Search Results

You are looking at 31 - 40 of 108 items for :

  • "air storage" x
  • Refine by Access: All x
Clear All
Free access

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.

Free access

M.C.N. Nunes, A.M.M.B. Morais, J.K. Brecht, and S.A. Sargent

`Chandler' strawberries (Fragaria ×ananassa Duch.) harvested three-quarter colored or fully red were stored in air or a controlled atmosphere (CA) of 5% O2 + 15% CO2 at 4 or 10 °C to evaluate the influence of fruit maturity and storage temperature on the response to CA. Quality evaluations were made after 1 and 2 weeks in air or CA, and also after 1 and 2 weeks in air or CA plus 1 day in air at 20 °C. By 2 weeks, strawberries of both maturities stored in air at 10 °C were decayed, however, strawberries stored in CA at 4 or 10 °C or air at 4 °C had no decay even after 2 weeks plus 1 day at 20 °C. Three-quarter colored fruit stored in either air or CA remained firmer, lighter (higher L* value) and purer red (higher hue and chroma values) than fully red fruit, with the most pronounced effect being on CA-stored fruit at 4 °C. CA was more effective than air storage in maintaining initial anthocyanin and soluble solids contents (SSC) of three-quarter colored fruit and fruit stored at 10 °C. Strawberries harvested three-quarter colored maintained initial hue and chroma values for 2 weeks in CA at 4 °C, becoming fully red only when transferred to air at 20 °C. Although three-quarter colored fruit darkened and softened in 10 °C storage, the CA-stored fruit remained lighter colored and as firm as the at-harvest values of fully red fruit. After 1 or 2 weeks in CA at either 4 or 10 °C plus 1 day at 20 °C, three-quarter colored fruit also had similar SSC levels but lower total anthocyanin contents than the initial levels in fully red fruit. CA maintained better strawberry quality than air storage even at an above optimum storage temperature of 10 °C, but CA was more effective at the lower temperature of 4 °C. Three-quarter colored fruit responded better to CA than fully red fruit, maintaining better appearance, firmness, and color over 2 weeks storage, while achieving similar acidity and SSC with minimal decay development.

Free access

Duane W. Greene

BAS-125 10W is a new plant growth retardant that was evaluated on `McIntosh' apples to control excessive vegetative growth. When applied at concentrations between 0 and 375 ppm, it significantly reduced terminal growth. As a result, light penetration into the tree was increased and fruit at harvest had more red color, and more were graded into the US Extra Fancy category. BAS-125 increased fruit set; thus, fruit were smaller, but firmer, at harvest. Treated fruit were firmer and had less decay following 20 weeks of regular air storage. Several different thinning strategies were employed to thin BAS-125-treated `Delicious' trees. In one experiment, the best thinning treatment was a combination spray containing 10 ppm NAA plus carbaryl at petal fall followed by 8 ppm NAA when fruit size averaged 10 mm. The best treatment in another experiment was a Wilthin application at 80% bloom followed by 8 ppm NAA plus carbaryl at petal fall. Recommendations for the successful use of BAS-125 10W in the Northeast will be discussed.

Free access

D.C. Elfving, E.C. Lougheed, C.L. Chu, and R.A. Cline

Foliar daminozide (DZ) applications to `McIntosh' apple trees (Malus domestics Borkh.) increased fruit color, reduced preharvest drop, resulted in greater firmness at harvest and after air storage, delayed starch hydrolysis, and reduced fruit ethylene production at harvest and after storage. Foliar paclobutrazol (PBZ) reduced preharvest drop and flesh firmness loss if applied within 5 weeks after full bloom (WAFB). Later applications had no effect. PBZ did not influence the progress of starch hydrolysis or ethylene production at harvest but reduced poststorage ethylene production in one season. Stem-cavity browning and brown core were increased by PBZ applied at 5 and 9 WAFB in 1987. In 1988, fruit soluble solids content (SSC) was reduced by a double application of PBZ and by uniconazole (UCZ). UCZ had little effect on `McIntosh' fruit other than the reduction in SSC. PBZ applications were less consistent in their effects than DZ. Chemical names used: butanedioic acid mono(2,2-dimethylhydrazide) (daminozide); ß-[(4-chlorophenyl) methyl]-α- -(l,l-dimethylethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol); ß-[(4-chlorophenyl)methylene]-α-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol (uniconazole).

Free access

Chen-Yi Hung, Cindy B.S. Tong, and John R. Murray

The color of red potatoes is due to an accumulation of anthocyanins in periderm tissues. The objective of this study was to examine the effect of several factors on tuber redness. Using the red tuber-producing S. tuberosum ssp. tuberosum cultivar Norland, we observed that chroma (intensity of redness) and anthocyanin content of greenhouse-grown tubers decreased as tuber weight increased. There was a slight or no increase in hue (tint). We used HPLC to determine that pelargonidin and peonidin are the major anthocyanidins (aglycones of anthocyanins) in tuber periderm. The ratio of pelargonidin to peonidin increased as tuber weight increased up to 25 g fresh weight. The decrease in chroma was not due to an increase in cell sap pH; we observed a decrease in cellular pH as tuber weight increased. Controlled-atmosphere storage had no effect on tuber chroma or anthocyanin content compared to air storage. Methyl jasmonate, sucrose, or light treatment did not increase anthocyanin accumulation. Tubers exposed to light had less anthocyanin than those kept in the dark. We are examining the developmental expression of anthocyanin biosynthetic genes, as well as the effect of maize transcription factors on anthocyanin synthesis, in tuber periderm.

Free access

Duane W. Greene

An experiment was initiated on mature `Morespur McIntosh'on M.7 rootstock to document the effects of repeated yearly applications of benzyladenine (BA) and naphthaleneacetic acid (NAA) on fruit quality at harvest, the development of storage disorders following regular air storage, and on return bloom. When analyzed over the 4-year period, thinning did not significantly reduce crop load. This result was due in large part to no thinning response one year and very poor set on all trees in another year. Thinners were effective at increasing return bloom over the course of the experiment. BA increased fruit weight but reduced red color compared with NAA treated and control trees. Fruit quality differences at harvests were attributed primarily to crop load effects. There were no fruit quality, return bloom, or storage disorders that could not be explained by treatment effects on crop load or due to previously known effects of individual thinners. The results of this experiment clearly suggest that there are no direct adverse effects following repeated use of either NAA or BA.

Free access

Raymond L. Granger, Y. Groleau, C. Fortin, Gilles L. Rousselle, and L.P.S. Spangelo

`QAS-13' is an advanced apple selection that has a proven performance and is in the process of becoming a new cultivar that carries the Vf gene for resistance to apple scab (Venturia inaequalis Cke. Wint.) derived from `Malus floribunda 821'. It combines field immunity to scab and cold tolerance under Quebec climate and soil conditions. The Ott.521 (Melba x 11-51) x `Spartan' cross was made in Ottawa in 1968. The fruits are very attractive and exhibit a smooth and shiny finish somewhat similar to that of `Spartan'. Their glossy, medium- to dark-red color is slightly striped over a greenish-yellow background and covers up to 85% of the fruit surface. Their picking season coincides with that of `Spartan', which is ≈1 week before that of `Red Delicious'. They are round-oblate to oblate in shape with an average diameter of 70 to 75 mm and weigh ≈140 g/fruit. The skin is smooth, thin, and moderately tough, with widely spaced conspicuous beige lenticels. Both the stem and calyx cavities are fairly deep. The stem resembles that of `McIntosh'. the `QAS-13' apples keep better than `McIntosh' apples both in CA and air storages. Taste panelists have consistently ranked the `QAS-13' apples above `McIntosh' apples both at harvest and after storage. The `QAS-13' trees are less vigorous than those of `McIntosh', but more productive. However, they have exhibited a slight susceptibility to frog eye leaf spot (Botryosphaeria obtusa) similar to that of `McIntosh'.

Free access

William D. Wolk, O.L. Lau, G.H. Neilsen, and Brian G. Drought

A study was undertaken to identify key factors associated with storage disorders in three commercially important apple cultivars in British Columbia and to determine how early in the season associations could be measured. Fruit mass, density, and concentrations of N, P, K, Ca, Mg, and dry matter were determined for `McIntosh', `Spartan', and `Golden Delicious' apples (Malus ×domestica Borkh) from ≈30 commercial orchards 9, 6, 3, and 0 weeks before harvest. Storage samples were collected at commercial harvest and evaluated for the development of internal breakdown (`McIntosh' and `Spartan') or bitter pit (`Golden Delicious') after 4 and 6 months of 0 °C air storage. Mass and [Ca] and the mass/[Ca] and [K]/[Ca] ratios were the factors most often significantly correlated with storage disorders within each year for all three cultivars. Correlations were as frequently significant 6 and 3 weeks before harvest as they were at harvest. Mass of `McIntosh' and `Spartan' was the only variable consistently related with breakdown in all 3 years of the study. There were no variables with a consistent relationship to bitter pit in `Golden Delicious'. Fruit [Ca] was associated with the relative levels of disorders within years but could not be associated with specific levels of disorders across all years.

Free access

Zhenyong Wang and David R. Dilley

We are investigating alternative strategies to control scald on apples. Ethanol vapors were applied to `Law Rome' and `Red Delicious' apples in the storage chambers by ventilating air through aqueous solutions of ethanol at different concentrations, and in modified atmosphere packages by adding various initial concentrations of ethanol vapor. Fruits in storage chambers treated with ethanol vapor at 1600 ppm for about 2 months showed no scald when stored for an additional period in air storage whereas the scald index in control was up to 2.33 (the highest is 3). The similar results in the modified atmosphere experiments confirmed that ethanol vapor could prevent apple scald. Ethanol vapor treatment was also correlated with a reduction of α-farnesene production by the fruits. α-farnesene is an isoprenoid metabolite in the pathway to carotenoid synthesis that has been implicated indirectly as a factor in scald development. Evidence for this based on diphenylamine (DPA) reducing the level of a conjugated terpene product of α-farnesene oxidation. Our results suggested that the control of scald by ethanol vapor treatment may be related to the reduction of α-farnesene production and its subsequent oxidation. Ethanol vapor treatment resulted in accumulation of ethanol in the fruits in direct proportion to the ethanol concentration administered and reduced the rate of ethylene production, and the internal ethanol levels dropped rapidly when fruits were returned to air without ethanol vapor.

Free access

Rawia El-Bassuoni and Marita Cantwell

Bell pepper fruits (green and red) were stored intact or prepared in dices (1 × 1 cm), washed with chlorinated water, biot dried, and stored in air or controlled atmospheres (air or 3% O2 with 0, 5 or 10% CO2) at 0, 5 or 10C for up to 20 days. Dicing resulted in respiration rates 2-3 times higher than those of intact peppers, but did not result in measureable increases in ethylene production. Samples were periodically transferred to 15C for 12 h before evaluation for visual quality, decay, discoloration, aroma, flavor, texture, and sugar content. Quality changes were similar for green and red fruit of the same cultivar. Intact peppers are chilling sensitive, but the quality of diced peppers was maintained best at 0C. The shelf-life of diced pepper at 10 and 5C was 1/2 to 2/3 that of intact peppers. Atmospheres containing 5 or 10% CO2 reduced decay and increased the shelf-life of diced peppers, but were not as effective as storage in air at 0C. Storage at 0C also resulted in greater retention of sugars than storage under other conditions. High CO2 atmospheres resulted in softening of pepper tissue and increased electrolyte leakage. Aroma and flavor scores declined more rapidly in CA than in air storage.