Volatiles profiling in Ceratonia siliqua (Carob bean) from Egypt and in response to roasting as analyzed via solid-phase microextraction coupled to chemometrics

Ceratonia siliqua is a legume tree of considerable commercial importance for the flavor and sweets industry cultivated mostly for its pods nutritive value and or several health benefits. Despite extensive studies on C. siliqua pod non-volatile metabolites, much less is known regarding volatiles composition which contributes to the flavor of its many food products. To gain insight into C. siliqua aroma, 31 volatile constituents from unroasted and roasted pods were profiled using headspace solid-phase micro extraction (HD-SPME) analyzed via quadruple mass spectrometer followed by multivariate data analyses. Short chain fatty acids amounted for the major volatile class at ca. (71-77%) with caproic acid (20%) and pentanoic acid (15-25%) as major components. Compared to ripe pod, roasted ripe pod was found less enriched in major volatile classes i.e., short chain fatty acids and aldehydes, except for higher pyranone levels. Volatiles mediating for unheated and hot carob fruit aroma is likely to be related to its (E)-cinnamaldehyde and pyranone content, respectively. Such knowledge is expected to be the key for understanding the olfactory and taste properties of C. siliqua and its various commercial food products.