Process for the production of frozen foods, particularly vegetables or fruits
A process for the production of frozen foods, particularly vegetables or fruits, including the stages of subjecting the food to a slight and slow dehydration, preferably by air convection, to partially eliminate its water content by between approximately 2 and 10% by weight, especially its outermost layer; allowing the food to rest to favor the redistribution of the free water contained therein and subjecting the food, after its packaging, to a rapid convection freezing treatment, either by immersion in an aqueous solution of salts or by the use of liquid nitrogen. In the case of chopped fruits, before the dehydration stage the portions are sprayed with an antioxidant product.
1. A process for the production of frozen foods, comprising the steps of:
i) subjecting the food to a dehydration treatment to partially eliminate the water content of an outermost layer of the food by between approximately 2% and approximately 10% by weight; and
ii) once the free water contained in the food has been redistributed, subjecting the food to a rapid convection freezing treatment;
wherein the dehydration treatment is carried out by convection blowing air having a humidity of 20% to 70% at a temperature less than 15° C.; and
wherein before freezing the food, the food is allowed to rest to favor the redistribution of the free water contained therein.
2. The process according to claim 1 , wherein the food is allowed to rest for a period comprised between approximately 1 hour and approximately 24 hours.
3. The process according to claim 1 , wherein the rapid freezing treatment is by immersion of the food in an aqueous solution at a temperature between approximately −30° C. and approximately −50° C.
4. The process according to claim 3 , wherein the food is fruit and the aqueous solution contains betaine at a suitable concentration for maintaining the water in liquid state at a temperature between approximately −35° C. and approximately −50° C.
5. The process according to claim 1 , wherein the food is packaged under a vacuum before being subjected to the rapid freezing treatment.
6. The process according to claim 3 , wherein the food is fruit and the aqueous solution contains a food-grade soluble substance at a suitable concentration for maintaining the water in liquid state at a temperature between approximately −35° C. and approximately −50° C.
7. The process according to claim 1 , wherein the rapid freezing treatment is carried out by intervention of liquid nitrogen.
8. The process according to claim 1 , wherein the food is fruit, which is chopped up before being subjected to the dehydration treatment, wherein the portions of fruit are sprayed with an antioxidant product.
9. The process according to claim 1 , wherein the food is a fruit or a vegetable.
10. The process according to claim 6 , wherein the food-grade soluble substance is potassium acetate or calcium chloride.
11. The process according to claim 8 , wherein the antioxidant product is ascorbic acid.