Dm. Obenland et Tr. Carroll, Mealiness and pectolytic activity in peaches and nectarines in response toheat treatment and cold storage, J AM S HORT, 125(6), 2000, pp. 723-728
Citations number
32
Categorie Soggetti
Plant Sciences
Journal title
JOURNAL OF THE AMERICAN SOCIETY FOR HORTICULTURAL SCIENCE
'Elegant Lady', 'O'Henry' and 'September Sun' peaches [(Prunus persica (L.)
Batsch (Peach Croup)] and 'Summer Bright' and 'Summer Grand' nectarines [(
Prunus persica (L.) Batsch f. nucipersica (Nectarine Group)] heated to a se
ed surface temperature of 47.2 degreesC over a period of 4 hours developed
mealy flesh sooner and to a much greater extent than nonheated fruit follow
ing cold storage at 5 degreesC for 1 to 3 weeks. Exo- and endopolygalacturo
nas activities were reduced following 3 to 4 hours of heating and may have
been responsible for the increased mealiness, Mealiness often developed in
defined regions rather than throughout the entire fruit. Comparison of juic
y and mealy regions within individual fruit revealed that mealy regions con
tained 65% and 86% less exo- and endopolygalacturonase activity, respective
ly, than juicy regions, whereas pectinmethylesterase activity was unchanged
. Extractable protein was reduced by >50% in the mealy regions of the fruit
. Intermittent warming periods of 24 hours at 20 degreesC at weekly interva
ls during storage at 5 degreesC were less effective in reducing mealiness i
n heat-treated than in control fruit. It is important that future work with
heat treatments and stone fruit closely monitor potential effects on this
disorder to avoid loss of market quality following treatment.