| The changing colour system, culture medium formula and making technology of test paper were optimized in this paper, effect of NaCl, agar on quality of test paper were analysed ,and detection time .precision was determined also. Compared with national standard method(PCA) the accuracy, as well as consistency were set by petrifilm method.Findings as follows:1 .TTC had effect on the test bacteria Coliform bacteria, Lactobacilus lactis, Acetobacter, the optimum changing colour occurred and maximum colonies obtained when concentration of TTC was 0.004%,the growth of colonies couldn't be fully coloured when concentration of TTC is below 0.004% and restrained when higher than 0.005%.Test paper macerated in 0.004% TTC compared with PCA ,the results hadn't remarkable differences(t=0.3558,P>0.05).2.Scheme of culture medium was designed by D-416-A,we got optimum desired results by tropical equation, when the code value of peptone, yeast exrtact,glucose,K2HPO4 were 1, 0.9, 1, 0.65, formula of NO.8 and NO. 10 had a little difference compared with optimum formula, they hadn't remarkable difference (P>0.05) by the double experiment .So the main composition of 100mL culture medium was peptone 2.59g,yeast extract 1.05g, glucose 0.239g, K2HPO4 0.35g .3.when studying on sterilization time we found that there was no bacteria left in culture medium in condition of 116℃/20min or 121℃/15min,but the colonies growth better in culture medium sterilized at 121℃/15min than at 116℃/20min.4.By L9(34) orthogonal experiment maceration temperature and time, drying temperature and time all had much effect on quality of test paper. Experiments showed that the test paper got the highest mark when macerated at 70℃/2min,dryed at 55℃/1 h.5.The usage of NaCl had been studied in this paper, the colonies grew best when adding NaCl 0.45g to 100mL culture medium.6.Agar had effect on quality of test paper, the mark of test paper descended and the colonies grew more slowly when concentration of agar was higher than 0.1%,moreover the mark of test paper was not high though the growth of colonies were normal when concentration of agar is less than 0.1 %.So the optimum concentration of agar in culture medium was 0.1 %.7.The quality of test paper improved when direactive glyceride, sucrose ester, Span-40 were added into macerating culture medium,different kinds of emulsion had different effect on quality of test paper.when concentration were higher than 0.15mg/mL there weren't remarkable effect on the quality. Test paper got the highest mark when concentration of Span-40 was 0.15mg/mL and the growth of bacteria weren't restrained.8.According to studying on character of test paper, (1) quantity of colonies didn't increase remarkably when cultivated more than 15h and there was no remarkable differences(P>0.05) compared with national standard method,(2) mixed bacteria and three kinds of beverages were tested, results showed that repeatability was from 0.9% to 4.714%,(3)compared with national standard method 363 beverage samples were tested,316 samples were qualified by test paper method and percent of pass was 87.05%,321 samples were qualified by national standard method and percent of pass was 88.40%,302 samples were qualified and 46 weren't qualified by two methods and consistency was 95.87%,absolute ratio of colonies was 1:0.9342.(4)vacuum dried vegetable, flavour powder and sauce in instant noodles were tested by test paper, absolute ratio of colonies obtained is from 0.7576 to 0.91,the results showed differences compared with national standard method.,(5)guarantee period of test paper is 180 days.9.Roughly estimating the cost of test paper method and national standard method were 12.6 ?and 18.3 ￥ separately in a single test.
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