Comparison of aroma-active compounds among three types of commercial milk chocolate: relationship to sensory perception

Applied of dynamic headspace dilution analysis ( DHDA) and headspace sensory evaluation, the prominent aroma-active compounds of three types of commercial milk chocolate were identified and compared.A total of 23 odorants were identified. All the data obtained from the quantification and sensory evaluation was analyzed by principal component analysis ( PCA) . The results showed that chocolate A had the relatively higher content of hexanal ( grassy) , furan, 2-pentyl- ( sweety) , Pyrazine and trimethyl- ( nutty) , while chocolate B had the higher content of 2-methyl butanal ( cocoa-like) , pyrazine, -dimethyl ( popcorn-like) , furfural ( potato-like) , benzyl alcohol ( medicine-like) , phenethyl alcohol ( rosy) , benzothiazole ( rubber-like) and acetylpyrrole, ( nutty) . Chocolate C predominated in the content of 2- methyl butyric acid ( fecal) , isoamyl benzoate ( sweety, honey- like) , furfuryl alcohol ( medicine-like) , tetramethylpyrazine ( roast-like) and phenethyl acetate ( honey- like, floral) .The correlation analysis showed that 2- methyl butanal and benzyl alcohol mainly contribute to the chocolate- like aroma of milk chocolate, while acetic acid, 2- methyl propionic acid and 3- methyl butyric acid mainly contribute the acid- like aroma, tetramethylpyrazine and phenethyl acetate mainly contribute to roast- like /nutty flavor. In addition, the intensity of sweety and milky of milk chocolate exhibited a noteworthy negative correlation compared to other note.