优化组合为:紫薯添加量52%,小麦淀粉量5%,泡打粉添加量0.16%;结合单因素实验结果白糖添加量为10%,植物油使用量为4%。以上述工艺配方进行验证试验,加工出的冷冻淮山紫薯球产品品质优良,其规范化综合因子得分为0.778,感官评分49,平均硬度866.36 g、弹性0.66、咀嚼性144.83 g。     

甘薯淀粉磷酸酯糊化特性研究

以甘薯淀粉为原料,与三偏磷酸钠反应,制得甘薯淀粉磷酸酯;并采用偏光显微镜、分光光度计、旋转粘度计等现代分析仪器,对所生成不同取代度的淀粉磷酸酯糊化特性进行了较为详细的研究。结果表明:甘薯淀粉磷酸酯糊化温度升高,其冷热粘度稳定性、冻融稳定性、耐盐能力较原淀粉有所提高,但透明度、凝沉性与原淀粉相比无明显优势;取代度的变化对这些性能有显著的影响。     

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.     

Effect of heat treatment on quality, thermal and pasting properties of sweet potato starch during yearlong storage

BACKGROUND: Proper postharvest handling and storage of sweet potato is an important link in the chain from producer to consumer or manufacturing industry. Heat treatments have been used as a non‐chemical means to modify the postharvest quality and reduce pathogen levels and disease development of a wide variety of horticultural products. The objective of this study was to investigate the effects of hot water treatment (HWT) on the quality, gelatinisation enthalpy and pasting properties of sweet potato starch during long‐term storage. The weight loss, sprouting, spoilage and sugar content of sweet potato were also determined. RESULTS: HWT significantly inhibited the sprouting and decay of sweet potato during the storage period. There were no significant differences (P < 0.05) in the pasting properties and onset (T_O), peak (T_P) and endset (T_E) temperatures of gelatinisation of sweet potato starch among all treatments, especially between heat‐treated and non‐heat‐treated samples. HWT also had no significant impact on the quality of the internal components of the roots. Less than 4% of the yearlong‐stored roots were discarded owing to spoilage. HWT supplied a lethal dose of heat to surface pathogens and black spot without damaging the nutritional and processing qualities of sweet potato. CONCLUSION: HWT was an effective method to reduce root sprouting and deterioration without significant impact on the quality of the internal components of sweet potato. This novel technique will open a new avenue to extend the storage life of sweet potato with good quality and minimal waste. Copyright © 2011 Society of Chemical Industry     

甘薯泥对面团流变特性及馒头品质的影响

利用粉质仪、拉伸仪、质构仪和色差计研究甘薯泥对面团流变特性及馒头品质的影响。结果表明,随着甘薯泥添加量的增加,面团吸水率、面团形成时间、稳定时间及粉质指数逐渐降低,弱化度增加;面团的拉伸曲线面积、拉伸阻力、拉伸比增大,延伸度降低,且醒发时间越长,其变化趋势越大。与白面馒头相比,甘薯泥的加入使馒头的比容、感官评分降低,胶黏性增大,馒头的亮度下降,色泽变暗,馒头具有浓郁的甘薯香味。     

PRODUCTION AND PROXIMATE COMPOSITION OF A HYDROPONIC SWEET POTATO FLOUR DURING EXTENDED STORAGE

In developing countries, where limited transport infrastructure exists, processing the sweet potato (Ipomoea batatas (L.) Lam) into flour provides an alternative to the difficulties associated with storage and transport of the raw roots. The objectives of this study were: (1) to process hydroponic sweet potato roots into flour; and (2) to evaluate the nutritive composition and the color of the processed hydroponic sweet potato flour during storage. The TU–82–155 hydroponic sweet potatoes were processed into flour and stored for five months at room and refrigerated temperatures. The sweet potato flour contained 3.0%, 4.5%, 1.0%, 1.0%, 90.6% moisture, ash, fat, protein, and carbohydrate, respectively, with no significant changes during storage. The *L values for the sweet potato flour increased as storage time increased, but the *a and *b values decreased. Hydroponic sweet potato roots could be processed into flour and stored at 4C or 21C to 25C for five months without deterioration in quality.     

甘薯块根膨大过程中质构特性和淀粉直/支比的研究

甘薯块根膨大过程中质构特性和淀粉组分的变化对甘薯的品质和用途有着重要影响。本研究选取3种甘薯类型和4个时期,通过质地多面分析法(TPA)和双波长碘比色法,分析其质构特性和淀粉直链淀粉和支链淀粉比值(淀粉直/支比)随块根膨大的变化规律。结果表明,甘薯淀粉直/支比在扦插后80天开始下降,至扦插后110天达到谷值,之后小幅回升;整体上,甘薯扦插后的天数与淀粉直/支比、内聚性和弹性呈显著负相关(r =-0.390, r= -0.367, P <0.05;r= -0.634, P <0.01);与硬度呈显著正相关(r= 0.590, P <0.01)。淀粉直/支比与块根的内聚性、弹性和咀嚼性呈显著正相关(r =0.368, P <0.05; r= 0.463, r= 0.642, P <0.01);综合分析发现,扦插后80~110天（块根膨大高峰期至膨大后期）收获的甘薯适合水果型(生食型)甘薯的开发。     

挤压重组紫薯米工艺优化 及其抗氧化活性研究

以籼米为主要原料,并添加紫薯粉制备挤压重组紫薯米。主要选取紫薯粉添加量、挤压温度、物料水分含量3个试验因素,以花色苷含量、质构品质和感官评分作为综合指标,进行单因素及响应面优化试验。获得最佳工艺参数为:紫薯粉添加量为10%、挤压温度为80 ℃、水分含量为26%。该工艺条件下获得的挤压重组紫薯米呈现亮紫色,且综合得分最高为71.08±0.79分。体外抗氧化活性试验结果表明,挤压重组紫薯米对DPPH和ABTS的清除率分别为86.71%、87.55%,显示其良好的抗氧化特性。     

甘薯生全粉对面团特性及馒头品质的影响

该实验以甘薯-小麦混粉为原料,探究甘薯生全粉添加量对混粉特性、混粉面团特性以及甘薯生全粉馒头综合品质影响的研究。结果表明,甘薯生全粉中主要成分为淀粉,含量约为64.60%;随着混粉中甘薯生全粉含量的增加,混粉的持水性从1.16 g/g增加至1.70 g/g,持油性呈先增大后减小的变化趋势。随着甘薯生全粉添加量增大,混粉粉质特性变差,面团加工品质降低;随着混粉面团中甘薯生全粉含量的增加,面团的TO、TP、TC、硬度逐渐增大,弹性逐渐减小;甘薯生全粉添加量在20%以内时,甘薯馒头感官评分大于70,馒头的质构、比容和白度仍在可接受范围内。综上所述,当甘薯生全粉添加量小于10%时,混合面团的加工特性和馒头品质较优;当甘薯生全粉添加量小于20wt%时,混合面团的加工特性和馒头品质在可接受范围内。