Effects of roasting on chemical composition and quality of different chestnut (Castanea sativa Mill) varieties

In view of the ongoing revival of the chestnut orchards in southern Switzer land, evaluation of chestnut quality represents an important issue. Chestnu ts are mainly consumed roasted. Three native varieties and a French one wer e roasted and submitted to sensory and chemical analysis in comparison to a commercial marrone variety imported from Italy. Weight loss due to roastin g ranged from 23 to 30%. Roasted chestnuts contained 260-350 g kg(-1) starc h, 50-102 g kg(-1) sucrose, 0.5-4.4 g kg(-1) fructose, trace amounts of glu cose and 9-15 g kg(-1) total fatty acids. The main fatty acid in chestnuts was linoleic acid, amounting to 49% of total fatty acids. Sensory analysis showed that acceptance of chestnuts was highly dependent on sweetness, whic h was related to sucrose content. It should be at least 90 g kg(-1). Variet al differences were observed in this study and it was shown that roasting c aused little change in composition. Thus chestnut varieties used for roasti ng have to be selected accordingly. The commercial variety Marrone di Cuneo confirmed its superiority with regard to suitability for roasting. Among t he Swiss varieties, only Luina exhibited satisfactory quality. (C) 2001 Soc iety of Chemical Industry.