Examples from various harvest regimes, storage regimes, cultivars and different packaging methods are presented to characterize volatile ester differences after cutting and how changes occur in characteristic flavors throughout the postharvest life of certain cut fruit products. In many fresh-cut cantaloupe cultivars and in honeydew, there was a relative increase in nonacetates and coinciding relative decrease in acetates during storage. A similar and consistent nonacetate:acetate ester ratio was conserved in cantaloupe from eastern and western U.S. regions, as well as different cultivars from the same field. Furthermore, similar ratios were observed in many melon cultivars over multiple years from different seasons and growing regions. Since many cultivars exhibited similar trends in 2-year repeated studies, the trend is apparently independent of year and season. Fresh-cut `Gala' apples, on the other hand, displayed a slightly different trend whereby both acetates and nonacetate esters decreased appreciably during storage. The hypothesis is put forward that recycling of esters during storage in certain fresh-cut fruits disturbs the delicate fine balance of characteristic volatiles. Consistently decreasing acetates along with increasing nonacetates could alter the overall perceived desirable flavor attributes during fresh-cut melon storage, even though volatile esters are still abundant.
Chunyu Zhang, Xuesen Chen, Hongwei Song, Yinghai Liang, Chenhui Zhao and Honglian Li
( Laurens, 1999 ). In apple, volatile components are composed of esters, alcohols, aldehydes, ketones, and ethers ( Dimick and Hoskin, 1983 ; Kakiuchi et al., 1986 ). Research by Kakiuchi et al. (1986) showed that esters are the most abundant flavor
Peter H. Dernoeden, John E. Kaminski and Jinmin Fu
single application, and large areas would require overseeding ( Branham et al., 2005 ). In an unpublished Maryland study, however, four summer applications of the ester formulation of triclopyr applied at 1.12 kg·ha −1 a.i. were shown to safely control
Nobuko Sugimoto, A. Daniel Jones and Randolph Beaudry
Esters are the primary aroma impact compounds produced in ripening apple fruit and normally account for 80% to 95% of the total volatiles emitted ( Paillard, 1990 ). Fresh apples autonomously produce an abundance of hexyl acetate, butyl acetate, and
Yan Li, Hongyan Qi, Yazhong Jin, Xiaobin Tian, Linlin Sui and Yan Qiu
identified in oriental sweet melon is attributed to several volatile compounds including alcohols, acids, aldehydes, and esters that are biosynthetically derived from FAs, amino acids, carotenoids, and terpenes ( Aubert and Bourger, 2004 ; Beaulieu and Grimm
Sastry Jayanty, Jun Song, Nicole M. Rubinstein, Andrés Chong and Randolph M. Beaudry
The temporal relationship between changes in ethylene production, respiration, skin color, chlorophyll fluorescence, volatile ester biosynthesis, and expression of ACC oxidase (ACO) and alcohol acyl-CoA transferase (AAT) in ripening banana (Musa L. spp., AAA group, Cavendish subgroup. `Valery') fruit was investigated at 22 °C. Ethylene production rose to a peak a few hours after the onset of its logarithmic phase; the peak in production coincided with maximal ACO expression. The respiratory rise began as ethylene production increased, reaching its maximum ≈30 to 40 hours after ethylene production had peaked. Green skin coloration and photochemical efficiency, as measured by chlorophyll fluorescence, declined simultaneously after the peak in ethylene biosynthesis. Natural ester biosynthesis began 40 to 50 hours after the peak in ethylene biosynthesis, reaching maximal levels 3 to 4 days later. While AAT expression was detected throughout, the maximum level of expression was detected at the onset of natural ester biosynthesis. The synthesis of unsaturated esters began 100 hours after the peak in ethylene and increased with time, suggesting the lipoxygenase pathway be a source of ester substrates late in ripening. Incorporation of exogenously supplied ester precursors (1-butanol, butyric acid, and 3-methyl-1-butanol) in the vapor phase into esters was maturity-dependent. The pattern of induced esters and expression data for AAT suggested that banana fruit have the capacity to synthesize esters over 100 hours before the onset of natural ester biosynthesis. We hypothesize the primary limiting factor in ester biosynthesis before natural production is precursor availability, but, as ester biosynthesis is engaged, the activity of alcohol acyl-CoA transferase the enzyme responsible for ester biosynthesis, exerts a major influence.
Nihad Alsmairat, Philip Engelgau and Randolph Beaudry
The synthetic and/or catabolic pathways of the amino acids valine, leucine, isoleucine, methionine, phenylalanine, and alanine contribute to the formation of odor-active alcohols, aldehydes, carbonyls, and esters in edible plant parts ( Azevedo et
Jinhe Bai, Elizabeth Baldwin, Jack Hearn, Randy Driggers and Ed Stover
-ionone, and nootkatone, which did not have a clear pattern in any specific cultivar/hybrid (data not shown). For aliphatic compounds, the largest group was esters with 16 components representing 0.5% to 11.6% of the total volatiles ( Table 1 ). The important
J.P. Mattheis, D.A. Buchanan and J.K. Fellman
Quantitative and qualitative changes in net production of volatile compounds by apples occurs during fruit development with a major transition to ester production occurring as fruit ripening begins. Ester production during fruit ripening is an ethylene-mediated response; however, differences in maturation patterns among apple cultivars led us to examine the relationship between ester production and onset of the ethylene climacteric in several commercial apple cultivars. Emission of volatile esters as a function of apple fruit development was evaluated for `Royal Gala', `Bisbee Delicious', `Granny Smith', and `Fuji' apple fruit during two harvest seasons. Apples were harvested weekly and analyses of harvest maturity were performed the day after harvest. Non-ethylene volatiles were collected from intact fruit using dynamic headspace sampling onto Tenax traps. Fruit from each harvest was stored at 1°C in air for 5 months (3 months for `Royal Gala') plus 7 days ripening at 20°C, then apples were evaluated for the development of disorders. The transition to ester production occurred after internal ethylene exceeded 0.1 μL for `Royal Gala', `Bisbee Delicious', and `Fuji'. Ester emission by `Granny Smith' apples remained low throughout the harvest period. Increased ester emission occurred after the optimum harvest date (as determined by the starch index and internal ethylene concentration) for controlled-atmosphere storage of `Bisbee Delicious' and prior to optimum maturity for `Royal Gala' and `Fuji'. A relationship between the potential for development of superficial scald and ester production at harvest was evident only for `Bisbee Delicious' apples.
Alejandra Ferenczi, Jun Song, Meisheng Tian, Konstantinos Vlachonasios, David Dilley and Randolph Beaudry
The effect of 1-methylcyclopropene (1-MCP) on biosynthesis of volatiles and fruit ripening in apple (Malus ×domestica Borkh.) was investigated using `Golden Delicious', `Jonagold', and `Redchief Delicious' fruit. Application of 1-MCP to `Golden Delicious' at the preclimacteric stage effectively inhibited ripening as determined by decreased expression of genes for 1-amino-1-cyclopropane carboxylic acid (ACC) oxidase (ACO), and ACC synthase, ACO protein content, climacteric ethylene production, respiration, and volatile ester biosynthesis. Exogenous ethylene applied after 1-MCP treatment did not induce ethylene production, respiration, or volatile production. Activity for alcohol acyltransferase, which catalyzes the final step in ester formation, was demonstrable for 1-MCP-treated fruit, indicating no strict limitation on ester formation is imposed by this enzyme and that ester formation in 1-MCP-treated apple fruit is at least partially limited by reduced substrate synthesis. Once volatile ester formation had been suppressed by 1-MCP, the recovery of volatile synthesis required ≈3 weeks for `Jonagold' and 4 weeks for `Delicious' when held in air at 22 °C. For the first 2 months of storage at 0 °C in air, `Jonagold' and `Delicious' required ≈3 weeks holding at 22 °C for volatile biosynthesis to initiate; after 5 months in refrigerated storage, volatile formation was evident at the time of removal from cold storage. For `Jonagold' fruit held in controlled atmosphere (CA) storage for 2, 5, and 7 months at 0 °C, at least 3 weeks holding at 22 °C were required for volatile formation to begin to recover. The maximal amount of volatile formation was reduced 50% by 1-MCP relative to nontreated control fruit. CA storage had a similar impact on maximal volatile formation. The marketing of 1-MCP-treated fruit soon after treatment might result in the delivery of fruit to the consumer with little likelihood of recovery of volatile ester formation prior to consumption.