Impact of Industrial Kitchen Processing Approaches on Nutritional and Sensorial Quality of Leek Products

Industrial kitchens contribute to enhanced efficiency and convenience in food provision. While existing guidelines primarily focus on food safety, it is essential to extend the focus to include nutritional and sensory quality as well. This study examines common processing approaches applied in industrial kitchens to understand their impact on the overall quality of leek (Allium ampeloprasum var. porrum). Currently, food in industrial kitchens is processed using one of the following approaches: (i) steam preparation followed by a holding time of maximally 3 h until serving (“single-heat-preparation”) or (ii) steam preparation, cold overnight storage, and reheating via microwaves or convection followed by a holding time of maximally 1 h until serving (“double-heat-preparation”). In this study, both processing approaches were applied to diced leeks and leek puree. Multiple health- and sensory-related quality attributes (e.g., vitamin C, S-alk(en)yl-l-cysteine sulfoxides, color and volatile compounds) were evaluated at different moments during processing. It could be concluded that vitamin C concentrations were strongly impacted by each heating step resulting in a strong reduction or complete loss of vitamin C at the final holding time. On the contrary, S-alk(en)yl-l-cysteine sulfoxides concentrations were stable during all processing steps. Moreover, the loss of green color was most noticeable in the leek puree and became more pronounced with longer holding times. Finally, the differences in volatile profiles between different processing steps were less outspoken than the differences between the fresh diced leeks/leek puree and the processed material immediately after preparation.

Graphical Abstract