Estudio de la estabilidad de vitamina C en sistemas modelo acuosos.

ROJAS A.M.L., GERSCHENSON L.N. Y ALZAMORA S.M.,

Buenos Aires, Argentina.

Congreso; VI Congreso Argentino de Ciencia y Tecnología de Alimentos y Primer Encuentro de Técnicos de Alimentos del Cono Sur.; 1994

Asociación Argentina de Tecnólogos de Alimentos (AATA) y Asoc. Latinoamer. y del Caribe de Ciencia y Tecnología de los Alimentos (ALACCTA).

he anaerobic L-ascorbic acid (AAs) destruction in glucose aqueous model systems (water activity, aW, 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 90ºC) 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) and 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 antimycotics, 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.