Accumulation of Steroidal Glycoalkaloids in Organs of Different Potato Varieties

To explore the accumulation rule of steroidal glycoalkaloids in potato tubers, stems and leaves for improving the comprehensive utilization of potato plants, two main potato cultivars Lishu 6 and Qingshu 9 in Yunnan province, and two new cultivars Dianshu 47 and Dianshu 23 with promotion potential were selected as experimental materials. The contents of α-chaconine and α-solanine in tubers, stems, and leaves at different growth periods were determined by means of ultra-high-performance liquid chromatography-tandem mass spectrometer (UHPLC-MS/MS). The results showed that the contents of steroidal glycoalkaloids in stems and leaves gradually increased with the advance of growth period and reached the highest at harvest. The total SGAs contents in stems and leaves of Dianshu 47 during harvest reached 256.84 and 427.25 mg/100 g·FW separately.It was significantly higher than that of the other three cultivars. The accumulation regulation of total SGAs contents in potato tubers were opposite to stems and leaves. With the maturity of tuber, contents of α-chaconine, α-solanine and total SGAs in epidermis, cortex and pith of tuber were gradually decreased. In addition, their contents in the edible parts (cortex and pith) were lower than the international recommended standard of 20 mg/100 g·FW, within safety range. In summary, the contents of steroidal glycoalkaloids decreased gradually with the maturity of potato, while increased with the maturity of potato in stems and leaves. In the harvest period, the contents of total steroidal glycoalkaloids in stems and leaves of Dianshu 47 was significantly (P<0.05) higher than that of the other three cultivars. The results suggested that Dian Shu 47 could be used as an alternative cultivar to extract glycoside alkaloids for the comprehensive utilization.