Abstract:
To find out the preferable technological parameters for tobacco stem conditioning with supercharged steam, the effects of steam pressure, conditioning time and moisture content in tobacco stem on the chemical components and color of tobacco stems and the sensory quality, filling power and structure of cut stems were studied with orthogonal experiments, and the preferable technological parameters were determined with comprehensive equilibrium method. The results showed that:1) Supercharged steam conditioning was beneficial to the Maillard reaction of sugars in stems, the balance of chemical components and the release of volatile aroma components in stems. The pectin content in stem decreased with the rise of steam pressure and the prolongation of conditioning time, and the variation range of color difference (△
E) enlarged with the increase of processing intensity. Moreover, the influences of steam pressure on pectin content and △
E reached an extremely significant level (
P < 0.01) and a significant level (
P < 0.05), respectively. 2) Within the tested range, the preferable technological parameters were steam pressure 0.3 MPa, conditioning time 60 s, moisture content in stem 25%. The tested samples offered the best aroma volatility and burnt-sweet aroma note, less woody odor and irritation, the filling power and long strand proportion increased, the contents of pectin and phenylalanine degradation products decreased by 10.05% and 7.24%, respectively; the content of Maillard reaction products increased by 29.28%, and the difference reached a significant level (
P < 0.05).