Effects Of Catechins On Keeping Fresh Of Duck Meat And Growth Of Duck And The Action Mechanisms

This experiment studied on the effects of catechins on fresh and antioxidant of duck invivo and in vitro. In vitro the fresh effects of catehins were conducted by two aspects(antioxidant and micro-bacteria). In vivo this experiment researched on the effects ofcatechins on production performance, carcass traits, meat characteristics, antioxidant activityand immune function of duck.This experiment studied the fresh effects of catehins on duck meat by two aspects(antioxidant and micro-bacteria).The result showed that catechins can improve colour, lower MDA and enhance T-AOC ofduck thigh and breast meat. The best efficiencies are small-leaves catechins and multiplecatechins (small-leaves catechins+V E) in the all catechins.The deposit of catechins showed obvious disciplinarian. The deposit of catechinspresented maximum in the third and fifth day as simple antioxidant, however the deposit ofcatechins presented maximum in the first and fifth day as multiple catechins. In the meantimekeeping color and oxidation resisting had relationship with the deposit of catechins. The maindeposits of catechins are EGC and EGCG.The experiment identified the common putrefying bacteria including Lactobacillus,Staphylococcus, Pseudomonas, Enterobacteriaceae, Listeria. Pseudomonas is the mainbacteria in duck meat and accounts for 85.00 percent. Staphylococcus accounts for 8.20percent. Lactobacillus accounts for 4.25 percent. Enterobacteriaceae accounts for 3.75 percent.Listeria accounts for 0.30 percent. The experiment proved that catechins can lower the originquantities of bacteria and inhibit the proliferation of bacteria. The inhibition of catechins onGram positive bacteria is better than on Gram negative bacteria.The antibacterial experiment improved that catechins has inhibitory effects on S.aureausand E.coli. The MIC of catechins on S.aureaus and E.coli respectively are 0.32 g/L和1.25g/L.The antibacterial effect of catechins was lowered above 80 degree centigrade. Acid andalkali all affect the antibacterial effect of catechins. The effect is little between pH 5～9, butbeyond pH 5 and above pH 9 the effect is strong. And alkali decreases the antibacterial ofcatechins more than acid. UV irradiation has a little influence on the antibacterial effect ofcatechins. This experiment proved that the antibacterial mechanisms of catechins are to restrainlogarithmic growth of S.aureaus and E.coli, to increase the permeability of bacterial cellmembrane (increase the leakage of protein and sugar). And then this experiment proved thatrestraining breath metabolism is not the antibacterial mechanism.To summarize catechins can improve color, keep fresh and prolong the exhibition time ofduck meat by the comprehensive effects of antioxidant and antibacterial. Catechins not onlyimprove the color and postpone oxidation of duck meat as antioxidant, but also restrainbacterial proliferation to arrive keeping fresh as antibacterial.There is no effects of catechins on the weight of duck, but improve the carcass trait ofduck (enhance the slaughter ratio, dressing weight ratio, lower the abdomen fat ratio).Effects of catechins on meat quality mainly are to lower the fat, drop loss and unsaturatedfatty acid, higher the protein, the ratio of protein/fat, polyunsaturated fatty acid, IMP and pH.Adding catechins in basic diet adjust the serum antioxidant enzyme of 42-days old duckinto a dynamic balance (enhanced the SOD activity, lowered the GSH-PX and CAT activities).Adding catechins in basic diet also lowered the BUN, blood sugar, TG, CHOL and LDL-Cand enhanced the HDL-C and globulins.Adding carechins in basic diet enhanced SOD activity, lowered T-AOC and MDA of42-days old duck meat. Thus adding catechins in basic diet can adjust duck's antioxidantactivity and is good for the meat quality.Adding catechins in basic diet adjust the immune function by enhancing the thymusindex, bursa index, spleen index, lysozyme activity, peripheral lymphocyte transformationrate and positive rate of ANAE reaction and by having no effects on serum immune globulins.