الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
This study, was carried out mainly to isolate and identify the dominant yeasts in high sugar foods, as well as to have a clear picture on the associated microorganisms in these products. The total counts of bacteria, osmophilic bacteria, coliforms, fecal Escherichia coli, Staphylococcus spp., Salmonella and Shigella, molds and yeasts were determined in sugarcane juice, fruit juice nectars (mango and koktel), jam (strawberry and fig), honey and halawa tahenia. Staphylococcus spp., Salmonella and Shigella were not detected in all samples. Most products were heavily loaded with microorganisms compared with the Egyptian Standards (ES). All microorganisms found in these products were tested in fresh and during storage at 7°C for 12 months except in sugarcane juice. One hundred and thirty-four yeasts were isolated from some of these high sugar foods. These yeasts in addition to 31 standard yeast strains were classified using the morphological and biochemical tests. A Vernetzüngsdiagram was automatically calculated by subjecting the obtained results to the EDV-programme. The numerical classification of the total 134 yeast isolates besides the 31 standard yeast strains resulted in 16 groups representing 16 yeast species forming clusters with high similarity, 11 ascosporogenous group i.e., Saccharomyces cerevisiae, Torulaspora delbrueckii, Debaryomyces hansenii, D. polymorphus, Kluyveromyces phaffi, Hansenula anomala, Schizosaccharomyces pombe, Zygosaccharomyces bailii, Pichia fermentants, K. marxianus var bulgaricus and Zygo. rouxii, while the other 5 groups were nonascosporogenous yeast i.e., Candida zeylanoides, C. parapsilosis, C. sake, Cryptococcus albidus and Rhodotorula glutinis. The most dominant yeast species found in sugarcane juice were ascosporogenous (66.11%) including S. cerevisiae (11.57%), T. delbrueckii (9.91%), D. hansenii (9.09%), Zygo. bailii (6.61%), D. polymorphus (5.78%), K. phaffi (4.13%), K. m. var bulgaricus (4.95%), Zygo. rouxii (3.30%), H. anomala (3.30%), Schizo. pombe (2.47%), and P. fermentants (4.95%), beside nonascosporogenous (33.88%) including C. zeylanoides (10.74%), C. parapsilosis (9.91%), C. sake (4.95%), Crypt. albidus (2.47%) and Rh. glutinis (5.78%). The dominant yeast species found in honey were Crypt. albidus (38.46%), K. phaffi (15.38%), C. zeylanoides (15.38%), D. hansenii (7.69%), D. polymorphus (7.69%), S. cerevisiae (7.69%) and P. fermentants (7.69%).