Development of shelf-stable foods fish pepes, chicken and meat dishes through radiation processing

Development of safe, shelf-stable foods are necessary to reduce dependence on refrigeration during their storage and distribution. Studies were conducted to develop preparation of shelf-stable meals (fish, chicken and meat dishes) using gamma irradiation sterilisation with a minimum dose of 45 kGy. Goldfish pepes are a very popular dish in Indonesia, particularly in West Java. They are prepared by marinating clean-fish with seasonings, wrapping in banana leaf, then cooking until well done in a pressure cooker for 45-60 min. The cooked fish is then vacuum packed in a plastic pouch, followed by a laminate of polyester/aluminium foil/polyethylene as an outer package. Irradiation was conducted under cryogenic conditions with a minimum dose of 45 kGy and the samples were kept at 28-30 deg. C post-irradiation. It was found that these irradiated fish pepes could be stored for more than one year at room temperature. The sensory quality, pH, moisture, protein and fat content were relatively stable during storage. The free radical content of the bone increased significantly with increasing irradiation dose, but decreased with time. Chicken pepes, opor, semur and curry casserole were also prepared and packed in laminated packaging materials prior to irradiation. Beef meat was used to make rendang, semur and empal. Results showed that the sterile samples vacuum packed in dry laminated bags made of PET 12μ/LDPE adh.2 /Al-foil 7μ/LDPE adh./LLDPE (C4) 50μ and comparable laminate pouches of PET 12μ/PE 20μ/Alu-Metalized PET 12μ/adh./LLDPE (C8) 50μ for chicken dishes only and stored at room temperature (28±2 deg. C) up to 18 and 10 months, respectively, were acceptable by taste panellists. No significant changes in moisture, total protein and fat content, pH, and vitamins were found in the sterile samples during storage. The banana leaf as an inner wrapper packaging material for producing radiation sterilised fish and chicken pepes plays an important role in the prevention of irradiation-odour in these products either during processing or storage. (author)