Quantification and comparison of acidic polysaccharides in edible fish intestines and livers using HPLC-MS/MS

Fish intestines and livers are usually considered as delicious and nutritious food in China. Acidic polysaccharides are important nutrients in these food of animal origin, but there is currently little information regarding their quantitative distributions. The present study demonstrated a method to quantify acidic polysaccharides simultaneously by analyzing their disaccharides produced from the acid hydrolysis using high-performance liquid chromatography (HPLC) coupled with triple quadrupole mass spectrometry. The recoveries for these acidic polysaccharides were all 97%-115% with relative standard deviation of 3.0%-9.0%. All of the acidic polysaccharides had good linearities. Then this method was applied to determine the composition of acidic polysaccharides in 5 edible fish livers and intestines. Besides well-known glycosaminoglycans (GAGs) including hyaluronic acid (HA), Chondroitin sulfate (CS), dermatan sulfate (DS) and heparin (HP), 4 novel acidic polysaccharides including 2 GAGs and 2 non-GAGs comprised of hexose-hexuronic acid repeating units were also found. CS and HP were the major acidic polysaccharides components in fish intestines and livers, respectively. The absolute amounts of acidic polysaccharides differed greatly in these fish tissues, but their proportions showed similarity in the same type of tissues. The present study demonstrated an effective method for acidic polysaccharides quantification, and revealed acidic polysaccharides compositions of edible fish livers and intestines.