Fluidized bed granulation is widely applied to improve the flowability, dispersibility, and solubility of a variety of powdered food products. In fluidized bed granulation processing of powdered food, water or an aqueous polysaccharide solution is usually sprayed as binder on the powder for granule growth. However, the increased moisture content of granules can result in product spoilage and elongates the successive drying period. To reduce the amount of binder in the granulation process, fluidized bed granulation technology using superheated steam (SHS) containing water micro-droplets (WMD) as binder has been developed. Spraying of SHS accelerated the granule growth by condensing on the powder; however, coarse granules were produced when SHS alone was sprayed. Spraying with an optimal ratio of SHS and WMD produced granules of uniform size, with less binder moisture than conventional processes using polysaccharide solutions.

We describe a polygeneration system that can run on neat plant oils, such as Jatropha and Pongamia, or standard diesel fuel. A prototype has been constructed using a compression ignition engine of 9.9 kW shaft output. It consumes 3 L/h of fuel and will produce 40 kg/h of ice by means of an adsorption refrigerator powered from the engine jacket heat. Steaming of rice, deep and shallow frying, and other types of food preparation heated by the exhaust gas have been demonstrated. In addition, the feasibility of producing distilled water by means of multiple-effect distillation powered by the engine waste heat is shown. Overall plant efficiency and potential savings in greenhouse gas emissions are discussed.

We examined the pasteurization effect of superheated steam containing micro-droplets of hot water (Aqua-gas, 115 deg C), superheated steam (120 deg C, 180 deg C) and hot water (100 deg C) to control Bacillus subtilis spores on the potato surface. Decimal reduction times of B, subtilis spores with the heating media were 2.8, 5.0, 6.3 and 6.8 minutes respectively. In case of the Aqua-gas, almost 90% of the spores were presumably washed away from the potato surface by condensed steam and the micro-droplets within 2.5 minute. After the condensation of the steam on the potato stopped, the potato surface was subsequently pasteurized effectively by the Aqua-gas since the surface was kept wet by the micro-droplets and it was heated with high temperature steam. To examine the pasteurization effect of actually cooking with these heating media, kakuni (boiled pork belly with soy sauce) and gyusuji (boiled beef tendon with soy sauce) were cooked using the Aqua-gas (115 deg C) , superheated steam (180 deg C) and a gas stove. The bacterial numbers of the food cooked with the superheated steam and the gas stove increased to more than 103CFU/g after 5 days of storage at 10 deg C. In contrast, the bacterial numbers of the samples cooked with the Aqua-gas were maintained at less than 300 CFU/g during storage.