Abstract
Pectic substance fractions and their concentrations in satsuma mandarin (Citrus un-shiu Marc. ) fruit were investigated in relation to maturation. The fruits of′Okitsu Wase′, an early maturing cultivar, and′Silverhill′, a common cultivar, were sampled at maturation from September 3, 1973 to January 28, 1974.
1. Early maturing cultivar
The contents of water- and sodium hexametaphosphate-soluble pectins in the peel increased, but that of the sodium hydroxide-soluble fraction decreased from early September to early December. Thereafter all of the fractions increased slightly.
Water- and sodium hexametaphosphate-soluble pectins in the pulp increased rapidly during late December, and thereafter decreased gradually. Sodium hydroxide-soluble pectin in the pulp increased rapidly from early September to early January of the following year, and then decreased.
In the segment wall, water- and sodium hexametaphosphate-soluble pectins increased gradually from early September to early January of the following year. The decrease was slower in sodium hydroxide-soluble pectins which continued to decrease until January.
2. Common cultivar
Sodium hexametaphosphate- and sodium hydroxide-soluble pectins in the peel decreased slowly throughout maturation.
Water- and sodium hexametaphosphate-soluble pectins in the pulp decreased gradually from early September to mid-October, and thereafter remained relatively constant up to early January of the following year. Sodium hydroxide-soluble pectins in the pulp decreased markedly from early september to late October, and thereafter increased rapidly up to late January of the following year.
The water-soluble fraction in the segment wall gradually increased until late November, and thereafter decreased slowly. Sodium hexametaphosphate-soluble pectins in the segment wall increased gradually from early September to late December, and then decreased gradually. The sodium hydroxide-soluble fraction in the segment wall decreased gradually from early September to late January of the following year.
