About
Superheated Steam

About overheated steam

Heating principal

Heating principal
  1. Direct heating method in which caloric steam directly contacts food ingredients.
  2. Since a generation of condensation heat which has a largest calorie arises contact point of the food, a heat dissipation to other than foods is small.

Due to the above 1 and 2, a high efficient heat transfer is achieved.

Advantages of steam cooking / Nutrient retention

Comparison of vitamin C content in vegetables after different heat treatments (Report from Inui et al (Osaka Prefecture University)

Vitamin C
(mg/100gFW)
Broccoli
Broccoli
Carrot
Carrot
Pumpkin
Pumpkin
Boil cooking 16.7±5.9 2.1±0.5 7.8±1.3
Superheated steam
(our device)
56.0±3.3 2.6±0.3 10.0±2.2
Raw 88.3±1.8 4.9±0.7 12.7±1.4
Values are expressed as means±SD, n=3

Comparison of vitamin C content in vegetables after different heat treatments (Report from Inui et al (Osaka Prefecture University)

Vitamin C (mg/100gFW)
Broccoli
Broccoli
16.7±5.9 56.0±3.3 88.3±1.8
Carrot
Carrot
2.1±0.5 2.6±0.3 4.9±0.7
Pumpkin
Pumpkin
7.8±1.3 10.0±2.2 12.7±1.4
Values are expressed as means±SD, n=3

It is verified that in superheated steam cooking, the retention of VitaminC in broccoli which contains a lot of vitamin C is high (63.4% retained)

In comparison with boil cooking…
  • Nutrient is not eluted into water
    Therefore an original sweet taste and natural flavor of vegetables are well maintained.
  • Physical collision due to boiling is not present and firmness is maintained

Advantages of steam cooking / Improvement of preserving property

  1. The following vegetables were subjected to a heat treatment for 80 seconds according to MSC (100°C) and boil cooking
  2. Vegetables were put into a tray and a lid thereof is lightly closed so that the vegetables contact with oxygen, followed by still standing for 24 hours at room temperature (ca. 20°C)
Broccoli Cabbage
Superheated steam (our device) Broccoli Superheated steam
Kept the green color
Cabbage Superheated steam
Kept the green color
Boil cooking Broccoli Boil cooking
Partially discolored
Cabbage Boil cooking
Discolored (whitish)
  1. The following vegetables were subjected to a heat treatment for 80 seconds according to MSC (100°C) and boil cooking
  2. Vegetables were put into a tray and a lid thereof is lightly closed so that the vegetables contact with oxygen, followed by still standing for 24 hours at room temperature (ca. 20°C)
Broccoli
Broccoli Superheated steam
Kept the green color
Broccoli Boil cooking
Partially discolored
Cabbage Cabbage Superheated steam
Kept the green color
Cabbage Boil cooking
Discolored (whitish)

It is confirmed that a process of degradation is well controled.

Comparison with other systems

Comparison conducted under a condition of boiling potatoes (pieces of app. 15 g)

Multi steam cooker Steam Convection Oven 10-stage gas system by company X Rotary pot (gas) capacity: 190 L
Processing ability 140kg / h 30kg / h 45kg / h
Electricity usage
(electricity expense)
4kW/h (76JPY/h) 0.54kW/h (10JPY/h)
Water consumption
(water expense)
48L/h (19JPY/h) 10L/h (4JPY/h) 225L/h (90JPY/h)
Steam consumption
(fuel expense)
110kg/h (737JPY/h)
Gas consumption 35kW/h (280JPY/h) 50kW/h (400JPY/h)
Cost for processing1kg of potatoes 5.9JPY 11JPY 10JPY