Abstract: 【Objective】 Cooking of potato is a main important processing method in China. The cooking quality of potato should be analyzed and classified according to the commercially processing criterion. Screening for cooking-processing potato lines according to potato tuber qualities and properties from varieties and advanced lines are efficient methods under current consumptions of potatoes. As the processing indexes are required for different production purposes, potato breeding schemes have to be improved and changed to suitable for different cooking-processing standards. 【Method】Selection at an early breeding stage, the characteristics with agronomic traits such as yield, tuber size, tuber shape, tuber colour, eye depth, diseases resistance and commodity rate were evaluated based on three different locations in three years. Fourteen potato varieties and lines were selected for cooking qualities test. Samples of potato tuber were cooked in boiling water steamer for 25 min. After cooled for 20 min and 7 days under room temperature, the tuber colour change, the hardness and softening of the tubers from before-cooking to after-cooking were determined and analyzed. The contents of dry matter, starch, total glycoalkaloid, sucrose, reducing sugars, free amino acids, chlorogenic acid, ascorbic acid, citric acid were measured. The effect of change of the above components on tubers umami, colour change and texture were analyzed. The essential cooking-processing indexes were defined. 【Result】Comprehensive analysis and assessment on agronomic characters of potato varieties and lines showed that the first-line for selecting cooking-processing potato is that the agronomic characters of potato should meet the commercial processing criteria. The content of reducing sugars should be below 0.4% because its effect on tuber sweet flavor. There were no significant difference between tuber umami and the content of free amino acids (30-70 µmol) in fourteen varieties and lines. The content of total glycoalkaloid should be below 150 mg·kg^-1, which negatively influences on tuber bitter flavor. The value of ΔE colour between the cooking end and seven day later after-cooking was the important colour index in potato cooking-processing. The tuber softening difference was another important index of potato cooking-processing. 【Conclusion】The present results indicated that the after-cooking tuber umami, colour change and texture are the most important cooking-processing indexes. The varieties Burbank, Shepody and lines 0724-58, 0712-66 are the better softening potato varieties and lines. The potato lines 0744-8 and 0722-26 are the better hard lines.

Key words: potato, cooking, flavor, colour, texture, softening