不同储藏时间及温度对新鲜甘薯淀粉特性的影响

摘 要 采用水提法提取甘薯淀粉,研究了不同贮藏温度下（4、13、20℃）甘薯中淀粉含量、直链淀粉含量、淀粉膨胀度和溶解度、淀粉酶活性以及甘薯淀粉的热力学特性的变化,并进一步采用RT-PCR技术分析了淀粉磷酸化相关的葡聚糖-水合双激酶（Glucan,Water Dikinase,GWD）家族基因的表达情况。结果表明,4℃下贮藏的甘薯淀粉含量下降最快,这可能与4℃下,总淀粉酶活性升高和GWD 1-1基因表达上调有关。低温贮藏条件下（4、13 ℃）,甘薯直链淀粉含量有所增加,会加快甘薯加工产品的回生过程;淀粉溶解度和膨胀势下降,淀粉溶解度的下降同样有利于淀粉的回生;低温贮藏下β-淀粉酶在淀粉降解过程中起主导作用。此外,13℃低温贮藏能加快热焓值的下降,使淀粉糊化过程加快。本研究结果将为甘薯淀粉食品加工提供参考。     

不同老化工艺对甘薯回生抗性淀粉制备率的影响

以甘薯淀粉为原材料,甘薯淀粉回生率为指标,研究冷藏、常温、真空减压和干燥箱干燥等不同老化工艺对甘薯回生抗性淀粉生成率的影响.结果表明,4℃冷藏条件下,老化72 h后甘薯淀粉回生率达到最高,由9.2％提高到13.4％;常温下,大气温度为16～19℃,大气湿度为68％～80％时,常温老化96 h后甘薯淀粉回生率达到最高,由9.9％提高到15.4％;真空干燥箱温度为30℃,真空度为0.08 MPa时98 h甘薯淀粉回生率最大为20.96％;干燥箱温度为30℃时,老化90 h甘薯淀粉回生率最大为15.38％;真空老化有利于甘薯淀粉回生.     

甘薯抗性淀粉研究进展

甘薯是重要的淀粉作物,其块根中抗性淀粉（resistant starch,RS）含量较高,具备良好的产品开发潜力。要进一步促进甘薯RS的应用和推广,不仅需要筛选或培育出RS含量更高的甘薯品种,还需要加大开发甘薯深加工淀粉产品。除调控淀粉合成相关基因的表达外,生产实际中还可通过调整栽培措施等方式提高甘薯RS的含量。通过化学修饰法、物理法和酶解法等方法可制备甘薯RS产品,也能提高产品中RS的含量。本文系统综述了近年来甘薯淀粉的保健效果、RS含量的测定方法、影响甘薯淀粉中RS含量的因素、RS的制备方法及其特性等方面的进展,为未来甘薯中RS的制备、产量提高、产品开发和推广提供理论依据和技术指导。     

甘薯的不同收获日期对其淀粉产量的影响

对河北省甘薯集中产区秦皇岛市卢龙县主要甘薯品种进行了2年的生长期采样动态研究表明,甘薯的收获时间不同,其淀粉的产出率和淀粉公顷产量也不同。如在最佳的收获时间段内,加工甘薯制取淀粉,就能提高甘薯淀粉的公顷产量,增加农民的收入和提高甘薯的社会经济效益。     

甘薯微孔淀粉制备技术及吸附性能研究

用淀粉糖化酶、α-淀粉酶、普鲁兰酶水解甘薯淀粉制备一种具有吸附功能微孔淀粉载体。研究表明,淀粉糖化酶对生甘薯淀粉作用力最强;淀粉糖化酶水解制备甘薯微孔淀粉最佳工艺条件是:温度45℃,pH值4,酶用量为1％,时间24小时,水解率为51.52％。微孔淀粉对色素、水溶性维生素、油脂的吸附能力远远高于原淀粉。通过交联反应能明显提高微孔淀粉的结构性能和吸附性能。     

甘薯的不同收获日期对其淀粉产量的影响

对河北省甘薯集中产区秦皇岛市卢龙县主要甘薯品种进行了 2年的生长期采样动态研究表明 ,甘薯的收获时间不同 ,其淀粉的产出率和淀粉公顷产量也不同。如在最佳的收获时间段内 ,加工甘薯制取淀粉 ,就能提高甘薯淀粉的公顷产量 ,增加农民的收入和提高甘薯的社会经济效益     

甘薯淀粉糊透明度及凝沉性初探

为了解甘薯淀粉糊的性质,采用分析方法对甘薯淀粉糊的透明度和凝沉性进行探索性研究,初步考察蔗糖、氯化钠、柠檬酸和羧甲基纤维素钠(CMC-Na)等对甘薯淀粉透明度和凝沉性的影响。结果表明,它们对甘薯淀粉透明度和凝沉性的影响不同,其中蔗糖、柠檬酸能提高甘薯淀粉糊的透明度,改善其凝沉性;氯化钠降低甘薯淀粉的透明度,加速其初期凝沉速度;CMC-Na对甘薯淀粉糊的透明度影响不大,但明显改善其凝沉性。     

甘薯淀粉的脱色研究

研究了甘薯淀粉氧化脱色的工艺条件，对影响甘薯淀粉氧化脱色的因素如氧化剂添加量、反应时间、反应温度和ｐＨ值进行了实验。结果表明，淀粉的白度与氧化剂Ｈ２Ｏ２添加量、反应温度、反应时间和ｐＨ值呈正相关性；并且淀粉的白度与Ｈ２Ｏ２添加量、反应温度呈指数关系，与反应时间和ｐＨ值呈线性关系；最佳脱色条件为３０％Ｈ２Ｏ２添加量６％（Ｗ／Ｗ）、反应温度４０℃、ｐＨ１１以及反应时间４ｈ。     

添加甘薯淀粉改革改善面条食用品质的研究

在小麦面粉中添加甘薯淀粉制做面条可显著改善面条口感,也是甘薯的一种重要食用途径。在添加甘薯淀粉的同时,还应添加藻酸钠,复合碱等面粉改良剂,来改善面团的加工和烹煮 特必傅明：甘薯淀粉、藻酸钠、复合三在面粉中的较适添加量分别为：１０％、０．２５％和０．１５％。     

常用淀粉对甘薯食品膨化质量的协同作用研究

纯甘薯制品膨化质量差，适量添加淀粉可显著提高膨化度、改善产品质构。本文以常用的高温膨化方式，考察了马铃薯、木薯、甘薯及玉米淀粉对甘薯制品膨化度和感官质量的协同作用。结果表明，以鲜甘薯质量为基准计的最佳工艺配方为：马铃薯淀粉20％、木薯淀粉5％、玉米淀粉10％。淀粉对甘薯膨化食品的影响显著性顺序为，马铃薯淀粉＞木薯淀粉＞玉米淀粉。其中马铃薯淀粉的影响极显著，而木薯、玉米淀粉的影响相对不显著。     

淀粉挤压法焦糖色素生产工艺研究

在以蔗糖为原料采用挤压法生产焦糖色素的基础上,采用正交实验的方法,对以淀粉为原料挤压法生产焦糖色素的工艺进行研究,重点考察了焦糖色素色率、水溶性等指标,确定挤压法焦糖色素的生产条件。     

The effect of shape,blanching methods and flour on characteristics of restructured sweetpotato stick

The blanching methods and controlling dry matter content used in the preparation of mashed sweetpotato (SP) for producing restructured sweetpotato stick (RSS) were studied. The two shapes of trimmed tuber were sliced and diced. Blanching was conducted by (i) boiling for 2 min in water at 100 °C and (ii) blanching in water at 100 °C containing 1% (w/v) sodium tripolyphosphate (STP) for 2 min. Controlling the dry matter content of dough was conducted by adding SP flour (0%, 5%, 10%, 15% and 20%). Chemical and physical characteristics were determined on the final product. The results from this study showed that blanching in 1% STP for 2 min improves colour and ash content of fried stick. Mixing of 5% SP flour with mashed SP produces suitable dough for further processing. RSS can be produced by a combination of blanching in 1% STP and mixing with 5% SP flour produce an intermediate hardness, high lightness and low redness colouration of RSS.     

鲜湿马铃薯粉条中明矾替代物的筛选研究

为筛选鲜湿粉条生产中适宜的明矾替代物,本研究以马铃薯淀粉为主要原料,采用挤压工艺加工鲜湿粉条,研究了8种添加剂对马铃薯淀粉凝胶特性、凝沉性和膨胀度的影响,并与钾明矾做对比,进而选择较优添加剂用以替代明矾,通过单因素与正交实验考察明矾替代物对粉条断条率和浑汤透光率的影响。结果表明：琼脂、卡拉胶和海藻酸钠可作为传统鲜湿马铃薯粉条加工中的明矾替代物,且当琼脂添加量为0.6%,卡拉胶添加量为0.4%,海藻酸钠添加量为0.8%时,生产所得粉条断条率为0%,浑汤透光率为93.20%,且感官评分与质构特性均接近于添加0.527%钾明矾的粉条。本研究结果为无明矾鲜湿马铃薯粉条的生产加工提供新的数据支撑。     

甘薯中淀粉测定方法的比较与优化

淀粉含量的测定方法多种多样,但是关于甘薯淀粉的测定方法,目前尚无统一标准。本研究通过对甘薯干基获得方式,淀粉水解方式以及还原糖测定方式三个主要因素对甘薯淀粉含量测定结果的影响进行探究。实验发现,冷冻干燥样品测定的淀粉质量分数比高温干燥样品显著高出38.43%,酸水解方式比酶水解显著高出6.51%。还原糖测定方法中,DNS1和DNS2测定方法分别比斐林试剂滴定法显著高出29.67%和9.47%,DNS1比DNS2测定方法显著高出20.04%。不同水解-还原糖测定方法纯淀粉回收率和加标淀粉回收率均处于95%~105%之间,变异系数均小于2%,准确度和精确度符合质控规范。综合分析表明,冷冻干燥酶水解DNS1法测定甘薯淀粉含量具有最高的准确性和精确性,冷冻干燥酸水解DNS2法则具有最佳的实用性和方便性。     

小麦淀粉与谷朊粉生产

指出了小麦淀粉与谷朊粉生产的重要性；简要叙述了小麦淀粉与谷朊粉生产的历史、典型工艺及最新动态。着重介绍了韦斯伐里亚公司的三相卧螺工艺，并对新旧工艺进行对比，指出了小麦淀粉与谷朊粉生产中的关键问题，并进行了探讨。     

Fried sweetpotato user preferences identified in Nigeria and Ghana and implications for trait evaluation

Fried sweetpotato quality is important for variety adoption in West Africa. To inform breeding efforts, the study developed a product profile for sweetpotato chunk fries using mixed qualitative and quantitative methods. Root characteristics, processing attributes, in-mouth attributes and appearance of fried product were critical to final product quality. Raw roots should be hard, have smooth skin and no off-odours. Peeled roots should be hard to slice and not sticky. Stickiness and moist surface indicate high moisture content, associated with excessive oil absorption during frying. Hard to slice roots connote high dry matter. Fried product should be crisp, slightly sugary and mealy, have a uniform colour with brown tint and not be soggy. Crispness, mealiness and short frying time with limited oil absorption may be functions of starch. Understanding starch characteristics and other attributes that contribute to quality fried sweetpotato is critical for breeding sweetpotato genotypes with superior quality for frying.     

不同基因型甘薯直链淀粉含量差异研究

研究快速测定甘薯淀粉中直链淀粉含量的方法,分析不同基因型甘薯直链淀粉含量差异。结果显示,该法测定直链淀粉与表观直链淀粉呈高度相关性（r=0.9992）,在取样0.50g、不脱脂的情况下,5份甘薯样品的直链淀粉含量与脱脂后的测定结果相比,误差小于或接近2%,接近国标允许的误差范围（GB8648-87）,表明该法适合于甘薯直链淀粉含量测定。不同品种甘薯直链淀粉含量存在一定差异,变幅为14.22%～35.12%,其中以黄心型变异系数最大,最有可能筛选到高直链淀粉品种或低直链淀粉品种。     

微粉碎甘薯原料的生料发酵

采用糖化酶和酵母菌,对粗粉碎、微粉碎两种不同粒径的甘薯进行生料发酵,探讨微粉碎甘薯生料发酵的可行性;并通过正交试验,调查中温α-淀粉酶、糖化酶和酒精酶三种酶用量对微粉碎甘薯生料发酵影响的显著性。试验结果表明,微粉碎甘薯生料发酵的速率和酒精度均显著高于粗粉碎甘薯;初始pH在5.0~5.5的范围内,发酵效果最好;酒精酶对微粉碎甘薯生料发酵具有显著性影响,在中温α-淀粉酶10 u/g、糖化酶500 u/g和酒精酶0.2%的条件下生料发酵,最高酒精度为10.7%,其原料淀粉的转化率达到82.5%。由此可见,通过微粉碎,可实现甘薯的生料发酵。     

Effect of Heat-Moisture Treatment and Acid Modification on Rheological, Textural, and Differential Scanning Calorimetry Characteristics of Sweetpotato Starch

Sweetpotato starches were characterized to understand the changes upon modification by acid and heat‐moisture treatment (HMT) in the rheological, differential scanning calorimetry (DSC), and textural characteristics of starch isolated from the sweetpotato variety PSP‐21 and to compare these findings with those of commercially available arrowroot starch. The native sweetpotato starch had a Type A pasting profile characterized by a high peak viscosity (PV) (741.5 rapid viscoanalyzer unit [rvu]), with a high breakdown (378.8 rvu) and low cold paste viscosity (CPV) (417.6 rvu). After HMT, there was a marked decrease in the PV (639.1), a very slight breakdown (113.5 rvu) and an increase in CPV (759.5 rvu), more like a Type C pasting profile. However, acid modification did not notably change the pasting profile of native sweetpotato starch. The DSC characteristics were also affected significantly after modifications. The gelatinization temperature parameter to onset (T_o) decreased significantly after HMT and acid modification. The gelatinization enthalpy decreased during HMT from 15.98 to 14.42 J/g. The gel strength of acid‐modified starch was the highest compared with that of HMT and native sweetpotato and arrowroot starches.     

Slowly digestible sweetpotato flour: Preparation by heat-moisture treatment and characterization of physicochemical properties

The preparation and physicochemical characteristics of sweetpotato flour with increased slowly digestible starch (SDS) fraction were investigated under various heat-moisture treatment (HMT) conditions. The optimum conditions for preparing slowly digestible sweetpotato flour established using response surface methodology were moisture content of 22%, temperature of 103°C, and treatment time of 5.8 h. The highest SDS content in heat-moisture treated sweetpotato flour was 57.6%. The relative crystallinity of heat-moisture treated sweetpotato flour decreased, but the X-ray diffraction pattern maintained the A-type. The DSC of the heatmoisture treated flour showed a decreased gelatinization temperature range and gelatinization enthalpy compared with native one. The viscosity profiles and values changed significantly with HMT, resulting in a higher pasting temperature, decrease of the viscosity values, and no breakdown. It indicates that heat-moisture treated sweetpotato flour is more stable at high temperatures and shear rates than native one.