Shelf Life Extension of Minimally Processed Cabbage and Cucumber through Gamma Irradiation

Abstract

The influence of irradiation of minimally processed cabbage and cucumber on microbial safety, texture, and sensory quality was investigated. Minimally processed, polyethylene-packed, and irradiated cabbage and cucumber were stored at refrigeration temperature (5 degrees C) for 2 weeks. The firmness values ranged from 3.23 kg (control) to 2.82 kg (3.0-kGy irradiated samples) for cucumbers, with a gradual decrease in firmness with increasing radiation dose (0 to 3 kGy). Cucumbers softened just after irradiation with a dose of 3.0 kGy and after 14 days storage, whereas the texture remained within acceptable limits up to a radiation dose of 2.5 kGy. The radiation treatment had no effect on the appearance scores of cabbage; however, scores decreased from 7.0 to 6.7 during storage. The appearance and flavor scores of cucumbers decreased with increasing radiation dose, and overall acceptability was better after radiation doses of 2.5 and 3.0 kGy. The aerobic plate counts per gram for cabbage increased from 3 to 5 log CFU (control), from 1.85 to 2.93 log CFU (2.5 kGy), and from a few colonies to 2.6 log CFU (3.0 kGy) after 14 days of storage at 5 degrees C. A similar trend was noted for cucumber samples. No coliform bacteria were detected at radiation doses greater than 2.0 kGy in either cabbage or cucumber samples. Total fungal counts per gram of sample were within acceptable limits for cucumbers irradiated at 3.0 kGy, and for cabbage no fungi were detected after 2.0-kGy irradiation. The D-values for Escherichia coli in cucumber and cabbage were 0.19 and 0.17 kGy, and those for Salmonella Paratyphi A were 0.25 and 0.29 kGy for cucumber and cabbage, respectively.

Electron-Beam Inactivation of a Norovirus Surrogate in Fresh Produce and Model Systems

“…Khattak et al (17) reported no significant differences in appearance, firmness, or flavor for cabbage treated with gamma radiation up to 3 kGy, although there were significant decreases in scores after 7 to 14 days of storage at 5uC. Bari et al (2) found that appearance, color, taste, and texture of cabbage treated at 1.0 kGy of gamma irradiation did not undergo significant changes.…”

Low‐Dose Irradiation Improves Microbial Quality and Shelf Life of Fresh Mint (Mentha piperita L.) without Compromising Visual Quality

“…The D10 value for S. typhimurium inoculated in minimally processed pineapple was 0.24 kGy (Shashidhar and others 2007). Khattak and others (2005) reported D‐values for S. Paratyphi A as 0.25 and 0.29 kGy in cucumber and cabbage, respectively. Our D10 value for nalidixic‐acid‐resistant Salmonella was slightly lower than previously reported D10 values, but fell in the range reported by Goularte and others (2004).…”

Inactivation of a Human Norovirus Surrogate, Human Norovirus Virus-Like Particles, and Vesicular Stomatitis Virus by Gamma Irradiation

“…Currently, the FDA has approved doses of up to 4.0 kGy to control foodborne pathogens in fresh iceberg lettuce and spinach (62). It has been shown that gamma irradiation effectively inactivated Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella in food products, including fresh produce, at this approved dose (5,17,34,45,59).…”