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'Fuji' apple ester accumulation in relation to harvest maturity. Apples were harvested at 2-week intervals during September and October from a commercial orchard near Vantage, Wash. Internal ethylene concentrations were <1 µL·L -1 until week 5. The 50-g composite samples were juiced and analyzed via purge-and-trap capillary gas chromatography.
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The aroma of fresh strawberries is composed of a mixture of volatile compounds with no single compound responsible for the characteristic strawberry aroma. Volatiles produced in strawberries are predominately esters, although alcohols, ketones, and aldehydes are also present in smaller quantities. The major volatiles contributing to aroma include e...
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... In 'Rome' apples, we noted a similar progression in total acetate ester accumulation during ripening. As apples advanced from early to mid-and postclimacteric stages, the concentration of acetate esters progressively increased (Fellman and Mattheis, 1995). In 'Fuji' apples, acetate esters begin to accumulate as apples approach harvest maturity (Fig. 6), with 2-methylbutyl acetate the predominant ...
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Volatile compounds are essential for food organoleptic characteristics and of great utility for the food industry as potential markers for authenticity purposes (e.g., variety, geographical origin, adulteration). The aim of this study was to determine the characteristic volatile compounds of strawberry samples grown in a soilless system by using he...
Citations
... Previous research has illustrated that esters account for 25~90% of total volatile components in most strawberry cultivars [10]. Methyl ester and ethyl ester significantly ...
Somaclonal variations in tissue cultures can be used in plant breeding programs. However, it is still unclear whether somaclonal variations and their original parent have differences in volatile compounds, and the candidate genes which result in the differences in volatile compounds also need to be identified. In this study, we utilized the ‘Benihoppe’ strawberry and its somaclonal mutant ‘Xiaobai’, which has different fruit aromas compared with ‘Benihoppe’, as research materials. Using HS-SPME-GC-MS, 113 volatile compounds have been identified in the four developmental periods of ‘Benihoppe’ and ‘Xiaobai’. Among them, the quantity and content of some unique esters in ‘Xiaobai’ were much higher than that in ‘Benihoppe’. In addition, we found that the contents and odor activity values of ethyl isovalerate, ethyl hexanoate, ethyl butyrate, ethyl pentanoate, linalool, and nerolidol in the red fruit of ‘Xiaobai’ were much higher compared with ‘Benihoppe’, which may result from the significantly increased expression of FaLOX6, FaHPL, FaADH, FaAAT, FaAAT1, FaDXS, FaMCS, and FaHDR in ‘Xiaobai’. However, the content of eugenol in ‘Benihoppe’ was higher than that in ‘Xiaobai’, which may result from the higher expression of FaEGS1a in ‘Benihoppe’ compared with ‘Xiaobai’. The results provide insights into the somaclonal variations that affect the volatile compounds in strawberries and can be used for strawberry quality improvement.
... Previous research has illustrated that esters account for 25~90% of total volatile components in most strawberry cultivars [10]. Methyl ester and ethyl ester significantly ...
... and sensory profile changes according to cultivars, stage of ripeness and environmental conditions (Forney and Kalt, 1997;Oliver et al., 2018). However, not all VOCs positively impact fruit quality determination, since the presence of specific compounds can be perceived as very undesirable by consumers. ...
... As a consequence, an imbalance between the ratio of ethyl and the remaining esters occurs during postharvest storage of fruits of ethanol-accumulating apple varieties and those of many other fruit-bearing species, most likely affecting aroma perception. The fruits of 'Granny Smith' and 'Royal Gala' apple varieties did not seem to accumulate ethanol under low-oxygen-pressure storage; however, a negative effect on ester synthesis, in particular straightchain esters, was observed, with the impact proportional to the decrease in O2 pressure [148][149][150][151][152][153][154]. This decrease can be explained by the fact that the LOX pathway requires the presence of oxygen. ...
Metabolic changes occurring in ripe or senescent fruits during postharvest storage lead to a general deterioration in quality attributes, including decreased flavor and ‘off-aroma’ compound generation. As a consequence, measures to reduce economic losses have to be taken by the fruit industry and have mostly consisted of storage at cold temperatures and the use of controlled atmospheres or ripening inhibitors. However, the biochemical pathways and molecular mechanisms underlying fruit senescence in commercial storage conditions are still poorly understood. In this sense, metabolomic platforms, enabling the profiling of key metabolites responsible for organoleptic and health-promoting traits, such as volatiles, sugars, acids, polyphenols and carotenoids, can be a powerful tool for further understanding the biochemical basis of postharvest physiology and have the potential to play a critical role in the identification of the pathways affected by fruit senescence. Here, we provide an overview of the metabolic changes during postharvest storage, with special attention to key metabolites related to fruit quality. The potential use of metabolomic approaches to yield metabolic markers useful for chemical phenotyping or even storage and marketing decisions is highlighted.
... The composition of volatiles in strawberries is dominated by esters, which account for 25-90% of the compounds (Forney et al. 2000), and they help to elevate the aroma of the strawberries by 50-200% during storage (Forney et al. 1998). Figure 1 shows that they range from 62.3 to 94.0% of the total aroma compounds, and 76% of the esters identified in the aroma of strawberries were found in cv. ...
... The composition of volatiles in strawberries is dominated by esters, which account for 25-90% of the compounds (Forney et al. 2000), and they help to elevate the aroma of the strawberries by 50-200% during storage (Forney et al. 1998). Figure 1 shows that they range from 62.3 to 94.0% of the total aroma compounds, and 76% of the esters identified in the aroma of strawberries were found in cv. ...
Strawberry fruits (cv. Evie2) were stored at 18 ± 1C for 2 days with a biobased and a polypropylene film in a passive and an active modified atmosphere packaging (MAP), and the packages were compared with a control (perfored) film. The effect of MAP on weight loss, color, flesh fruit firmness, soluble solids content, titratable acidity and aroma volatiles was monitored. Passive and active atmosphere with the biobased film resulted in low O2 values. Fruits wrapped with the polypropylene film in the passive atmosphere were firmer than fruits stored in the other MAP condition and they exhibited the highest value of luminosity. Strawberries stored under active MAP condition with the biobased film showed the highest ester concentration (880.87 μg/kg) and ethyl was the dominant fraction. Considering the main qualitative traits and the aroma compounds measured, the perfored film was the only film that can be suggested to be used at 18 ± 1C.Practical ApplicationsThe modified atmosphere packaging (MAP) combined with high temperature could result in changes in quality and affect the main volatile compounds of strawberries along the storage. In this work, we evaluated two wrapping films (a polypropylene and a biobased film from starch corn) to store strawberries under different MAP conditions (active and passive) at high temperatures. Treatments able to maintain the most important qualitative traits and the aroma composition of fruits near to the harvest (0 day) could be considered when the cold conditions are not guaranteed in a distribution chain.
... The principle flavor compounds include esters [5], ketones, terpenes [6], furanones [7], aldehydes [8], alcohols, and sulfur-containing compounds. The concentrations of individual volatiles are highly dependent on species [9], environment and harvest date [2,[10][11][12], cultivar, postharvest treatment and fruit developmental stage [13]. ...
There is interest in improving the flavor of commercial strawberry (Fragaria × ananassa) varieties. Fruit flavor is shaped by combinations of sugars, acids and volatile compounds. Many efforts seek to use genomics-based strategies to identify genes controlling flavor, and then designing durable molecular markers to follow these genes in breeding populations. In this report, fruit from two cultivars, varying for presence-absence of volatile compounds, along with segregating progeny, were analyzed using GC/MS and RNAseq. Expression data were bulked in silico according to presence/absence of a given volatile compound, in this case γ-decalactone, a compound conferring a peach flavor note to fruits.
Computationally sorting reads in segregating progeny based on γ-decalactone presence eliminated transcripts not directly relevant to the volatile, revealing transcripts possibly imparting quantitative contributions. One candidate encodes an omega-6 fatty acid desaturase, an enzyme known to participate in lactone production in fungi, noted here as FaFAD1. This candidate was induced by ripening, was detected in certain harvests, and correlated with γ-decalactone presence. The FaFAD1 gene is present in every genotype where γ-decalactone has been detected, and it was invariably missing in non-producers. A functional, PCR-based molecular marker was developed that cosegregates with the phenotype in F1 and BC1 populations, as well as in many other cultivars and wild Fragaria accessions.
Genetic, genomic and analytical chemistry techniques were combined to identify FaFAD1, a gene likely controlling a key flavor volatile in strawberry. The same data may now be re-sorted based on presence/absence of any other volatile to identify other flavor-affecting candidates, leading to rapid generation of gene-specific markers.
BACKGROUND
The influence of low oxygen on the biosynthesis of aroma‐related esters and alcohols in strawberries has been well revealed. However, how low‐oxygen conditions affect other volatile compounds, such as terpenes and furans, is still to be elucidated.
RESULTS
The effects of 2 kPa O2 low oxygen on the biosynthesis of aroma in ‘Benihoppe’ strawberries were comprehensively investigated in this study. The results showed that, like esters, the accumulations of key terpene alcohols and furans in strawberries were also inhibited by 2 kPa O2 low oxygen during storage and subsequent shelf life, which was associated with the down‐regulation of expression of FaNES1 (nerolidol synthase) and FaOMT (O‐methyltransferase). However, no anaerobic fermentation occurred in ‘Benihoppe’ strawberries since no ethanol and acetaldehyde were produced under the 2 kPa O2 condition. As expected, the 2 kPa O2 condition suppressed the respiratory intensity and lowered the energy charge to maintain the quality of strawberries. The negative effects of low‐oxygen storage on aroma accumulations and the energy charge of strawberries were more pronounced when transferred to the period of shelf life.
CONCLUSION
The 2 kPa O2 condition caused a full‐scale loss of aroma in ‘Benihoppe’ strawberries, including esters and alcohols as well as terpenes and furans, which was mainly reflected in the reduction of aroma emissions rather than the production of off‐flavor, probably due to the reduced expressions of related genes and energy charge. © 2022 Society of Chemical Industry.
Breeding crops for improved flavor is challenging due to the high cost of sensory evaluation and the difficulty of connecting sensory experience to chemical composition. The main goal of this study was to identify the chemical drivers of sweetness and consumer liking for fresh strawberries (Fragaria × ananassa). Fruit of 148 strawberry samples from cultivars and breeding selections were grown and harvested over seven years and were subjected to both sensory and chemical analyses. Each panel consisted of at least 100 consumers, resulting in more than 15,000 sensory data points per descriptor. Three sugars, two acids and 113 volatile compounds were quantified. Consumer liking was highly associated with sweetness intensity, texture liking, and flavor intensity, but not sourness intensity. Partial least square analyses revealed 20 volatile compounds that increased sweetness perception independently of sugars; 18 volatiles that increased liking independently of sugars; and 15 volatile compounds that had positive effects on both. Machine learning-based predictive models including sugars, acids, and volatiles explained at least 25% more variation in sweetness and liking than models accounting for sugars and acids only. Volatile compounds such as γ-dodecalactone; 5-hepten-2-one, 6-methyl; and multiple medium-chain fatty acid esters may serve as targets for breeding or quality control attributes for strawberry products. A genetic association study identified two loci controlling ester production, both on linkage group 6 A. Co-segregating makers in these regions can be used for increasing multiple esters simultaneously. This study demonstrates a paradigm for improvement of fruit sweetness and flavor in which consumers drive the identification of the most important chemical targets, which in turn drives the discovery of genetic targets for marker-assisted breeding.
Diazinon is the most important pesticide of sweet cherry and one possible tactic to detect its residues is sensing the aromatic
volatiles released by fruit with using electronic-nose. Electronic-nose (e-nose) machines are designed to detect the diazinon
residue in sweet cherries. It was equipped with ten sensors (MOS type), that each of them reacts to specific volatile compounds in the samples. The mathematical method to analyze the results in this paper are artificial neural networks (ANN),
principal components analysis (PCA) and linear discriminant analysis (LDA). PCA analysis characterized 90–96% of the
variance in data for toxic and non-toxic sweet cherries in four ripeness grades (RGs). The best structure (10–4-2) can classify the samples in two classes (toxic and non-toxic) in ANN analysis with a precision of 100%. The accuracy of the LDA
analysis for detection diazinon residue was 97%. Sensors TGS813, RGS822, TGS2602, and MQ3 showed the best response
for detection of diazinon.
