The aim of the study was the evaluation of twelve forms of winter squash (Cucurbita maxima Duch.): cultivars Amazonka, Ambar and Karowita, 8 inbred lines (1235, 1236, 1243, 1245, 1249, 1307, 1309, 1310) and 1 F₁ hybrid (1311) for the content of free sugars and polysaccharides in their fruits. The entries were analyzed for dry matter, free sugars: fructose, glucose, mannose, saccharose; and polysaccharides: amylose, holocellulose, cellulose. Free sugars and amylose were analyzed by means of high performance liquid chromatography (HPLC), and holocellulose and cellulose using the gravimetric method. The hemicellulose content was calculated as the difference between the amounts of holocellulose and cellulose. The dry matter content in the fruit ranged between 4.0% and 25.1% of fresh weight, while the total sugars in the fruit ranged between 2.29% and 8.58%. The amylose content was estimated at 0.19% to 1.36% of fresh weight. The content of cellulose in the fruit ranged between 0.29% and 4.10%, while that of hemicelluloses – from 0.18% to 7.33% of fresh weight. Line 1310 and Ambar were characterized by the highest content of dry matter, amylose, holocellulose, cellulose and hemicelluloses in the fruit. A high additive correlation was determined between dry matter content in the fruit and the respective figures for holocellulose (r = 0.9175), cellulose (r = 0.9234), hemicelluloses (r = 0.8876), amylose (r = 0.7198) and the total carbohydrates (r = 0.8902).

key words: winter squash, polysaccharides, amylose, cellulose, hemicelluloses, HPLC.