title: Influences of superheated steam roasting on changes in sugar, amino acid and flavour active components of cocoa bean (Theobroma cacao).
abstract: BACKGROUND
  Roasting is one of the important unit operations in the cocoa-based industries in order to develop unique flavour in products. Cocoa beans were subjected to roasting at different temperatures and times using superheated steam. The influence of roasting temperature (150-250°C) and time (10-50 min) on sugars, free amino acids and volatile flavouring compounds were investigated.
  
  
  RESULTS
  The concentration of total reducing sugars was reduced by up to 64.61, 77.22 and 82.52% with increased roasting temperature at 150, 200 and 250°C for 50 min, respectively. The hydrophobic amino acids were reduced up to 29.21, 36.41 and 48.87% with increased roasting temperature at 150, 200 and 250°C for 50 min, respectively. A number of pyrazines, esters, aldehydes, alcohols, ketones, carboxyl acids and hydrocarbons were detected in all the samples at different concentration range. Formation of the most flavour active compounds, pyrazines, were the highest concentration (2.96 mg kg-1) at 200°C for 10 min.
  
  
  CONCLUSIONS
  The superheated steam roasting method achieves the optimum roasting condition within a short duration Therefore, the quality of cocoa beans can be improved using superheated steam during the roasting process. © 2017 Society of Chemical Industry.
authors.affiliation: Food Technology Division, School of Industrial Technology, Universiti Sains Malaysia, Pulau Pinang, Malaysia.|Department of Food Engineering and Tea Technology, Shahjalal University of Science and Technology, Sylhet, Bangladesh.
authors.forename: Wahidu
authors.initials: W
authors.lastname: Zzaman
authors.affiliation: Food Technology Division, School of Industrial Technology, Universiti Sains Malaysia, Pulau Pinang, Malaysia.
authors.forename: Rajeev
authors.initials: R
authors.lastname: Bhat
authors.affiliation: Food Technology Division, School of Industrial Technology, Universiti Sains Malaysia, Pulau Pinang, Malaysia.
authors.forename: Tajul Aris
authors.initials: TA
authors.lastname: Yang
authors.affiliation: Food Technology Division, School of Industrial Technology, Universiti Sains Malaysia, Pulau Pinang, Malaysia.
authors.forename: Azhar Mat
authors.initials: AM
authors.lastname: Easa
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D002099:Cacao / Q000737:chemistry*; D003296:Cooking / Q000295:instrumentation / Q000379:methods*; D005421:Flavoring Agents / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D012639:Seeds / Q000737:chemistry*; D013227:Steam; D000073893:Sugars / Q000737:chemistry*; D013649:Taste; D013696:Temperature
chemical_list: D000596:Amino Acids; D005421:Flavoring Agents; D013227:Steam; D000073893:Sugars
keywords: cocoa bean; flavour compound; free amino acid; roasting; sugar; superheated steam