Antioxidative Activity of Products from Chitosan-Glucosamine Maillard Reaction

• Main Authors: Ke-Ming Liang, 梁克明
• Other Authors: Chin-Fung Li
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/93356172442947538409

碩士 === 國立臺灣大學 === 食品科技研究所 === 88 === The objective of this research was to improve the solubility of chitosan by Maillard reaction fromα-chitosan and reducing sugar, and expected them to have good antioxidative actions to increase its application as functional foods. The 1%α-chitosan and 0.2% reducing sugar (glucosamine or glucose) dissolved in 0.2M acetic acid, which adjusted to pH 6.0, were heated at different temperature and time to prepare the water soluble Maillard reaction products (MRPs) . These products were investigated for their basic properties, antioxidative activities and antibacterial abilities. The basic properties of water soluble chitosan products by Maillard reaction included yield, solubility, browning degree of Maillard reaction and degree of deacetylation. The yield was 70-98% at different Maillard reaction conditions. At higher reaction temperature of MRPs from glucose, the yield was highest. The solubility of MRPs decreased as rising temperature. The solubilities of MRPs from chitosan and glucosamine are 0.688-0.969 g/dL were better than the other products with glucose. For the degree of browning by Maillard reaction, which was measured by the absorbance at 420 nm, they were apparently higher for that reacted at higher temperature and longer time of period. The degree of deacetylation in chitosan seemed to have no influence for Maillard reaction. Under the same reaction conditions, the Maillard reaction with glucosamine were proceeded easily than with glucose. Moreover, the products at higher reaction temperature resulted in lower degree of deacetylation. On the aspect of antioxidative activity, it included the scavenging of DPPH free radical and superoxide anion, reducing power and chelating ability of metal ions. Because of different Maillard reaction conditions, their products were different in kinds, quantity and distribution. It caused different antioxidative activities. In scavenging DPPH free radical, the products’ activity were higher as temperature and time increased. At the same reaction conditions, the scavenging activity of the MRPs from glucosamine was better than the products from glucose. Its best activity is 50%. In the case of scavenging superoxide anion ability, the activity of products reacting at 50℃ was the best. When reaction time was prolonged, the scavenging ability of MRPs from glucosamine was increased, but that with glucose products gave the opposite result. In the experiment of reducing power, MRPs from glucosamine have better reducing power at higher reaction temperature and longer reaction time. Its absorbance is 0.86-0.95. While the reducing power of MRPs made with glucose was better at lower reaction temperature and shorter reaction time (the absorbance is 1.2). In the experiment of metal ion chelating ability, water soluble MRPs of chitosan had better chelating ability on copper ions than ferric ions. The MRPs from glucosamine have good chelating ability with that obtained from higher temperature and longer time, then the chelating ability of MRPs made from glucose at lower temperature and shorter time were better. On the aspect of chelating ability with ferric ion, the MRPs from any kinds of Maillard reaction conditions had only 10-15% chelating ability. In the experiment of antibacterial ability of water soluble MRP’s from chitosan-glucosamine, the antibacterial abilities depended on different bacteria strains. The MRPs from lower reaction temperature and shorter reaction time gave better antibacterial abilities. If the MRPs’ with higher extent of Maillard, the ability became inferior. In addition, comparing with the results of deacetylation of MRPs, the antibactrial ability of the products against the same strains decreased as the deacetylation of MRPs was decreased. This suggested that the amino group of the products played an improtant role in the antibacterial ability.