Effect of Supercritical CO^sub 2^ Modified with Water Cosolvent on the Sterilization of Fungal Spore-Contaminated Barley Seeds and the Germination of Barley Seeds

• Published in: Journal of food safety Vol. 33; no. 1; p. 94
• Main Authors: Park, Hyong Seok, Choi, Hee Jung, Kim, Kyoung Heon
• Format: Journal Article
• Language: English
• Published: Westport Blackwell Publishers Inc 01.02.2013
• Subjects: Barley; Carbon dioxide; Food safety; Germination; Penicillin; Sterilization
• ISSN: 0149-6085; 1745-4565

We have investigated the effects of supercritical carbon dioxide (SC-CO2) modified with water as a cosolvent on the inactivation of Penicillium oxalicum spores inoculated on barley grains and also on the germination yield of the SC-CO2-treated barley grains. After SC-CO2 treatment at different conditions of temperature, cosolvent (water) content and treatment times, the number of colony-forming units (cfus) of fungal spores and the germination of SC-CO2-treated barley grains were analyzed. Among the SC-CO2 treatment parameters, the cosolvent content was the most significant factor affecting the inactivation yields of P. oxalicum spores. When the pressure of SC-CO2 was fixed at 10 MPa, the optimal conditions obtained by ridge analysis of response surface methodology were cosolvent content of 231 μL, temperature of 44C and treatment duration of 12 min, which resulted in a 6.8 log10 reduction of cfu. However, the germination yield of barley grains decreased significantly by treating with SC-CO2 modified with water. For example, the addition of only 300 μL water in the SC-CO2 treatment reduced the germination yield from 65.4% to 1.4% at the same SC-CO2 treatment conditions (40C, 10 MPa, and 20 min). [PUBLICATION ABSTRACT]