F. Schierbaum et B. Kettlitz, STUDIES ON RYE STARCH PROPERTIES AND MODIFICATION .3. VISCOGRAPH PASTING CHARACTERISTICS OF RYE STARCHES, Starke, 46(1), 1994, pp. 2-8
Pasting characteristics of native as well as of physically and chemica
lly modified rye starches have been characterized and compared with th
e other triticeae starches and starches from maize and potatoes. Norma
l and pressure viscograph techniques were applied. Additional, ridgeli
metry investigation were performed with the gels formed from the visco
graphically prepared pastes. Rye as well as wheat and triticale starch
es exhibit unique, typical gelatinization behaviour, late onset of con
sistency gain, low but highly stable cooking consistency, consistency
gain of the two-threefold on cooling. Gels are of statistically lower
firmness as those of maize starch. Higher degrees of consistency, good
cooking stability and high consistency gain on cooling were achieved
after treatment in the pressure viscograph (max. temp. 120 degrees C).
Physical treatment like annealing, heat-moisture treatment, extractio
n by aqueous solvents, drying procedures result in different but in ea
ch case typical change of properties: shift of onset consistency gain,
lower maximum consistency values, lower consistency gain on cooling.
Gelfirmness will be enhanced in every case. The pasting characteristic
s of heat-moisture treated wheat starch differ from this by remarkably
higher consistency values. Possible reasons for this are discussed. S
uccination (0.7-2.1%) changes the pasting characteristics towards the
potato starch type, lower onset temperatures of consistency gain, very
high values in maximum consistency, diminished cooking stability. The
gels formed are smooth and turbid. Acetylation (0.7-2.3%) changes the
pasting characteristics towards the maize starch type, maximum consis
tencies are lower compared with succinated triticeae starches. Ac cont
ents of 0.7% inhibit the formation of rigid gels.