Fruit Volatile Compounds Research Articles

Identification and variation of specific volatile compounds during fruit development and postharvest stage in Japanese apricot (Prunus mume Sieb. et Zucc.) fruit

AbstractFruit aroma of Japanese apricot is distinct, and the specific volatile compounds are not clearly known during fruit development and during post‐harvest stage. This study therefore aimed to explore the volatile compounds present during these stages. The volatile compounds were analysed by headspace solid‐phase microextraction and gas chromatography–mass spectrometry. OAV, PCA and electronic nose techniques were used to determine the characteristic aroma components. Enzyme‐linked immunoassay (ELISA) was also applied to determine the activity of enzymes. The results showed that in the cultivars ‘Xiyeqing’ a total of 52 components that included 20 terpenes, 15 aldehydes, 9 esters, 3 ketones and 5 other substances were detected during fruit development and post‐harvest stage. While in the cultivar ‘Xiaoyezhugan’ a total of 49 components that included 25 terpenes, 7 aldehydes, 11 esters, 1 alcohol, 3 ketones and 2 other substances were also detected during fruit development and post‐harvest stage. We concluded that the characteristic volatile compounds of mature Japanese apricot fruit were (+)‐limonene, linalool, damascenone, β‐damascenone and nonanal, finding the basis for the fruity, floral and sweet aroma of the Japanese apricot fruit. Further analysis indicated that low temperature inhibited the synthesis of esters and terpenes, and dark conditions were more favourable to the synthesis of volatile compounds than light conditions. Short‐term storage of Japanese apricot fruit at room temperature and dark conditions was conducive for the maintenance of volatile compounds, and low‐temperature storage was the most destructive to the fruit volatile compounds. These findings form a theoretical foundation for exploring the specific volatile compound of Japanese apricot and helped to determine the optimal storage condition of post‐harvest stage for Japanese apricot fruit.

Thermal Degradation of Bioactive Compounds during Drying Process of Horticultural and Agronomic Products: A Comprehensive Overview

Over the last few decades, many researchers have investigated in detail the characteristics of bioactive compounds such as polyphenols, vitamins, flavonoids, and glycosides, and volatile compounds in fruits, vegetables and medicinal and aromatic plants that possess beneficial properties, as well as consumer acceptance and preference. The main aim of this article is to provide an updated overview of recent research endeavors related to the effects of the drying process on the major bioactive/effective compounds in agricultural products. Particular emphasis was placed on details related to the changes occurring in vitamin C, polyphenols, flavonoids, glycosides and volatile compounds, as well as the antioxidant activity. An analysis of the degradation mechanisms of these compounds showed that vitamin C, phenols, flavonoids and glycosides react with oxygen during the convective drying process under high drying temperatures, and the reaction rate results in degradation in such bioactive compounds due to high reducibility. On the other hand, high temperature results in a short drying time, thus minimizing the degradation of bioactive compounds. The reviewed research works addressing this trend revealed that the ideal drying temperatures for retaining vitamin C, polyphenols, flavonoids, glycosides, volatile compounds and their antioxidant activity were 50–60 °C, 55–60 °C, 60–70 °C, 45–50 °C, 40–50 °C and 50–70 °C, respectively. In conclusion, to maintain plant bioactive components, convective drying at relatively low drying temperatures is strongly recommended.

The Aroma Volatile in ‘Nanguo’ Pear: A Review

The aroma of fruit is an important indicator that reflects the quality of its flavor. The ‘Nanguo’ pear (Pyrus ussuriensis Maxim.) is a typical fruit in Liaoning Province, China, that has an attractive aroma during fruit ripening. Fruit volatile compounds are primarily composed of esters, alcohols, aldehydes, ketones, lactones, terpenoids and apocarotenoids. The primary characteristic volatile compounds of the ‘Nanguo’ pear are esters. The contents of aldehydes decrease, and the contents of esters increase as the fruit ripens. The aroma changes from ‘green’ to ‘fruity.’ Thus, it has been a favorite of consumers in China and throughout the world for its attractive aroma. This review systematically summarizes advances in the research methods, components, types and biosynthetic pathways of volatile compounds, and the factors that affect the aroma volatiles in the ‘Nanguo’ pear, particularly the regulation by hormones that has been studied in recent years and delineates the research problems and prospects. The aim is to provide critical information for further research on the qualities of fruit flavor and provide a more scientific basis to improve the quality of fruit flavor during the development and storage of the ‘Nanguo’ pear.

Effect of Postharvest Treatments on the Biosynthesis of Fruit Volatile Compounds: A Literature Review

Abstract: Fruits have different aromatic profiles according to their stage of ripeness, therefore, volatile compounds profile is an important quality attribute, which also determines flavor and aroma characteristics, making this profile a perfect option to guide the optimization of postharvest treatment of fruits. In this context, the objective was to discuss the effects of postharvest treatments, associating them with the biosynthesis of volatile compounds in fruits. There are three major groups of fruit flavor precursors: carbohydrates, amino acids, and fatty acids. The biosynthesis of volatile compounds is directly related to metabolic changes that occur according to the fruit ripening stage. This process occurs under the regulation of hormones, which have ethylene as one of the main agents. Several hormones are also part of this complex mechanism and interact by regulating ethylene levels positively or negatively to form a fine adjustment. Therefore, hormonal treatments have an impact on the biosynthesis of volatile compounds in different ways. Other postharvest treatments such as cold storage, controlled atmosphere, and UV radiation can also impact the volatile compounds biosynthesis, but are generally used synergistically, which circumvents the negative effects on the aromatic profile of the fruits.

Volatiles in Berries: Biosynthesis, Composition, Bioavailability, and Health Benefits

Volatile compounds in fruits are responsible for their aroma. Among fruits, berries contain many volatile compounds, mainly esters, alcohols, terpenoids, aldehydes, ketones, and lactones. Studies for volatile compounds in berries have increased extensively as the consumption of berry products rapidly increased. In this paper, we reviewed biosynthesis and profiles of volatiles in some berries (strawberry, blueberry, raspberry, blackberry, and cranberry) and their bioavailability and health benefits, including anti-inflammatory, anti-cancer, anti-obesity, and anti-diabetic effects in vitro and in vivo. Each berry had different major volatiles, but monoterpene had an important role in all berries as aroma-active components. Volatile compounds were nonpolar and hydrophobic and rapidly absorbed and eliminated from our body after administration. Among them, monoterpenes, including linalool, limonene, and geraniol, showed many health benefits against inflammation, cancer, obesity, and diabetes in vitro and in vivo. More research on the health benefits of volatile compounds from berries and their bioavailability would be needed to confirm the bioactivities of berry volatiles.

Effect of the Seasonal Climatic Variations on the Accumulation of Fruit Volatiles in Four Grape Varieties Under the Double Cropping System.

The double cropping system has been widely applied in many subtropical viticultural regions. In the 2-year study of 2014–2015, four grape varieties were selected to analyze their fruit volatile compounds in four consecutive seasons in the Guangxi region of South China, which had a typical subtropical humid monsoon climate. Results showed that berries of winter seasons had higher concentrations of terpenes, norisoprenoids, and C6/C9 compounds in “Riesling,” “Victoria,” and “Muscat Hamburg” grapes in both of the two vintages. However, in the “Cabernet Sauvignon” grapes, only the berries of the 2014 winter season had higher terpene concentrations, but lower norisoprenoid concentrations than those of the corresponding summer season. The Pearson correlation analysis showed the high temperature was the main climate factor that affected volatile compounds between the summer and winter seasons. Hexanal, γ-terpinene, terpinen-4-ol, cis-furan linalool oxide, and trans-pyran linalool oxide were all negatively correlated with the high-temperature hours in all of the four varieties. Transcriptome analysis showed that the upregulated VviDXSs, VviPSYs, and VviCCDs expressions might contribute to the accumulations of terpenes or norisoprenoids in the winter berries of these varieties. Our results provided insights into how climate parameters affected grape volatiles under the double cropping system, which might improve the understanding of the grape berries in response to the climate changes accompanied by extreme weather conditions in the future.

Comparison of Spondias tuberosa Arruda accessions by fruit volatile compounds using multivariate analysis

In this study, the volatile organic compounds from Spondias tuberosa fruits of 16 accessions with different origins were extracted by solid-phase microextraction in headspace mode (HS-SPME) and analyzed by gas-chromatography coupled to mass spectrometry (GC-MS). The volatile compounds present in the fruit from the 16 accessions were identified and submitted to multivariate analysis, with the main volatile compounds identified (from a total of 25) being: ethyl butanoate, α-pinene, myrcene/ethyl caproate, limonene, ocimene isomers, linalool/nonanal and p-menth-1-en-4-ol. The major chemical classes were terpenes (about 7-72%) and esters (about 14-72%). The relative chromatographic areas of the volatile compounds were used in Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA), which accumulated 67.69% of the explained variance. The compounds classified as esters and terpenes were the main compounds responsible for forming distinct groups. The PC1 and PC2 enabled distinguishing the percentage of compounds responsible for grouping in the PCA quadrants and the HCA shows the grouping of these compounds.

Ripening stages and volatile compounds present in strawberry fruits are involved in the oviposition choice of Drosophila suzukii (Diptera: Drosophilidae)

Drosophila suzukii (Diptera: Drosophilidae) is an invasive polyphagous pest that causes economic losses in berry production worldwide. Its damage is caused by the ovipositor used to lay eggs into fruits, which also introduces microorganisms that hasten fruit spoilage and serve as food for larvae, leading to non-marketable fruits. Strawberry cultivars more resistant to D. suzukii can help in the management of this pest. Therefore, the aim of this study was to compare the susceptibility of Albion, Monterrey, and San Andreas, worldwide important strawberry cultivars, to D. suzukii harvested at three ripening stages (epidermis with 50%, 75%, and 100% of red surface). Moreover, fruit volatile compounds and their effect over D. suzukii female and male attraction were identified. Free-choice and non-choice bioassays were carried out to check oviposition preference. Fruit trait effects on oviposition preference were determined. Additionally, the volatile organic compounds active in D. suzukii antennas, and their contribution to pest attraction were analyzed. Both, cultivar and ripening stage affected fruit choice in the free-choice bioassay (p < 0.001). More mature fruits (sweeter and less firm) were more oviposited. However, in the no-choice bioassay neither the cultivar nor the ripening stage affected the oviposition choice (p = 0.998). Total amount of volatiles did not explain the oviposition choice, suggesting the relevance of specific volatiles. (±)-Linalool affected D. suzukii females (p = 0.0053) behavior and needs further investigation for being used as an attractant in mass-capture lures, monitoring and toxic baits, and assisting in oviposition control.

Analysis of Grape Volatiles Using Atmospheric Pressure Ionization Gas Chromatography Mass Spectrometry-Based Metabolomics.

Analysis of volatile compounds in fruits and plants can be a challenging task as they present in a large amount with structural diversity and high aroma threshold, the information on molecular ion can be very useful for compound identification. Electron ionization gas-chromatography-mass spectrometry (EI-GC-MS) which is widely used for the analysis of plant volatiles has a certain limitation providing the limited capability to characterize novel metabolites in a complex biological matrix due to hard fragmentation level. Atmospheric pressure ionization using APGC source in combination with high-resolution time-of-flight mass spectrometry (TOF-MS) provides an excellent combination of GC with high-resolution mass spectrometry. The APGC-MS approach provides several advantages over the conventional EI and CI based GC-MS techniques in metabolomics studies due to highly reduced fragmentation, which preserves molecular ion, and accurate mass measurement by HRMS allows to deduce the elemental composition of the volatile compounds. Moreover, the use of MSE mode provides spectral similarity to EI in high-energy mode which can be used for the further confirmation of metabolite identity. We describe an APGC-MS-based untargeted metabolomics approach with a case study of grape volatile compounds and the development of a spectral library for metabolite identification.

Oviposition Responses of Female Mediterranean Fruit Flies (Diptera: Tephritidae) to Fruit Volatile Compounds.

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann), is one of the most important pests of fruits worldwide. In the present study, we investigated the ovipositional response of C. capitata females to 37 compounds of fruit volatiles from various chemical groups and the dose response to five of them. Red plastic hollow hemispheres (domes) were used as oviposition substrates in all tests. Twenty of the compounds tested increased female egg laying compared to control substrates that contain no chemicals. With 16 compounds, similar number of eggs was deposited in treated and in control oviposition substrates. One terpene ((±)-linalool) reduced egg laying indicating a deterrent ovipositional effect. Both the esters and aldehydes tested increased the ovipositional responses in C. capitata. Most of the monoterpene hydrocarbons increased oviposition, while oxygenated monoterpenes, sesquiterpenes hydrocarbons, and oxygenated sesquiterpenes had mostly neutral effect. Ethyl hexanoate and R-(+)-limonene increased oviposition in the majority of doses tested. Different doses of (-)-linalool elicited differential female ovipositional responses. In contrast, valencene and citral, regardless of dose did not affect female oviposition. Practical implications of these findings are discussed.

Chemical Physical Characterization and Profile of Fruit Volatile Compounds from Different Accesses of Myrciaria floribunda (H. West Ex Wild.) O. Berg through Polyacrylate Fiber.

Among the many species of native fruit of Brazil that have been little explored, there is Myrciaria floribunda (also known as rumberry, cambuizeiro, or guavaberry), a species with significant variability, which has fruits of different colors (orange, red, and purple) when ripe. The physical-chemical characteristics evaluated were fruit weight (FW), seed weight (SW), pulp weight (PW), number of seeds (NS), longitudinal diameter (LD), transverse diameter (TD), format (LD/TD), hydrogen potential (pH), soluble solids (SS), titratable acidity (TA), and ratio (SS/TA); further, the volatile organic compounds (VOCs) of nine accesses of rumberry orchards were identified. The averages of the variables FW, SW, PW, NS, LD, TD, shape, and firmness were 0.76 g, 0.22 g, 0.54 g, 1.45, 10.06 mm, 9.90 mm, 1.02, 2.96 N, respectively. LD/TD data showed that the fruits have a slightly rounded shape (LD/TD = 1). The averages for pH, SS, TA, and SS/TA were 3.74, 17.58 Brix, 4.31% citric acid, and 4.31, respectively. The evaluated parameters indicated that the fruits can be consumed both in natura and industrialized, with the red-colored fruits presenting a good balance of SS/TA, standards demanded by the processing industries. Thirty-six VOCs were identified, with emphasis on the sesquiterpenes. Caryophyllene (21.6% to 49.3%) and γ-selinene (11.3% to 16.3%) were the most predominant compounds in rumberry fruits.

Volatile Compounds in Fruit Peels as Novel Biomarkers for the Identification of Four Citrus Species.

The aroma quality of citrus fruit is determined by volatile compounds, which bring about different notes to allow discrimination among different citrus species. However, the volatiles with various aromatic traits specific to different citrus species have not been identified. In this study, volatile profiles in the fruit peels of four citrus species collected from our previous studies were subjected to various analyses to mine volatile biomarkers. Principal component analysis results indicated that different citrus species could almost completely be separated. Thirty volatiles were identified as potential biomarkers in discriminating loose-skin mandarin, sweet orange, pomelo, and lemon, while 17 were identified as effective biomarkers in discriminating clementine mandarins from the other loose-skin mandarins and sweet oranges. Finally, 30 citrus germplasms were used to verify the classification based on β-elemene, valencene, nootkatone, and limettin as biomarkers. The accuracy values were 90.0%, 96.7%, 96.7%, and 100%, respectively. This research may provide a novel and effective alternative approach to identifying citrus genetic resources.

Biochemical profiling of aroma and flavonoid compounds in certain genotypes of pummelo

Pummelo fruit volatile compounds are mainly comprised of esters, alcohols, aldehydes, ketones, lactones, hydrocarbons, terpenoids and acids. A total of 50 volatile aroma compounds were identified in pummelo juice which includes 9 hydrocarbons, 10 monoterpenoids, 20 sesquiterpenoids, 9 alcohols, 2 aldehydes and ketones. Limonene was the most abundant compound, representing 0.750 to 49.331 per cent of the total aroma volatiles identified in the juice of pummelo. Among flavonoids 12 compounds identified, Naringenin was found to be high followed by catechin and other compounds. Naringenin levels play an important role in determining the bitterness of pummelo and limonene contributes for the pleasant orange flavour of the juice. Among all the accessions observed, the pink pulp accession 22(4) had high amount of naringenin (601.66 ng/ml) and the low level (100.02ng/ml) was recorded in white pulp accession 20(1) which may be useful as a parent for development of less bitter pummelo.

Evaluation of biocontrol capacity of Pseudomonas graminis CPA-7 against foodborne pathogens on fresh-cut pear and its effect on fruit volatile compounds

The application of microorganisms to control the growth of foodborne pathogens is an alternative to the use of chemical additives. In this work, Pseudomonas graminis CPA-7 was tested as a biocontrol agent against Salmonella enterica and Listeria monocytogenes on fresh-cut pear under conditions that simulate its commercial application at 5 ± 1 °C (under a modified atmosphere and antioxidant solution). The quality of the fresh-cut fruit, including the ethanol and acetaldehyde contents and the volatile profile, was determined. After the storage period, the L. monocytogenes population was reduced by 1-log unit by the presence of CPA-7; however, CPA-7 was not found to have antagonistic activity against S. enterica. The fruit quality (total soluble solids content and titratable acidity) was not negatively affected by CPA-7. The ethanol and acetaldehyde contents increased during the shelf-life of the fruit regardless of the presence of CPA-7. Some volatile compounds were key factors for discriminating samples from the two groups (the control group and the group that was inoculated with CPA-7). Some components are common in the volatile profile of pear (methyl acetate, 3-methylbutyl acetate, 1-butanol, 1-hexanol, and hexanal), and thus increases in their contents could enhance consumers flavour perception.

The interaction of storage temperature and duration on aroma volatiles in tomato fruit

Maintaining good flavor and aroma of fresh tomato (Solanum lycopersicum) fruit can be challenging. Storage temperature affects the synthesis of aroma volatiles and holding fruit at chilling temperatures can inhibit volatile synthesis. To gain a better understanding of the role temperature plays in volatile formation during postharvest storage and ripening of tomato, volatile profiles were assessed over a range of temperatures and storage times. Greenhouse grown tomatoes of the cultivar 'Trust' were harvested at the pink to light red stage of ripeness and held at 1, 10, 18 or 24°C and 85% RH. Fruit were sampled for volatile analysis after 0, 3, 6, 10 and 13 d. In addition, at each sampling time fruit were held for an additional 3 or 10 d at 20°C and then sampled for volatile analysis. Volatiles were analyzed from homogenized fruit tissue using headspace-GC-MS. Total volatile concentrations in tomato fruit increased about 3-fold after 10 or more days at 18°C. The most abundant volatile compounds in fruit held for 10 d at 18°C included hexanal, followed by 2-methylbutanol, E-2-hexenal, 6-methyl-5-hepten-2-one, 3-methylbutanal, 2-isobutylthiazole, 3-methylbutanol, geranylacetone, β-ionone, and pentanal. Little change in volatile composition occurred in fruit held at 1 or 10°C for 10 d. However, when fruit held for 3 d at 1 or 10°C were warmed to 20°C for an additional 10 d, total volatile concentration increased 6- and 4-fold, respectively when compared to initial values. In addition, volatile composition was similar to that in fruit held at 18°C, but concentrations were higher. When fruit held for 10 or 13 d at 1 or 10°C were warmed to 20°C for an additional 10 d, volatile synthesis was inhibited. Fruit held at 24°C for 10 d had volatile concentrations similar to those from fruit held at 18°C. While tomato fruit can tolerate chilling temperatures for short durations, prolonged exposures to temperatures below 10°C should be avoided since they can inhibit aroma volatile synthesis and thus impact tomato flavor.

Attraction of Apple Maggot Flies (Diptera: Tephritidae) to Synthetic Fruit Volatile Compounds and Food Attractants in Michigan Apple Orchards

Attraction of Apple Maggot Flies (Diptera: Tephritidae) to Synthetic Fruit Volatile Compounds and Food Attractants in Michigan Apple Orchards

Thap Maeo bananas: Fast ripening and full ethylene perception at low doses

Brazil is a major producer and consumer of various banana types. Thap Maeo is a promising cultivar for the market due to its resistance to Black and Yellow Sigatoka disease. However, a lack of information and postharvest technologies concerning Thap Maeo physiology seems to be a significant problem limiting its expansion in the market. Thus, this study aims to establish Thap Maeo fruit's physical, biochemical, and physiological aspects, defining the best ethylene dosage for treatment considering fruit ripening parameters. Bananas were harvested and monitored during both natural and ethylene-induced ripening processes. Assessments of pulp firmness, peel color and endogenous ethylene production showed different profiles between ethylene-treated and non-treated fruits, whereas the ethylene responses concerning the carbohydrates and hormones profiles, as well as the ethylene receptors expression, were observed in all ethylene-treated fruits, even applying low concentrations of the hormone. It thus indicated the high ethylene-sensitivity of Thap Maeo cultivar. Such postharvest behaviors reverberate in lower ethylene requirements for treatment, which was established at 10μLL−1. Ethylene-inducible changes in fruit volatile compounds throughout ripening are also discussed.

HS-GC-MS-O analysis and sensory acceptance of passion fruit during maturation.

The odor-active compounds of the conventional yellow passion fruit influence the aroma during ripeness and the acceptance of the juice. HS-GC-MS and GC-OSME analysis and sensory acceptance of the conventional passion fruit from different stages of ripeness were studied to characterize the aroma of the fruit and, aroma and flavor of the juice. Ethyl butanoate, ethyl hexanoate and propyl acetate showed high odoriferous importance in the passion fruit from the 1/3 yellow skin color. Cis-3-hexen-1-ol and diethyl carbonate plus the odor-active compounds from the 1/3 yellow skin color showed high odoriferous importance in the 2/3 yellow skin color, and butyl acetate and alpha-terpineol plus the same odor-active compounds from 2/3 were the most important for the 3/3 yellow skin color. There was difference in the aroma and flavor of the juices, with higher acceptance means for the passion fruit from the 3/3 yellow skin color. The passion fruit volatile compounds peak area, odoriferous intensity and sensory acceptance of the juices increased during ripeness, indicating that the conventional passion fruit characteristic aroma is completely expressed when the fruit reaches the whole maturation, at the 3/3 yellow skin color.

Volatile compounds of fruits of raspberry ‘Meeker’ and blackberry ‘Čačanska Bestrna’ propagated by standard techniques and in vitro micropropagation

Volatile compounds of fruits of raspberry ‘Meeker’ and blackberry ‘<b>Č</b>a<b>č</b>anska Bestrna’ propagated by standard techniques and in vitro micropropagation

Determination of fatty acids and volatile compounds in fruits of rosehip(Rosa L.) species by HS-SPME/GC-MS and Im-SPME/GC-MS techniques

In this study, we aimed to compare fatty acid and volatile compound compositions of four rosehip species, namely Rosa pimpinellifolia, R. Villosa, R. Canina, and R. Dumalis, by gas chromatography with flame ionization detector (GC/FID) and headspace and immersion solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME/GC-MS and Im-SPME/GC-MS) techniques. The total lipid contents in fruits of the rosehip species varied from 5.83% (R. Villosa) to 7.84% (R. Dumalis). A total of 21 fatty acids were detected and quantified. In all species, except R. Canina, polyunsaturated fatty acids (PUFAs) predominated over saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs). Palmitic acid is the major SFA in R. Villosa (5.50%), R. Canina (8.27%), and R. Dumalis (7.46%). Oleic acid is the most abundant MUFA, and linoleic and α-linolenic acids are the most abundant PUFAs. Sixty-two volatile compounds were detected by the HS-SPME/GC-MS technique, and 54 volatile compounds were determined by the Im-SPME/GC-MS technique. Fifty-three volatile components of rosehips have been detected for the first time in this study. While 19 acids, 9 aldehydes, 6 ketones, 18 alcohols, 5 esters, 2 terpenes, and 2 phenols were identified by HS-SPME/GC-MS, 20 acids, 5 aldehydes, 8 ketones, 13 alcohols, 5 esters, 1 terpene, and 2 phenols were identified by Im-SPME/GC-MS. The HS-SPME/GC-MS technique allowed identification of a larger number of volatile compounds and thus is more efficient than the Im-SPME/GC-MS technique.