49B-14 |
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S. M. Lee, Food Engineering, National Kinmen Instituteof Technology, 2, Da Hsueh Rd., Jinning Township, Kinmen County 892, Taiwan (R.O.C.), Kinmen, Taiwan and B. S. PAN, Food Science, National Taiwan Ocean University, 2, Pei-Ning Road, Keelung, Taiwan 20224, R.O.C., Keelung, 202, Taiwan. The sorghum distillery residue (SDR) has been an underutilized by-product with an estimated production of 150 ton/day in Kinmen, Taiwan. Sorghum distillery showed antioxidant and blood thinning effects on grey mullet fed during winter, but inhibited their growth. The content of tannin was found 3.3 mg/g on dry weight basis. A detannin method was needed to utilize SDR as feed ingredient. The objectives of this study were to test the physiological effects of SDR. In order to utilize it as a nutraceutical ingredient in feed for cultured fish a detannin treatment with polyethylene glycol (PEG) was tested to prevent the inhibition of dietary SDR on feed protein digestion and growth of cultured grey mullet. In addition, using fish as an animal model for preliminary screening of nutraceutical effects on blood circulation was also studied. An in vitro digestibility test was developed using the digestive enzymes extracted from fish gut to simulate the in vivo digestion of grey mullet. Growth trials were done in summer and winter seasons each for 60 days. Rheological properties, hemolysis, morphology of red blood cells and lipoxygenase activities of fish blood were examined to evaluate the bioactivities of SDR. The protein digestibiltiy of SDR was 47% lower than that of the control. Inhibition of trypsin activity correlated with the amount of SDR extract used (r=0.98) and decreased significantly (p<0.05) when the SDR extract was pretreated with polyethylene glycol (PEG), a tannin binding agent. A detannin method was suggested to eliminate the adverse effects while taking advantage of the nutraceutical benefits of the underutilized SDR or other grain by-products for uses in culturing fish, which may also be used as a test animal model for prescreening bioactivities of functional foods.
Session 49B, Aquatic Food Products: General
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