Abstract:

In order to study the factors that influence the adsorption of non-sugar by calcium carbonate during the process of carbonation in multi-component syrup and to clarify the effects of CO₂ flow rates on CaCO₃ particles,the morphologies,formation rate and sizes of the CaCO₃ particles were characterized by means of SEM and FBRM. Moreover,the color value,the content of reducing sugar and the apparent purity were determined as the indexes. Experimental results show that ( 1) the CaCO₃ particles are cube-shaped at a lower CO₂ flow rate while they are rod-like at a higher flow rate; ( 2) the CaCO₃ particle chord lengths obtained by using an on-line FBRM are within a range of 1 ～ 100 μm,and the range becomes wider with the increase of the CO₂ flow rate; ( 3) fast carbonation can protect the reducing sugar from destruction; ( 4) when the CO₂ content is constant,with the increase of the CO₂ flow rate,the color value of clarified juice decreases while the corresponding apparent purity improves; ( 5) the CO₂ flow rate has little influence on the adsorption of the inorganic cations of K ⁺ ,Na ⁺ ,Ca^{2 +} and Mg^{2 +} ; and ( 6) within an appropriate flow rate range of 300~900mL /min,fast carbonation proves to be a feasible clarification technology.

Key words: sugar juice clarification, calcium carbonate, adsorption, carbonation, color value, apparent purity