| 摘要 |
A glucose-isomerising enzyme is added to a glucose-contg. liquid and the liquid is subjected to isomerisation conditions. During isomerisation a small amount of a water-soluble salt of sulphurous acid is present in a quantity which is sufficient to reduce visibly the formation of colour produced in the absence of salt. The quantity of salt is pref. sufficient to produce 0.02-0.3% SO2 in the liquid. Pref. salt is Mg sulphite or -bisulphite. The pref. micro-organisms used to produce the enzyme are Streptomyces ATCC 21175 and 21176. Pref. pH of the liquid during isomerisation is 6.5-7.5. Cell material containing the enzyme is used for isomerisation. This contains foreign matter which produces discolouration of the final product. The salts included reduce the colour and have a protecting effect on the glucose-isomerising enzyme, esp. at higher temps. so that smaller quantities of enzyme are necessary to give the same yield of fructose. The isomerised glucose syrup is used for the sweetening of sauces, tinned fruits, confectionery etc. |
