Freezing of Vegetables by Direct Contact With Aqueous Solutions of Ethanol and Sodium Chloride

Aqueous freezant (AF 15–15) consisting of 15% NaCl and 15% ethanol with a −19.3°F solubility limit was developed for direct contact freezing of vegetables. Carrots (3/8 in. dice) and peas were frozen and cooled to 2.5°F in 1.5 min of immersion and beans (1 in. cut) and whole kernel corn were frozen and cooled to 2.5°F in 2.5 min of immersion. AF 15–15 frozen and blotted peas, beans and corn contained 0.72–0.82% NaCl and were statistically indistinguishable from air‐blast frozen vegetables in organoleptic ratings. Air‐blast frozen carrot dice were preferred over AF frozen dice which contained 1.77% NaCl. A mixture of all of the above vegetables frozen in AF 15–15 was slightly favored over an air‐blast frozen mixture (6.7 vs 5.8 score). AF frozen vegetables showed a small (2.3–0.9%) weight gain, whereas the air‐blast frozen vegetables showed losses of from 3.9–13.3% with respect to fresh weight.