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J. W. Scott and Elizabeth A. Baldwin

Fruit of 10 tomato (Lycopersicon esculentum Mill.) cultigens, including five typical fresh market F1's, two rin/ + F1's, two very firm (ultrafirm) inbreds, and an antisense PG F1, were harvested at mature green, breaker, and table ripe stages of development, passed over a grader and taken to a lab (21°C) for analyses of soluble solids, titratable acidity and firmness at the table ripe stage. Shelf life was also measured. Cultigens varied in response to both solids and acids at the three harvest stages, thus there was no clear effect of harvest stage on these variables. The rin /+ F1's and ultrafirm inbreds were significantly firmer than the other cultigens at the table ripe and breaker stages. Shelf life tended to decrease with maturity at harvest. One rin /+ F1 had the greatest shelf life at all harvest stages. Ultrafirm and antisense PG cultigens had greater shelf life than the other six cultigens at the table ripe stage.

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Niels O. Maness, Gerald H. Brusewitz, and T. Gregory McCollum

Impact testing was used to assess the variables related to bruise resistance for four peach [Prunus persica (L.) Batsch] cultivars. The effects of cultivar, ripeness, drop height, and firmness on fruit bruise incidence, bruise volume, respiration, and ethylene evolution rates of freshly harvested peaches were determined. The impact variables peak impact force, contact time, absorbed energy, and percent absorbed energy were measured at three stages of fruit ripeness and at three fruit drop heights. Each of the impact variables changed with fruit ripeness. Cultivars differed in their characteristic response to impact. Fruit impact, under the low to moderate impact energies used, had negligible effects on fruit respiration and ethylene production for the cultivars studied. Bruise incidence and volume increased with drop height and especially with advancing stage of ripeness. Under conditions we used, peach fruit bruise severity could be determined by either bruise incidence in or bruise volume of mesocarp tissue.

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Zoltán Pék, Lajos Helyes, and Andrea Lugasi

( Dumas et al., 2003 ), so at the end of the ripening process, fruits stored at 15 °C and vine-ripe contained statistically higher lycopene content. This agrees with the finding of Helyes et al. (2007) that found the fruit surface temperature has a

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Ana Morales-Sillero, R. Jiménez, J.E. Fernández, A. Troncoso, and G. Beltrán

and Kourís-Lazos, 1996 ). Factors such as cultivar, weather and soil conditions, fruit ripeness, agronomic practices, and oil extraction process modify oil chemical composition and organoleptic characteristics ( García et al., 1996 ; Salvador et al

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Mohsen Hatami, Siamak Kalantari, Forouzandeh Soltani, and John C. Beaulieu

). The fruit mature ≈1 month after pollination and detach from the plant when ripe ( Hatami et al., 2016 ). The stripes change color as the fruit approaches maturity. The dark-green stripes become intense orange, maroon, or brown and the light

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Bao-Cheng Ma, Wan-Li Tang, Li-Yan Ma, Ling-Ling Li, Lu-Bin Zhang, Shi-Jiang Zhu, Chuxiong Zhuang, and Donald Irving

and MeJA to determine the possible relationship between chitinase gene expression and resistance to anthracnose disease in harvested bananas during development from the green to the ripe stage. We also tested physical (heat) and chemical (H 2 O 2 - and

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B.D. Horton

Variability in maturity within a peach (Prunus persica, L. Batsch) fruit was estimated by measurements of force and the soluble solids concentration (SSC) at 16 coordinates around the peach at five maturity stages: 1) about one-half final swell (immature); 2) 85% final swell (green); 3) firm-ripe and similar to chip #3 of the Clemson Univ. system; 4) firm-ripe and similar to chip #5; and 5) tree-ripe. Firm-ripe 3 and 4 stages were firm enough to ship, but the tree-ripe stage was too soft. Firmness measured with a 4.7-mm-diameter penetrometer tip from two cultivars indicates a strong trend for the peach tip and cheeks to be firmer than tissue at other coordinates. Coordinates at the equator and around the stem end are generally firmer than coordinates at lat. 45°N, particularly in stages 3, 4, and 5. The SSC in juice from a cylinder of fruit adjacent to the puncture was higher at long. 90°E-W than at the sutures and higher at lat. 0° than at 70°S. Variance increased for force and decreased for SSC between maturity stages to the firm-ripe stage. The coordinate technique might be used to characterize and select cultivars that would be most suitable for once-over harvests.

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D.J. Huber

Tomato fruit transformed with the PG-antisense gene have been shown to exhibit persistent structural competence and extended shelf-life compared with normal, PG-containing lines. In this study, PG-antisense and nontransformed, wild-type fruit were examined for electrolyte efflux trends during ripening and following extended storage at the full-ripe stage. Pericarp disks from PG-antisense fruit showed minimal differences in net electrolyte efflux compared with the normal, wild-type fruit at the mature-green through ripe stages of development. Following extended storage (14 days) of ripe fruit, or in response to storage at chilling (1°C) temperatures, significantly higher (25%–33%) values for proportional electrolyte efflux were observed for wild-type fruit. Additionally, ripe wild-type fruit following extended storage or in response to chilling injury exhibited increased (15%–20%) total soluble electrolytes, particularly in tissues subjected to freeze-thaw versus thermal-disruption. Although PG-antisense fruit do exhibit increases in net electrolyte efflux during ripening, the enhanced efflux and electrolyte generation from wild-type ripe fruit during extended storage was due, in part, to the release of polyelectrolytes originating from pectin hydrolysis. These data may explain the divergence in postharvest performance and structural integrity of PG-antisense and normal, wild-type fruit during post-ripe storage and also suggest that modification of the apoplastic environment resulting from developmental increases in electrolyte efflux can enhance the catalytic activity of PG in vivo.

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Wilhelmina Kalt, Christopher Lawand, Daniel A.J. Ryan, Jane E. McDonald, Horst Donner, and Charles F. Forney

The antioxidant properties of blueberries have been examined only in ripe fruit, although fruit of different maturities are used in processed food products. In this study, highbush blueberry cultivars Bergitta, Bluegold, and Nelson highbush blueberry fruit at different stages of ripeness were examined to characterize differences in oxygen radical absorbing capacity (ORAC) and the phenolic components responsible for ORAC. Underripe fruit at different stages of maturity were also stored at 20 °C for up to 8 days to assess changes in ORAC and phenolic content. Anthocyanin content was substantially higher in fruit of more advanced stages of ripeness. In contrast, the phenolic content and ORAC were lower in the riper fruit. Anthocyanins continued to form during storage, although rate of pigment formation declined after about 4 days. Less anthocyanin pigment was formed in the less ripe fruit. After 8 days of storage, the anthocyanin content of fruit harvested 5% to 50% or 50% to 95% blue exceeded that of ripe fruit. Up to 60% of the total phenolic content could be accounted for by anthocyanins. ORAC was positively correlated with total phenolic content (R 2 = 0.78), but not with anthocyanin content.

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P. Perkins-Veazie, J.K. Collins, and S. Pair

The red flesh of watermelon contains the fat-soluble carotenoid pigment lycopene. A high level of lycopene in human blood serum has been correlated with a reduced incidence of several cancers. This experiment was done to determine the variation in lycopene content among watermelon cultivars and ripeness stages. Ten melons per cultivar of hybrid, open-pollinated, and triploid (seedless) types were selected from field plantings at Lane, Okla. Additionally, 20-melon, quarterly shipments of hybrid or triploid types were used from commercial growers. Melons were cut transversely and a 100-g sample of heart tissue was removed from the center, frozen at –80 °C, extracted with a hexane–acetone–ethanol mixture and pigment quantified at 503 nm. Unripe melons (about 3 to 5 days from fully ripe) had 18% less lycopene than ripe melons. The average lycopene content of all ripe melons sampled (open-pollinated, hybrid, triploid) was 47.82 μg/g (n = 247 melons), while that of ripe hybrid and triploid melons was 54.76 μg/g (n = 209 melons). Lycopene content of ripe melons varied among cultivars, from as little as 33.96 μg/g in `Crimson Sweet' to as much as 75.72 μg/g in `Scarlet Trio'. These results indicate that fresh watermelon has a naturally high level of lycopene and that potential for enhanced lycopene content is already present in the germplasm of commercial cultivars.