about 65% to 75% monounsaturated fatty acids (oleic and palmitoleic) and 10% to 15% polyunsaturated fatty acids (linoleic) ( Ozdemir and Topuz, 2004 ). Total oil content may exceed 30%, depending on cultivar and maturity ( Woolf et al., 2004 ). The
Nancy J. Chen, Marisa M. Wall, Robert E. Paull, and Peter A. Follett
John C. Beaulieu and Jeanne M. Lea
have demonstrated previously that muskmelon fruit harvested at different maturity deliver stored cubes differing significantly in flavor and textural attributes ( Beaulieu et al., 2004 ). Subsequently, muskmelon fruit were evaluated during development
Roberto I. Vazquez-Ochoa and Maria T. Colinas-Leon
Maturity at harvest influenced storage life of guava (Psidium guajava L.) fruit kept at 3.5, 7, or 11C and 80% or 88% RH. Quality characteristics considered were firmness, pH, titratable acidity, ascorbic acid and soluble solids concentrations, and weight loss. Chilling injury was observed only in guavas harvested at the mature-green stage and kept at 3.5 or 7C. The storage life of fruit kept at 11C was reduced due to fungal attack. The best results were obtained with guavas harvested at the color-turning stage followed by storage at 7C and 80% RH for 3 weeks. These fruits had good appearance 5 days after removal from storage.
Peter J. Hofman, Marcelle Jobin-Décor, and Janet Giles
The potential to use percentage of dry matter (DM) and/or oil of the flesh of `Hass' avocado as a maturity standard to determine the latest harvest for acceptable fruit quality, was investigated. `Hass' avocado fruit were harvested from early October to mid-January from a commercial orchard in subtropical Queensland. The percentage of DM and oil changed little during the harvest period, and the eating quality of the flesh remained high. However, the incidence of body rots (caused mainly by Colletotrichum sp.) and the flesh disorders grey pulp and vascular browning, increased with harvest. These results indicate that percentage of DM and oil are not reliable late-maturity standards because of the inconsistent change with later harvests, and that disease and internal disorders can be the main determinants of latest acceptable harvest, rather than eating quality.
John C. Beaulieu
A likely reason why consumers are not repeat buyers of many fresh-cut fruit is inconsistent or unsatisfactory flavor and/or textural quality. Research toward understanding mechanisms responsible for generation, and/or loss of flavor compounds in fresh-cut fruit is limited. Solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) were utilized to study flavor volatile profiles in anthesis-tagged cantaloupe (Cucumis melo L. var. reticulatus Naud. cv. Sol Real) during growth, development, and for fresh-cuts prepared from fruit with five distinctly different harvest maturities. One-quarter-slip fruit had a clearly green, well-attached peduncle; 1/2-slip fruit had a distinct abscission detectable at the peduncle, 3/4-slip fruit were approaching commercial harvest, full-slip (FS) fruit are or will cleanly separate from the vine with light pressure; and over-ripeness (OR) was precisely categorized as 2 days past FS. Recovery of total volatiles displayed a linear response and most volatile classes (except aldehydes) generally followed a trend upon processing where FS > 3/4-slip > 1/2-slip > 1/4-slip. On day 0, only 70.0%, 37.7%, and 20.5% total volatiles were recovered in 3/4-slip, 1/2-slip, and 1/4-slip fruit, compared to FS fruit. During fresh-cut storage, percent total esters followed an increasing linear trend that was maturity-dependent. Percent total aromatics and percent aldehydes followed a linear trend that was maturity-dependent whereby 1/4-slip > 1/2-slip > 3/4-slip > FS. During storage, the relative percentage of acetates decreased, and displayed a maturity-dependent curvilinear trend. The magnitude of the slope decreased with maturity, indicating that the effect of storage time decreased as maturity increased. In FS, 3/4-slip, 1/2-slip, and 1/4-slip cubes, acetates comprised 66.9% of all compounds recovered on day 0 yet, only 26.1% to 44.2%, and 21.3% to 32.6% remained on days 9 and 14, respectively. For all maturities, a curvilinear increase in relative percentage of nonacetate esters was observed during storage. There was a uniform change in the ester balance (nonacetate ester:acetate ratio) during fresh-cut storage, which was independent of initial processing maturity. The overall ester ratio changed roughly 2-fold after just 2 days in optimum storage, and after 5 days it increased more than 3-fold. The shift in endogenous ester compounds could be partially responsible for the apparent loss of characteristic flavor in fresh-cut cantaloupe through long-term storage.
Sylvie Jenni and Gaetan Bourgeois
based on percentage of expected head size reached, which can be highly variable and therefore difficult to evaluate with precision. Furthermore, growers are using not only head size, but also head firmness, to define commercial maturity. After heading
Linda M. Boyd and Andrew M. Barnett
timed or excessive pruning can reduce fruit DMC, delay maturity, and reduce concentrations of inorganic nutrients in fruit ( Candolfi-Vasconcelos and Koblet, 1990 ; Siham et al., 2005 ; Valladares et al., 2007 ). Trunk girdling interrupts the phloem
Christopher B. Watkins, Mustafa Erkan, Jacqueline F. Nock, Kevin A. Iungerman, Randolph M. Beaudry, and Renae E. Moran
`Honeycrisp' is a new apple [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] cultivar that has been planted extensively in North America, but the storage disorders soggy breakdown and soft scald have resulted in major fruit losses. The effects of harvest date and storage temperature on fruit quality and susceptibility of fruit to these disorders have been investigated in Michigan, New York, and Maine. Internal ethylene concentrations were variable over a wide range of harvest dates, and a rapid increase in autocatalytic ethylene production was not always apparent. The starch pattern index, soluble solids content, titratable acidity and firmness also appear to have limited use as harvest indices. Development of soggy breakdown and soft scald is associated with later harvest dates and storage of fruit at temperatures of 0 to 0.5 °C compared with higher storage temperatures. It is recommended that `Honeycrisp' be stored at 3 °C, although storage disorders still can occur at this temperature if fruit are harvested late. In addition, greasiness development may be worse at higher storage temperatures.
Max G. Villalobos-Acuña, William V. Biasi, Sylvia Flores, Elizabeth J. Mitcham, Rachel B. Elkins, and Neil H. Willits
; Gapper et al., 2006 ; Ju and Curry, 2000 ; Watkins et al., 1995 ; Whitaker and Solomos, 1997 ). The main objective of this study was to evaluate the effect of preharvest treatments with 1-MCP on premature fruit drop, maturity changes before harvest
Uttara C. Samarakoon, Keith A. Funnell, David J. Woolley, and Edward R. Morgan
and, additionally, can have a long harvest window. Anecdotally, the variation has been observed among cultivars, and among plants of the same cultivar. This variation in harvest maturity makes it difficult to schedule harvest operations and target high