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Gelatinization and Liquefaction of Starch with a Heat Stable α‐Amylase
Author(s) -
LEE Y.C.,
KIM K.T.
Publication year - 1990
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1990.tb03938.x
Subject(s) - starch , slurry , cooker , extrusion , liquefaction , moisture , amylase , materials science , barrel (horology) , water content , chemistry , food science , chemical engineering , composite material , biochemistry , organic chemistry , geotechnical engineering , archaeology , history , enzyme , engineering
Sweet potato and corn starches were gelatinized and liquefied to dextrose equivalent (DE) 10 in a steam‐jacketed kettle or in a twin‐screw extrusion cooker in a single step process with a heat stable ex‐amylase. The time required to gelatinize and liquefy 20% starch slurries in a kettle at 95°C was 45 to 50 sec. Starch powder (10 kg/hr) and water (2‐6 kg/hr) were fed to an extrusion cooker to adjust the moisture contents of the starch from 20 to 55% (wet basis) and gelatinized and liquefied to DE 10 at a barrel temperature of 120°C or above with 2 to 3% (w/w) a‐amylase added. The optimum conditions for the operation were to feed starch with water to maintain 50% moisture and 2% heat stable a‐amylase at a barrel temperature of 120°C.