Respiration rate and bruising incidence were assessed in new cherry (Prunus avium L.) cultivars adapted to high temperatures. `Bing', `Brooks', `Tulare', and `King' respiration rates were evaluated at 0,5,10, and 20C, and bruising susceptibilities at 0, 10, 20, and 30C. `Bing' was the least susceptible to bruising and had the lowest respiration rate at all temperatures. Respiration rate increased with temperature in all cultivars. Impact bruising damage was greatest in all cultivars when fruit flesh was below 10C. Vibration damage was not influenced by fruit temperature. Our results suggest that the cherry cultivars assessed should be handled at temperatures between 10 and 20C during packing to minimize bruising damage. Due to increased respiration rates at higher temperatures, however, fruit should be cooled to 0C within 4 to 6 hours after harvest.
Carlos H. Crisosto, David Garner, Jim Doyle, and Kevin R. Day
Randolph M. Beaudry
Blueberry fruit were sealed in 0.00254 cm (1 mil) thick, 200 cm2 low density polyethylene pouches, which, in turn, were sealed in containers continually purged with gas mixtures containing 0, 20, 40 or 60 kPa CO2 and held at 15C. Sampling the gas composition of the enclosed package permitted accurate determination of O2 uptake, CO2 production and the respiratory quotient (RQ) despite the high background CO2 levels. O2 uptake was minimally affected by the CO2 treatments. CO2 production, however, increased at CO2 partial pressures over 20 kPa, resulting in an elevated RQ at 40 and 60 kPa CO2. Raising the CO2 partial pressure caused the fruit to become more sensitive to lowered O2, raising the O2 partial pressure associated with the RQ breakpoint.
A.S.A. Rahman, D.J. Huber, and J.K. Brecht
Bell pepper (Capsicum annum var. Jupiter) fruit were exposed to 1.5% O2 for 1 to 5 days at 20C to examine whether the low-O2-induced poststorage respiratory suppression (PRS) in whole fruit could be due to limitations in mitochondrial oxidative capacity. Mitochondrial oxidative capacity was not affected after storing bell peppers for 1 day in 1.5 % O2. Extending the storage period from 1 to 5 days in 1.5 % 0, resulted in PRS of CO2 production for about 55 hours after transfer to air, and a marked reduction in the oxidative capacity of isolated mitochondria. Mitochondrial activity was suppressed for 10 hours after transfer to air but, within 24 hours, bad recovered to values comparable to those of mitochondria from fruit stored continuously in air. Storing bell peppers in 1.5% O2 for 5 days resulted in a reduction in the respiratory control (RC), while ADP/O ratios were not affected. The reduction was temporary since the RC attained normal activity after returning bell peppers to air. Cyanide-sensitive cytochrome and CN-insensitive pathways were suppressed after storing fruit in 1.5 % O2 for 5 days. After returning fruit from a low-O2 atmosphere to air, the alternative pathway recovered at a greater rate than the cytochrome pathway.
Zienab F.R. Ahmed and Jiwan P. Palta
inhibiting PLD. The results of our study on reduction of ion leakage from the peel and pulp tissues are consistent with this suggestion. Fruit respiration rate and ethylene production are the main physiological factors that change and define the climacteric
Keith T. Birkhold, Karen E. Koch, and Rebecca L. Darnell
Carbon dioxide exchange, dry weight, C, and N content of `Bonita' and `Climax' blueberry (Vaccinium ashei Reade) fruit were measured from anthesis through fruit ripening to quantify developmental changes in amounts of imported C and N required for fruit development. Net photosynthesis occurred in fruit of both rabbiteye cultivars from petal fall through color break. During this time, fruit net photosynthesis declined from 16 μmol CO2/g fresh weight (FW) per hour for `Bonita' and 22 μmol CO2/g FW per hour for `Climax' to 0.2 μmol CO2/g FW per hour for both. Dark respiration for both cultivars declined following petal fall from 16 μmol CO2/g FW per hour to 3 μmol CO2/g FW per hour before increasing at fruit ripening to 9 μmol CO2/g FW per hour. Fruit C content was constant at 0.43 mg C/mg dry weight (DW) throughout development, while N content declined from 0.05 mg N/mg DW at petal fall to 0.01 mg N/mg DW at ripeness. DW accumulation and respiration accounted for 63% and 37%, respectively, of the total C requirement for fruit development. Fruit photosynthesis was estimated to contribute 15% of the total C required for fruit development in both cultivars; however, fruit photosynthesis supplied 50% of the C required during the first 10 days after bloom and 85% during the 5 days after petal fall. This large, early contribution of C from fruit photosynthesis may aid in the establishment of fruit until the current season's vegetative growth can supplement plant carbohydrate reserves in providing C for fruit development.
F. Kappel, P. Toivonen, D.-L. McKenzie, and S. Stan
Several sweet cherry (Prunus avium L.) cultivars were stored in air or modified-atmosphere packages (MAP) at 1 °C for 2 or 4 weeks, respectively. The new cultivars included `Santina', `Sumpaca Celeste', `Sumnue Cristalina', `Sumste Samba', `Sandra Rose', `Sumleta Sonata', and `Skeena', and the standards were `Lapins', `Sweetheart', and `Bing'. Fruit were rated for defects (stem browning, stem shrivel and fruit surface pitting), and fruit quality at harvest and after storage. Weight loss during storage was influenced by year, storage treatment, and cultivar. Stem shrivel, stem browning, and fruit surface pitting varied among cultivars and years. Generally, fruit stored in MAP had higher fruit firmness than at harvest or when stored in air. The respiration rate of fruit was lower in later than in earlier maturing cultivars, but respiration rate at harvest was not related to any of the quality measurements taken after storage.
T-B Huang, R.L. Darnell, and K.E. Koch
Water and carbon budgets of individual citrus fruit were determined throughout their growth to quantify the demand for sucrose and water relative to developmental changes. Fruit transpiration, water accumulation, photosynthesis, respiration, and C gain were measured during this period for grapefruit (Citrus paradisii Macf.) and calamondin (Citrus madurensis Lour.). On a whole-fruit basis, estimated rates of grapefruit transpiration and mean daily water inflow decreased after the first third of development, whereas water apparently was lost freely throughout growth of the smaller, thin-peeled calamondins. Estimates of daily fruit C import remained relatively similar during the majority of grapefruit growth, increasing rapidly only as fruit neared maturation. A similar trend was observed in calamondins, although rates were more variable. Overall, estimated mean daily water inflow into “developing grapefruit decreased relative to that of sucrose inflow, resulting in a progressively higher ratio of sucrose transport to net water inflow. Values for these ratios rose from ≈; 10 to >300 g sucrose/liter of water, reaching levels of net water and sngar transfer that could both be accommodated by citrus phloem alone. Any additional entry into grapefruit appears to have been offset by xylem back-flow, because no other net water influx was observed.
Matthew W. Fidelibus, Karen E. Koch, and Frederick S. Davies
humidity for 24 h. The jars were then sealed for 1 h, and respiration rate was calculated from the CO 2 in the headspace as measured by a gas chromatograph (Gow-Mac Instrument, Bridgewater, NJ). Carbohydrate analysis. After fruit respiration
Shin Hiratsuka, Yuka Yokoyama, Hiroshi Nishimura, Takayuki Miyazaki, and Kazuyoshi Nada
of high fruit respiration at 99 DAFB ( Fig. 4B ). For the control fruit, there were two respiration peaks: the first peak was at 99 DAFB and the second was at 126 DAFB. After fruit bagging, gross photosynthesis was reduced to 70% of controls at 99
Sylvia M. Blankenship
Banana fruit respiration rates and quality parameters such as peel color, pulp pH and soluble solids content were examined at 14°C under a number of controlled atmosphere (CA) environments. CA conditions were 1%, 2%, 4%, or 8% oxygen with or without 5% carbon dioxide. Each treatment combination was also done with or without 50 μL·L–1 ethylene added to the atmospheres. Green banana fruit were either gassed with ethylene (triggered) or ungassed. One percent oxygen was too low to consistently give undamaged bananas. The addition of 5% carbon dioxide to the controlled atmosphere increased fruit respiration rate whereas air plus 5% carbon dioxide showed decreased respiration when compared to air control fruits. Green, triggered fruit partially ripened under the CA conditions. Pulp pH and soluble solids content changed in a normal ripening pattern, however peel color was poor. Addition of ethylene to the atmospheres advanced fruit ripening somewhat in all fruit. When green, ungassed bananas were placed under CA, the presence of ethylene in the atmosphere did not cause the bananas to turn yellow, although some changes in pH and soluble solids were detectable. In triggered fruit the presence of ethylene in the storage advanced ripening with higher oxygen concentrations promoting faster ripening. Bananas that have ripened under CA conditions are not as high quality as those ripened in air in terms of visual appearance.