改性淀粉对月饼豆沙馅料品质影响的研究

本文研究了不同淀粉对月饼豆沙馅料的持水性、成型性、耐高温性和口感的影响。结果表明,己二酸交联醋酸酯化蜡质玉米改性淀粉能明显有效地提高月饼豆沙馅料的成型性、持水性,同时能提供爽滑细腻的口感;磷酸盐交联木薯改性淀粉也可提供良好的口感,但相对于己二酸交联醋酸酯化蜡质玉米改性淀粉,持水性稍差,不过上述两种改性淀粉都比小麦淀粉效果好,因此,己二酸交联醋酸酯化蜡质玉米陡陛淀粉非常适合于豆沙馅料的生产,给豆沙馅料提供了良好的持水、成型和爽滑细腻口感的品质。     

交联羟丙基淀粉在蚝油中的应用

以木薯淀粉和蜡质玉米淀粉为原料,对其进行交联羟丙基改性,研究改性前后淀粉在蚝油中的应用效果,结果表明,未改性的原淀粉在蚝油中的应用效果不理想,而交联羟丙基木薯淀粉和交联羟丙基蜡质玉米淀粉都具有良好的稳定性、粘稠度和感官效果.     

交联和羟丙基改性对蜡质玉米淀粉糊性能的影响

本研究采用蜡质玉米淀粉为原料,湿法工艺制备了磷酸酯双淀粉(1412)、羟丙基淀粉(1440)和羟丙基二淀粉磷酸酯(1442),通过对蜡质玉米淀粉(WS)和3种变性淀粉(1412、1440、1442)在黏度、抗剪切、耐酸性、冻融稳定性和透明度等性能的比较,探讨了羟丙基醚化和交联改性处理对蜡质玉米淀粉糊性能的影响。试验结果显示:⑴羟丙基改性处理降低了淀粉的糊化温度,提高了淀粉峰值黏度,透明度和冻融稳定性得到显著改善,但热稳定性、耐酸性和抗剪切均较差;⑵磷酸盐交联改性的磷酸酯双淀粉糊化温度升高,峰值黏度降低,糊液在抗剪切、耐酸性方面得到显著改善,但糊液透明度降低,冻融稳定性未得到改善;⑶通过交联和羟丙基改性的羟丙基二淀粉磷酸酯,兼具有磷酸酯双淀粉和羟丙基淀粉的共同特性。     

几种蜡质玉米变性淀粉的性质研究

比较了不同蜡质玉米变性淀粉的性质。重点考察了羟丙基蜡质玉米淀粉、己二酸醋酸酯淀粉和羟丙基己二酸醋酸酯淀粉的凝沉性、冻融稳定性、粘度、透明度、耐盐、耐酸性及淀粉糊的外观。     

变性淀粉对汤圆耐煮性的影响

为了解决速冻汤圆耐煮性较差的问题,研究选取不同种类的木薯基变性淀粉与糯米粉复配,以新鲜汤圆和速冻汤圆为研究对象,探究了变性淀粉种类和添加量对汤圆耐煮性的影响。将4种木薯基变性淀粉与糯米粉进行复配,通过测定汤圆粉的黏度及汤圆的硬度,比较变性淀粉对汤圆粉糊化性质及汤圆耐煮性的影响差异,确定适合添加的变性淀粉种类及添加量。结果显示,磷酸酯淀粉对汤圆耐煮性有提高作用,且羟丙基二淀粉磷酸酯(羟丙基质量分数为3.3%,中等交联度)作用效果更显著,而羟丙基淀粉(羟丙基质量分数为3.0%)有良好的抗回生效果。两种变性淀粉复合添加时既可以提高汤圆耐煮性,同时也能起到良好的抗回生效果。汤圆粉的较佳配方为羟丙基二淀粉磷酸酯(羟丙基质量分数为3.3%,中等交联度)、羟丙基淀粉(羟丙基质量分数为3.0%)、糯米粉的质量比为8:2:90,此条件下汤圆耐煮性得到明显的提高。该结论旨在为速冻汤圆的生产加工和变性淀粉在速冻食品中的应用提供一定的理论参考。     

一步法制备蜡质玉米复合变性淀粉工艺研究

以蜡质玉米淀粉为原料,环氧丙烷为醚化剂,三偏磷酸钠为交联剂,氢氧化钠为催化剂,无水硫酸钠为膨胀抑制剂,采用一步法湿法工艺制备了蜡质玉米复合变性淀粉。研究了环氧丙烷、三偏磷酸钠、氢氧化钠、无水硫酸钠用量对产品取代度和反应效率的影响,结果表明:交联羟丙基复合变性淀粉反应时膨胀抑制剂无水硫酸钠的适宜用量为13%,催化剂Na OH适宜用量为1.2%,醚化剂适宜用量为10%,反应时间为16 h,反应温度为45℃;三偏磷酸钠用量对产品取代度和反应效率影响较小;并制备了羟丙基复合变性淀粉,为蜡质玉米淀粉的应用和变性淀粉的开发提供了理论参考。     

不同类型变性淀粉的理化特性比较

以8种类型变性淀粉为研究对象,对其冻融稳定性、糊化特性、透明度、凝沉性、凝胶强度等理化特性进行研究。结果表明,预糊化羟丙基二淀粉磷酸酯蜡质玉米淀粉的冻融稳定性最好;蜡质玉米氧化淀粉的透明度最佳;乙酰化二淀粉磷酸酯马铃薯淀粉、羟丙基二淀粉磷酸酯蜡质玉米淀粉、羟丙基二淀粉磷酸酯木薯淀粉、预糊化羟丙基二淀粉磷酸酯蜡质玉米淀粉的凝沉性较强,而蜡质氧化淀粉几乎无凝沉性;乙酰化二淀粉己二酸酯木薯淀粉的凝胶强度最大;羟丙基二淀粉磷酸酯蜡质玉米淀粉的最高黏度值最大,消减值最大;乙酰化二淀粉磷酸酯玉米淀粉的糊化温度最高;乙酰化二淀粉磷酸酯玉米淀粉的冻融稳定性、凝沉性优于乙酰化二淀粉磷酸酯马铃薯淀粉,且凝胶强度较高;羟丙基二淀粉磷酸酯蜡质玉米淀粉的黏度明显高于羟丙基二淀粉磷酸酯木薯淀粉,而后者的冻融稳定性、透明度、凝沉性优于前者。     

几种不同品种淀粉及羟丙基产物糊液性质比较研究

以薯类淀粉(木薯,马铃薯)及禾谷类淀粉(普通玉米、蜡质玉米、高直链玉米及糯米)为原料,以环氧丙烷为醚化剂。制备了羟丙基变性淀粉。反应条件:淀粉乳质量分数40%、反应温度40℃、无水Na_2SO_4添加量12%(以淀粉干基计)、NaOH添加量1.2%、环氧丙烷添加量12%、反应时间18h。分别对原淀粉及在相同的反应条件下制备的羟丙基变性淀粉糊性质做了对比研究。不同品种淀粉糊性质存在很大差别。经过羟丙基改性。淀粉糊液粘度性质、冻融稳定性、透光率、都有不同程度的改善,但凝沉性质不能准确反映羟丙基化对蜡质玉米淀粉和糯米淀粉糊液性质的改善。     

不同交联度木薯羟丙基淀粉在麻糬面包中的应用

为扩大并深入变性淀粉在面制品的应用开发,分析了不同交联度木薯羟丙基淀粉的黏度曲线、粒径及沉降积,并研究其对麻糬面包的外观、口感、组织结构等感官评价,以及对麻糬面包比容、质构的影响。结果表明,随交联度增加,淀粉的沉降积逐渐减小,耐热性增强,糊化温度逐渐提高,淀粉糊的粒径先增加后降低;在应用效果上,轻交联的木薯羟丙基淀粉在组织结构、加工性能、口感上优于深交联木薯羟丙基淀粉,在比容、弹性及硬度上也表现良好。综合评定轻交联木薯羟丙基淀粉308效果最好,且与预糊化变性淀粉按4:1复配时,能显著提高麻糬面包的比容、弹性、组织结构,且口感清爽、保型性好,为麻糬面包最优淀粉配比。     

不同直链淀粉含量对羟丙基氧化玉米淀粉性质的影响

本文采用蜡质玉米、普通玉米和高直链玉米淀粉为原料,改变有效氯添加量,制备羟丙基氧化淀粉,通过XRD、DSC、Brabender粘度仪等测定手段,研究不同直链淀粉含量对羟丙基氧化淀粉理化性质的影响。实验表明,直链淀粉含量对羟丙基化和氧化程度影响显著,其中直链淀粉含量高有利于羟丙基化,而不利于氧化;X-射线衍射分析发现,改性淀粉没有改变晶型,随氧化程度增加,淀粉分子结晶度下降,直链淀粉含量越高,下降趋势越缓;DSC测试和Brabender粘度分析表明,直链淀粉含量直接影响到羟丙基氧化淀粉糊化特性,糊化温度:高直链普通蜡质,糊粘度:蜡质普通高直链,糊化焓:蜡质普通高直链;通过观察淀粉的偏光特性和颗粒表面形态,发现直链淀粉含量越高,羟丙基氧化淀粉的偏光十字越弱,颗粒越不易破碎。     

Phase transition of cross-linked and hydroxypropylated corn (Zea mays L.) starches

The thermal behaviors of three chemically modified starches (cross-linked waxy corn, hydroxypropylated regular corn, and hydroxypropylated and oxidized waxy corn) were studied using light microscopy, SEM, DSC, XRD, and HPSEC. During the gelatinization process, molecular and crystalline order losses occurred independently from each other. Oxidation treatment altered the effects of hydroxypropylation on starch gelatinization. Both cross-linking and hydroxypropylation tended to preserve granular crystalline order during initial stages of gelatinization. The crystallinities and X-ray patterns of each starch remained essentially unchanged prior to phase transition.     

In vitro Digestibility of Hydroxypropylated and Cross-linked Waxy and Non-waxy Rice Starches

In vitro digestibility of hydroxypropylated and cross-linked waxy and non-waxy rice starches was investigated to find the proper resistant starch (RS) assaying method for chemically modified starches. RS and total dietary fiber (TDF) content of hydroxypropylated and cross-linked waxy and non-waxy rice starches were measured using the approved AOAC RS assay procedure (AOAC method 2002.02) and the AOAC TDF assay procedure (AOAC method 985.29). Hydroxypropylation did not alter the RS content of waxy and non-waxy rice starches (less than 1% of RS). Cross-linking also did not change the RS content of waxy and non-waxy rice starches (less than 1% of RS). It is interesting to note that non-RS content decreased with increasing hydroxypropylation (97-80%) and cross-linking (99-95%) in both waxy and non-waxy rice starches. This indicates that some fraction of RS in hydroxypropylated and cross-linked waxy and non-waxy rice starches cannot be measured using approved AOAC RS and TDF assay procedures. Therefore, the RS and TDF assay procedures performed in this study are not appropriate to determine the RS content of chemically modified starch. Further investigation is needed to develop a method to determine the RS content of chemically modified starch.     

FLOW CURVES, STRESS RELAXATION AND CREEP MEASUREMENTS OF STARCH GELS

Flow curves, stress relaxation, and creep compliance were measured for various types of corn starch gel that underwent different degrees of modification. The four starches were native corn starch, medium hydroxypropylated distarch phosphate, highly hydroxypropylated distarch phosphate, and distarch phosphate. All the starches exhibited pseudo-yield stress behavior at low shear rates and shear-thinning at higher shear rates. Stress relaxation data at different strains indicated strain-softening phenomenon for all starches. Higher degrees of cross-linking decreased the half relaxation time due to the addition of rigid filler into the matrix. Increasing the concentration increased the relaxation modulus for all starches. Creep compliance and recovery measurements were conducted over the range of 3.2 Pa-320 Pa. In the linear viscoelastic region, the compliance data were not dependent on the magnitude of stress applied. As concentration increases, higher stress magnitude leads to nonlinear behavior. The creep compliance data were fitted into the Ninomiya and Ferry relation from dynamic viscoelastic data and the Maxwell-Voigt model. Ninomiya and Ferry overpredicted the relaxation data while the Maxwell-Voigt model fitted the data reasonably well.     

Pasting properties of hydroxypropylated starches before or after proteinase treatment

To examine the effect of starch protein on hydroxypropylation, corn (normal and waxy) and potato starches were hydroxypropylated with propylene oxide at two levels (8.3 and 12.3% based on dry basis of starch weight) before or after proteinase (thermolysin) treatment, and then pasting properties of the starches were measured. For normal corn starch, protein appeared to be involved in hydroxypropylation, especially at the higher concentration of reagent (12.3%); the starch hydroxypropylated after proteinase treatment (Enz‐HP) showed less reaction efficiency than that only hydroxypropylated (HP) or proteinase treated starch after hydroxypropylation (HP‐Enz). This suggests a possible reaction between some of the reagent and the starch proteins that exist in the channel and surface of the starch granules. However, not much difference was found with the waxy corn starch, as it contains much lower amounts of amylose and protein than normal corn starch. The potato starch, which has no channels, showed complicated protein effects. For potato starch, a different access of the enzyme and chemical reagents to the granule matrix could be possible.     

Influence of corn starch type in the rheological properties of a white sauce after heating and freezing

The freeze/thaw and heating stability of white sauces prepared with two modified waxy corn starches (hydroxypropyl distarch phosphate and acetylated distarch adipate) and two native corn starches (waxy and normal) are compared.     

Studies on Starch Phosphates. Part 3. On the Esterified Phosphates in Some Cereal Starches

Some cereal starches were investigated whether glucose phosphate residues were in the polysaccharides. Significant amounts (6–15 ppm, as P) of glucose 6-phosphate were found in the acid hydrolysates of corn, waxy corn, rice and waxy rice starches. After the extensive action of bacterial α-amylase on these starches phosphorylated oligosaccharide (α-LPD) was recovered in reasonable yield by a DEAE-Sephadex column chromatography. The α-LPDs prepared from two sources of waxy rice starch contained 81.8 and 94,3% of P₀ at the 6th position of glucose residues and the rest of P₀ at the 2nd and/or 3rd positions of glucose residues. All these results show that these starches have glucose phosphate residues. In wheat starch, however, no evidence for the presence of glucose phosphate residues has been obtained.     

变性淀粉对速冻水饺质量的影响

分析不同原料(蜡质玉米淀粉、木薯淀粉和马铃薯淀粉)制备的羟丙基淀粉的性能,并将羟丙基蜡质玉米淀粉,羟丙基木薯淀粉和羟丙基马铃薯淀粉分别添加到面粉中,研究其对速冻水饺品质的影响。实验表明:变性淀粉添加量为3%～4%(以面粉干基计),面团含水量为44%～45%时,速冻水饺的冷藏稳定性最好。其中添加羟丙基蜡质玉米淀粉在减少速冻水饺的冻裂率,改善速冻水饺的透明度、光泽和色泽方面效果最明显。     

普通玉米杂交种间原淀粉与羟丙基淀粉糊化性质关系的研究

本文采用湿法在实验室的条件下提取了17种普通玉米杂交种淀粉，并制取了羟丙基淀粉。采用快速粘度测定仪（RVA）测定了所有淀粉的糊化性质参数。结果表明：羟丙基淀粉提高了所有原淀粉的峰值和破损值；降低了所有原淀粉的谷值、终粘度、回生值、出峰时间和成糊温度；原淀粉和羟丙基淀粉的糊化性质参数在普通玉米杂交种间均达到了极显著相关水平，表明了羟丙基淀粉并没有改变原淀粉在普通玉米杂交种间的糊化性质差异性。羟丙基淀粉的糊化性质参数间的相关性显著水平发生了明显的变化，表明了不同的普通玉米杂交种的羟丙基淀粉的糊化性质参数的变化幅度是不同的。但是，羟丙基和原淀粉的相同糊化性质参数间的相关性都达到极显著的正相关水平，说明了羟丙基淀粉与原淀粉的糊化性质参数间存在密切关系，二者的糊化性质又存在着一致性。     

不同蜡制玉米淀粉对肌原纤维蛋白凝胶特性的影响

将蜡制玉米淀粉、酯化蜡制玉米淀粉和交联酯化蜡制玉米淀粉以添加量分别为0%、2%、4%、6%、8%、10%添加到肌原纤维蛋白中,形成蛋白淀粉复合物,研究3?种淀粉对肌原纤维蛋白凝胶保水性、质构特性、白度值、表面疏水性、流变特性和微观结构的影响。结果表明,相比纯肌原纤维蛋白,淀粉均能显著提高复合凝胶的保水性、硬度和弹性（P＜0.05）,且随添加量的增加而显著增加（P＜0.05）,但在添加量为10%时,各指标上升不显著（P＞0.05）,其中交联酯化蜡制玉米淀粉效果最好;3?种淀粉均能增加复合凝胶的白度值,但交联酯化蜡制玉米淀粉的添加会使复合凝胶的白度值过大（P＜0.05）,对色泽不利;同时,淀粉能显著提高复合蛋白的表面疏水性和凝胶的弹性模量（P＜0.05）,且随着添加量的增加而显著增加（P＜0.05）,与肌原纤维蛋白凝胶相比,复合凝胶结构趋于致密均匀。在实验的3?种淀粉中,除色泽因素外,交联酯化蜡制玉米淀粉提高凝胶性能的效果要优于其他两种淀粉。?