sweet sensory descriptors and green apples with grassy, acidic, or sour sensory descriptors ( Daillant-Spinnler et al., 1996 ). Upon tasting, internal quality characteristics such as flavor, sweetness, sourness, and texture attributes are also
Esnath T. Hamadziripi, Karen I. Theron, Magdalena Muller, and Willem J. Steyn
Denise Neilsen, Gerry Neilsen, Sunghee Guak, and Tom Forge
end point with data expressed as g/100 mL malic acid equivalents. An additional random subsample of 10 fruit at harvest was used to calculate incidence of disorders including water core, sunburn, internal breakdown, and bitter pit. Analysis of variance
Ahmed F. El-Shiekh and David H. Picha
Peaches stored in air for 40 days at OC developed severe internal breakdown and poor quality after transferring them to 20C to ripen. Comparable fruit stored under controlled atmosphere (1% O2 + 5% CO2) and then ripened at 20C had no breakdown and retained good quality. Fruit stored under CA had less reducing sugars but more sucrose than air stored fruit. Fruit pH increased and titratable acidity decreased over a 40 day storage period. Citric acid increased slightly while malic acid decreased during storage. Little or no differences in overall acidity and individual organic acids existed between CA and air storage. Little or no change in individual phenolic acid content occurred during storage or between CA and air storage. Internal color darkened and became redder with storage. CA stored fruit was significantly firmer than air stored fruit. Sensory evaluation indicated CA stored fruit was more acidic, sweeter, and had better overall flavor than air stored fruit.
Carlos H. Crisosto, R. Scott Johnson, Kevin Day, and Ted DeJong
Studies on the influences of “orchard factors” such as cultivar, harvest time, crop load, fruit canopy position, irrigation, and nitrogen regimes were investigated for plums, nectarines, and peaches at the Kearney Agricultural Center (San Joaquin Valley, Calif.a). These preharvest factors affected internal browning and mealiness incidence differently. More-reliable benefits of treatments to eliminate or reduce internal breakdown may be accomplished by using outer canopy fruit. Optimum quality expression and subsequent consumer satisfaction for each cultivar can be achieved by understanding the role of preharvest factors and harvest time on fruit quality and potential postharvest life.
Myong-Dong Cho, Yong-Koo Kim, and Hee-Seung Park
`Yumyeong' peach has the desirable characteristics of long shelf-life and specific non-melting nature with a long harvest period. However, some fruits harvested too late show fruit pithiness symptoms or internal breakdown. This study was conducted to analyze the differences between fruit flesh pithiness and internal breakdown symptoms and to find out the source of flesh pithiness in `Yumyeong' peach. The rate of flesh pithiness was higher in fruit harvested late in the season. Sugar and malic acid contents showed no differences between the normal and flesh pithiness fruits, but the acidity was significantly lower and was affected by low citric acid content in flesh pithiness fruit. In flesh pithiness fruits, calcium contents were low both in skin and flesh. Occurrence of flesh pithiness fruits was high in the years with low precipitation and high temperature for 2 months before harvest. In observations on morphological characteristics, the parts showing flesh pithiness consisted of smaller cells than the normal parts. Tonoplasts disintegrated and the number of dead cells was high in internal breakdown fruits, while the tonoplasts were intact, with contracted vacuoles, in flesh pithiness fruits. Tylosises were observed in vascular tissues around the flesh pithiness; therefore, it was assumed that those tylosises restrict flesh tissue development, resulting in flesh pithiness. Other varieties (`Fantasia', `Wolmi' and `Hakuto') also showed tylosis, and smaller cells were observed in the flesh tissue of these cultivars, indicating abnormal growth of the flesh part. These results suggest the possibility of the occurrence of pithiness-like symptoms in other peach varieties.
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.
Zhiguo Ju, Eric A. Curry, Yousheng Duan, Zhiqiang Ju, and Aixin Guo
Preclimacteric `Bartlett' pears (Pyrus communis L.) were dipped for 3 min in either corn (Zea mays L.) or soybean [(Glycine max (L.) Merrill] oil emulsion immediately after harvest and stored at 0 °C. Untreated control fruit developed higher percentages of senescent scald, core breakdown, and decay after 15 weeks storage. Both treatments inhibited senescent scald, core breakdown, and decay in a similar and concentration dependent manner. Complete control of senescent scald and core breakdown was achieved by emulsions at 5% and 10%, and of decay by emulsion at 10%. Compared with controls, emulsion treatments delayed and reduced internal ethylene accumulation and volatile production in early storage and increased them in late storage. Compared with controls, fruit treated with oil contained similar levels of internal O2 and CO2 in early storage and higher CO2 and lower O2 in late storage. While control fruit lost commercial value after 15 weeks at 0 °C plus 5 days at 20 °C, oil-treated fruit exhibited normal color change, and had higher soluble solids, titratable acidity, and volatile production. Microscopic examination revealed that emulsion-treated fruit had a continuous surface film conforming to the contour of the fruit.
Jayson K. Harper and George M. Greene II
This study quantifies the discounts and premiums associated with various quality factors for processing apples (Malus domestica Borkh.). Discounts and premiums were estimated using a hedonic price model and quality data from a total of 137 samples representing three processing apple cultivars (45 `York Imperial', 43 `Rome Beauty', and 49 `Golden Delicious'). Price discounts in the sample were statistically significant for fruit size, bruising, bitter pit, decay, misshapen apples, and internal breakdown. Commonly cited defects, such as insect damage and apple scab, did not cause significant price discounts.
Stephen R. Drake
`Anjou' pears (Pyrus communis L.) were placed in controlled-atmosphere (CA) storage immediately after harvest (<24 hours) or after a 10-day delay in refrigerated storage, and held there for 9 months at 1C. Oxygen in all atmospheres was 1.5% and CO2 was at either 1% or 3%. Atmospheres in the flow-through system were computer-controlled at ±0.1%. After removal from CA storage, pears were evaluated immediately and after ripening at 21C for 8 days. Pears stored in 3% CO2 were firmer, greener, and displayed less scald, internal breakdown, and stem-end decay than pears stored in 1% CO2. In addition, no internal discoloration of `Anjou' pears was evident when held with 3% CO2. `Anjou' pears held in 3%. CO2 retained the ability to ripen after long-term storage. A 10-day delay in atmosphere establishment had little or no influence on the long-term keeping quality or ripening ability of `Anjou' pears.
S.R. Drake, E.A. Mielke, and D.C. Elfving
`Concorde' pears from three plantings were harvested at various maturities, stored in regular (RA) or controlled atmosphere (CA) storage and their quality evaluated. Starting at a firmness of 57.0 N (12.81 lbf), `Concorde' pears can be harvested over a period of 14 days with no loss in quality and be good candidates for either RA or CA storage. A 14-day delay in harvest resulted in a one box size increase. Regardless of the time of harvest, `Concorde' pears can be stored in RA for periods not to exceed 90 days. RA storage beyond 90 days resulted in reduced appearance, poor pedicel condition, and enhanced internal breakdown. Early harvest should be considered when RA storage is expected to exceed 90 days; however astringency may develop. Regardless of harvest, `Concorde' pears can be stored for 180 days in CA with no quality loss, particularly if the CA composition is 1.5% oxygen (O2) and 1.0% carbon dioxide (CO2). Internal breakdown can be a problem in CA if the CO2 exceeds 1.0%. Low O2 (<1.5%) CA is not recommended for `Concorde' pears.