Postharvest application of chelated and nonchelated calcium dip treatments to commercially grown honey dew melons: effects on peel attributes, tissue calcium concentration, quality, and consumer preference following storage.
Lester, G. E. and Grusak, M. A.
HortTechnology. Volume 11, Issue 4, 2001, Pages 561-566.
2001
บทคัดย่อ
Commercially grown honey dew fruits (Cucumis melo cv. Honey Brew, Inodorus group) typically are harvested before abscission because fruits cut unripe have a longer storage life than fully ripe fruits. However, because fully ripe fruits contain higher concentrations of soluble solids (predominantly as sugars), an attribute that increases their preference among consumers, methods are being explored to extend the storage life of fully ripe fruits. In this study, fully abscised honey dew fruits (collected from Rio Grande City, Texas, USA) were evaluated for tissue attributes and consumer preference following postharvest dipping in either chelated or non-chelated calcium (Ca) solutions at 0, 0.08, 0.16 or 0.24 M. Calcium sources were an amino acid-chelated Ca, ethylenediamine tetraacetic acid (EDTA)-chelated Ca, or calcium chloride (CaCl2), with each provided at three different rates. Fruits were evaluated at harvest, and after 14 or 22 days of commercial storage. Evaluations on peel surface changes (colour and disorders), hypodermal-mesocarp tissue Ca concentration, flesh firmness, soluble solid concentration, and consumer preference of the edible flesh were conducted. Peel colour became yellow and lighter during storage for all fruits, with higher Ca rates resulting in more intensely yellow fruits. Hypodermal mesocarp tissue Ca concentration was 0.90 mg g-1 of fresh weight (900 ppm) at harvest, and declined in all fruits by 22 days of storage. Peel disorders (disease and spotting) were none to slight for all fruits by 14 days of storage, but by 22 days of storage, disease incidence ranged from none to severe, depending on the Ca source and rate. Fruit firmness declined in all fruits throughout storage, with the smallest declines measured in fruits treated with the amino acid-chelated Ca. Soluble solid concentration in fully ripe fruits was 12.3% at harvest, and showed either no decline or a slight decline with storage among the treatments. Consumer preference was highest for freshly harvested fruits, but fruits were desirable even after 22 days of storage across all treatments. Postharvest application of Ca at less than or equal to 0.16 M Ca in an amino acid-chelated form, versus EDTA-chelated Ca or CaCl2, slowed honeydew melon senescence so that after 22 days of commercial and retail storage, the fruits were of high marketable quality, and there was no detrimental effect on consumer preference for the edible flesh.