Flavour formation in the coffee substitute ‘lupin coffee’ related to the formation of acrylamide

A coffee substitute derived from sweet lupins (<i>Lupinus angustifolius</i> L.) was investigated for the first time with regard to the impact of the roasting process on flavour formation, acrylamide generation, and amino acid behaviour. Roasting was carried out batchwise at temperatures between 98 °C to 220 °C. 55 volatile compounds were semi-quantified using headspace SPME GC-MS. Maillard reaction products, particularly substituted pyrazines and furans, constituted the majority of the volatiles formed. The flavour of "lupin coffee" was described as strongly roasted and reminiscent of coffee, though less complex than traditional coffee. Flavour development became evident at temperatures of 195 °C and above. The highest acrylamide concentration detected was 111 μg/kg at 220 °C which is considerably below the EU benchmark levels established for coffee substitutes. This work provides a solid foundation for future investigations aimed at minimising process contaminants while preserving the desired flavour.