PT  - JOURNAL ARTICLE
AU  - G. L. Robertson
AU  - R. Eschenbruch
AU  - K. J. Cresswell
TI  - Seasonal Changes in the Pectic Substances of Grapes and Their Implication in Juice Extraction
AID  - 10.5344/ajev.1980.31.2.162
DP  - 1980 Jan 01
TA  - American Journal of Enology and Viticulture
PG  - 162--164
VI  - 31
IP  - 2
4099  - http://www.ajevonline.org/content/31/2/162.short
4100  - http://www.ajevonline.org/content/31/2/162.full
SO  - Am J Enol Vitic.1980 Jan 01; 31
AB  - Three pectin fractions — water soluble, oxalate soluble, and hydroxide soluble — of three New Zealand grown grape varieties were measured during ripening and at harvest. In all cases the total pectin content decreased during ripening.It is suggested that when the concentration of the water soluble fraction exceeds 10 mg anhydrogalacturonic acid per 100 g of grapes, the grapes will form a glutinous mass on crushing from which it will be difficult to extract all the juice. These results are discussed in the context of the present knowledge on pectins in juice extraction.