The present invention relates to a reaction tank for treating sugar syrup, a continuous sugar dissolving apparatus, and method. The reaction tank comprises a syrup inlet arranged at a bottom of the reaction tank, an adsorbent inlet arranged at the bottom of the reaction tank, and a syrup outlet arranged at an upper sidewall of the reaction tank, wherein a mesh plate arranged within the reaction tank and above the syrup inlet. The reaction tank of present invention can be used in a continuous sugar dissolving apparatus and method, and can allow for better control of the reaction time of the syrup and the adsorbent to enable coloring matter and impurities in the syrup to be removed more sufficiently.

Provided is a resin solid acid capable of reducing intermediate stage production costs by omitting the synthetic resin carbonization step and allowing sulfo groups to be introduced directly into the synthetic resin, and a method for producing that resin solid acid. The resin solid acid is a sulfo group-modified resin obtained by introducing sulfo groups into a raw material resin in an uncarbonized state, the yield of the sulfo group-modified resin based on the weight of the uncarbonized raw material resin is 80% or more, the amount of sulfo groups in the sulfo group-modified resin is 1 mmol/g or more, and the raw material resin is in the form of a powder, granules or fibers. In addition, the method for producing the resin solid acid is a production method for obtaining a sulfo group-modified resin by comprising a step for adding a sulfonating agent in the form of any of sulfuric acid, fuming sulfuric acid or chlorosulfonic acid to a raw material resin in an uncarbonized state, and a step for heating the uncarbonized raw material resin at 200°C or lower.

Provided is a method for efficiently producing sugar and simultaneously efficiently producing ethanol. A method for producing sugar characterized by comprising a pretreatment step in which a plant-origin sugar solution is fermented by a microorganism having no sucrose-degrading enzyme and a step for producing sugar from the fermented sugar solution. A method for producing sugar characterized by comprising a pretreatment step in which a plant-origin sugar solution is fermented by a microorganism in the presence of a sucrose-degrading enzyme inhibitor and a step for producing sugar from the fermented sugar solution.

The present invention is directed to a composition comprising carbohydrates obtainable from carob and carbohydrates obtainable from at least one further fruit.