Enzymatic Conversion of Starch in Twin-Screw HTST-Extruder

Wheat starch was liquefied to DE 25–30 employing heat stable α-amylase and twin-screw Werner & Pfleiderer Continua 58 HTST-extruder. Most significant reduction in batch saccharification time was obtained when starch was liquefied as a slurry containing 60% water at 120°C mass temperature, feed rate 1 500 g min⁻¹, screw rotation rate 250 min⁻¹, and 0.9% (w/w, d.s.) Novo Termamyl 120 L α-amylase was added immediately after initiation of gelatinization in the extruder. Saccharification was carried out at 60°C employing 0.36% (w/w, d.s.) Novo glucoamylase 150 L to reach a DE 96 in 22 h. Best total conversion was, however, obtained when also saccharification was initiated in the extruder by adding glucoamylase just before the die element, after lowering mass temperature to 60°C, and by allowing the saccharification to continue at 60°C after extrusion processing to reach a DE 94 in 5 h and DE 97 in 21 h.     

Computations of ESR Coupling Constants in Organic Radicals. II. Nitro derivatives of the phenyl radical

We compute the ESR coupling constants and the geometries of a set of nitro derivatives of the phenyl radical. We consider the three mononitrophenyls, the six dinitrophenyls and 2,4,6-trinitrophenyl. The computations are based on the use of the Gaussian 82 Program Package with the STO-3G basis set. There are no experimental data available.