What Do We Know about the Chemistry of Strawberry Aroma?

Abstract

The strawberry, with its unique aroma, is one of the most popular fruits worldwide. The demand for specific knowledge of metabolism in strawberries is increasing. This knowledge is applicable for genetic studies, plant breeding, resistance research, nutritional science, and the processing industry. The molecular basis of strawberry aroma has been studied for more than 80 years. Thus far, hundreds of volatile organic compounds (VOC) have been identified. The qualitative composition of the strawberry volatilome remains controversial though considerable progress has been made during the past several decades. Between 1997 and 2016, 25 significant analytical studies were published. Qualitative VOC data were harmonized and digitized. In total, 979 VOC were identified, 590 of which were found since 1997. However, 659 VOC (67%) were only listed once (single entries). Interestingly, none of the identified compounds were consistently reported in all of the studies analyzed. The present need of data exchange between "omic" technologies requires high quality and robust metabolic data. Such data are unavailable for the strawberry volatilome thus far. This review discusses the divergence of published data regarding both the biological material and the analytical methods. The VOC extraction method is an essential step that restricts interlaboratory comparability. Finally, standardization of sample preparation and data documentation are suggested to improve consistency for VOC quantification and measurement.

Recent Advances in Hormonal Regulation and Cross-Talk during Non-Climacteric Fruit Development and Ripening

“…Later, it was demonstrated that under ABA stimulation the ABAR promotes ripening in strawberry fruit [19,48,95], through ABA binding [96]. The downregulation of FaABAR expression inhibits ripening, without rescued by addition of exogenous ABA, suggesting a crucial role for the ABAR receptor in strawberry ripening [46]. Regarding the FaABAR interaction with other potential signaling proteins, a leucine-rich repeat receptor-like kinase LRR-RLK gene, named as FaRIPK1 (for red-initial protein kinase 1), has been localized in the nucleus and plasma membrane, and its binding to FaABAR regulates strawberry fruit ripening [94].…”

“…Also, flavour can be determined by the presence of molecules such as anthocyanins and tannins, that grant slight and pleasing astringency [28]. Aroma, one of the most valued attributes of raspberry [44] and strawberry [45,46] fruits, is a parameter that depends on a number of factors such as concentration, combination, and the perception threshold of different volatile compounds [45][46][47], and the main aroma components include lipid-derived compounds, phenolic derivatives, amino acid-derived compounds, and mono-and sesquiterpenes [47].…”

Impact of Beneficial Microorganisms on Strawberry Growth, Fruit Production, Nutritional Quality, and Volatilome

“…Strawberry aroma is mainly due to the complex blend of volatile organic compounds (known as volatilome—Bicchi and Maffei, 2012 ; Ulrich et al, 2018 ), which also contribute to the fruit flavor (Forney et al, 2000 ; Forney, 2001 ; Prat et al, 2014 ; Schwieterman et al, 2014 ). Although these molecules have a big impact on fruit sensorial qualities, they are found in very low concentrations (ranging between about 0.001 and 0.01% of fruit fresh weight) (Buttery, 1981 ).…”

Exploring the Characteristics of an Aroma-Blending Mixture by Investigating the Network of Shared Odors and the Molecular Features of Their Related Odorants

“…Hence, STR seems to be a difficult odor to define because no molecule is simply described with an STR. Strawberry is a very widespread fruit worldwide, but its odor is one the most complex natural odors, and thus it is difficult to clearly describe [42]. The case of Et-iB, which is the STR component in the target mixture, is an interesting example.…”

“…The strawberry furanone is another case of such an ambiguity. This monocyclic molecule is considered to substantially influence the odor of strawberry fruit [42]. However, the aroma description is complex and has stronger caramellic and cooked odors than it does fresh fruit odors ("fruity, caramelized pineapple-strawberry odor & taste; roasted" [33]; "intense caramellic, fruity, jam like odor with some resemblance to the odor of maltol; also reminiscent of cooked pineapple" [44]).…”