RETENTION OF NUTRIENTS IN CANNED BUFFERED AQUEOUS-SOLUTIONS AS INFLUENCED BY ROTATIONAL STERILIZATION IN A STEAM AIR RETORT

Aqueous mixtures of ascorbic acid and thiamin hydrochloride dissolved in 0.1 M phosphate buffer (pH 5.5) were sealed in small glass vials (1 .8 mL capacity) and placed in 307 X 409 (87 mm diameter, 115 mm height ) cans filled with vegetables. In addition, aqueous buffered solutions of vitamins were also directly filled into separate 307 X 409 cans an d vacuum sealed. All cans were subjected to approximately equivalent a ccumulated process lethalities (F-o similar to 10 min) in a rotary ste am/air retort. Process variables were retort temperature (110-130 degr ees C) and rotation speed (0-20 rpm). Percentage retention of the vita mins in each sample was determined experimentally using a HPLC techniq ue. The study indicated that processing at 110 degrees C yielded signi ficantly lower retention (p<0.05) of both vitamins, relative to 120 an d 130 degrees C. However, the rotation speed did not have a significan t effect (p>0.05) on the retention of vitamin in either cans or in-can vials. Estimated ascorbic acid and thiamin retention using experiment al time-temperature data and published kinetic parameters showed fairl y good agreement with experimental data.