Air heat, methyl jasmonate dip, and vapor treatments with the ethylene action inhibitor 1-methylcyclopropene (MCP) were used to evaluate their effects on ripening-related characteristics and susceptibility to fungal decay in `Golden Delicious' apples (Malus ×domestica Borkh.) through 5 months of storage at 0 °C and ripening at 20 °C for 7 days. Preclimacteric fruit were treated with MCP vapor at a concentration of 1 μL•L-1 for 18 h at 20 °C, 38 °C air for 4 days, methyl jasmonate dip at concentrations of 10-5 and 10-4 for 3 min at 20 °C, combinations thereof, or left untreated before storage in air at 0 °C. One set of untreated fruit was stored in a controlled atmosphere of 1.5 O2 and 2.5% CO2 at 0 °C. The MCP treatment and CA storage delayed ripening, as indicated by better retention of green peel color and flesh firmness, and the reduced respiration, ethylene production rates, and volatile (both flavor- and superficial scald-associated) levels that were observed upon transferring the fruit to 20 °C. The MCP treatment followed by air storage delayed ripening more than CA storage. The heat treatment also delayed ripening but hastened skin yellowing. While methyl jasmonate dips had no significant effect on ripening, they were the only treatments used that reduced the incidence of postharvest decay and discolored the surface of some fruit. The results indicate that MCP may provide an effective alternative to CA for maintaining quality during cold storage and ripening. The results also indicate that methyl jasmonate dip treatment may reduce postharvest decay of fruit while maintaining fruit quality.
Robert A. Saftner, Judith A. Abbott, William S. Conway, and Cynthia L. Barden
H.P. Vasantha Rupasinghe, Dennis P. Murr, Jennifer R. DeEll, and Murray D. Porteous
Flesh softening is a major quality parameter that can limit long-term storage of apple cultivars. This study investigated the combined effects of preharvest AVG (Retain™) application, 1-methylcyclopropene (1-MCP; EthylBloc™) exposure at harvest, and commercial controlled atmosphere (CA) storage (2.0% O2 + 2.5% CO2) on flesh softening of `Empire' apple. Treatments were assigned in a split-split-plot experimental design; AVG and no AVG application as the main-plot, CA and air storage as the sub-plots, and 0, 0.1 0.5, 1.0 mL·L–1 1-MCP as the sub-sub-plots. Apples were removed from storage at 70 and 140 days after harvest and kept up to an additional 2 weeks at 20 °C for post-storage assessment of ripening. Preharvest AVG application of `Empire' fruit delayed maturation slightly as determined by starch index at harvest, but did not affect fruit size at harvest nor flesh softening in storage. All levels of 1-MCP were equally effective in controlling fruit softening both in air and CA, as 1-MCP-treated fruit were ≈2.5 kg firmer than untreated fruit. This firmness advantage was still evident even after 2 weeks at 20 °C, with CA-stored fruit holding their firmness the best. When all three technologies were combined, treated fruit were overall 156% firmer than control fruit (no AVG, no 1-MCP, air-stored). As well, ethylene production and emanation of aroma volatiles were reduced significantly in these fruit. Therefore, the synergism of AVG, 1-MCP and long-term CA storage could potentially hold flesh firmness and other ripening parameters of apples to values near those found at harvest.
N. Lallu, J. Burdon, D. Billing, D. Burmeister, C. Yearsley, S. Osman, M. Wang, A. Gunson, and H. Young
There are three main systems for the removal of carbon dioxide (CO2) from controlled atmosphere (CA) stores: activated carbon (AC) scrubber, hydrated lime scrubber, and nitrogen (N2) flushing. Each system is likely to have a different effect on the accumulation of volatiles other than CO2 in the store atmosphere, and these volatiles may influence the storage performance of the produce. `Hayward' kiwifruit (Actinidia deliciosa) were stored at 0 °C (32.0 °F) under 2% oxygen (O2) and 5% CO2 in CA rooms fitted with one of the three systems. In a fourth CA room, fruit were stored at 0 °C under air conditions. All four stores had their atmosphere scrubbed for ethylene. The store atmospheres and fruit firmness were monitored at intervals up to 27 or 14 weeks of storage in the 1999 or 2000 season, respectively. At the end of CA storage, and after an additional 4 weeks of air storage at 0 °C, fruit were evaluated for rots and physiological pitting. Linear discriminant analysis (LDA) showed the three CO2 removal systems altered the volatile profiles of the store atmospheres differently. CA storage delayed fruit softening markedly, and once returned to air, softening resumed at a rate equivalent to that of fruit of equivalent firmness that had not been CA stored. There was little effect of CO2 removal system on the fruit softening during storage. Although CA storage resulted in a higher incidence of rots, there was little difference among CO2 removal systems compared to the main effect between air and CA storage. Similarly, CA storage delayed the appearance of physiological pitting, although the incidence increased rapidly during an additional 4 weeks of storage in air, and was higher than for fruit stored throughout in air. Among the CO2 removal systems, N2 flushing resulted in fruit with the lowest incidence of physiological pitting. It is concluded that different CO2 removal systems alter room volatile profiles but may not consistently affect the quality of `Hayward' kiwifruit during CA storage.
Eric A. Curry and Duane W. Greene
CPPU was applied to whole spur `Delicious' apple (Malus domestica Borkh.) trees in central Washington at 0,6.25,12.5,25, or 50 mg·liter-1 at full bloom (FB) or FB plus 2 weeks. At both application times, the flesh firmness of treated fruit linearly increased with increasing concentration. CPPU applied at 0,5,10,15, or 20 mg·liter-1 to spur `Delicious' trees in Massachusetts at king bloom resulted in a linear increase in flesh firmness at harvest and following 28 weeks in air storage at 0C. CPPU did not affect the incidence of senescent breakdown, decay, or cork spot. Fruit length: diameter (L/D) ratios generally increased at all doses. Fruit weight was not influenced at either location. All CPPU concentrations reduced return bloom on `Delicious' apples in Massachusetts in 1989. Of the 10, 20, or 40 mg·liter-1 treatments for `Empire' apples, only CPPU at 40 mg·liter-1 reduced return bloom. CPPU applied to `Empire' apples in Massachusetts did not effect fruit set, soluble solids concentration, L/D, or firmness; however, fruit weight increased linearly with concentration. CPPU applied at 100 mg·liter-1 retarded preharvest fruit drop of `Early McIntosh' in Massachusetts for ≈7 days but was not as effective as NAA at 20 mg·liter-1. In a larger semicommercial trial, `Delicious' fruit treated with CPPU at 5,10, or 15 mg·liter-1 at FB, petal fall (PF), or PF plus 1 week, respectively, were harvested and graded over a commercial packing line. Malformities caused by CPPU at the highest doses reduced packout, although all CPPU application rates reduced the percent fruit culled due to poor color. CPPU increased packed fruit size, since the size of fruit (64 mm in diameter) in the >150-fruit/box size decreased, while the size of fruit (72 mm in diameter) in the 100- and 130-fruit/box sizes increased. Treated fruit stored for 7 months at 1C were firmer than nontreated controls. Chemical names used: N-(2-chloro-4-pyridyl)- N' -phenylurea (CPPU); 1 naphthalene-acetic acid (NAA).
Renae E. Moran, Jennifer R. DeEll, and Dennis P. Murr
durations were pooled for analysis because there was no effect on soft scald or soggy breakdown. In 2004 and 2005, fruit were subjected to no preconditioning or 4 d of preconditioning at 21 °C followed by air storage at 1.5, 3.0, or 4.5 °C for 5 months. In
Carolina A. Torres, Omar Hernandez, Maria A. Moya-León, Ivan Razmilic, and David R. Rudell
harvest to predict “stain” appearance postharvest are shown in Table 1 . Fig. 2. ( A ) “Stain” incidence (%) and (B) its probability during regular air storage (0 °C, >90% relative humidity) of ‘Fuji’. Table 1. Logistic regression equations for “stain
Jennifer R. DeEll, Jennifer T. Ayres, and Dennis P. Murr
effect of 1-MCP on internal browning in ‘Empire’ apples ( DeEll et al., 2007 ; Fawbush et al., 2008 ; Watkins and Nock, 2005 ). Core browning is reduced by 1-MCP in ‘McIntosh’ apples held in air storage at 0.5 °C ( Watkins et al., 2000 ), but is
Nihad Alsmairat, Carolina Contreras, James Hancock, Pete Callow, and Randolph Beaudry
similar result for rabbiteye blueberries ( Vaccinium ashei Reade) with an atmosphere of 15 kPa CO 2 and 2.5 kPa O 2 leading to a loss in firmness relative to air storage in as little as 4 weeks’ storage for Centurion and Maru cultivars. Cranberry
Jeremy Burdon, David Billing, and Paul Pidakala
when air storage was extended from 4 to 6 weeks is a reflection of the variability in time taken for the fruit to start ripening at storage temperature. This is seen in the ripening times for individual fruit at harvest being in the range 8–17 d. Low
Richard L. Bell and Tom van der Zwet
‘Bartlett’. In air storage at –1 °C, fruit will store for as long as 111 d without superficial scald or internal breakdown. When harvested firm but optimally mature, the fruit will ripen without postharvest chilling, but 10 to 12 d at 20 °C were required to