Potato and its products have become indispensable foods and snacks for most people. Steroidal glycoalkaloids (SGAs) occur in all tissues of the potato, and consuming potatoes with a high SGA content harms human health. Therefore, the effects of different cooking methods on the SGA content in potato foods were investigated in this study. The results indicated that adding food-grade acetic acid during the manufacturing process did not affect the SGA content in stir-fried shredded potatoes or fresh mashed potatoes. However, the SGA content in potato food after peeling was significantly lower than that in non-peeled food, and the volume ratio of potato skin to flesh decreased with the increase of the potato tuber volume. Therefore, potato breeders and farmers should make the most hard to increase the proportion of commodity potato via corresponding science and technology. In addition, frying significantly reduced the SGA content in potato chips. Further research indicated that SGAs degraded slowly at 150°C, while they degraded rapidly at 190°C within 30 min. The temperature of rapeseed oil in the frying process can be as high above 200°C. Thus, frying significantly decreased the SGA content in potato chips, which could be attributed to temperature. These results will provide a theoretical basis and practical guidance for potato breeding and cooking.

An ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method has been optimized and validated to simultaneously monitor steroidal glycoalkaloids (SGAs), α-chaconine and α-solanine, in potato samples stored under natural indoor conditions in Kunming. Two different analytical columns (Hypersil Gold C18 and ZORBAX RRHD HILIC Plus) were assessed. The ZORBAX RRHD HILIC Plus showed better separation for the SGAs. The samples in the present method were directly extracted with 10% acetic acid aqueous solution. The recoveries of SGAs in the potato flesh and skin were in the range of 86.3 to 92.3% and 86.5 to 90.5% with a precision of 2.2 to 4.5% and 3.2 to 5.3%, respectively. The intra- and inter-day validation data for accuracy were in the range of 85.00 to 105.11% with a coefficient of variation (CV) of 1.88 to 8.91% and 98.50 to 100.59% with a CV of 2.11 to 8.22%, respectively. High correlation coefficients (R² = 0.9997 for α-chaconine and R² = 0.9996 for α-solanine) were obtained at 2 to 400 μg L⁻¹ SGAs. The results showed that the validation parameters of the method were in the acceptable range as recommended by the United States Food and Drug Administration (USFDA) guidelines. In addition, the SGA contents were significantly higher in the skin than those in the flesh, and significantly increased with time in the skin, but not in the flesh of potato samples.