The effects of ethanol vapors, controlled atmosphere (CA) storage, and a combination of both on superficial scald development on `Granny Smith' apples (Malus ×domestica Borkh.) are reported. The major result was that ethanol vapors, applied in cold storage, prevented scald development over a week at 20 °C in apples that had been CA-stored for 4 months, then left for 1 month in cold air storage. Interrupting CA storage aimed to reproduce industry practices when fruit in part of storage rooms has to be sold and the remaining fruit is held in air for later sale. The estimated cost and further development of this method are discussed.
C. Chervin, J. Raynal, N. André, A. Bonneau, and P. Westercamp
Hirofumi Terai, Hironobu Tsuchida, Masashi Mizuno, and Noriyoshi Matsui
Tomato fruit were given a short-term (24 h) high CO2 (80%) or N2 (100%) treatment and then transferred to air storage at 20 °C. The CO2 treatment stimulated ACC oxidase activity and ethylene production, whereas the N2 treatment increased ACC content but did not increase ethylene production. Both CO2, and N2 treatments delayed ripening for one day, but fruit ripened normally. Although short-term 80% CO2, had a stimulating effect, and 100 % N2 had no effect on ethylene production, ripening was delayed slightly by both treatments. Chemical name used: 1-aminocyclopropane-1-carboxylic acid (ACC).
Renae E. Moran and Patricia McManus
1-Methylcyclopropene (1-MCP) maintained firmness of `Macoun' apple (Malus ×domestica Borkh.) above 50 N after 90 to 100 days regular air storage when harvested at a starch index of 2.7 to 3.5, and after 50 days when harvested at a starch index past 4.0. Softening of `Macoun' was slowed by 1-MCP in both preclimacteric and climacteric fruit, but for a shorter duration in climacteric fruit. 1-MCP reduced but did not eliminate the occurrence of senescent breakdown. The effect of 1-MCP on coreline browning was inconsistent, reducing its occurrence in 2002 and 2003, but increasing its occurrence in 2001 when fruit were harvested at an advanced maturity.
O.L. Lau and R. Yastremski
`Golden Delicious' apples (Malus domestics Borkh.) were subjected to either 0C controlled-atmosphere (CA) storage or to a postharvest coating of 1.0% to 2.5% Nutri-Save (NS; a polysaccharide derived from shellfish) plus air storage. NS-coated apples were greener and firmer and had higher titratable acidity (TA) and more shrivelled and injured fruit than the control after storage in air at 0C for 5 to 6 months and ripening in air at 20C for 7 days. Poststorage washing increased skin injury, and low relative humidity during ripening increased shriveling of NS fruit. NS applications led to an accumulation of CO2 and C2H4 and a small reduction of O2 in the fruit core cavities. The use of 1.5% O2 + 1.5% CO2 in the storage atmosphere was more effective than NS plus air storage in maintaining flesh firmness (FF) and TA without increasing fruit shrivel or skin injury. NS treatments maintained FF and a green skin in fruit ripened in air at 20C for 2 or 4 weeks following harvest, but some shrivel was evident by 4 weeks. Better retention of skin greenness was the only benefit derived from a poststorage NS treatment of CA-stored fruit during the shelf-life test.
Frank J. Peryesa and Stephen R Drake
Fruit growers and shippers have suggested that excessive rates of boron (B) in foliar nutrient sprays may reduce quality of stored apples. Foliar B sprays were applied by handgun in mid-July to bearing apple trees (Malus domestica Borkh. cv. Starking) at rates of 0, 11.3,22.6 g B/tree. Fruits of uniform size (220 g) were analyzed for B content at harvest and for quality indices at harvest, after 10 days ripening postharvest, after 3 months refrigerated air storage, and after 8 days ripening poststorage. Whole fruit B concentration was directly proportional to B application rate. At all sampling times fruit firmness, soluble solids, titratable acidity, and internal and external color parameters were independent of whole fruit B concentration. Fruit disorders were unrelated to treatment except for internal breakdown after 8 months refrigerated air storage, which was positively related to whole fruit B concentration. Increases in fruit B were relatively greater in the core tissue, suggesting that some of the applied B entered the fruit through the tree vascular system.
Susan Lurie, Joshua D. Klein, and Ruth Ben Arie
A prestorage heat treatment of 38C for 4 days applied to `Granny Smith' apples (Malus domestics Borkh.) before regular air storage at 0C inhibited the development of superficial scald. Heat-treated apples stored for 3 months had superficial scald levels similar to diphenylamine (DPA)-dipped apples, while all nontreated control apples had scald. After 5 or 6 months of storage, this inhibition of scald development by prestorage heat treatment declined. The prestorage heat treatment inhibited the accumulation of α-farnesene and conjugated trienes in apple cuticle during storage, while DPA inhibited only α-farnesene oxidation. This treatment may be a substitute for chemical treatments against scald not only for short-term storage of `Granny Smith' but possibly also for other scald-susceptible apple cultivars.
Mette Larsen and Christopher B. Watkins
Firmness and aroma composition of strawberry fruit (Fragaria ×ananassa Duch. cv. Pajaro) stored in air or treated with 20% CO2 for up to 12 days at 0C were analyzed upon removal from storage. Fruit firmness increased after 2 days in CO2, while the composition of aroma compounds in the fruit was unaffected at this time. Ethanol and ethyl hexanoate accumulated after 3 days during high CO2 treatment, but these compounds usually decreased during subsequent cold storage in air. Ethyl butanoate and ethyl acetate also accumulated but continued to increase after 6 and 9 days of CO2 storage, respectively. This study suggests that treatment of strawberry fruit with CO2 after harvest, followed by air storage at 0C, can maintain firmness while minimizing off-flavor development.
Duane W. Greene and Wesley R. Autio
BA, NAA, and carbaryl at 75, 6, and 600 mg·liter-1, respectively, were applied alone or in combination to `Starkrimson Delicious' in 1989 and `Redspur Delicious' apples (Malus domestica Borkh.) in 1990. BA was effective alone, but when combined with carbaryl it thinned excessively. Thinning failed when BA was combined with NAA because many seedless pygmy fruit were formed and they persisted until harvest. BA and carbaryl were more effective than NAA at increasing return bloom. Return bloom was more closely related to total seed count than to final set. BA improved flesh firmness at harvest and after cold storage. None of the treatments influenced the development of calcium-related storage disorders following air storage. Chemical names used: benzyladenine (BA); naphthaleneacetic acid (NAA).
Teresa Palma, David W. Stanley, José M. Aguilera, and Juan P. Zoffoli
The objective of this work was to obtain information for designing modified-atmosphere packages for storing and transporting cherimoyas. Respiration rates of `Conchs Lisa' cherimoyas at 10C were monitored in a flow-through system using O2 consumption and CO2 production under atmospheres containing 5910, 10%, 15%, or 20% O2. Under normal atmosphere (20% O2), the respiration curve exhibited atypical climacteric rise 15 days after harvest, while 15% and 10 % O2 delayed this event. Fruit kept in 5% O2 did not show a detectable climacteric rise and did not produce ethylene. All fruit ripened normally after being transferred to air storage at 20C; however, the time needed to reach an edible condition differed with treatment and was inversely proportional to O2 content. Delay of the climacteric by 5 % O2, coupled with the continued ability to ripen, makes this procedure suitable for controlled- or modified-atmosphere cherimoya packaging.
M. Meheriuk, D.-L. McKenzie, G.H. Neilsen, and J.W. Hall
Four green apple (Malus domestica Borkh.) cultivars, `Granny Smith', `Mutsu', `Newtown', and `Shamrock', were subjected to a factorial experiment of two rates of nitrogen fertilization and three concentrations of foliar urea sprays for 4 years. The higher rate of N (160 kg N/ha) had no effect on ground color or fruit quality relative to the lower rate of 80 kg N/ha. Urea sprays enhanced green pigmentation in `Granny Smith' and `Newtown' at harvest and retarded yellowing of fruit in all cultivars during air storage at 0C. Response was similar for urea at 0.5% and 1%, and urea sprays did not adversely affect quality. Urea sprays increased fruit N by 23% and 47% for the 0.5% and 1% concentrations, respectively.