食品成分对山药淀粉老化度和冻融稳定性的影响

研究了氯化钠、蔗糖、单甘酯对山药淀粉老化度和冻融稳定性的影响,结果表明山药淀粉的老化度随氯化钠浓度的增大而有所增大,随蔗糖浓度、单甘酯浓度的增大而有所减小;山药淀粉的冻融稳定性随氯化钠浓度、蔗糖浓度、单甘酯浓度的增大而改善,氯化钠、蔗糖、单甘酯对山药淀粉的冻融稳定性有促进作用。     

四种食品添加剂对马铃薯淀粉老化性的影响

以马铃薯淀粉为原料,研究单硬脂酸甘油酯、羧甲基纤维素钠、瓜尔豆胶及β-环糊精对马铃薯淀粉老化度、粘度的影响。结果表明:4种添加剂均可改善马铃薯淀粉的老化性,瓜尔豆胶降低老化度的作用效果最为明显,与未加任何添加剂的淀粉相比,老化度从33.54%降低至16.74%;羧甲基纤维素钠对马铃薯淀粉老化后粘度的提升最为显著,与未加添加剂的马铃薯淀粉相比,粘度从4.64Pa·s提高至18.24Pa·s。     

支链聚合度对菠萝蜜种子淀粉老化特性的影响

本研究以菠萝蜜种子淀粉(jackfruit seed starch,JFSS)为原材料,将其分离成直链淀粉和支链淀粉。将直链淀粉与五种不同支链聚合度的支链淀粉以1:1质量比进行混合,并进行糊化/老化处理,制备具有不同支链聚合度的老化JFSS(retrograded JFSS,RJFSS:M1’、M5’、M6’、M11’和BD’)。M1的支链聚合度最低,BD的支链聚合度最高。5种RJFSS样品显示出从致密到松散结构的显著变化。高脱水收缩形成致密结构,低脱水收缩相反。支链聚合度增加,5种RJFSS样品的Avrami指数和转变温度升高,重结晶速率、老化焓、老化度、相对结晶度、吸光度比降低。热力学特性、结晶结构和短程分子有序度的结果证实了不同支链聚合度RJFSS的老化特性。结果表明,支链聚合度是影响淀粉在贮藏过程中老化特性的重要结构因素。     

支链聚合度对菠萝蜜种子淀粉热力学特性的影响及老化动力学分析

为了探究支链聚合度对淀粉老化的影响,利用差示扫描量热仪结合Avrami方程,研究不同支链聚合度菠萝蜜种子淀粉(jackfruit seed starch,JFSS)凝胶后贮藏过程中的老化焓变和老化动力学。结果表明:支链聚合度降低,JFSS凝胶后老化过程形成更多趋于有序排列的结晶,老化速率从0.336增加到0.513,不同聚合度JFSS成核方式为瞬间成核;随贮藏时间的延长,JFSS老化度增大;支链聚合度与Avrami指数呈显著正相关(p<0.05);支链重均聚合度与凝胶化焓呈极显著负相关(p<0.01),数均聚合度凝胶化焓呈显著负相关(p<0.05);支链重均聚合度与贮藏0~7 d的老化焓变均呈现显著负相关(p<0.05)。支链聚合度是影响淀粉贮藏过程中老化特性的重要结构因素。     

淀粉冻融稳定性的研究进展

淀粉的冻融稳定性直接影响速冻面食的品质。综述了冻融处理对淀粉理化性质和结构特征的变化及冻融稳定性的主要影响因素,对可能的作用机理进行了分析和探讨。为速冻面食的工业生产和品质优化提供了一定的理论参考。     

菠萝蜜种子淀粉特性研究进展

对菠萝蜜种子淀粉的颗粒特性、淀粉糊的老化特性、粘度特性以及淀粉的加工特性等进行了详细介绍,从而为菠萝蜜种子的深加工提供理论依据.     

菠萝蜜种子淀粉提取及其理化性质的研究

以菠萝蜜种子为原料提取并纯化种子淀粉,对种子的化学组成及种子淀粉的性质进行了测定。结果表明:菠萝蜜种子含淀粉62.63%,实验室条件下种子淀粉的提取率为42.3%,菠萝蜜种子淀粉在透明度、冻融稳定性、膨胀度、低温溶解性均低于马铃薯淀粉,易老化,浓度>60 g/L的淀粉糊在90℃以上粘度较大,<70℃粘度下降并趋于稳定。     

支链聚合度对菠萝蜜种子淀粉理化特性的影响

从菠萝蜜种子淀粉(jackfruit seed starch,JFSS)分离直链淀粉和支链淀粉,将相同直链淀粉(50%)混合5种不同支链淀粉,制备具有不同支链聚合度的JFSS(M1′、M5′、M6′、M11′和BD′),探究支链聚合度对JFSS理化特性的影响。结果显示:M1′具有最低的支链聚合度(189 506),BD′具有最高的支链聚合度(431 481)。随着支链聚合度增加,5种JFSS样品的脱水收缩、凝胶化焓、峰值黏度、谷值黏度、崩解值、最终黏度、回生值、相对结晶度和吸光度比分别从72.87%、15.59J/g、4 755cP、3 548cP、1 207cP、5 751cP、2 203cP、33.22%、1.56(M1′)降低至66.79%、13.84J/g、2 717cP、1 971cP、746cP、3 158cP、1 187cP、27.94%、1.45(BD′)。然而转变温度和糊化温度分别从48.19,60.39,75.32,77.55℃(M1′)升高到52.39,64.54,78.47,81.60℃(BD′)。冻融稳定性、热特性、结晶结构、短程分子序列的结果表明,支链聚合度是影响淀粉理化特性的重要结构因素。     

菠萝蜜种子淀粉颗粒的物化特性研究

利用SEM、X-射线衍射、聚焦光束发射测量仪、Brabender黏度仪、DSC等研究菠萝蜜种子淀粉的物化性质。结果表明,菠萝蜜种子淀粉颗粒多呈半椭圆形,断口为\     

菠萝蜜种子淀粉颗粒性质的研究

以菠萝蜜种子为原料,提取并纯化菠萝蜜种子淀粉,对菠萝蜜种子淀粉的颗粒形貌、X-光衍射图样、直链和支链淀粉含量、溶解度和膨胀度、淀粉糊的冻融稳定性等特性进行了研究。结果表明:菠萝蜜种子淀粉颗粒的大小为5～25μm,平均粒径为15μm,多呈半球形和球形,具典型的偏光十字;淀粉颗粒的晶体结构属C型;用偏十字消光法测定淀粉糊化温度,糊化起始、终止温度分别为68.2、78.3℃;该淀粉的直、支链淀粉分别为24.2%、75.8%;菠萝蜜种子淀粉的溶解度和膨胀度不同于玉米和马铃薯淀粉,其膨胀度在76℃以后迅速增加并大于玉米淀粉,更相似于马铃薯淀粉。     

老化因素对大米抗性淀粉制备的影响

研究老化因素对大米抗性淀粉（RS）制备得率的影响效果。先将大米淀粉制成4个不同糊化度（30％：30min和60min；60％：30min和60min）的原料粉，然后选取温度、pH、老化时间，Ca^2＋添加量作为老化因素，采用四因素三水平正交设计，根据Rs得率筛选优化组合。结果是采用30％的淀粉乳（干基），糊化30rain，在中性条件下，添加1％Ca^2＋于60℃老化12h，RS最高得率达到了19％。老化因素对RS的影响为：时间〉温度〉Ca^2＋〉pH。     

INFLUENCE OF FLAVORING ON THE VISCOELASTIC PROPERTIES OF STARCH GELS DURING GELATION AND LONG-TIME RETROGRADATION

The effect of three different aroma compounds on the texture of starch dispersions during gelation and retrogradation was studied. Oscillatory measurements were used to follow gelation and to check the structure of the starch dispersions after retrogradation up to 28 days. Rheological tests did not indicate any effect of the presence of any of the aroma compounds on the mechanism of gelation. During long‐time retrogradation, some added aroma compound did. We assume that this is a consequence of the ability of aroma compounds to form a complex or to show another type of interaction with starch molecules like entrapment in the amorphous regions of starch. Linalool is known to form complexes with amylase, but did not induce texture modifications, probably because, in our experiments, the added amount of this compound was too low. Isoamyl acetate, which according to literature interacts with amylopectin, exhibited a weak effect after 3 or 4 weeks, depending on the amount added. Octanal also increased gel stiffness after 3 weeks. This phenomenon is consistent with the observation that this aroma compound can form complexes with starch as demonstrated by X‐ray diffraction in this study.     

EFFECT OF SUGARS ON THE THERMAL AND RETROGRADATION PROPERTIES OF OAT STARCHES

The thermal and retrogradation properties of oat starches from two cultivars (NO 753-2 and AC Stewart) were characterized in the presence of glucose, fructose and sucrose at a concentration of 36% w/v. In both oat starches, amylose leaching (AML) and swelling factor (SF) decreased in the presence of sugars (sucrose > glucose > fructose). These decreases were more pronounced in AC Stewart starch. The decrease in AML showed that sugars interact with amylose chains within the amorphous regions of the starch granule. The gelatinization transition temperature and the enthalpy of gelatinization increased in the presence of sugars (sucrose > glucose > fructose). The above increase was also more pronounced in AC Stewart starch. The decrease in SF and the increase in gelatinization parameters indicated that these changes were influenced by the interplay of factors such as starch-sugar interaction, changes in water structure in the presence of sugars, and the antiplastizing properties of sugars relative to water. The retrogradation enthalpy and the X-ray diffraction intensities of NO 753-2 and AC Stewart starch gels (stored at 4C) increased in the presence of sugars (glucose > fructose > sucrose). These changes were more pronounced in NO 753-2 starch. The results showed that interaction (during storage) between leached amylopectin and sugar molecules was the main causative factor influencing oat starch retrogradation.     

麦芽糖产率与淀粉液化程度关系的研究

研究了麦芽糖的理论与淀粉液化程度的关系,当应用麦芽糖 生成酶可水解麦芽三糖时,麦 芽糖的产率为［０ ．９７７５ － ９ Ｄ Ｅ／（２０ － ２ Ｄ Ｅ）］ ×１００ ％ ;当所用麦芽糖 生 成 酶 不 能 水 解 麦 芽 三 糖 时, 麦 芽 糖 的 产 率 为［０ ．９３２５ － ２７／（２０ － ２ Ｄ Ｅ）］ ×１００ ％ 。理论关系式 与实验结果良好。     

EFFECT OF PHYSICAL PROPERTIES OF FOOD PARTICLES ON THE DEGREE OF GRAININESS PERCEIVED IN THE MOUTH

Nineteen food materials were pulverized and passed through standard sieves to prepare samples with different particle sizes (23–500 μm). Each sample was tested for physical properties, and sensory evaluation tests were conducted to obtain the graininess threshold value and the degree of graininess discrimination. The graininess threshold value tended to decrease and the degree of graininess discrimination tended to increase with increasing degree of circularity, with decreasing solubility, with decreasing water absorption rate- particle size coefficient, and with increasing WK₂/K₁. The degree of graininess discrimination tended to increase with increasing particle size and increasing WK₂. With a multiple-regression analysis, the graininess threshold value was expressed by six physical properties, and the degree of graininess discrimination was expressed by eight physical properties, each with high contribution rates.