ABSTRACT
Ozone has a wide antimicrobial spectrum which, combined with a high oxidation potential, makes it an attractive processing option for the food industry. Relatively small quantities of ozone and short contact times are sufcient for the desired antimicrobial effect and it rapidly decomposes into oxygen, leaving no toxic residues (Muthukumarappan, Halaweish, and Naidu 2000). Ozone
9.1 Introduction .......................................................................................................................... 127 9.2 Ozone .................................................................................................................................... 128
9.2.1 Ozone Generation ..................................................................................................... 129 9.2.2 Application of Ozone ................................................................................................ 129 9.2.3 Rheological Properties of Food Hydrocolloids ........................................................ 130 9.2.4 Effect of Ozone on Rheological Properties of Cereals and Grains .......................... 132 9.2.5 Effect of Ozone on Food Texture ............................................................................. 132 9.2.6 Effect of Ozone on Oil .............................................................................................. 133
9.3 Dense-Phase Carbon Dioxide (DPCD) ................................................................................. 134 9.3.1 Dense-Phase Carbon Dioxide (DPCD) Treatment System ....................................... 135 9.3.2 Effects of Dense-Phase Carbon Dioxide (DPCD) on Food Texture ......................... 135 9.3.3 Effect of Dense-Phase Carbon Dioxide (DPCD) on Rheological Properties of
Dairy Products .......................................................................................................... 136 9.3.4 Effect of Dense-Phase Carbon Dioxide (DPCD)-Assisted Extraction on
Rheological Properties ............................................................................................. 138 9.3.5 Dense-Phase Carbon Dioxide (DPCD)-Assisted Extrusion ..................................... 138 9.3.6 Effect of Dense-Phase Carbon Dioxide (DPCD) on Food Microstructure .............. 140
9.4 Conclusions and Future Trends ............................................................................................ 141 References ...................................................................................................................................... 141
decomposes, producing numerous free radicals, predominantly hydroxyl free radicals, which increase with increasing temperature and pH (Graham 1997). The interest in ozone as an antimicrobial agent is based on its high biocidal efcacy and wide antimicrobial spectrum. Ozone is a powerful broad-spectrum antimicrobial agent that is active against bacteria, fungi, viruses, protozoa, and bacterial and fungal spores (Khadre, Yousef, and Kim 2001). Ozone is 50% more effective than chlorine and is active over a wider spectrum of microorganisms than chlorine and other disinfectants. It reacts up to 3000 times faster than chlorine with organic materials and produces no harmful decomposition products (Graham 1997). Excess ozone autodecomposes rapidly to produce oxygen and thus it leaves no residues in food. Such advantages make ozone attractive to the food industry and consequently it has been declared as generally recognized as safe (GRAS) for use in food processing by the U.S. Food and Drug Administration (FDA) in 1997 (Graham 1997). Ozone subsequently gained approved as a direct food additive for the treatment, storage, and processing of foods in the gaseous and aqueous phases in 2001 (Khadre et al. 2001).
