Formation of Methyl Pyrazine during Cocoa Bean Fermentation

Selamat, Jinap and Harun, Siti Mordingah and Mohd. Ghazali, Norsiati (1994) Formation of Methyl Pyrazine during Cocoa Bean Fermentation. Pertanika Journal of Tropical Agricultural Science, 17 (1). pp. 27-32. ISSN 0126-6128

[img] PDF
3807Kb

Abstract

A study on the effect of four fermentation techniques currently practised in Malaysia on the types and amount of pyrazines produced and the growth of Bacillus sp. in cocoa beans was carried out. Freshly harvested beans were fermented using wooden shallow (032m in depth), medium (0.61 m), deep (0. 9Om) boxes for 6 d and turned every 4B h for the shallow and medium fermentations, and every 24 h for the deep fermentation; beans that had undergone 10 d pod storage were also fermented in shallow box for 5 d and turned on 4Bth hour. Samples were determined for nib pH, titratable acidity, fermentation index and pyrazines. Number of Bacillus sp. bacteria were monitored and identified. The type and amount of pyrazines detected varied with the techniques employed. Pod-stored samples contained 2,3,5,6-tetramethylpyrazine (19. Bug/1OOg) and the highest concentration of 2,3,5-trimethylpyrazine (23.0ug/ 100g), 2,5-dimethylpyrazine (154. Bug/1 OOg) and total pyrazine (177. 6ug/1 OOg). Samples fermented in shallow and medium box fermentations contained 2,3,5-trimethylpyrazine and 2,5- dimethylpyrazines; those of the deep box contained only 2,5-dimethylpyrazine. Bacillus sp. increased along with 2,3-dimethylpyrazine, 2,3,5trimethylpyrazine and total pyrazine as fermentation Period increased, with a correlation (r2) of 0.90. The isolated Bacillus sp. were identifted as B. subtilis and B. megaterium. 2,5-dimethylpyrazine was present in all samples; the component could be common in cocoa fermented in Malaysia.

Item Type:Article
Keyword:cocoa beans, fermentation, wooden box fermentation, fermentation, pyrazines, Bascillus sp. fermentation index, bean pH, pod-storage
Publisher:Universiti Putra Malaysia Press
ID Code:3248
Deposited By: Nasirah Abu Samah
Deposited On:25 Nov 2009 00:58
Last Modified:27 May 2013 07:06

Repository Staff Only: item control page

Document Download Statistics

This item has been downloaded for since 25 Nov 2009 00:58.

View statistics for "Formation of Methyl Pyrazine during Cocoa Bean Fermentation"


Universiti Putra Malaysia Institutional Repository

Universiti Putra Malaysia Institutional Repository is an on-line digital archive that serves as a central collection and storage of scientific information and research at the Universiti Putra Malaysia.

Currently, the collections deposited in the IR consists of Master and PhD theses, Master and PhD Project Report, Journal Articles, Journal Bulletins, Conference Papers, UPM News, Newspaper Cuttings, Patents and Inaugural Lectures.

As the policy of the university does not permit users to view thesis in full text, access is only given to the first 24 pages only.