Preservation of minced meats by using medium and high-dose levels of gamma irradiation

The effect of medium [2.5-10 kGy] dose irradiation and high [20-70 kGy] dose irradiation on the microbiological, chemical and organoleptical properties of minced meat samples was studied. It was found that irradiation dose of only 5 kGy greatly reduced all microbial counts and completely eliminated all non-spore forming pathogenic bacteria contaminated minced meat samples. Consequently, this irradiation dose extended the refrigerated [3°C +/- I] storage life of these products for more than 8 weeks. This irradiation dose almost did not affect the chemical composition, particularly the main amino acids and main fatty acids of minced meat samples. Panelists could not differentiate between irradiated minced meat samples at this dose and unirradiated samples. High doses irradiation, i.e. 40 and 70 kGy were sufficient and efficient for sterilizing minced meat samples and in obtaining long-stable minced meat products [two years] at ambient temperature. These irradiation doses slightly reduced [not more than 7%] aspartic acid, glutamic acid, methionine and lysine of minced meat. It also decreased the relative percentage of total unsaturated fatty acids by not more than 17%. These high irradiation doses caused loss of C18:3 and C20:1

Irradiation for shelf-life extension and improvement of the hygienic quality of cold-smoked herrings and hot-smoked eels

A shelf-life extension and improving the hygienic quality of cold- smoked herrings and hot-smoked eels were done using gamma irradiation. The preparation of each product was described. Dose level of 5 kGy extended the shelf-life of cold-smoked herrings with 48% moisture and 8% salt up to 4 months at room temperature compared by one month for the unirradiated samples. This irradiation dose was also sufficient and efficient for eliminating the risk resulting from pathogenic bacteria and mycotoxigenic fungi, which may be present in smoked fish. Application of 7.5 kGy of gamma rays appeared to be effective and sufficient for eliminating the anaerobic and pathogenic bacteria in the hot-smoked eels [60% moisture and 1.5% salt] packed in polyamide- polyethylene bags under vacuum condition. It has remarkable effect in decreasing the total aerobic bacteria and hence extending the shelf- life of smoked eels to more than 60 days under cold storage [3 +/- 1C] compared by only 15 days for the unirradiated samples. This dose greatly affect the flavor of this product. Irradiation dose of 5.0 kGy appeared to be optimum for extending the shelf-life and improving the hygienic quality of hot-smoked eels without changing their attractive flavor