Browsing by Author "Tissera, W.M.J.C.M."

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Extract Extraction and Purification of Chitin and Chitosan from Portunus p e agi c u s Crab Shell Waste
    (Uva Wellassa University of Sri Lanka, 2016) Tissera, W.M.J.C.M.
    Portunus pelagicus shell waste is highly accumulated in Sri Lankan seafood processing factories, but not many efforts have been taken on utilizing this crab shell waste for commercial level chitin and chitosan extraction with a higher percentage purity. The objective of this study was to modify and develop a scale-up, simple, and high-yielding chemical method for extraction and purification of chitin and chitosan from locally underutilized Portunus pelagicus crab shell waste. Modified process including pretreatment (hot water), pre-demineralization (acetic acid), demineralization (citric acid), deproteinization (NaOH), decolorization (n-butanol) deacetylation (NaOH), and purification (EDTA and SDS) was optimized to obtain a new combination of treatments. Pre-demineralization was introduced as a new step when developing the process. Citric acid was found as the best alternative organic acid to replace HC1 in demineralization. The final product was characterized by X-Ray Diffraction Spectroscopy and Fourier Transform Infrared Spectroscopy. The yields of crude chitin, crude chitosan, and purified chitosan were 32.52±0.68%, 26.28±0.47%, and 21.780.34% respectively whereas in the control chitin and chitosan the yields were 20.34±0.72% and 13.79±0.93% respectively (p<0.05). The percentage purity of the final product on a weight basis was 82.54±1.73% with a degree of deacetylation of 85.84±2.45%. The XRD data revealed that chitosan extracted from the developed methodology is a semi-crystalline compound with two characteristic crystalline peaks. Chitosan produced from the developed method showed significant results in physicochemical parameters namely moisture (5.27+0.39%), ash (1.95±0.22%), whiteness index (72.37±0.66%), and functional properties namely Water Binding Capacity (318.74+0.48%), Fat Binding Capacity (351.66±0.69%) DPPH free radical scavenging activity (61.12±0.59%) and metal chelating activity (40.19±0.47%) compared with the control (p<0.05) and showed positive antimicrobial activity against locally isolated E. coli at 2.5mg/ml. Thus the methodology developed can be used to obtain high purity and high-quality chitosan with optimum physicochemical and functional properties from crab shell waste. Keywords: Portunus pelagicus, shell waste, Chitosan, Pre-demineralization, XRD, Percentage Purity
  • No Thumbnail Available
    Item
    Extraction and Purification of Chitin and Chitosan from Portunus pelagicus Crab Shell Waste
    (Uva Wellassa University of Sri Lanka, 2021) Tissera, W.M.J.C.M.; Rathnayake, S.I.; Abeyrathne, E.D.N.S.
    Crab (Portunus pelagicus) shell waste is highly accumulated in Sri Lankan seafood processing factories, but not many efforts have been taken on utilizing it for commercial level chitin and chitosan extraction with a higher percentage purity. Therefore the objective of this study was to modify and develop a scale-up, simple, and high-yielding chemical method for extraction and purification of chitin and chitosan from locally underutilized Portunus pelagicus crab shell waste. A modified process including pre-demineralization (acetic acid), demineralization (citric acid), deproteinization (NaOH), decolourization (n-butanol) deacetylation (NaOH), and purification (EDTA and SDS) was optimized to obtain a new combination of treatments. Pre-demineralization was introduced as a new step when developing the process. Citric acid was found as the best alternative organic acid to replace HCl in demineralization. The final product was characterized by X-Ray Diffraction (XRD) Spectroscopy and Fourier Transform Infrared (FTIR) Spectroscopy and various physicochemical and functional properties were analyzed. Control chitin and chitosan samples were produced using a conventional method for comparison. The yields of crude chitin, crude chitosan, and purified chitosan were 32.52±0.68%, 26.28±0.47%, and 21.78±0.34% respectively whereas in the control chitin and chitosan the yields were 20.34±0.72% and 13.79±0.93% respectively (p<0.05). Percentage purity of the final product on a weight basis was 82.54±1.73% with a degree of deacetylation of 85.84±2.45%. The XRD data revealed that chitosan extracted from the developed methodology is a semi-crystalline compound with two characteristic crystalline peaks at 2θ =9.05° and 19.1° and Crystallinity Index of 67.22%. FTIR analysis revealed that developed chitosan was comparable with control chitosan. Chitosan produced from the developed method showed higher results in physicochemical parameters namely moisture (5.27±0.39%), ash (1.95±0.22%) whiteness index (72.37±0.66%), and functional properties namely water binding capacity (318.74±0.48%), fat binding capacity (351.663±0.69%) DPPH free radical scavenging activity (61.12±0.59%) and ferrous chelating activity (40.19±0.47%) compared with the control (p<0.05). Developed chitosan had no antimicrobial activity for Salmonella and Micrococcus but showed positive antimicrobial activity against locally isolated Escherichia coli at 2.5mg/ml. Thus the developed methodology can be used to obtain high purity and high-quality chitosan with better physicochemical and functional properties from crab shell waste Keywords: Portunus pelagicus; Shell waste; Chitosan; Pre-demineralization; XRD; Percentage purity