Intensive processing reduces quality of grains: a triangulation of three assessment methods

Abstract

ABSTRACT The presented study evaluated different manufacturing procedures of breakfast cereals in view of their ability to preserve the natural quality of the raw material, as this is recommended by the EU Regulation 2018/848 for organic farming and the Demeter guidelines. From four crops (spelt, buckwheat, rice and quinoa), different products were manufactured: flakes, roasted flakes from cooked grains, extrudates from dough, and puffed grains. The samples (in total n = 18) were analysed for positive (thiamine, folate, lysine) and negative (acrylamide) health-related constituents, delayed fluorescence by Fluorescence Excitation Spectroscopy (FES) and food-induced emotions by the EmpathicFoodTest (EFT). The results showed that the four crops reacted similarly to the manufacturing processes, but the sensitivity of the crop was different for the health-related constituents, with spelt and rice showing greater sensitivity with respect to acrylamide formation and thiamine loss, than buckwheat and quinoa (though differences at the individual crop level were not statistically verified). The different assessment methods led to largely consistent evaluations of the processing methods: after extrusion, puffing and roasting flakes, significant quality losses were observed. Depending on the parameter of the test method, the classification of the degradation due to processing differed slightly: lysine degradation was significantly higher in puffed products (especially in rice and spelt) and acrylamide concentration was high (> 200 µg kg-1) in roasted and puffed spelt. The methods EFT and FES rated extruded samples particularly unfavourably. The least harmful process in all parameters was the production of flakes.