Sirichai Songsermpong

A Continuous Fluidized Bed Microwave Paddy Drying System Using Applicators with Perpendicular Slots on a Concentric Cylindrical Cavity

This article presents a continuous fluidized bed microwave drying system that provided a higher drying capacity than that provided by comparable conventional hot air drying systems. Its applicator consists of perpendicular slots over a concentric cylindrical cavity that is excited by perpendicular waveguides. The paddy to be dried was dropped vertically into the center of the applicator while hot air at 60°C, heated by magnetron ventilation, was injected from the opposite direction. Statistical data on the temperature distribution of the paddy, which scattered over the whole volume of the applicator, were collected and analyzed together with the probability of its orientation, position, and density. A suitable system was proposed, constructed, and tested. It provided good quality dried paddy, similar to that from a fluidized bed drying system. The systems maximum leakage power of 4.8 mW/cm2 was well within the safety standard. With only 5.2 kJ of energy consumption, this system reduced the moisture content of a large quantity of paddy from 24 to 14% (wb) with a capacity of 3.1 kg/h. The energy cost for drying was US

Modeling of Dielectric and Thermal Properties of Protein-Enriched Instant Noodles as a Function of Food Chemical Composition

47.7/ton.

Lethality and quality evaluation of in-packaged ready-to-eat cooked Jasmine rice subjected to industrial continuous microwave pasteurization

Abstract Dielectric property measurement instruments are expensive and not readily available. Hence, models of the dielectric and thermal properties of protein-enriched instant noodles (PEIN) were developed as a function of the product moisture, protein, ash, fat, carbohydrate, and crude fiber contents. The chicken meat, egg yolk, and seaweed in PEIN varied from 0 to 30, 0 to 15, and 0 to 6 g/100 g flour, respectively. Results revealed that protein, fat, and ash contents of PEIN increased by chicken meat, egg yolk, and seaweed supplementation. Regression equations indicated that the moisture and protein contents significantly (P ≤ 0.05) increased, while the fat content decreased the dielectric and thermal properties. The R2 values of the dielectric constant and loss factor, thermal conductivity, and specific heat equations were 0.75, 0.87, 0.78, and 0.98, respectively. Finally, no significant differences (P > 0.05) between the properties values predicted from the model equations and the experimental data (not included in the development of model equations) was observed which indicated a good model fit.

The effects of freeze, dry, and wet grinding processes on rice flour properties and their energy consumption

ABSTRACT The use of the pasteurization unit as a measure of the lethal effect of heating processes and overall quality of ready-to-eat Jasmine rice was determined in order to compare the conventional and microwave technology. Cooked Jasmine rice was packed in a polypropylene plastic cup and sealed with a lidding film, then subjected to a continuous microwave system (eight 800 W; 2450 MHz) and conventional steamer. The pasteurization unit, log reduction, microorganism count, color, instrumental textural property, and sensory attributes were investigated over a 30-day storage at 8°C. The pasteurization process time was reduced from 420 s under the conventional process to 216 s under the microwave process for a 5-log reduction of L. monocytogenes. The microwave heating showed greater effectiveness for shelf life, extending the product from 7 days (conventional) to 30 days. Cooked rice after heating by microwave was whiter and showed lower hardness than the conventional heated sample. Throughout storage, sensory attributes of the pasteurized product heated by microwave were acceptable by panelists. The addition of 15% trehalose or 1% soybean oil into the rice before cooking decreased the hardness of the cooked rice during storage. This study successfully demonstrated that the continuous microwave pasteurization process, compared to the conventional process, required less process time for ready-to-eat cooked Jasmine rice and extended the shelf life while providing better product quality.