Nghiên cứu chiết rút và khảo sát tính kháng khuẩn của chitosan tan trong nước từ vỏ tôm thẻ chân trắng (Litopenaeus vannamei)

Abstract

The aim of research was to produce water-soluble chitosan and inhibit bacterial growth from the white leg shrimp shell (Litopenaeus vannamei) through deacetylation of chitin in NaOH solution to obtain the crude chitosan. Next, crude chitosan was treated in acetic acid solution at various concentrations and different times to convert it into the water-soluble chitosan. The result showed that chitin was treated in NaOH at the concentration of 50% for 36 hours to collect chitosan with degree of deacetylation (93.1%), viscosity (20 mPas) and high recovery yield (46.8%). The crude chitosan was soaked in acetic acid 2% in the presence of H2O2 4% for 4 hours to collect the water-soluble chitosan. The solubility of water-soluble chitosan reached to 88.6% and FTIR spectrum showed that the functional groups were almost similar to crude chitosan. The antibacterial activity of water-soluble chitosan was lower than the crude chitosan with the concentration inhibited Escherichia coli, Staphylococcus aureus, Salmonella typhimurium of water-soluble chitosan was 8% while the concentration of crude chitosan was 2%. However, the water-soluble chitosan could be enhanced the application in food processing field.