Factors affecting the fungal contamination of some fruit juices packaged in Tetra Pak

Local market is full of various kinds of fruit juice products packaged in different packaging materials as a result of the evolution of some added agents and different methods of pasteurization processes to fit these packages, as most of these containers fill cold. Some fungi have been found in fruit juices. Microscopically examination of fungal isolates obtained from fruit juices samples indicates the presence of the following species: Byssochlamys nivea, Byssochlamys fulva, Neosartorya ficsheri, Pencillium italicum, Aspergillus flevus, Talaromyces macrosporus and Aspergillus niger. The effect of sucrose, sodium benzoate and storage conditions on the shelf life of juices packaged in Tetra Pack containers was studied. Mango, orange, pineapple, grape, strawberry and apple juices containing various concentrations of sucrose (100 ml of each type) were put in 100 ml capacity conical flasks with stopper. Each juice was inoculated with ascospores of one local isolate to a fin al concentration of 120 to 140 ascospores /ml of juice and then pasteurized at 80°C for 30 min. A set of 72 inoculated flasks with 12 controls were stored at 4 to 5°C, and two sets, one protected with 0.01% sodium benzoate, were stored at room temperature (25 to 28°C). Shelf life study on all juices for 64 days indicate that fruit juices either stored at 4 to 5°C or containing sodium benzoate and stored at room temperature could be protected from spoilage by these fungi for 64 days. Addition of sucrose at levels of 8% of apple juice, 9% of mango juice, 30% of pineapple juice, 31% of strawberry juice, 31.5% of orange juice and 33.0% of grape juice, significantly (P= 0.05) prevented the activation of ascospores during cold storage.