Optimization of 60Coγirradiation process for food

Abstract

This study aims at improving the irradiation processing capability of the 60Coγ-radiation source and ensuring the quality of irradiated food.Thus,different stacking thicknesses and irradiation box structures were selected as process parameters,and the absorbed dose and unevenness of irradiated foods with different densities were measured and analyzed.The results showed that the spatial dose field distribution was symmetric with the center point of the source plate,symmetrically distributed above and below the center,and that the absorbed dose at the center was the highest.With increasing distance from the center,the absorbed dose decreased,and unevenness was observed.The greater the stacking thicknesses of products with the same density,the higher was the unevenness.There was no obvious effect of stacking thickness on low-density products.Combined with the dose distribution of the empty field,when the unevenness was greater than 1.4,the main contradiction was transformed into the influence of stacking thickness,mainly because of the inhomogeneity of the outer and central surfaces.At this time,in order to increase the utilization rate ofγ-rays,the minimum dose and loading amount should be determined for the product with a density of less than 0.36 g/cm3,consider thinning instead of tiling for the product with a density of more than 0.36 g/cm3.For products with a density of 0.3 g/cm3,the spatial distribution of the irradiation field at a height of 5 cm from the bottom of the irradiation box was better than that of the punch.In addition,theγ-ray utilization of the irradiation box height and punch increased by 8.26%and 8.30%,respectively,compared with those for the original irradiation box.Therefore,the loading capacity and the structure of the irradiation box can be considered to reduce the minimum absorbed dose of food,thereby improving the energy utilization rate and production efficiency ofγ-rays during food irradiation.