FNH 200 Chapter Notes - Chapter 10: Electronvolt, Irradiation, Lipid Peroxidation
1 Feb 2019
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Ionizing energy: short wavelengths used in irradiation, good penetrating power. 10. 3 food irradiation: application of radiation in form of ionizing energy, gamma rays from cobalt-60 or cesium 137, x rays from machine operated = 5 mev, electrons from machine operated = 10 mev. The gray: unit of energy absorbed by food: 1000 grays=1 kgy. 10. 4 effects of ionizing energy absorbed by food-preservation principle: produce free radicals, extremely reactive. Inactivate mos, enzymes, alter food consituents during irradiation: direct/indirect effects, h2o2 =antimicrobial agent, kills bacteria,yeasts,moulds. Free radicals also produced in body during metabolism. Irradiated food does not have enough energy to induce radioactivity: exposed to min 15 mev to be radioactive, max outputs 5 or 10 mev. Formation of unique radiolytic productions: not significant, no harmful effects. Proposed methods of minimizing undesirable changes during irradiation. Irradiation in frozen state: water frozen= free radicals produced at lesser extent, delay free radical diffuxion/migration into food, d10 values change b/c water frozen.
