1. A process for the production of frozen foods, comprising the steps of:
i) subjecting the food to a slow and slight dehydration treatment to partially eliminate the water content 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.
2. The process according to claim 1, wherein before freezing the food, the food is allowed to rest to favor the redistribution of the free water contained therein.
3. The process according to claim 2, wherein the food is allowed to rest for a period comprised between approximately 1 hour and approximately 24 hours.
4. The process according to claim 1, wherein the dehydration treatment is carried out by convection blowing humid non-saturated air at a temperature less than 15\xb0 C.
5. The process according to claim 1, wherein the rapid freezing treatment is by immersion in an aqueous solution at a temperature between approximately \u221230\xb0 C. and approximately \u221250\xb0 C. according to the type and size of the food.
6. The process according to claim 5, wherein the food is fruit and in that the aqueous solution contains betaine at a suitable concentration for maintaining the water in liquid state at a temperature between approximately \u221235\xb0 C. and approximately \u221250\xb0 C.
7. The process according to claim 1, wherein the food is packaged under a partial vacuum before being subjected to the rapid freezing treatment.
8. The process according to claim 5, wherein the food is fruit and in that 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 \u221235\xb0 C. and approximately \u221250\xb0 C.
9. The process according to claim 1, wherein the rapid freezing treatment is carried out by intervention of liquid nitrogen.
10. The process according to the previous claims claim 1, wherein the food is fruit, which is chopped up before being subjected to the dehydration treatment, and wherein the portions of fruit are sprayed with an antioxidant product.
11. The process according to claim 1, wherein the food is a fruit or a vegetable.
12. The process according to claim 1, wherein the step of subjecting the food to a slow and slight dehydration treatment partially eliminates the water content of the food’s envelopment or outermost layer by between approximately 2% and approximately 10% by weight.
13. The process according to claim 8, wherein the food-grade soluble substance is potassium acetate or calcium chloride.
14. The process according to the previous claims claim 1, wherein the antioxidant product is ascorbic acid.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A hydraulic pressure control device comprising a housing formed with an input port, an output port and a discharge port, and a proportional pressure control valve and a hydraulic pressure generator mounted in said housing, said proportional pressure control valve having a spool valve and a return spring for biassing said spool valve, said spool valve bringing said output port into communication with said discharge port in a non-operated state, bearing hydraulic pressure on its opposed pressure-bearing surfaces having a difference in area, and moving to a balance point where the sum of the hydraulic pressure and the force of said return spring balances with an external force applied opposite thereto to change over connections of said output port to said input port and said discharge port, adjust the degree of opening of fluid passages, and adjust the hydraulic pressure at said output port to a value corresponding to the external force, said hydraulic pressure generator combined with said proportional pressure control valve, said hydraulic pressure generator comprising a second piston for transmitting a force to said spool valve through a second spring, a first piston for transmitting a force to said second piston through a first spring and an output port, wherein said first piston receives the brake pedal force as the external force, pressurizes and outputs brake fluid introduced into a fluid chamber between said first piston and said second piston.
2. A brake device for a vehicle comprising the hydraulic pressure control device as claimed in claim 1, a pressure source connected to said input port of said hydraulic pressure control device, wheel brakes in a first line connected with said output port, wheel brakes in a second line connected with said output port of said hydraulic pressure generator, and a copy valve actuated by the hydraulic pressure difference between the first line and the second line to open and close a passage extending from said hydraulic pressure generator to the wheel brakes in the second line, said copy valve having a piston bearing fluid pressure in the first line on one side for pressurizing the wheel brakes in the second line, and a reservoir connected to said discharge port of said proportional pressure control valve, wherein brake fluid is supplied from said reservoir to a fluid chamber between said first and second pistons of said hydraulic pressure generator, and during failure of said pressure source, the hydraulic pressure generated in said hydraulic pressure generator is supplied to the wheel brakes in said second line.
3. A brake device for a vehicle as claimed in claim 2 wherein the spring force of said first spring of said hydraulic pressure generator is greater than the sum of the force of said second spring and the sliding resistance of said second piston, and wherein brake fluid is pressurized by said first piston after said second piston has reached the end point of its travel.
4. A brake device for a vehicle as claimed in claim 3 wherein a pressure-bearing unit having a housing and a piston mounted in said housing for bearing the hydraulic pressure of said pressure source on one side is provided, and wherein one end of a reaction-force spring for returning the brake pedal is supported on the other side of said piston of said pressure-bearing unit.
5. A brake device for a vehicle as claimed in claim 2 wherein a reaction-force spring for returning the brake pedal is provided between said second piston and said proportional pressure control valve.
6. A brake device for a vehicle as claimed in claim 5 wherein a relief valve which opens at a preset pressure and permits a fluid flow from said hydraulic pressure generator toward said copy valve and a check valve that permits only a fluid flow from said copy valve toward said hydraulic pressure generator are arranged parallel to each other in a passage in the second line.
7. A brake device for a vehicle as claimed in claim 6 wherein a bypass which brings said reservoir and the wheel brakes in the second line into communication with each other while bypassing said relief valve, check valve and copy valve is provided, and a check valve which permits only a fluid flow from said reservoir toward the wheel brakes in the second line is provided in said bypass.
8. A brake device for a vehicle as claimed in claim 5 wherein in a passage extending from said hydraulic pressure generator toward said copy valve, an electromagnetic valve for opening and closing the passage is provided which closes while the brake pedal is operated with the pressure source normally working or while pressure is reduced by said proportional pressure control valve to a pressure lower than the hydraulic pressure generated in said hydraulic pressure generator, and opens if the pressure source fails.
9. A brake device for a vehicle as claimed in any of claims 5-8 wherein a predetermined gap is provided between the brake pedal and said first piston, and wherein until said gap is absorbed, the operating force to the brake pedal is inputted to said first piston through a dummy spring having a smaller spring constant than said reaction-force spring.
10. A brake device for a vehicle as claimed in any of claims 3-9 wherein a pressure-adjusting unit is provided between said copy valve and the wheel brakes, said pressure-adjusting unit comprising an electromagnetic valve for increasing and reducing the wheel brake pressure based on a command from an electronic control device, a low-pressure fluid reservoir for storing the brake fluid discharged from the wheel brakes, and a power-driven pump for pressurizing the brake fluid stored in said low-pressure fluid reservoir and returning it toward the wheel brakes.