【目的】研究香蕉果实抗性淀粉形成机理,为选育高抗性淀粉香蕉品种和调控抗性淀粉合成提供理论基础。【方法】以‘巴西’蕉(Musa acuminata L.AAA group cv.Brazilian)果肉为试材,对香蕉果实采前和采后抗性淀粉含量变化及其与其他类型淀粉相关关系进行分析。【结果】香蕉果实发育过程中,总淀粉、直链淀粉、支链淀粉及抗性淀粉含量整体呈上升趋势,后熟过程中各种淀粉含量逐渐下降;乙烯处理加速了总淀粉、直链淀粉和支链淀粉的降解,但抗性淀粉降解速度较自然后熟慢;1-MCP处理香蕉果实各种淀粉含量呈先增后降的单峰曲线变化。相关性分析表明:香蕉采前果实抗性淀粉合成与直链淀粉含量变化呈显著正相关,与总淀粉和支链淀粉含量变化不相关;1-MCP处理后,抗性淀粉含量变化与直链淀粉含量达到显著正相关水平,与总淀粉含量变化不相关。【结论】香蕉果实抗性淀粉形成与直链淀粉含量密切相关,在香蕉果实发育过程中可通过调控直链淀粉含量促进抗性淀粉合成。

[Objective]The research on resistant starch formation from banana fruit will provide a theoretical basis for practical schemes for breeding cultivars with high starch resistance and improving resistant starch content in banana fruit. [Method]Banana (Musa acuminata L. AAA group cv. Brazilian) pulp was used to investigate the changes of resistant starch content and correlation with the other types of starch.[Result]The content of total starch, amylose, amylopectin, and resistant starch gradually increased in banana fruit during development, and decreased in banana fruit during postharvest. After treatment with ethylene, the degradation of total starch, amylose, and amylopectin was accelerated;however, the rate of resistant starch degradation was slower than that of the natural ripened (untreated). A single peak was observed for starch content of banana fruit after treatment with 1-methylcyclopropene (1-MCP). Correlation analysis showed that resistant starch formation had a positive corre

采用SEM、HPLC、UV/可见光光度分析法、酶降解等一系列分析手段,研究不同直链淀粉含量玉米淀粉结构及其降解性质,从分子层面进一步阐释淀粉分子结构对其自身降解特性影响.将直链淀粉按其分子量不同,分为高分子量直链淀粉分子和低分子量直链淀粉分子,低分子量直链淀粉分子对淀粉性质影响比淀粉中其它淀粉分子成分影响更为突出.

SEM,HPLC,UV/visible photometer and enzymatic digestion were utilized for studying maize starch structures and digestion properties. The influence of starch molecular structure on starch digestion properties was explained from molecular point of view. Amylose was separated into higher molecular weight amylose and lower molecular weight amylose on the basis of its molecular weight. The lower molecular weight amylose plays more important roles on starch properties than other molecules in starch.

以郑麦366淀粉和美硬NS淀粉为原料,通过球磨微细化处理对淀粉的理化特性进行改性。结果表明:球磨时间对淀粉的颗粒特性和淀粉糊特性均有较大影响,随着球磨时间延长,淀粉中损伤淀粉含量增幅较大。球磨6 h处理后淀粉颗粒中偏光十字大部分消失;与原淀粉相比,淀粉糊透明度、沉降体积、冻融稳定性均降低,而热水溶解度却呈上升趋势。

Zheng Mai 366 starch and U.S. hard NS starchas raw materials,physicochemical propertiesof these starch weremodifiedwere mechanically treated with a ball mill. Results showed thatprolonged ball milling treatment time have great impact on starch particle characteristics and paste properties. Prolonged ball milling treatment time cause the increase of damagedstarch content,and polarization cross of the two kinds of wheat starch mostly disappeared.Compared to native starch, prolonged ball milling treatment time result in the decrease of transparency,sedimentation volume and stability of frost thawing of starch paste,as well as the increase of hot-water solubility.

以绿豆、奶花芸豆、红小豆、豌豆、英国红芸豆、小扁豆为材料,采用湿磨法提取淀粉,以大米、小麦淀粉为对照,对杂豆淀粉的理化特性进行分析研究。结果表明:6种杂豆淀粉颗粒形貌相似,颗粒普遍较大,呈圆形或椭圆形,均匀度较好。在相同制备条件下,杂豆淀粉间的水分、灰分和蛋白质差异较明显。杂豆淀粉间的直链淀粉和回生淀粉含量差距不大,均达40%以上。淀粉的溶解度和膨润力均随温度的升高而增加。杂豆淀粉间的透光率差异显著,普遍较小麦、大米淀粉的透光率要好。杂豆淀粉间的糊化特性差异显著,热特性差异不显著,淀粉分子结晶度相近,糊化难易程度比较接近。杂豆淀粉与小麦、大米淀粉理化性质差异显著。

Starches were extracted from mung beans,phaseolus vulgaris,red bean,pea,british red kid-ney beans and lentils by wet -grinding method.Their physicochemical properties were analyzed by com-pared with wheat and rice starches as the control groups.The results showed that starch''s particles of the beans were similar with bigger granularity,and circular or elliptic shape,and good uniformity.There was significant difference of moisture,ash and protein between each of the beans prepared under the same conditions.The contents of amylose and retrograded starch among the beans starch had little difference,each above 40%.The starch swelling power and solubility increased along with the rise of temperature.There was significant difference in light transmittance among the beans starch which was better than that of wheat starch and rice starch.There was significant difference in gelatinization charac-teristics among the beans starch.Among the beans starch,there were no significant differe

为了促进淀粉基复合材料中淀粉基质与预处理纤维表面更好的结合,解决热塑性淀粉的再结晶问题,分别采用甲酰胺、尿素、甘油、乙二醇按照10∶2、10∶2.5、10∶3、10∶3.5、10∶4的比例对天然玉米淀粉进行了塑化,同时研究了甲酰胺-尿素复合塑化淀粉和甘油-乙二醇复合塑化淀粉。通过解读红外光谱图谱,塑化剂主要通过与淀粉分子中的羟基形成氢键对淀粉进行塑化,破坏淀粉的晶体结构,最佳塑化比为m(淀粉)∶m(塑化剂)=10∶3,其中甲酰胺与淀粉形成的氢键最强,塑化效果最好。X射线衍射曲线的研究表明,甲酰胺-尿素复合塑化淀粉的结晶度最低,小于1.5%,且复合塑化剂的最佳配比为m(甲酰胺)∶m(尿素)=2∶1。纤维-淀粉分子搭接模型的建立显示了热塑性淀粉与纤维间氢键结合的机理,塑化效果越好,淀粉塑化克服了纤维与淀粉的表面不相容的缺陷,淀粉基质均匀地覆盖在纤维表面。

In order to promote the combination of the starch matrix and fiber pretreated in the composites and solve the problem of the recrystallization of thermoplastic starch,this paper respectively takes formamide,ure-a,glycerol and glycol as the plasticizer by the proportion of 10∶2,10∶3,10∶4.From FT-IR spectra,the plas-ticizer plasticized starch mainly through the intermolecular hydrogen bonding with -OH in starch molecules, and the optimal rate of starch:plasticizer is 10∶3.And the hydrogen bonding between formamide and starch was strongest and the plasticizing effect was the best.X-ray diffraction curves have shown that the crystallinity of formamide-urea compound plasticizing TPS is lowest and less than 1 .5%.And the optimal formula of com-pound plasticizer is formamide∶urea = 2∶1 .Fiber-starch schematic of water’s bridge-connection showed good adhesion between TPS matrix and fibers.