Tempoyak is fermented durian (tropical seasonal fruit) pulp with a characteristic durian smell and creamy yellow color and is widely consumed in both Malaysia and Indonesia as a side dish and condiment1. A condiment or table sauce is a spice, sauce, or preparation that is added to food to impart a specific flavor, to enhance the flavor, or, in some cultures, to complement the dish.
As a condiment, tempoyak is consumed with fish and vegetable dishes. This condiment is made by mixing the durian pulp with salt and fermenting under partially anaerobic conditions at ambient temperature in a closed container. Fermentation usually takes 4-7 days and the durian pulp texture changes from a solid to a semisolid with an acidic odor and dominant taste.
The sour taste is attributed to the acid produced by Lactic Acid Bacteria (LAB) during fermentation.
Earlier studies have shown that LAB is the predominant microorganisms in tempoyak2. The LAB provides several potential health and nutritional benefits and is known as pro-biotic. Bacteria that live in human intestines and control the balance of intestinal micro-flora elicit physiological and beneficial health effects to the host and are referred to as pro-biotic.
Durian can be eaten fresh, used as a flavoring agent for ice cream or processed into candies and other delicacies; however, with consumers’ current desire for natural and healthy foods, isolating useful microorganisms from traditional fermented products has become the target of several investigations. Thus, a new study was carried out which aimed to identify the predominant lactic acid bacteria present in tempoyak made in Indonesia, based on LAB phenotypic characteristics and antimicrobial activity3.
For this purpose, experimental methods were performed for measuring the chemical composition of tempoyak; isolation and purification of LAB; characterization of selected isolates; isolation of genomic 16S rRNA; microscopic, macroscopic, molecular identification and determination of antimicrobial action using E. coli, S. aureus and L. monocytogenes as indicator bacteria were performed.
It was observed that gram staining showed that the isolates were Gram-positive, catalase-negative bacilli. The largest inhibitory zone was obtained from the isolate against S. aureus followed by that against L. monocytogenes and the smallest inhibitory zone was produced against E. coli.
The PCR results showed that the DNA fragment was 1482 bp. The sequencing results from the isolated tempoyak sample showed that the LAB isolated was Lactobacillus fermentum strain CAU6337. The catalase and fermentation type results were also uniform. PCR and BLAST results showed similarity with Lactobacillusfermentum.
Keywords:
Durian, LAB, tempoyak, Lactobacillus fermentum, strain CAU6337, PCR and BLAST, DNA fragment, isolation and purification of LAB, gram staining, probiotic, microflora.
References:
- Battcock, M. and S. Azam-Ali, 1998. Fermented Fruits and Vegetables: A Global Perspective. Food and Agriculture Organization, Rome, Italy, ISBN: 9789251042267, Pages: 96.
- Amiza, M.A., J. Zakiah, L.K. Ng and K.W. Lai, 2006. Fermentation of tempoyak using isolated tempoyak culture. Res. J. Microbiol., 1: 243-254.
- Juliyarsi, I., Hartini, P., Yuherman, Djamaan, A., Arief, …and Endang Purwati, 2018. Characterization of Lactic Acid Bacteria and Determination of Antimicrobial Activity in Tempoyak from Padang Pariaman District, West Sumatra, Indonesia. Pak. J. Nutr., 17: 506-511.
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