Carbohydrate profiling of six purple-fleshed sweetpotatoes at different harvest stages

The quality of table-stock sweetpotatoes is significantly influenced by carbohydrates. The study investigated the changes of dry matter, starch, amylose, soluble sugar and 22 sugars in six purple-fleshed sweetpotatoes (PFSPs) with different anthocyanin contents harvested at 75, 105, 135, 165 days after transplanting, and revealed the accumulation pattern of carbohydrates in PFSPs. The dry matter accumulated constantly. The starch content decreased at 165d in GZ1, GZ9, GZ10 and G95–1, while GZ2 and G20 continued to accumulate with more starchiness taste. The accumulation of soluble sugars was primarily observed in 75–135 days, with sucrose, glucose, and D-fructose representing the predominant sugars. The proportion of sucrose varying from 41.75 % to 87.07 %, but decreased at 165d accompanying with the increasing of glucose and fructose. GZ1 exhibited the most favorable taste profile with higher sweetness and GZ10 accumulated sugar rapidly at 165d, making it the most suitable for harvesting later. While GZ2, GZ9, G20 and G95–1 accumulated carbohydrates rapidly in 75–135 days, which can be harvested appropriately early. This study can provide a theoretical basis for the selection and breeding for better quality of PFSPs.