Sains Malaysiana 40(2)(2011): 135–138

 

Volatile Compounds and Lactic Acid Bacteria in Spontaneous Fermented Sourdough

(Sebatian Meruap dan Bakteria Asid Laktik daripada Doh Masam melalui Fermentasi Spontan)

 

W.Y. Kam, W.M. Wan Aida*, A.M. Sahilah & M.Y. Maskat

Food Science Program, School of Chemical Sciences and Food Technology

Faculty of Science and Technology, Universiti Kebangsaan Malaysia

43600 UKM, Bangi, Selangor D.E., Malaysia

 

Received: 4 December 2009 / Accepted: 9 August 2010

 

ABSTRACT

 

The aim of this study is to identify the predominating lactic acid bacteria (LAB) in a spontaneous fermented wheat sourdough. At the same time, an investigation towards volatile compounds that were produced was also carried out. Lactobacillus plantarum has been identified as the dominant species of lactobacilli with characters of a facultative heterofermentative strain. The generated volatile compounds that were produced during spontaneous fermentation were isolated by solvent extraction method, analysed by gas chromatography (GC), and identified by mass spectrophotometer (MS). Butyric acid has been found to be the main volatile compound with relative abundance of 6.75% and acetic acid at relative abundance of 3.60%. Esters that were formed at relatively low amount were butyl formate (1.23%) and cis 3 hexenyl propionate (0.05%). Butanol was also found at low amount with relative abundance of 0.60%. The carbohydrate metabolism of Lactobacillus plantarum may contributed to the production of acetic acid in this study via further catabolism activity on lactic acid that was produced. However, butyric acid was not the major product via fermentation by LAB but mostly carried out by the genus Clostridium via carbohydrate metabolism which needs further investigation

 

Keywords: Lactic acid bacteria; lactobacillus; sourdough; spontaneous fermentation; volatile compound

 

ABSTRAK

 

Kajian dilakukan untuk mengenal pasti kehadiran spesies utama bakteria asid laktik yang terdapat dalam doh masam yang difermentasi secara spontan. Di samping itu, sebatian meruap yang terhasil semasa fermentasi juga dikaji. Lactobacillus plantarum dikenal pasti sebagai spesies utama yang bersifat jenis heterofermentatif fakultatif. Sebatian meruap yang terhasil semasa fermentasi spontan telah diasingkan secara kaedah pengekstrakan pelarut diikuti dengan analisis kromatografi gas (GC), dan pengenalpastian oleh spektrofotometer jisim (MS). Asid butirik merupakan sebatian meruap utama dengan kelimpahan relatif 6.75%. Asid asetik didapati terhasil dalam kelimpahan relatif 3.60%. Ester yang terhasil pada tahap kelimpahan relatif yang rendah termasuk butil format (1.23%) dan cis-3-heksil-propionat (0.05%). Butanol juga dikesan dalam amaun yang rendah dengan kelimpahan relatif 0.60%. Metabolisme terhadap karbohidrat oleh Lactobacillus plantarum yang menghasilkan asid asetik juga berkemungkinan besar dipengaruhi aktiviti katabolisme terhadap asid laktik yang terhasil. Walau bagaimanapun, asid butirik bukan hasil utama daripada fermentasi oleh LAB tetapi lebih daripada fermentasi oleh genus Clostridium melalui metabolisme karbohidrat dan kajian yang lebih mendalam diperlukan.

 

Kata kunci: Bakteria laktik asid; doh masam; fermentasi spontan; lactobacillus; sebatian meruap

 

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*Corresponding author; email: wawm@ukm.my

 
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