Influence of system composition on ascorbic acid destruction at processing temperatures
The anaerobic L-ascorbic acid (AAs) destruction in glucose aqueous model systems (water activity, a(w), 0.94) of pH 3.5, 4.1 and 5.0 was studied. The AAs degraded as a function of time and temperature (70, 80 and 90°C) with a behaviour that, in general, could be described by first order kinetics exc...
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| Autores principales: | , |
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| Formato: | JOUR |
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00225142_v74_n3_p369_Rojas |
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| Sumario: | The anaerobic L-ascorbic acid (AAs) destruction in glucose aqueous model systems (water activity, a(w), 0.94) of pH 3.5, 4.1 and 5.0 was studied. The AAs degraded as a function of time and temperature (70, 80 and 90°C) with a behaviour that, in general, could be described by first order kinetics except for AAs in the system containing L-lysine, in which the results adjusted to zero order. The increment of pH from 3.5 to 5.0 accelerated AAs destruction and browning reactions. The addition of tin(II) or lysine to the glucose medium, increased AAs loss and browning. No difference was observed in AAs degradation and colour intensity when sorbic or propionic acid were used as anti-mycotics, at pH 3.5. Packaging the glucose system of acid pH with an air chamber, produced a faster destruction of AAs and browning of the solution than the one observed for the same system in anaerobic condition. In aerobic condition, the presence of glucose produced a lesser degradation of AAs than the one observed in the system without humectants. |
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