Abstract: In a microcapsule of the multi-core structure comprising a plurality of particles which are made of a core material comprising natural carotenoid and an edible oil, and a wall which is made of a coating material based on gelatin, the particles have a mean particle size of 0.01-5 .mu.m, the gelatin has a jelly strength of at least 100 blooms, and the microcapsule has a water content of up to 10% by weight. The microcapsule has a strength enough to protect natural carotenoid from oxidation and deterioration for a long time and to withstand tableting pressure.

Abstract: A method for sulfonating olefins comprising the steps of mixing (A) internal olefins having 8 to 22 carbon atoms with (B) alpha-olefins having an average carbon atom number, larger by 3 to 7 than that of the internal olefins (A) in a weight ratio of (A)/(B)=95/5 to 5/95, and sulfonating the resultant mixture with a sulfonating agent. Thus, internal olefins can be sulfonated at a high conversion.

Abstract: A process for effectively removing unreacted oil from a surfactant slurry containing the same comprising:continuously feeding steam from one side of a pressure vessel into an anionic surfactant slurry containing unreacted oil in the pressure vessel while maintaining a pressure in the system of at least 5 kg/cm.sup.2 ; andsimultaneously discharging the anionic surfactant slurry from the other side of the pressure vessel into a low pressure region to effect vaporization of the unreacted oil from the anionic surfactant slurry.