Food Processing and Cooking with New Heating System Combining Superheated Steam and Hot Water Spray

Abstract

Superheated steam (SHS) was applied to food processing because of advantages including efficient heat transfer by latent heat, and prevention of product oxidation. SHS heating solves problems such as water absorption and dissolution of solid content from foods caused by hot water or saturated steam heating; however, it causes low product yield due to its high drying capacity. To fix these problems, a new system using SHS around 115°C and a spray of hot water micro droplets (WMD) has been developed. The SHS+WMD system has simultaneously improved the quality and yield of blanched potatoes and other vegetables. In addition, it was found that WMD increased the heat transfer efficiency of SHS. This was presumably because WMD reduced the thermal resistance of the condensed water layer on the product surface by stirring the condensate. Due to this effect, the required time for the surface pasteurization of some kinds of raw vegetables decreased. A standard plate count of bacterium on cucumber fruit decreased from 10 5 CFU/g to 300 CFU/g with a slight texture change by SHS+WMD heating for 30 s. The SHS+WMD system is currently used in the food industry for cooking potato salad, and preprocessing meat, as well as the pasteurization of fishery products in Japan.

Generation of an Unstable Rotating Arc and Its Application to Steam Superheating

“…Its heating atmosphere is clean and it returns water after cooling. It has been used in several industrial fields including decomposition of harmful matter, desiccation of waste, and sterilization and cooking of food (3)(4)(5)(6)(7) . Conventionally, steam is heated in contact with wire heaters or high-frequency inductive heaters.…”

Effect of Superheated Steam and Conventional Baking on Physiochemical Properties of High Fiber Bread

“…Superheated steam causes changes such as starch gelatinization, enzyme destruction, protein denaturation, color and texture changes and deodorization (Devahastin et al, 2004); (Tang and Cenkowski, 2000); (Tang and Cenkowski, 2001). Superheated steam in food processing has not only used for drying but also for heat treatment of food products and this is due to the advantages of superheated steam oven over convection oven including enhance product quality and preservation of nutritional components in food products (Sotome and Isobe, 2011). Increase in temperature and time caused increase in a* and b* values of color in both heat treatments.…”

“…Advantages of superheated steam oven over conventional oven include an oxygen free environment, enhanced product quality, improved energy efficiency, higher drying rate, and reduced impact on the environment when condensate is reused (Prachayawarakorn et al, a, 2006Prachayawarakorn et al, 2004 b, andTang et al, 2005). Superheated steam helps in preventing lipid oxidation whilst preserving nutritional components in food products (Sotome and Isobe, 2011). Food products have better aroma when dried with superheated steam.…”