Ozone : Physico - Chemical Properties and Whiteness Increasing Application on Fish Products

Abstract

Ozone is the substance which is produced from oxygen in the air and electric energy or ultraviolet ray by changing oxygen’s chemical structure from O2 to O3 in 1 molecule. In 1840, ozone was first found by the German Scientist, C. F. Schonbein. Its qualification is water soluble at low temperature and can be applied as ozone solution which has the sanitizing property in water. According to this principle, there is a development of ozone generator for business which lets oxygen gas flows through electric stream in the discharge gap which is the result of produced electrical stream from the dielectric surface. The breakdown of ozone depends on pH value, temperature, and ultraviolet ray. There are 2 types of chemical breakdown reaction of ozone namely indirect and direct. Currently, there are many ways of using ozone namely 1) damaging toxin or biotoxic agents, 2) using as oxidized organic compounds, 3) damaging pathogenic microorganism, 4) eliminating unwanted odours, and 5) bleaching. In 1997, Dee Graham certified that ozone could be used for cleaning tools, machines, and grounds of the food processing factory. He also motivated the United States Department of Agriculture (USDA) to certify ozone by specifying the standard of “generally recognized as safe” (GRAS). Moreover, the United States for Food and Drug Administration (USFDA) officially accepted ozone in both gaseous and aqueous phases on June 26, 2001. In terms of ozone’s mechanism of “revised whiteness”, the previous research found that washing fish by ozone water could increase more lubricity value and whiteness than other ways. Because of the losing of myoglobin and bleaching, ozone would destroy the structure of porphylin in myoglobin and haemoglobin, but ozone would cause the gelation. In addition, the previous research related to the test of ozone for producing mackerel surimi found that ozone oxidized the free sulfhydryl group on protein molecule which caused the disulfide bond. Ozone could also oxidized the disulfide and led to the cysteic acid. In other words, ozone could destroy disulfide bond which led to sulfonic acid. This process caused the protein denaturation that caused the reduced capacity of gelation. As for the using of ozone for revised whiteness of horse mackerel fish, it was washed by using ozone in distilled water , and was controlled by washed water temperature lower than 5 ํC. It was found that this process could revised whiteness for 10-20 minutes because ozone was the strong oxidizing agent which could destroy the structure of porphylin. Besides, it could increase the proficiency of various composition separated by floating with bubble. Therefore, “soluble pigment” might be destroyed by this floating. As for the test of using the cooled water and washing with alkaline solution, it was found that it took long time or had to wash many times in order to revised. Moreover, it was found that ozone could revised whiteness and reduce the quantity of myoglobin and total pigment content for producing surimi by washing mackerel meat with 0.04 M ozone in citrate buffer at pH 3 for 30 minutes. In conclusion, washing fish by using of ozone must consider the residual ozone in water because if there is no residual ozone, it will be ineffective.