Chemometric fatty acidomics to distinguish between yeast and sourdough breads from Serbia and Turkey

Abstract

A targeted gas chromatography-flame ionization detection profiling method was used to study the distribution of fatty acids amongst yeast and sourdough breads, as a basis for developing a novel strategy for classification into relevant groups employing chemometric algorithms. Authentic sourdough bread samples were produced by spontaneous sourdough fermentation. Common yeast-leavened breads, made from refined and wholegrain flours, were obtained from commercially sources. Retail samples were collected from Serbian and Turkish markets. Bread crumbs, crusts and whole slices were analysed separately. C18:2n6c, C18:1n9c, C16:0, C18:0, and C18:3n3 were the most abundant fatty acids in all bread samples. Short-chain and odd-chain fatty acids were detected, however, in minor quantities. Principal component analysis was used to explore differences between bread types and gave an insight into the potential of a fatty-acidomic approach for authentication purposes. The similarity percetage (SIMPER) test allowed the selection of fatty acids with a high discrimination potential, which were further employed as matrices for construction of a discriminant analysis classification model. Fatty acids proved to be excellent chemical descriptors for classification of bread crumbs, resulting in 100% correct classification obtained for two groups, namely, spontaneous sourdough versus yeast fermentation and wholegrain versus refined wheat flour content.