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。     

羟丙基化反应对普通玉米杂交种淀粉糊化性质的影响

采用实验室的方法提取了普通玉米杂交种淀粉,并制取羟丙基淀粉。采用快速黏度测定仪(RVA)分析所有淀粉的糊化性质,结果表明:羟丙基化改变了所有原淀粉的糊化性质参数即提高了所有原淀粉的峰值(Peak)和衰减值(Breakdown),降低了所有淀粉的谷值(Trough)、终黏度(Final)、回生值(Setback)、出峰时间(pTim e)和糊化温度(pTem p)。但对不同的糊化性质参数及不同的玉米杂交种影响的幅度是不同的。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的相关性均达到了极显著水平,说明普通玉米杂交种间淀粉的糊化性质差异在羟丙基化反应之前就已经存在。羟丙基化使原淀粉的糊化性质参数间的相关性显著水平发生了不同的变化,表明羟丙基化对不同的普通玉米杂交种及其淀粉的糊化性质参数的影响是不同的。     

食用羟丙基二淀粉磷酸酯的特性研究

探讨了羟丙基二淀粉磷酸酯的耐盐性、耐酸性、耐高温、抗剪切稳定性及透明度等性质，为其在食品中的应用提供一定的理论依据。     

食用羟丙基二淀粉磷酸酯的制备及应用

研究了玉米淀粉的羟丙基化和羟丙基淀粉的磷酸酯交联，采用正交试验对工艺进行优化以确定最佳的工艺条件，此外还对改性淀粉在食品中的应用作用了探索。     

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。     

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。     

三种羟丙基二淀粉磷酸酯对木薯淀粉特性的影响

为了研究三种羟丙基取代度相同、交联程度不同的羟丙基二淀粉磷酸酯（HDP）对木薯淀粉（TS）特性的影响,本文测定了三种羟丙基二淀粉磷酸酯的交联度,进行了淀粉糊液状态观察,在木薯淀粉中分别添加三种羟丙基二淀粉磷酸酯后,测定淀粉体系的冻融稳定性,并通过透明度测定、质构分析（TPA）和差示扫描量热法（DSC）对三种羟丙基二淀粉磷酸酯的添加对木薯淀粉老化性质的影响进行了研究。研究发现,添加三种羟丙基二淀粉磷酸酯均降低了木薯淀粉的析水率;在4℃储存过程中,添加羟丙基二淀粉磷酸酯后,木薯原淀粉的硬度有所改善,其透明度下降速率变缓,熔融焓值（ΔH）降低。三种羟丙基二淀粉磷酸酯的添加均改善了木薯淀粉的冻融稳定性,抑制了木薯淀粉的老化,而交联度较高的两种羟丙基二淀粉磷酸酯效果更佳。     

交联作用对合成交联羟丙基玉米淀粉的影响

以合成的羟丙基玉米淀粉为原料,以三偏磷酸钠为交联剂研究了交联作用对合成交联羟丙基玉米淀粉的影响,并探究了羟丙基玉米淀粉粘度与取代度、交联羟丙基玉米淀粉粘度与交联度之间的关系。结果表明交联剂用量、交联时间、交联温度和交联pH值是影响合成交联羟丙基玉米淀粉的主要因素,羟丙基和交联羟丙基玉米淀粉的最高粘度分别随取代度和交联度的升高而增加;冷却至室温,粘度分别随取代度和交联度的升高而减小。     

影响马铃薯羟丙基二淀粉磷酸酯黏度特性的因素研究

通过测定变性淀粉的Brabender黏度特性,研究了马铃薯淀粉(PS)品质(依黏度指标分为优级粉、一级粉和合格粉三级)、磷酸酯化程度、羟丙基醚化程度、产品电导率对马铃薯羟丙基二淀粉磷酸酯(HPSP)黏度特性的影响。实验结果显示:(1)马铃薯淀粉的品质对糊化温度和峰值黏度有较大影响,以优级品为原料制备的羟丙基二淀粉磷酸酯的糊化温度最低,峰值黏度最高;(2)轻度磷酸酯化的羟丙基二淀粉磷酸酯具有较高的峰值黏度和冷黏度,随着磷酸酯化程度的提高,马铃薯羟丙基二淀粉磷酸酯的糊化温度增高,峰值黏度降低;(3)羟丙基醚化对马铃薯羟丙基二淀粉磷酸酯的黏度值影响较小,随羟丙基含量的升高,糊化温度明显降低,峰值黏度和冷黏度则略有上升;(4)随着马铃薯羟丙基二淀粉磷酸酯电导率的降低,产品的糊化温度降低,峰值黏度和冷黏度升高。     

羟丙基玉米淀粉的制备及特性研究

本文研究了用环氧丙烷制备羟丙基玉米淀粉的反应条件以及羟丙基化对玉米淀粉糊特性的影响,在反应条件中,着重研究了淀粉乳浓度、环氧丙烷用量、反应温度和时间对醚化程度以及反应效率的影响规律,试验表明：羟丙基化能大大提高玉米淀粉糊的抗剪切性能和抗盐性能,使淀粉糊的透明度和冻融稳定性都有所增加。     

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.     

不同制粉工艺对面粉粉质特性和糊化特性的影响

脱皮制粉工艺先除去小麦部分皮层,再入磨,使后序的皮磨以及清粉系统大大简化.本试验利用两种工艺加工面粉后,用RVA测定和分析了面粉粉质特性和糊化特性的变化.结果表明,脱皮工艺下面粉的损伤淀粉含量减少、淀粉平均粒度变大、α-淀粉酶含量减少;降落数值和平均粒度分布分别与低谷粘度呈显著正相关（r=0.581,p＜0.05;r=0.603,p＜0.05）,衰减度和平均粒度呈显著的负相关（r=0.605,p＜0.05）;制粉工艺对中筋的南阳白麦和高筋的8901二等粉的影响最为显著,脱皮工艺下这两种面粉的峰值粘度和最终粘度明显增加,并且其衰减度较大;脱皮工艺的低谷粘度均高于传统工艺的同等面粉,但回生值较低.     

ISOLATION AND PHYSICOCHEMICAL CHARACTERIZATION OF STARCHES FROM DIFFERENT BANANA VARIETIES

The physicochemical properties of the starches extracted from three varieties of banana indigenous to Thailand were investigated. The Thai names of these varieties are Hak Muk, Nam Wa Kom, and Ta Nee. Starch from all three varieties were found to contain 30.9% to 32.0% amylose. Other components were moisture (11.47 to 11.76%), protein (0.22 to 0.93% dry weight basis dwb), lipid (0.07to 0.11 % dwb) and ash (0.07to 0.17% dwb). X‐ray diflraction patterns showed Hak Muk and Nam Wa Kom were of B type whereas Ta Nee was of C type. All three varieties showed strong paste stability to both thermal heating and mechanical shearing but high retrogradation. The banana starch paste stability in digerent pH slurries pH 7 to 4.5) indicated that they are suitable for food application that require high amylose and high retrogradation afer processing.     

COMPOSITION AND PASTING PROPERTIES OF STARCH FROM TWO COCOYAM CULTIVARS

ABSTRACT

The composition and pasting properties of starches from two cocoyam cultivars were evaluated and compared with cassava starch. The starch, amylose and amylopectin contents of Xanthosoma and Colocasia cultivars ranged from 79.2 to 79.8%, 23.3–23.6%, 56.1–56.2% and 77.6–77.8%, 25.4–25.7%, 52.1–52.2%, respectively. The Xanthosoma and Colocasia starches had significantly low levels (0.12–0.24%) of lipid, with trace concentrations of crude fiber. Manihot utilissima had significantly (P ≤ 0.05) higher starch and amylopectin but lower amylose contents than Colocasia and Xanthosoma starches. Average granule sizes of Xanthosoma and Colocasia starches ranged from 4.3 to 5.6 µm and 2.5–3.4 µm, respectively. Xanthosoma and Colocasia starches showed restricted swelling and solubility patterns with high initial gelatinization temperatures ranging from 78.3 to 78.5C and 74.6–74.8C, respectively. Between 19.0–19.2% and 16.8–17.1% soluble carbohydrates were obtained from Xanthosoma and Colocasia starches, respectively, at 95C. The Xanthosoma starches had higher peak, hot paste and cooked paste viscosities and stability than Colocasia starches.

PRACTICAL APPLICATIONS

This study shows that the application of cocoyam starches in food would depend largely on the knowledge of their physicochemical properties which differed with the cultivars. The properties of importance include composition, granular characteristics, swelling, solubility and pasting characteristics. The low lipid content of Xanthosoma and Colocasia starches was important to their functionality because lipid complexes with carbohydrates and reduce swelling and solubility of starches by restricting gelatinization. Xanthosoma starches had significantly higher amylopectin but lower amylose contents than Colocasia starches. The relatively high amylose contents and smaller granular characteristics were associated with the low swelling and solubility patterns of starches from both cultivars. Xanthosoma starch had higher solubilities than Colocasia starch at higher temperatures (80–95C). Xanthosoma brasillience and Xanthosoma sagittifolium starches had superior viscosity stabilities than Colocasia antiquorum and Colocasia esculenta starches, and would be useful in baked products like biscuits, cakes and breads. C. esculenta and C. antiquorum starches would be desirable in sauces, soups and as thickeners in products requiring continuous heating and stirring where viscosity is not desired.     

魔芋葡甘聚糖酯化交联改性研究

三偏磷酸钠为魔芋葡甘聚糖进行酯化交联改性。结果表明，反应最佳条件为三偏磷酸钠；魔芋葡甘聚糖=1：10(w／w)，反应PH为2，反应温度50℃，反应时间2h。改性KGM透明度、粘度、冻融稳定性均比未改性KGM明显改善，并具有一定的耐酸耐高温能力，且有相当的抑菌效果。     

EFFECTS OF KERNEL PROPERTIES AND POPPING METHODS ON POPCORN QUALITY OF DIFFERENT CORN CULTIVARS

Three popcorn genotypes, Koç Cin (composite), Nermin Cin and Ant Cin-98 (hybrid) were investigated for the effects of kernel size (4  <  D  <  5 and 5  <  D  <  6), popping methods (conventional and microwave) and moisture content (10, 12 and 14%) on popcorn quality. The relationships between physical kernel properties and popping characteristics were also researched. The Nermin Cin popcorn cultivar had the highest expansion volume, flake size and the lowest percentage of unpopped kernel values among genotypes. 5  >  D  >  6 mm kernel fraction and the conventional method produced higher popcorn quality in all popcorn cultivars. The optimum moisture levels for the highest expansion volume changed between 12 and 14% for different cultivars. The correlation coefficient between kernel properties (width, sphericity, L , a and b) and expansion volume were found significant ( P <  0.01) in microwave popping method. Color a had high direct effects on expansion volume in conventional and microwave popping methods according to path coefficient analysis. L values of popcorn cultivars negatively correlated with expansion volume in both popping methods.

PRACTICAL APPLICATIONS

Physical parameters like width, sphericity and color values were found important in predicting popping quality. Color values should be used to predict expansion volume instead of classic physical properties for ease ofmeasurement. Conventional popping method, 5 > D > 6 kernel size and 12–14% moisture content parameters should be used for optimum popcorn quality.     

EFFECT OF SUGAR AND GUMS ON THE PASTING PROPERTIES OF CASSAVA STARCH

Pasting properties of cassava starch solutions were prepared with different types of sugars (glucose, sucrose and fructose) at different levels as 10.71, 19.35, 32.43% and gums (gum acacia, guar gum and gum tragacanth) at 0.1, 0.2, 0.3, 0.4% levels, respectively, were analyzed using the Rapid Visco Analyzer. The pasting temperature increased with increase in the sugar concentration in cassava starch–water system and the maximum 78.27C at 32.43% sucrose solution. The peak viscosity (PV) and breakdown viscosity (BD) decreased with increase in the sugar concentration. Hot paste viscosity and cold paste viscosity decreased progressively with increase in sugar concentration in fructose and glucose solution. The PV and BD increased with increase in guar gum concentration and was maximum 5,704 and 3,773 mPa·s at 0.4% concentration, respectively.

PRACTICAL APPLICATIONS

Cassava starch performs most of the functions where maize, rice and wheat starch are currently used. In food industry, cassava starch is used in extruded snacks for improved expansion, as a thickener in foods, in processed baby foods as a filler material and bonding agent in biscuit and confectionary, textile, pharmaceutical, paper and cosmetic industries. Cassava starch can be converted to maltotriose, maltose, and glucose as well as to other modified sugars and organic acids. Starch from cassava can be used to make gelatin capsules. Starches and gums are often used together in food systems to provide texture, control moisture, water mobility, improve overall product quality and stability, reduce cost and facilitate processing. Cassava starch, due to its high swelling power, is reported to yield better quality instant noodles.