73C-11 |
Combined effect of headspace and temperature over the shelf life of retort pouch black bean and rice burrito combat rations. |
J. J. RODRIGUEZ1, D. R. Sepulveda1, G. I. Olivas1, S. Clark2, H. Warner2, and G. V. Barbosa-Cánovas1. (1) Biological Systems Engineering Department, Washington State University, Smith Hall Room 213, Pullman, WA 99164, (2) Food Science and Human Nutrition, Washington State University, Food Science and Human Nutrition building, Pullman, WA 99164
Military requirements establish a minimum shelf life of 36 months for Meals Ready-to Eat (MRE) individual military rations when stored at 80oF. The amount of headspace gas present in pouches has been identified as an area of concern, as technical problems prevent producers from complying with the maximum allowed headspace level (10cm3). This study was directed to determine the maximum headspace level that can be allowed by the specifications without causing a detrimental effect on the product. Black bean and rice burritos were packaged and retorted in flexible pouches with four different headspace levels (10, 20, 30, 40cm3). The influence of the headspace level over the color, water activity, lipid oxidation and sensory quality was periodically assessed throughout a 6 months storage period at 40, 80 and 100oF. Gas composition inside the pouches was also periodically evaluated to determine the amount of oxygen present in the headspace. No differences in color or water activity were found among the samples packaged under different headspaces (p>0.01). Lipid oxidation was not detected at a minimum detection level of 500-ppb hexanal/headspace, at any time during the storage period. Trained panelists determined samples packaged with 10cm3 headspace had a lighter and more glossy crust appearance and firmer beans than samples with 40cm3 headspace. The trained panel also found that samples stored at 40oF were more-moist and sticky and less compressed than samples stored at 100oF. Overall acceptability was considered marginal by consumer panelists. Burritos stored at 100oF were less acceptable than those stored at 40 and 80oF after the third month of storage. Oxygen concentration inside the pouches was found to be independent of the headspace level. Headspace of Black Bean and Rice Burrito can be raised, if needed, up to 30cm3 without detrimental effect on sensory and physicochemical attributes.
Session 73C, Food Engineering: Transport Processes and Kinetics
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