title: A comparative study of aroma-active compounds between dark and milk chocolate: relationship to sensory perception.
abstract: BACKGROUND
  The most important aroma-active compounds of two types of chocolate and cocoa liquor used for their production were analysed by gas chromatography-olfactometry-mass spectrometry (GC-O-MS) and aroma extract dilution analysis (AEDA). Furthermore, the relationship between odorants and sensory perception of chocolate was measured by quantitative analysis, sensory evaluation and correlation analysis. In addition, some chemicals were added to the original dark or milk chocolate to validate their roles in the aroma property of chocolate.
  
  
  RESULTS
  A total of 32 major aroma-active compounds were identified in the chocolate with the flavour dilution factors of 27-729 by AEDA, including seven aldehydes, six pyrazines, three pyrroles, four carboxylic acids, four lactones, two alcohols, two ketones, one ester, one pyrone, one furan and one sulfur-containing compound. Further quantitative analysis showed that dark chocolate had higher contents of pyrazine, pyrrole, carboxylic acids, alcohols and Strecker aldehydes, whereas the concentration of lactones, esters, long chain aldehydes and ketones were higher in the milk type.
  
  
  CONCLUSIONS
  Differences in volatile composition and descriptive flavour attributes between the dark and milk chocolate were observed. The relationship between aroma-active compounds and sensory perception in the chocolate was verified.
authors.affiliation: Laboratory of Molecular Sensory Science, Beijing Technology and Business University, Beijing, 100048, China.
authors.forename: Jianbin
authors.initials: J
authors.lastname: Liu
authors.forename: Mengya
authors.initials: M
authors.lastname: Liu
authors.forename: Congcong
authors.initials: C
authors.lastname: He
authors.forename: Huanlu
authors.initials: H
authors.lastname: Song
authors.forename: Jia
authors.initials: J
authors.lastname: Guo
authors.forename: Ye
authors.initials: Y
authors.lastname: Wang
authors.forename: Haiying
authors.initials: H
authors.lastname: Yang
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Su
mesh_terms: D000328:Adult; D000818:Animals; D002099:Cacao / Q000737:chemistry*; D002182:Candy; D005260:Female; D005421:Flavoring Agents / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans; D008297:Male; D008892:Milk; D009812:Odorants / Q000032:analysis*; D009822:Oils, Volatile / Q000032:analysis*; D013649:Taste; D055549:Volatile Organic Compounds / Q000032:analysis*; D055815:Young Adult
chemical_list: D005421:Flavoring Agents; D009822:Oils, Volatile; D055549:Volatile Organic Compounds
keywords: aroma extract dilution analysis (AEDA); chocolate; gas chromatography-olfactrometry-mass spectrometry (GC-O-MS); sensory perception; solvent-assisted flavour evaporation (SAFE)