Gelation of starch paste cooked with crude extract of labiate herb (Mesonaprocumbens Hemsl.)

Crude extract of Mesona procumbens Hemsl. (CEM), dark brown liquid was extr acted with a weak alkaline from dried labiate herb grown in Taiwan. When ta pioca starch was cooked rapidly with dilute CEM solution, sticky cold paste formed hard gel like agar. The Sol is one of the popular desserts in Taiwa n. Rheological behaviors of the gel were investigated. The cooking viscosit y by Rapid Visco-Analyzer and the dynamic modulus of cold paste body were i ncreased as the concentration of GEM. The optimum concentration of CEM was 2% for tan delta, but of starch was saturated at 5% for G'. Thf similar beh aviors of gel were recognized as for potato and waxy corn starch. However, it was no effect on the crude extract of Japanese perilla. Therefore, the g elling effect to starch paste may be the characteristic of Mesona herb. Whe n the same process was applied to the paste that was completely dispersed i n an autoclave, it did not form a gel. It appears that the gelation needs t o existence of swollen starch granules, though it was glutinous starch of a mylose free. Higher modulus of the gel was obtained at pH 7.0 and by dialys is of GEM.