Development of shelf stable chiffon cake using gamma irradiation

Gamma irradiation combined with mild preservative was applied to extend the shelf life of chiffon cake stored at ambient temperature. Reduction of specific volume, hardness, springiness, chewiness and crumb yellowness was noticed after irradiation at 2-10 kGy, whereas crust yellowness and peroxide values increased. Panelists could detect a decline in chiffon cake qualities, especially odor and texture. Although overall acceptability scores significantly decreased (p < 0.05) at doses above 4 kGy, the scores did not differ significantly (p ≥ 0.05) between 2 kGy and 4 kGy. Thus, a dose of 4 kGy was recommended for chiffon cake irradiation to encourage microbiological safety. Ordinary chiffon cake quickly spoiled due to mold growth while storing for 3 d. Calcium propionate at 3 g/kg could not prolong chiffon cake shelf life. This preservative had poor efficacy when employed with chiffon cake that had intermediate aw of 0.85 and basic pH of 8.24. Gamma irradiation at 4 kGy, with or without 1.5 g/kg calcium propionate, effectively extended the shelf life of chiffon cake to 90 d without mold growth detection. However, storage of no longer than 75 d was recommended when oxidative rancidity was concerned. The ability of 4 kGy irradiation to decontaminate Aspergillus flavus was successfully assured.