# Volatiles in Berries: Biosynthesis, Composition, Bioavailability, and Health Benefits
## 3 The Chemical Composition of Volatile Compounds in Berries
### Strawberry  
Strawberries (_Fragaria_ spp.) are the most consumed berry fruit for their sweet taste and unique aroma [86]. The consumption of strawberry products, such as jams, juices, and puree, has significantly increased [87; 88]. Strawberries are rich in volatile compounds responsible for the strawberry flavor and aroma [89; 90]. Volatile compounds in strawberries have been extensively studied, and more than 360 volatile compounds have been identified [91]. These compounds include esters, which were qualitatively and quantitatively dominant, terpen, furanones, sulfur, lactones, alcohols, and carbonyls. In the study of [PERSON] et al., a total of 42 volatiles were detected, with 19 esters, 10 alcohols, and 6 terpen being the most abundant in the strawberry samples analyzed [65].  
Sters are the most abundant and major aroma volatiles affecting the aroma of strawberries [92]. Among 19 ester compounds, methyl butanoate, methyl hexanoate, ethyl acetate, and hexyl acetate were the major ester compounds [65]. Terpenes are important compounds to the flavor and possess many preferable aroma profiles [93]. Among six terpen, limonene and \(\alpha\)-terpinene were the main compounds in strawberries [65]. Although strawberries contained many alcohol compounds, alcohols did not affect the strawberry flavor notably. In addition, c-decalactone (peach-like aroma) contributes significantly to the strawberry flavor. Hexanal, trans-2-hexenal, and cis-3-hexen-1-ol are responsible for the green, unripe aroma of the strawberry. The furanones 2,5-dimethyl-4-hydroxy-3(2H)-furanone (furaneol) and 2,5-dimethyl-4-methoxy-3(2H)-furanone (mesifurane), which have the sweet, floral, and fruity aroma, are major furans found in strawberries [65].  
Summarizing some strawberry volatile studies, volatile components that are consistently considered important aroma compounds include ethyl butanoate, ethyl hexanoate, methyl butanoate, ethyl 3-methylbutanoate, fureneol, and linalool [66; 85; 94]. Additional compounds that have been reported include 2-heptanone, mesifurane, cis-3-hexenal, ethyl 2-methylpropanoate, 2,3-butanedione, 3-methylbutyl acetate, methyl hexanoate, and ethyl 2-methylbutanoate [67]. Eight different strawberry varieties (Sabrosa, Albion, Sweet Ann, Festival, Fortuna, Ventana, Camarosa, and Rubygem) were examined to investigate the volatile composition [72]. With headspace solid-phase micro-extraction gas chromatography-mass spectrometry (HS-SPME/GC-MS), esters (31 volatiles), especially ethyl hexanoate were detected as major compounds [72]. The most detected compounds were esters (31 compounds), which give fruity and floral characteristics to strawberries [72]. The SPME/GC-MS is one of the most common and effective methods for volatile analysis. SPME fiber samples the volatile compounds from air and thermally desorbs the sample in the injection port of a GC system [95; 96]. In [PERSON] et al., 55 volatiles were found in the strawberry extract, with monoter being the predominant volatiles (43% of total volatile concentration) [69]. It was followed by acids, esters, furan, aldehydes, alcohol, ketones, and alkylbenzene. Predominant compounds in strawberry extract were myrtenol, butanoic acid, mesifurane, ethyl butanoate, and hexyl butanoate.  
\begin{table}
\begin{tabular}{l c c c c c} \hline \hline
**Compound** & **Strawberry** & **Blueberry** & **Raspberry** & **Blackberry** & **Cranberry** \\ \hline _Hydrocarbons_ & & & & & \\ Octane & & [78] & & & \\ Ethyl benzene & & [78] & & & \\ p-xylene & & [78] & & & \\ Mayylene & & [78] & & & \\ B-ocimene & & & [76] & & \\ \hline _Lactones_ & & & & & \\ \(\gamma\)-decalactone & [65] & & & & \\ Butyrolactone & & [78] & & & \\ \(\delta\)-octalactone & & & [79] & & \\ \(\delta\)-decalactone & & & [79] & & \\ \hline \hline \end{tabular}
\end{table}
Table 1: _Cont._