对比研究了三种不同品种南瓜（蜜本、东升、翠栗）淀粉的理化特性。结果表明：三种南瓜淀粉中脂肪和蛋白质含量分别在0.15~0.25%和0.09~0.57%之间；直链淀粉和可溶性直连淀粉含量则依次在26.4~29.0%和4.48~7.40%之间，东升淀粉中直链淀粉和可溶性直链淀粉的含量明显高于其他两种南瓜淀粉。淀粉颗粒大小均在5~15 μm之间，平均直径为10 μm，属于偏小的淀粉颗粒，且多为无规则的椭圆或卵圆形。结晶结构均属于B型，结晶度分别为30.9%、42.7%、43.3%。东升和翠栗淀粉的起始糊化温度和糊化终止温度范围分别为73.21~82.76 ℃、78.66~89.88 ℃，而蜜本淀粉出现双峰现象，其糊化温度范围为69.00~75.67 ℃和77.70~86.17 ℃。蜜本淀粉具有较低的溶解度和膨胀度，凝沉稳定性较差，透光率最高；东升淀粉的溶解度和透明度较低，但凝沉性和冻融稳定性较好；而翠栗淀粉的溶解度和膨胀度最高，但冻融稳定性最差。

The physicochemical characteristics of pumpkin starches from three cultivars (Miben, Dongshen and Cuili) were comparatively studied. The results showed that crude fat contents in three pumpkin starches varied between 0.15% and 0.25%, while crude protein varied between 0.09% and 0.57%. The amylose contents changed between 26.4% and 29.0%, and soluble amylose contents ranged between 4.48% and 7.40%. Dongshen pumpkin starch showed apparently higher contents of amylose and soluble amylose than the other two pumpkin starches. Scanning electron microscopy showed that pumpkin starches consisted of oval granules at the size of 5~15 μm with an average diameter around 10 μm. X-ray diffraction studies showed that all pumpkin starches exhibited a B-type diffraction pattern and the degrees of crystallinity were 30.9%, 42.7% and 43.3%, respectively. The ranges of initial and terminated gelatinization temperature of Dongsheng and Cuili pumpkin starches were 73.21~82.76 ℃ and 78.66~89.88 ℃, respectively. While MiBen pumpkin starch had a bimodal phenomena with two gelatinization temperature ranges being of 69.00~75.67℃ and 77.70~86.17 ℃. MiBen pumpkin starch had the lowest solubility, swellability and sediment stability, but the highest paste light transmittance. Dongsheng pumpkin starch had low solubility and paste light transmittance, but moderate to good sediment stability and freeze-thaw stability. CuiLi pumpkin starch had the highest solubility and swell-ability, but showed the lowest freeze-thaw stability.

广东省科技计划农业领域引导项目（2010B020312008）；广州市科技计划项目（2010Z1-E191）