Removal of S-Methylmethionine Sulfonium from Satsuma Mandarin Juice

S-Methylmethionine sulfonium (MMS), the precursor of dimethylsulfide (DMS) in Satsuma mandarin juice, was removed to depress the production of DMS. The latter contributes to the characteristic off-flavor during processing and storage of the juice. A gel type resin with a strong acid ion exchanger was most suitable for removing MMS from the juice. When the concentration of MMS was reduced from 16.1 εM in untreated juice to 10.1 εM in treated juice, the required amount of resin was 0. 83% (v/v) of the treated juice. Amino nitrogen decreased from 22. 7 to 20. 5 mg%, acidity from 0. 73 (pH 3. 48) to 0. 72%(pH 3. 55), while ash content increased from 0.29 to 0. 32% during treatment of juice. On the other hand, soluble solids and ascorbic acid content and juice color did not change. The off-flavor from this treatment was unperceivable. Elution with 2 M potassium hydroxide solution resulted in recovery of MMS and regeneration of resin. After 10 days at 37°C the difference between treated and untreated juice was regarded as significant, and this difference increased with time. The shelf life of juice could be doubly extended by reducing MMS content to 10 εM.