Controlled atmosphere (CA) storage for 30 or 60 days reduced quality losses for `Jonagold', `Golden Delicious', `Delicious', `Granny Smith', and `Fuji' apples (Malus domestica Borkh.). After 30 days `Jonagold' and `Golden Delicious' from CA were firmer, had higher acidity, and were less yellow (more green) than apples from regular atmosphere (RA) storage. `Delicious' and `Granny Smith' were firmer after 60 days of CA storage than fruit from RA. In addition, `Granny Smith' from CA had more acid and were greener than apples from RA. After 8 days of ambient storage, little loss in firmness and no loss in acid content occurred with `Jonagold' or `Golden Delicious' from CA compared to the significant loss in firmness and acid when stored in RA. After ambient storage for 8 days, `Jonagold', `Golden Delicious', and `Granny Smith' retained a freshly harvested apple color with more green and less yellow development when stored in CA rather than RA. In `Fuji', the treatments had no effect except for improved acid retention if stored in CA. A combination of 30 days CA followed by 30 days RA produced `Jonagold', `Golden Delicious', and `Delicious' that were superior in quality to apples from 60 days RA.
S.R. Drake and Tom Eisele
Red color of 2 strains (`Bisbee' and `Red Chief) of `Delicious' apples was increased (25%) by a 10 day delay beyond recommended harvest date. Color of `Oregon Spur' did not change during this 10 day period. Soluble solids content and size were also increased, but firmness decreased by 12%. In 2 of 3 years, firmness at harvest was 73 N or greater in all strains and these fruit lost little firmness during 9 months of CA. Poor firmness (<63 N) at harvest resulted in fruit with unacceptable firmness (53 N) after storage regardless of harvest time or strain. Loss in fruit quality was evident after a 5 day delay in atmosphere establishment with no further loss after a 10 day delay. `Oregon Spur' had the best color regardless of harvest, followed by `Bisbee' and `Red Chief. All strains (`Oregon Spur', `Bisbee' and `Red Chief) had good quality after long term CA. Sensory panelists could not distinguish flavor differences between strains, harvest dates or delay in storage establishment.
S.R. Drake and S.K. Ivanov
In 1989 and 1990, `Golden Delicious' apples from controlled-atmosphere (CA) storage (1% O2; 3% CO2) averaged 8.5 N firmer after 30 days and 13.5 N firmer after 60 days of storage than apples from regular-atmosphere (RA) storage. After 7 days of ambient storage, `Golden Delicious' apples from CA storage were 10.3 N firmer than apples from RA storage. Little change in color was evident in `Golden Delicious' apples from CA storage after 30 or 60 days, but a distinct increase in yellow color was evident in apples from RA storage after only 30 days. The quality (color, firmness, and acidity) of `Golden Delicious' apples stored for 30 days under CA and then 30 days under RA was superior to that of `Golden Delicious' apples after 60 days of RA storage and similar to that of `Golden Delicious' apples after 60 days of CA storage. `Granny Smith' apples, traditionally a very firm apple regardless of the type of storage, averaged 3.3 N firmer after 30 days of CA storage (1% O2; 1% CO2) and 5.8 N firmer after 60 days of CA storage when compared to apples from RA storage. Little change in color was evident in `Golden Delicious' apples regardless of storage length, but under ambient storage temperatures, `Golden Delicious' apples from CA storage maintained their green color longer. Titratable acidity of both `Golden Delicious' and `Granny Smith' apples depended on growing season, and neither `Golden Delicious' nor `Granny Smith' apples showed consistent trends in titratable acidity after either RA or CA storage.
S.R. Drake and H.R. Mofiitt
MeBr fumigation of `Anjou' pears reduced external skin color values and increased the incidence of scald whether applied immediately after harvest or after 5 months of controlled-atmosphere (CA) storage. MeBr treatment did not influence external color of `Bosc' pears (Pyrus communis L.). Internal discoloration of `Bosc' pears was apparent only in fruit from CA storage and those that were not in good physiological condition before fumigation. Internal discoloration was apparent by either objective or subjective procedures. Firmness values of `Bosc' pears increased with MeBr fumigation and treated pears softened as readily as nonfumigated pears. Reaction of these winter pears to MeBr fumigation was not dose-dependent. Chemical name used: methylbromide (MeBr).
S.R. Drake and H.R. Moffitt
`Fuji', `Gala' and `Jonagold' apples (Malus×domestica Borkh.) from either regular-atmosphere (RA) or controlled-atmosphere (CA) storage can be fumigated with methyl bromide (MeBr) with minimal effects on fruit quality. Some quality loss, particularly in internal color, was possible at 48 and 56 g·m−3 MeBr doses for `Fuji', `Gala', and `Jonagold' apples from CA storage. `Braeburn' apples from either RA or CA storage were not good candidates for MeBr fumigation, particularly at 10 °C. Observed internal damage indicated that `Braeburn' apples from RA or CA cannot be fumigated with MeBr. Apples with watercore displayed increased internal breakdown after fumigation with MeBr. Regardless of cultivar, only apples of superior quality could tolerate the stress of MeBr fumigation.
S.R. Drake and T.A. Eisele
Red color of two strains of `Delicious' apples was increased (25%) by a 10-day delay beyond recommended harvest date for long-term controlled atmosphere (CA) storage. Soluble solids content (SSC) and size also increased, but, depending on strain, up to 12% of firmness was lost at harvest with a 10-day delay. In 2 of 3 years, firmness values in all strains were 73 N or greater, and these fruit lost little firmness during 9 months of CA storage. Soft fruit (<63 N) at harvest resulted in unacceptable firmness after storage, regardless of harvest time or strain of `Delicious'. Immediate (<24 h) establishment of CA conditions resulted in good-quality fruit after storage. Quality loss was evident after a 5-day delay in atmosphere establishment, with no further loss after a 10-day delay. `Oregon Spur' apples had the best red color regardless of harvest. Sensory panel profiles were unable to distinguish among strains, harvest dates, or delays in time of atmosphere establishment. Caution should be exercised when initiating new harvest or storage procedures because growing conditions can vary from one location to another.
S.R. Drake and D.C. Elfving
Three commercial `Lapins' sweet cherry (Prunus avium) orchards were used for this study during three crop seasons. Orchards were selected based on the historical average date of commercial harvest. The difference in commercial harvest date among the three orchards was 5 to 7 days. Three harvests were carried out in each orchard each year: 1) beginning 4 to 5 days before commercial harvest, 2) at commercial harvest, and 3) 4 to 5 days after commercial harvest. Fruit quality was determined after 0, 7, 14, and 21 days of storage. Harvesting fruit up to 5 days later than normal commercial harvest resulted in increases in fruit weight and soluble solids content along with no loss of firmness or change in acidity. Pedicel color did not change as harvest was delayed. Changes in visual ratings of both fruit and pedicel appearance with delayed harvest were detectable in only 1 of 3 years. Neither pitting nor bruising was influenced by harvest date. The amount of pitting or bruising present was related more to the year of harvest than to harvest date. Delaying harvest a short time beyond the normal commercial harvest date could enhance consumer appeal and increase fruit value. Storage time after harvest resulted in reduced fruit and pedicel appearance, but only beyond 14 days of storage.
S.R. Drake and E.M. Kupferman
Modified Atmosphere Packaging (MAP) in combination with temperature control were investigated for qualify enhancement of sweet cherries (Prunus avium L.). `Bing', `Lambert' and `Rainier' cherries (1 kg/pkg/rep) were wrapped in 1 of 3 different MAP films (5,303; 8,900 and 11,286 cc/sq M/24 hrs of O2 and stored at 0 or 4 C for 3 weeks. Post-storage evaluations included both fruit and stem color, fruit firmness, weight loss, soluble solids, titratable acidity, bruising and pitting valuations, respiration rates and visual assessment. MAP films helped maintain fruit and stem color, and fruit firmness, Whereas weight loss and bruising were reduced. Visual assessment was best with fruit in MAP film packages, There was little change in soluble solids and titratable acidity among fruit in the different MAP films. Control (unwrapped) fruit had considerably higher soluble solids and titratable acidity than wrapped fruit. This difference in soluble solids and titratable acidity between control and MAP fruit was associated with a considerable weight loss in the control fruit. Respiration rates of the fruit varied among the different MAP films and was cuitivar dependent. Fruit stored at 0 C had better quality after 3 weeks of storage than fruit stored at 4 C.
J.T. Raese and S.R. Drake
Calcium sprays (CaCl2, Mora-Leaf-Ca + Link Ca, or Stopit) increased fruit Ca concentrations and reduced the incidence of cork spot of `Anjou' pears (Pyrus communis L.) during four seasons. All Ca sprays increased yield relative to the control. All sprays resulted in some injury to leaves and fruit, but fruit was acceptable for marketing. At the low rate, Stopit sprays were the least injurious. Early season sprays, in June to July, produced less leaf and fruit injury than late-season sprays, in July to August, or early + late-season sprays. Early or late-season Ca sprays resulted in slightly larger fruit than early + late sprays. Either late or early + late-season sprays led to higher Ca concentrations in fruit cortex than early sprays.
J. Thomas Raese and S. R. Drake
Sprays of calcium materials were applied at high volume rates (620 g Ca/400 liters) with a handgun during early June, late June, and mid-July versus mid-July, early August, and late August for five years, 1985 to 1989. Leaf injury was most severe for the late sprays but no spray injury was observed on the fruit surfaces. Bitter pit was markedly reduced with all sprays except CaSO4. In some years, bitter pit was controlled better with the early sprays. Either early or late sprays improved fruit quality including overall appearance, reduced scald development, improved red color of the skin, increased fruit firmness and reduced incidence of bitter pit in cold air (0°C) storage. Soluble solids and acidity in the fruit was not affected by calcium sprays. Leaf Ca was higher from the late spray applications than from the earlier applications. All calcium chloride spray materials resulted in increased fruit peel and cortex Ca. Calcium nitrate sprays tended to increase fruit nitrogen concentrations leading to undesirable higher N:Ca ratios in the fruit.