Survey for the compounds of white spots of Sufu and their inhibitory method

To explore the material basis of white spots on Sufu and the inhibitory method,the white spots and Sufu of different brands or varieties were used as material to find out the solubility,combustibility,composition of amino acids,and the content of crude protein and calcium ion. And inhibitory method of white spot was studied through Mucor strain inducing and adding antioxidant and the results were: the white spots of Sufu was soluble in formic acid solution,the content of crude protein was 38.45%,and the content of calcium was 0.05 g /100 g,which showed that the composition of white spot was the consisted of free tyrosine based crystalline mixture. Comparing the content of amino acid of different brands or varieties of the Sufu found that the formation of white spot was related to the process of Sufu.The content of amino acidsin Mucor strain after inducing were differences and white spots were found,which showed that physical inducing of Mucor cannot solve the problem of white spots completely.After adjusting alcohol degrees,13% of alcohol was the least white spots in Sufu. In the later of fermentation,antioxidant soy was oflavones and tea polyphenols were added,and the fermentation under temperature lasted for half a year. The result was no white spots being found,which showed that the addition of antioxidant can inhibit Sufu from white spots obviously.