الفهرس 
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Abstract
ABSTRACT
Chitosan was prepared from shrimp shells by three different preparation methods: preconditioning process (method І), common process (method ІІ) and autoclaving process (method ІІІ). The amount of chitosan was 19.2, 21.9 and 26.1%, respectively. The physico-chemical and functional properties of chitosan were measured. Production of chitosan was conducted using four fungal strains, Rhizopus oryzae ATCC 46242, Aspergillus niger NRRL 595, Mucor rouxii ATCC 24905 and Gongronella butleri NRRL 1307 under submerged culture conditions. The amount of extractable chitosan varied widely among the fungal strains. The effect of incubation period, different carbon and nitrogen sources, aeration rates and pH values on the amount of extractable chitosan by the four fungal strains was investigated. The antimicrobial activity of shrimp shells and fungal chitosans against 13 bacterial strains and 4 fungal strains was investigated. The antioxidant activity of chitosan was measured with 2, 2- diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method. The effects of shrimp shells and fungal chitosans on body weight gain, food intake and plasma lipoprotein concentrations in rats were measured. The effect of different concentrations, i. e. 0, 0.25, 0.5 and 1% of chitosan on the shelf-life of minced meat during refrigerated storage at 4 °C for 10 days was measured.
Key words: Chitosan, antioxidant activity, antimicrobial activity, preconditioning process, autoclaving process, fungal strains, hypocholesterolemic, shelf-life.