Strain Differences in Chemical Components in Very Early Ripening Mutants of Satsuma Mandarin with Special Reference to Limonoid Compounds

Abstract

The physical and chemical properties of fruits used as raw materials for juice processing were examined among 12 strains in 6 classes of very early ripening mutants of Wase satsuma mandarin (Citrus unshiu Marc. var. praecox Tanaka) with special reference to the limonoid compounds.
All the strains used in these experiments completely fulfilled the criteria of the Japanese Agricultural Standard (JAS) for single-strength juice. On the basis of these criteria, the sugar, citric acid, ascorbic acid (vitamin C), amino-nitrogen and ash contents in the very early ripening mutants were suitable for juice processing.
However, the contents of limonoid compounds of these strains were much higher than those of Wase and Common satsuma mandarin at the usual harvest time. Such high contents may cause the so called "delayed bitterness" in their juice products after processing with an In-Line juice extractor. Therefore, to alleviate this shortcoming, it is suggested that the fruits should be harvested at the full ripening stage.
Although the mutants were classified into 6 maturation types based on the variations of acid contents and coloring time of the fruit, the maturation time could not be estimated on the basis of the contents of limonoid compounds.