Cherries pitted prior to canning or treated with daminozide had lower drained weights, more total anthocyanin, more turbid syrup, darker Agtron red values, and were softer than nonpitted or nontreated cherries. USDA color grade was higher, but USDA character grade was reduced when cherries were pitted or treated with daminozide. CaCl2 applied as either a 3% dip prior to pitting or as a 1% addition to the syrup increased the firmness, decreased the turbidity of the syrup of pitted and nonpitted cherries, and reduced the number of split fruit in nonpitted cherries. CaCl2 improved the USDA character grade of pitted and nonpitted cherries, and daminozide-treated cherries. Delaying harvest by 8 days reduced drained weight losses, increased total anthocyanin content, pH and soluble solids, and resulted in a darker red canned cherry as measured by the Agtron. CaCl2 compensated for the reduced USDA scores for character caused by pitting or daminozide, increasing character to equal that of nonpitted or nontreated, respectively. Chemical names used: butanedioic acid mono(2,2-dimethylhydrazide) (Daminozide).
Highly significant correlations were obtained for reflectance color (Agtron) with anthocyanin content in both fresh and canned dark sweet cherries (Prunus avium L.) and also for both reflectance color and anthocyanin content with subjective USDA color. Soluble solids, titratable acidity, pH, and a soluble solids/titratable acidity ratio were not good indicators of color development in sweet cherries. Reflectance color could be used to predict USDA color from fresh or canned dark sweet cherries.
This study was conducted over three crop seasons using 'Delicious' (Scarletspur strain) apple trees on MM.111 rootstock. The bioregulators aminoethoxyvinylglycine (AVG) and ethephon (ETH) were applied alone or in combinations at various time intervals before harvest. Fruit response to bioregulators was evaluated at harvest and after storage. AVG applied 4 weeks before first harvest retarded starch loss at harvest, retained greater firmness, and reduced internal ethylene concentration and watercore of fruit at harvest and after both regular and controlled atmosphere storage. AVG did not influence peel color (hue values), but the flesh color of treated apples was more green. AVG in all instances tended to reduce the sensory scores for apples and apple juice. In contrast, ETH enhanced starch hydrolysis, flesh color development (green to more yellow), and soluble solids concentration while reducing titratable acidity levels. ETH had no influence on fruit firmness at harvest, but reduced firmness levels after storage in an inverse relationship to the concentration applied. Sensory values for whole apples were not influenced by ETH treatment, but ETH improved sensory preference for apple juice, particularly at early harvest. Applying AVG before ETH enhanced soluble solids and sensory scores for both fruit and juice. Treating with AVG followed by ETH at 150 mg·L–1 permitted the maintenance of satisfactory firmness values (>53.4 N) after long-term storage along with better quality and sensory perceptions. Using specific combinations of both AVG and ETH permitted ETH-mediated improvements in objective and perceived fruit quality to be obtained without the losses in flesh firmness and storability due to uncontrolled ethylene evolution and ripening typically observed when ETH is applied alone preharvest.
In a study conducted over three crop seasons, Ethrel (ETH) increased the Brix, sucrose, and sorbitol content of 'Scarletspur Delicious' apple juice while reducing the fructose content. Both longer preharvest exposure to, and higher concentrations of, ETH had a stronger influence than application closer to harvest and/or at lesser amounts. Time of ETH application tended to influence individual carbohydrates more so than amount of ETH applied. ETH reduced total acidity and also reduced apple juice individual acid (quinic and malic) contents with longer preharvest exposure or higher concentrations. Aminoethoxyvinylglycine [AVG (ReTain)] reduced both Brix and sucrose content of 'Scarletspur Delicious' apple juice, but had no influence on either total acidity or individual acid contents. Combinations of AVG with ETH tended to counteract the influence of either used alone on total Brix, carbohydrates, total acidity and individual acids. Mineral content of 'Scarletspur Delicious' apple juice was not strongly influenced by application of either ETH or AVG.
This study was conducted over two crop seasons using `Scarletspur Delicious' and `Gale Gala' apple trees (Malus ×domestica). The bioregulators aminoethoxyvinylglycine (AVG), ethephon (ETH), and 1-methylcyclopropene (MCP) were applied at various times before or after harvest. Fruit response was evaluated at harvest and after regular atmosphere (RA) and controlled atmosphere (CA) storage [2.0% oxygen (O2) and <2.0% carbon dioxide (CO2) at 0 °C] and quality of whole and juice apple products evaluated. AVG reduced starch loss and ethylene production, enhanced firmness, and reduced cracking in `Gale Gala,' but reduced sensory acceptance of apples and apple juice. ETH intensified starch loss, ethylene production, and reduced firmness, but did not affect `Gale Gala' fruit cracking. AVG followed by ETH reduced starch loss, ethylene production, and cracking and maintained firmness. This combination also aided in sensory acceptance of apples but reduced sensory preference of apple juice. Exposure to postharvest MCP improved flesh firmness retention and reduced ethylene production after both RA and CA storage. MCP either favored or reduced sensory acceptance of whole apples, depending on the particular season, but reduced sensory preference of apple juice. Sensory scores for `Scarletspur Delicious' apples were more strongly modified by bioregulators than were `Gale Gala' apples.
‘Delicious’ and ‘Golden Delicious’ apples (Malus domestica Borkh.) on seedling rootstock were grown with trickle and sprinkler irrigation, both operated at high frequency of irrigation (daily). Trees with trickle irrigation developed lower leaf water potentials and produced less vegetative growth than trees with sprinkler irrigation, but fruit and productivity were similar. Apples from the trickle-irrigated trees had less water content and higher soluble solids than those from sprinkler-irrigated trees. Titratable acidity tended to be lower and both red color in ‘Delicious’ and yellow color in ‘Golden Delicious’ tended to be higher in fruit from trickle-irrigated trees than from sprinkled trees; firmness at harvest was similar regardless of irrigation procedure. Storage life was not influenced consistently by irrigation. Where differences did occur, the fruit from trickle-irrigated trees was softer after storage. Changes in fruit quality similar to those observed in trickle-irrigated trees were produced by imposing, through high frequency deficit irrigation with sprinklers, similar moisture deficits on apple trees, as measured by leaf water potential.
Sweet cherries (Prunus avium `Bing') exposed to 113 or 117 °F (45 or 47 °C) in an atmosphere of 1% oxygen with 15% carbon dioxide (balance nitrogen) were heated to a maximum center temperature of 112 or 115 °F (44 or 46 °C) in 41 or 27 min, respectively. Heated cherries had similar incidence of pitting and decay, and similar preference ratings after 14 days of storage at 34 °F (1 °C) as nonheated or methyl bromide fumigated fruit. Heated cherries and methyl bromide fumigated cherries were less firm after 14 days of cold storage than nonheated, control fruit. The stems of methyl bromide fumigated cherries were less green than heated or nonheated cherries. Cherries exposed to 113 °F had lower titratable acidity than nonheated cherries, fumigated cherries, or cherries exposed to 117 °F. Cherry quality after 14 days of cold storage was not affected by hydrocooling before heating (5 min in water at 34 °F) or by method of cooling after heating (hydrocooling, forced air cooling, or static air cooling). Cherries stored for 14 days at 34 °F in 6% oxygen with 17% carbon dioxide (balance nitrogen) had similar market quality as cherries stored in air at 34 °F. Results suggest that `Bing' sweet cherry can tolerate heating in an atmosphere of low oxygen containing elevated carbon dioxide at doses that may provide quarantine security against codling moth (Cydia pomonella) and western cherry fruit fly (Rhagoletis cingulata).
Gibberellic acid (GA) applied at 20 ppm 4−6 weeks before harvest increased the ascorbic acid content of fresh and processed ‘Rainier’ cherries (Prunus avium L.) while also increasing fruit size and yellow color. Anthocyanin content was also reduced. GA treated fruit rated higher according to USDA processed fruit grades. Ascorbic acid content did not change with maturity. There was no interaction between GA and maturity on ascorbic acid content (2-Chloroethyl)phosphonic acid (ethephon), applied at 500 ppm 1 to 3 weeks before harvest, reduced fruit size compared with untreated fruit. Fruit treated with succinic acid-2,2-dimethylhydrazide (daminozide) at 2000 ppm 2 weeks after full bloom reduced the weight per fruit after processing but not before processing. This was reflected in a greater loss in drained weight. Daminozide increased anthocyanin content and reduced yellow and green color of fresh fruit.
‘Golden Delicious’ apples (Malus domestica Borkh.) from trickle-irrigated plots were more mature than sprinkle-irrigated apples. Trickle-irrigated apples were higher in yellow color, soluble solids, and pH. Titratable acidity and moisture were less in fresh and stored apples that were grown with trickle irrigation. Applesauce from trickle-irrigated apples was superior in consistency and developed less free liquor (weep) than sauce from sprinkle-irrigated apples. Drip losses were greater in frozen apple slices from sprinkle-irrigated apples. Canned or frozen apple slices were firmer when produced from apples that were sprinkle-irrigated. The color of apple products from trickle-irrigated apples was superior to the products from sprinkle-irrigated apples. These differences resulted from treatments where leaf water potential differed by only 1 to 2 bars, –14 and –12 bars with trickle and –12 and –11 bars with sprinklers in 1978 and 1979.
Butanedioic acid mono-(2,2-dimethylhydrazide) (daminozide) increased the red color and anthocyanin content of fresh and processed sweet cherries (Prunus avium L.). Daminozide had no effect on the USDA color grade for processed dark sweet cherries but reduced the USDA character of processed dark sweet cherries and increased drained weight losses regardless of cultivar. The use of daminozide on light sweet cherries resulted in reduced USDA color grade for the processed product. A 2-week delay in harvest also increased red color and anthocyanin content of sweet cherries, and increased the USDA color grade of the processed ‘Bing’, ‘Chinook’, and ‘Rainier’ cherries. In addition, it reduced the USDA character grade of processed ‘Chinook’ but not of ‘Bing’ and ‘Rainier’ sweet cherries.