Effects of a Novel Convection Heated Roasting Method on Aroma and Umami Taste Components of Vegetable- and Meat-Based Extracts

Roasting has been widely used in manufacturing food products, ensuring microbial safety, and improving extraction efficiency. Roasting treatment affects various qualities such as the chemical composition, physical properties, colour, aroma, and texture of food. This study determined the effect of novel convection heated roasting on aroma and taste components, that is, amino acids (AAs) and nucleotides in vegetables, meat, and their products. Heat treatment conditions were confirmed with a temperature condition of 250°C for 20–50 min for each raw material. The individual raw materials were each subjected to a convection oven process, then mixed together, and pressurised by heating at 121°C for 3 hours to prepare a key-based broth for use in Korean soup dishes. As for aroma components, aroma of fermented spirits, unpleasant aroma, and bad aroma were observed in the absence of roasting. By contrast, convection heated roasting-related aroma components such as savoury fatty aroma, coffee aroma, and roasted barley aroma were observed in the finished products after roasting. The products’ sensory profile presumably changed from negative to positive owing to roasting. By roasting, in the case of raw material extracts, the total AA and glutamic acid contents increased to 24.1–38.1%, and for the finished product, the total AA and glutamic acid contents slightly increased to 5.8–8.9%. However, no significant effect of roasting was found on nucleotides. In conclusion, it was concluded that the positive aroma component as well as the total amount of AA (umami taste) increased owing to roasting. The present results contribute immensely to the food industry as the enhancement of taste and aroma can help with the production of more palatable foods as desired by food consumers, thereby increasing the sales of nutritious foods that otherwise consumers may not buy.