RIPENING BEHAVIOR AND COMBINED FUNGICIDE AND PRESTORAGE HEAT-EFFECTS ON DECAY CONTROL OF BOSC PEARS IN AIR OR STEP-WISE LOW-OXYGEN STORAGE

Citation
Pm. Chen et al., RIPENING BEHAVIOR AND COMBINED FUNGICIDE AND PRESTORAGE HEAT-EFFECTS ON DECAY CONTROL OF BOSC PEARS IN AIR OR STEP-WISE LOW-OXYGEN STORAGE, Postharvest biology and technology, 6(3-4), 1995, pp. 235-248
Citations number
23
Categorie Soggetti
Agriculture,Horticulture,"Food Science & Tenology
ISSN journal
09255214
Volume
6
Issue
3-4
Year of publication
1995
Pages
235 - 248
Database
ISI
SICI code
0925-5214(1995)6:3-4<235:RBACFA>2.0.ZU;2-O
Abstract
'Bosc' pears (Pyrus communis, L.) harvested at commercial maturity wit h flesh firmness (FF) of 75 Newton (N) from the southern district of O regon were stored in either air or step-wise low O-2 at -1 degrees C d uring the 1992-'93 and 1993-'94 seasons. The levels of O-2 in the step -wise low O-2 Storage were maintained and increased from 0.5% for four months to 1.0% for two months, and finally to 1.5% for two months whi le the CO2 concentration in the storage was kept below 0.05%. Air-stor ed fruit were capable of ripening normally with good dessert quality a fter one, two, and three months of storage. These fruit softened to be tween 9.7 N and 15.0 N and reached the ethylene climacteric peak on da y 7 or 8 of ripening at 20 degrees C. The ripened fruit developed a bu ttery and juicy texture as indicated by an apparent reduction of extra ctable juice (EJ) from 67 ml juice per 100 g fresh weight (FW) of unri pened pulp tissue to less than 45.0 mi juice per 100 g FW of ripened p ulp tissue. Fruit in air storage for four and five months reached the ethylene climacteric peak on day 4 of ripening but did not soften prop erly. Fruit stored in step-wise low O-2 for six, seven and eight month s reached the ethylene climacteric peak on day 6 of ripening. Step-wis e low-O-2-stored fruit softened properly to 12 N or lower and reduced EJ to 49 ml 100 g(-1) FW (six and seven months of storage) or 59 ml 10 0 g(-1) FW (eight months of storage) on day 8 of ripening. Based on th e analyses of ethylene production, fruit softening and reduction of EJ during ripening, fruit stored in the step-wise low O-2 Storage for si x, seven and eight months maintained a physiological state similar to the fruit stored in air for one to three months. The combination of pr estorage heat (28 degrees C for one day) and step-wise low oxygen stor age effectively reduced side rot by 60 and 63% in 1993 and 1994, respe ctively. Even greater decay control was obtained with the fungicides i mazalil and Exp10412A on inoculated fruit, and thiabendazole plus capt an on non-inoculated fruit.