Peter Byoun U Yim
2 กันยายน 2557
Rice bran is a by-product of rice milling and has been underused for a long time; however, it has been discovered that rice bran oil has high nutritional compounds such as antioxidants and phytosterols. There has been considerable effort to produce wide range of products from rice bran oil. This oil has a high smoking point (232 °C), and cheaper to produce than other high smoking pointoils such as peanut and grapeseedoils. Since Thailand is one of the top rice exporting country in the world and has abundant supply of rice bran, research and development of rice bran oil products should be emphasized in our country.
One of possible products of rice bran oil is in a powder form as food ingredient or additive; however, it has been difficult to make rice bran oil powder using a sprayer dryer due to its high smoking point.Spray dryer cannot evaporate the rice bran oil higher than the oil’s smoking point to make rice bran oil powder. When an oil has high smoking point, it has to employ polymer emulsifier to encapsulate oil-water product to make it possible to be make it solid state from the liquid state of rice bran oil alone.
Oils-in-water encapsulations are not only important in producing dry oil powders for food ingredients, they have potential to be used in chemical, drug, and cosmetic industries. The encapsulation process is scientifically interesting as well as useful, because it involves chemical and physical phenomena of hydrophobic and hydrophilic barriers under the influence of temperature, pH, pressure, and humidity.
Bio-polymers such as poly-carbohydrate, poly-peptide or a mixture of poly-carbohydrate and poly-peptide), are used in making oil-water emulsion products. Once small (several hundred nanometers)stable oil droplets in the emulsion are formed, the mixture can be dried using a spray dryer to make powder.