糯玉米子粒淀粉形态和结构对硬度的影响

以京科糯2000等3个糯玉米品种为试验材料，系统分析糯玉米子粒淀粉形态和结构对硬度的影响及各指标的相关性。结果表明，不同糯玉米品种子粒蒸煮后硬度最低的是京科糯768（2 342.00 g），其次是京科糯2000（2 504.50 g），分别比苏玉糯2号低35.50%和31.02%；蒸煮后子粒回生值以京科糯2000（966.25 g）最低，其次是京科糯768（1 142.25 g），分别比苏玉糯2号低28.56%和15.55%。不同品种糯玉米淀粉结晶度表现，苏玉糯2号（43.64%）>京科糯2000（40.96%）>京科糯768（40.59%）。淀粉颗粒平均粒径以京科糯2000最大，其次是京科糯768，苏玉糯2号淀粉颗粒平均粒径最小。相关分析表明，蒸煮后子粒硬度及蒸煮后子粒回生值与淀粉结晶度呈显著正相关，与淀粉平均粒径呈显著负相关。综合分析表明，淀粉结晶度小、淀粉颗粒大是京科糯768和京科糯2000子粒硬度小的主要原因。

Effects of Starch Morphology and Structure on Hardness of Waxy Maize Grain

Three glutinous maize varieties, including Jingke2000, were used as test materials to systematically analyzed the effects of grain starch morphology and structure on hardness and the correlation of various indexes of waxy maize. The results showed that Jingkenuo768 had the lowest hardness after cooking, followed by Jingkenuo2000; The hardness difference at 0-12 h after cooking was the lowest in Jingkenuo2000, followed by Jingkenuo768. The crystallinity of different varieties of waxy maize starch was Suyunuo2(43.64%) > Jingkenuo2000(40.96%) > Jingkenuo768(40.59%), and the average particle size of Jingkenuo2000 was the largest, followed by Jingkenuo768, and Suyunuo2 was the smallest. Correlation analysis showed that grain hardness after cooking and grain hardness difference at 0-12 h after cooking were significantly positively correlated with starch crystallinity and negatively correlated with average starch particle size. The high crystallinity and large grain size of maize starch are the main reasons for the low grain hardness of Jingkenuo768 and Jingkenuo2000.