Small-fruited cherry tomato accession PI 270248 [Lycopersicon esculentum Mill. var. cerasiforme (Dunal) A. Gray] with high fruit sugars was crossed to large-fruited inbred line Fla.7833-1-1-1 (7833) (L. esculentum) that had normal (low) fruit sugars. The F1 was crossed to PI 270248 and 7833 to obtain BCP1 and BCP2, respectively, and self-pollinated to obtain F2 seed. The resulting population was used to study the inheritance of high sugars from PI 270248. Continuous sugar level frequency distributions of BCP1, BCP2, and F2 suggest that the trait is under polygenic control. Additive variation was significant, but dominance variation was not. There was a heterozygote × heterozygote type of epistasis present that likely caused the F1 sugar level to skew nearly to the level of the high sugar parent. The F2 mean sugar level was lower than the midparent level. Broad-sense heritability was 0.86. There was a significant line × season (fall, spring) interaction where lines with higher sugars were affected more by seasons than lines with lower sugars. Sugar level, in general, was higher in spring. Higher solar radiation in spring than in fall may explain the sugar level difference between the seasons.
N. Georgelis, J.W. Scott, and E.A. Baldwin
N. Georgelis, J.W. Scott, and E.A. Baldwin
Small-fruited cherry tomato accession PI 270248 (Lycopersicon esculentum Mill. var. cerasiforme Dunal) with high fruit sugars was crossed to large-fruited inbred line Fla.7833-1-1-1 (7833) that had normal (low) fruit sugar. Sugars in the F2 were positively correlated with soluble solids, glucose, fructose, pH, and titratable acidity, and inversely correlated with fruit size. Earliness was not significantly correlated with sugars but was negatively correlated with fruit size. Thus, the lack of a sugar-earliness correlation indirectly indicates a trend for early tomato plants to be lower in sugars than later maturing plants. Sugars were not correlated with yield or pedicel type. Fruit from indeterminate plants had significantly more sugars than from determinate plants. Six random amplified polymorphic DNA (RAPD) markers linked to high sugars were found, five dominant (OPAE 4, UBC 731, UBC 744, UBC 489, UBC 290) and one co-dominant (UBC 269). Five of the markers were also linked to small fruit size and one of these also was linked to low yield (UBC 290). The sixth marker (UBC 269) was linked to indeterminate plant habit. UBC 731, UBC 489, and possibly OPAE 4 were in one linkage group, while UBC 744 and UBC 290 were in another linkage group. Combinations of all the markers together explained 35% of the sugar variation in the F2 grown in Spring 2002.
J.W. Scott, B.K. Harbaugh, and E.A. Baldwin
V. Alleyne, E.A. Baldwin, and R. D. Hagenmaier
Experimental formulations of candelilla, zein, and polyvinylacetate (PVA) were investigated as alternatives to commercial apple-coating formulations of shellac and carnauba wax. Coatings or a deionized water control were applied to `Red Delicious' apples. Effects on quality attributes, internal atmospheres, sensory flavor, and volatile composition were evaluated. Treated fruit were stored at 5 °C for 7 days followed by 14 days at 21 °C. Zein and PVA formulations exhibited gloss levels comparable with commercial formulations. Although shellac-coated apples maintained the highest gloss over the 21-day storage period, gloss of zein-coated apples was comparable to shellac after fruit were removed from storage at 5 °C. On removal from cold storage there was no difference in firmness among coated and uncoated apples, but, after a 14-day period at 21 °C, shellac-coated fruit were significantly firmer than all other treatments. Shellac- and candelilla-coated apples contained higher CO2 than uncoated fruit and lower O2 than all coated fruit except those coated with PVA. PVA-coated apples contained significantly higher ethylene than uncoated fruit. Candelilla coating was most effective in reducing weight loss while PVA and zein had no effect. Shellac and carnauba coatings reduced weight loss relative to uncoated fruit. There were no differences in perception of sweetness, acidity, off-flavor, and overall flavor. Effects of coating formulations on apple flavor volatile composition will be discussed.
E.A. Baldwin, M.O. Nisperos-Carriedo, and M.G. Moshonas
Tomato (Lycopersicon esculentum Mill.) fruit, cvs. Sunny and Solar Set, were analyzed at five ripening stages for ethylene and CO2 production. Homogenates from the same fruit were prepared for determination of color, flavor volatiles, sugars, and organic acids. Changes in the levels of these compounds were compared to the pattern of climacteric ethylene production. Of the flavor volatiles measured, only eugenol decreased during ripening in both cultivars and 1-penten-3-one in `Sunny' tomatoes. Ethanol and trans-2-trans- 4-decadienal levels showed no change or fluctuated as the fruit ripened while all other volatiles measured (cis- 3-hexenol, acetaldehyde, cis- 3-hexenal, trans-2- hexenal, hexenal acetone, 6-methyl-5 -hepten-2-one, geranylacetone, and 2-isobutylthiazole) increased in concentration, peaking in the turning, pink, or red stage of maturity. Synthesis of some volatile compounds occurred simultaneously with that of climacteric ethylene, CO2 and lycopene production. `Solar Set' fruit exhibited higher levels than `Sunny' of all flavor components except ethanol and hexanal in the red stage. There were no differences in organic acid levels between the cultivars; however, `Solar Set' had higher levels of sugars. Changes in acid and sugar levels showed no temporal relationship to climacteric ethylene or CO2 production.
J.A. Narciso, E.A. Baldwin, A. Plotto, and C.M. Ference
Strawberry is an important fruit crop in Florida. Yearly losses can be attributed to pre- and postharvest decay incited by Botrytis cinerea P. Micheli ex Pers. and postharvest decay resulting from primarily Rhizopus stolonifer (Ehrenb. ex Fr.) Vuillemin. In this study, the sanitizer peroxyacetic acid (100 μL·L−1) was sprayed on flowers and developing strawberries 1, 2, and 3 d preharvest. Most of the time, fruit sprayed 3 days before harvest had significantly less decay than fruit sprayed 1 day preharvest or not sprayed when stored at 18 °C. Strawberries sprayed in the field with peroxyacetic acid and then coated postharvest with 1% chitosan coating had reduced decay compared with fruit only treated preharvest with peroxyacetic acid (PAA) for up to 12 days in storage. Sensitivity of B. cinerea hyphae and conidia to PAA was shown by the presence of a zone of inhibition using the disc assay method.
T.M.M. Malundo, E.A. Baldwin, R.L. Shewfelt, H. Sisson, and G.O. Ware
Fruit flavor is a function of sensory perception of taste, aromatic and chemical feeling factor components in the mouth. The specific role of sugars and acids in potentiating flavor perception of volatile compounds and chemical feeling factors is not well known for many fruits. This study was conducted to determine the effects of selected levels of sugars and acids on perception of 3 taste (sweet, sour, bitter), 6 aromatic (banana, grassy, orange peel, peach, pine/turpentine, sweet potato), and 2 chemical feeling factor (astringent, biting) flavor notes in diluted, fresh mango homogenate using a trained descriptive panel. Perception of all flavor descriptors except sour were enhanced by increasing the sugar concentration. An increase in acid concentration enhanced perception of sweet, sour and biting notes while lowering perception of the astringent, peach and pine/turpentine notes. Brix-to-acid ratio (BAR) was found to be an effective chemical indicator for perception of sourness but was not effective for perception of sweetness. These results provide insight into optimum balances of sugars and acids as they influence mango flavor perception specifically in preparation of juice blends, selection of cultivars for specific fresh markets, or determination of optimum ripeness in the marketplace.
R. Potjewijd, M.O. Nisperos, J.K. Burns, M. Parish, and E.A. Baldwin
Varying the cellulose component of coating formulations affected the survival of two yeast biocontrol agents, Candida guillermondii (Castelani) Langeron and Guerra strain US7 and Debaryomyces sp. strain 230, when these yeasts were incorporated into the coating. Using methylcellulose as the main film-former gave the most recovery of the yeasts after an incubation period for both strains. Significant control of decay on naturally infected `Pineapple' and `Valencia' oranges [Citrus sinensis (L.) Osb.] was demonstrated for US7 in a methylcellulose-based coating for the first 2 to 4 weeks of storage at 16C and 90% relative humidity. During this time, US7 in methylcellulose formulations was similar in decay control to a commercial shellac coating with imazalil at 2000 mg·liter–1. A US7 concentration of at least 105 colony-forming units/cm was maintained on the coated fruit surface of `Valencia' oranges for 3 weeks of storage. Suppression of decay by US7 was improved by the addition of glucose and calcium chloride to the coating formulation. Although nearly equal in concentration recovered, Debaryomyces strain 230 was not as effective as US7 in disease suppression of `Pineapple' oranges. The addition of US7 to Nature Seal, a coating material made with methylcellulose, had neither a quantitative nor a qualitative effect on the pathogen population compared to the same formulation without the antagonist. Chemical name used: 1-[2-(2,4-dichlorophenyl)-2-(2-propenyloxy)ethyl]-1H-imidazole (imazalil).
R.J. Bender, J.K. Brecht, E.A. Baldwin, and T.M.M. Malundo
To determine the effects of fruit maturity, storage temperature, and controlled atmosphere (CA) on aroma volatiles, mature-green (MG) and tree-ripe (TR) `Tommy Atkins' mangoes (Mangifera indica L.) were stored for 21 days in air or in CA (5% O2 plus 10% or 25% CO2). The MG fruit were stored at 12 °C and the TR fruit at either 8 or 12 °C. Homogenized mesocarp tissue from fruit that had ripened for 2 days in air at 20 °C after the 21-day storage period was used for aroma volatile analysis. The TR mangoes produced much higher levels of all aroma volatiles except hexanal than did MG fruit. Both MG and TR mangoes stored in 25% CO2 tended to have lower terpene (especially p-cymene) and hexanal concentrations than did those stored in 10% CO2 and air-stored fruit. Acetaldehyde and ethanol levels tended to be higher in TR mangoes from 25% CO2 than in those from 10% CO2 or air storage, especially at 8 °C. Inhibition of volatile production by 25% CO2 was greater in MG than in TR mangoes, and at 8 °C compared to 12 °C for TR fruit. However, aroma volatile levels in TR mangoes from the 25% CO2 treatment were in all cases equal to or greater than those in MG fruit treatments. The results suggest that properly selected atmospheres, which prolong mango shelf life by slowing ripening processes, can allow TR mangoes to be stored or shipped without sacrificing their superior aroma quality.
E.A. Baldwin, T.M.M. Malundo, R. Bender, and J.K. Brecht
Mango fruit, cv. Tommy Atkins, were harvested from two grove sites in south Florida at mature green (MG) and tree ripe (TR) maturities. The fruit were either coated with one of two coatings (NS = Nature Seal® 4000, a polysaccharide coating, or CW = carnauba wax) or left uncoated (control) and stored in humidified air or held in a controlled atmosphere (CA = 5% O2 plus 25% CO2) at 12 °C for 21 days followed by 2 days in air at 20 °C. There were 12 fruit for each treatment/maturity stage combination replicated by grove site. After storage, the pulp was homogenized for later consumer or descriptive panel analysis. Measurements for total soluble solids (SS), pH, titratable acidity (TA), and flavor volatile compounds were also made. TR-harvested fruit were sweeter and generally more aromatic than MG-fruit as determined by sensory and/or chemical analysis. NS-coated fruit were more sour, bitter, and astringent compared to controls and CA-treated fruit. NS-coated fruit received lower overall consumer scores than CW-coated fruit, but were not different from controls or CA-treated fruit. This was reflected also in descriptive panel ratings. There were no differences based on storage treatment for SS, pH, or TA; however, NS-coated fruit were higher in acetaldehyde, methanol and ethanol compared to control or CA-treated fruit. Correlation and regression analysis showed significant relationships between sensory and chemical data.