不同熟化处理方式及多酚类物质对马铃薯全粉消化特性的影响

为开发一种低血糖生成指数(glycemic index,GI)的马铃薯产品,采用直接冷藏处理12、24、48 h及超声结合冷藏处理12 h等4种不同熟化处理方式制备马铃薯全粉,以抗性淀粉的含量为判断指标,筛选出抗性淀粉含量最高的马铃薯全粉;选用原花青素、茶多酚、绿原酸3种多酚,与马铃薯全粉共孵育,得到多酚马铃薯复合粉,采用4-硝基苯-α-D-吡喃葡萄糖苷(4-nitrophenyl-indole-D-glucopyranoside,pNPG)法测定其对α-葡萄糖苷酶抑制作用,并通过体外消化法测定多酚对马铃薯全粉消化特性的影响。结果表明:熟化后冷藏处理24 h的马铃薯全粉抗性淀粉含量最高,为4.32%,是未处理马铃薯全粉中抗性淀粉含量的2.1倍;原花青素-马铃薯复合粉对α-葡萄糖苷酶抑制作用最强,其半抑制浓度(IC50)为26.35 mg/mL,与对照组相比,抑制作用增加19.14%;体外消化试验中,与对照组样品GI值94.4相比,原花青素-马铃薯复合粉GI值最低,为52,属于低GI产品。该研究对于低GI马铃薯产品的开发具有重要指导意义。

Effects of Different Curing Treatment Methods and Polyphenols on Digestibility of Potato Whole Powder

In order to develop a low glycemic index(GI)potato product,this research uses four different ripening treatment methods,direct cold treatment of 12,24,48 h and the ultrasonic combined with cold treatment of 12 h to prepare potato whole flour;and use the content of resistant starch as a judgement index to selecte the potato whole flour with the highest content of resistant starch;there are three kinds of polyphenols,proanthocyanidins,tea polyphenols and chlorogenic acid,were selected and incubated with the whole potato powder to obtain polyphenol potato composite powder.Used the 4-nitrophenyl-indole-D-glucopyranoside(pNPG)method to determine its inhibitory effect on a-glucosidase,and determined the effect of polyphenols on the digestibility of potato flour with vitro digestion.The results of this study shows:the content of resistant starch in the whole potato flour treated with cold storage for 24 hours after ripening was the highest(4.32%),which was 2.1 times the resistant starch content of untreated potato whole flour.Proanthocyanidin-potato compound powder had the strongest inhibitory effect onα-glucosidase,and its semi-inhibitory concentration(IC50)was 26.35 mg/mL.Compared with the control group,its inhibitory effect increased by 19.14%;in the in vitro digestion test,compared with the control group sample glycemic index(GI)value of 94.4,the proanthocyanidin-potato composite powder had the lowest GI value of 52,which belongs to low GI product.This research had important guiding significance for the development of low-GI potato products.