Preparation,Characterization And Application Of Sugar Clarifying Agent For Aminated Magnetic Diatomite

With the development of social economy and with the improvement of national living standard,people pay more and more attention to the sulfur-free residue,high quality,safety and health of sugar products.This requires us to develop technology about new sugar clarification.In this work,diatomite,modified by amination with chitosan,was used as the adsorption matrix.According to the principle of magnetic separation,diatomite was magnetized to endow the material with recycling characteristics.Therefore,a new type of sugar clarifying agent,namely amination magnetic diatomite?Amino-magnetic diatomite,AMD?,was prepared via a co-precipitation method combined with cross-linking treatment.The main research contents are as follows:?1?Diatomite was purified and the specific surface area was increased by1.522 times.The decolorization rate and purity difference were increased by15.36%and 0.26%,respectively.?2?Through single factor and orthogonal test,the preparation conditions were optimized:chitosan content was 0.75g,ammonia nitrogen concentration was20%,glutaraldehyde was 2.5 mL,and crosslinking temperature was 30°C.The AMD was applied to clarify the mixed juice.The results show that the purity and decolorization rate of clear juice were 2.83%and 52.70%,respectively.Moreover,the structure of AMD was characterized by SEM,FTIR and VSM and so on.?3?The optimum technological conditions of AMD clarification and decolorization were studied by response surface test:P₂O₅ at 349.99 mg/L,AMD at 0.83 g/L,the second-heating temperature at 79.47°C and PAM at 1.98mg/L.The above proportions have the best clarifying effect.The results prove that the purity difference,decolorization rate and turbidity were 3.30%,61.33%and 41.08 MAU,respectively.And AMD has better clarification effect and excellent regeneration performance.?4?AMD method were evaluated from the clarification effect,physical and chemical indexes and element analysis,and it was found that AMD method achieved high purity,low color value and sulfur-free clarification,which could be used as a new clarifying agent to clarify sugarcane sugar mixture.?5?The clarification and decolorization mechanism of gallic acid?GA?and caffeic acid?CA?in sugar cane juice adsorbed by AMD was investigated.The results showed that the maximum adsorption capacity of AMD for GA and CA was 31.949 mg/g and 27.640 mg/g,respectively.The adsorption fitted better with the Lagergren pseudo-second-order model and the Langmuir model,which was a physically spontaneous endothermic process of monolayer adsorption.The results above show that AMD,as a new sugar clarifier,has better clarification effect on mixed sugarcane juice.