Irradiation and heating effects on microbiological, physicochemical, and sensory characteristics of ground pork

Thumbnail Image
Date
1996
Authors
Navanugraha, Usana
Major Professor
Advisor
Dennis G. Olson
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Altmetrics
Authors
Research Projects
Organizational Units
Organizational Unit
Journal Issue
Is Version Of
Versions
Series
Abstract

Radiation resistance of Listeria monocytogenes Scott A in ground pork patties, packaged in air and under vacuum, was studied. The patties were irradiated, using an electron accelerator, at the irradiation temperatures of 2°C and 48°C. Lower numbers of L. monocytogenes Scott A were recovered when irradiation was carried out at 2°C and the aerobic condition was secured during irradiation and recovery. The order of radiation sensitivity from low to high was obtained from the combination treatments of heated/vacuum > refrigerated/vacuum > heated/air > refrigerated/air suggesting a thermorestoration at 48°C. D-values of 0.42, 0.37, 0.36, 0.31 kGy were found from these treatments respectively;Storage-life extension of un-inoculated ground pork, irradiated at 1kGy, was studied utilizing similar treatments. Irradiation reduced mesophilic, psychrotrophic, and lactic acid bacteria by 1.5, 1.5, and 1.2 log cycles respectively. Non-irradiated samples, packaged in air, reached the spoilage level within 5 days (refrigerated samples) to 6 days (heated) when stored at 2°C. Their vacuum packaged counterparts reached the spoilage level between 16 (refrigerated) to 26 days (heated). Irradiation appeared to extend the storage-life of ground pork for an extra 18 and 25 days (total storage-life = 23 and 31 days) in the refrigerated/air and heated/air-packaged samples. In vacuum-packaged samples, irradiation added the storage-life of 9 (heated) and 10 days (refrigerated) to the total storage-life of 35 and 26 days;Sensory evaluation of ground pork receiving similar treatments was carried out. In uncooked samples, untrained panelists preferred (p 0.05) in irradiated samples, and particularly very high (13 mg malonaldehyde/1000 g on week 4) in the refrigerated/air-packaged pork. However, their flavor and aroma preference scores, were not significantly (p > 0.05) different. The treatment that showed the longest shelf-life and overall high preference scores, in all attributes, was vacuum packaging followed by irradiation at 48°C.

Comments
Description
Keywords
Citation
Source
Copyright
Mon Jan 01 00:00:00 UTC 1996