Aims: To evaluate the microbial count and palatability acceptance of spoiled fish after treatment with traditionally used natural solution. Methodology and results: To compare microbial count of spoiled fish before and after treatment with natural solution practiced by local people in Malaysia, 10 g of spoiled fish was respectively rinsed with 100 mL of 0.1% of natural solution such as Averrhoa bilimbi extract, rice rinsed water, rice vinegar, Citrus aurantifolia extract, salt, flour, and Tamarindus indica extract. Flesh of fish rinsed with rice vinegar was found to be able to reduce microbial count (CFU/mL = 0.37 X 107) more than 4.5 times when compared to spoiled fish (CFU/mL=1.67x 107). Spoiled fish that was treated with rice vinegar was prepared into a cutlet and fried. The cutlet was subjected to palatability acceptance study by a group of residents in Palm Court Condominium, Brickfields, Kuala Lumpur. The palatability study from the Cronbach alpha shown that the taste have the reliability of 0.802, the aroma has the reliability of 0.888, colour with the reliability of 0.772, texture or mouth feel have reliability of 0.840 and physical structure of the cutlet is 0.829. Conclusion, significance and impact of study: Treatment of spoiled fish using rice vinegar as practice by local people traditionally shown a significant reduction in microbial count and the vinegar-treated fish could be developed into a product that is safe and acceptable by the consumer.

Aims: Acetic acid bacteria (AAB) are a group of Gram-negative or Gram-variable bacteria that oxidise ethanol during the production of vinegar. The aim of this study was to isolate the AAB from both Lansium domesticum (Dokong) and Nephelium lappaceum (Rambutan), mother of vinegars (MV) and vinegars, as a potential starter culture for vinegar production. Methodology and results : The MV and vinegar samples were collected from six to eight weeks of fermented Dokong and Rambutan vinegar from the Food Laboratory of Universiti Malaysia Kelantan (UMK), Jeli. The enriched samples were inoculated on selective Carr and GYC solid media. From the Carr medium, thirty-seven isolates that showed a yellow clear zone and seventy-eight isolates that showed a halo clear zone on the GYC medium were selected. Sixty isolates that produced higher total acidity (>60%) were characterized by Gram staining. Sixteen Gram-negative and fourteen Gram-variable isolates were subjected to 2.0% ethanol Carr medium to select for ethanol tolerance. Five ethanol-tolerant isolates were suitable for 16S rRNA gene sequence analysis and molecular identification because they had 4% to 10% ethanol tolerance level utilisation on Carr solid medium. Based on the morphological and biochemical characteristics, isolates DV1 and RMV30 were Gram-variable. Meanwhile, RMV2, RMV19 and RMV37 were Gram-negative bacteria. RMV2, RMV19, RMV30 and RMV37 isolates were catalase-positive and oxidase negative. Only DV1 was catalase and oxidase positive. From the BLAST analysis, the obtained nucleotide sequences showed 100% homology, with RMV2, identified as Acetobacter fabarum, and DV1, RMV19, RMV30 and RMV37 were identified as A. pasteurianus. Conclusion, significance and impact of study Based on 16S rRNA gene sequences, five isolates were identified as Acetobacter species: Four isolates, DV1, RMV19, RMV30 and RMV37 strains, were identified as A. pasteurianus and RMV2 was identified as A. fabarum. DV1, RMV2, RMV19, RMV30 and RMV37 showed significant differences at (p<0.05) for ethanol utilisation at 4% and the highest toleration up to an ethanol concentration of 10%. The ability to tolerate high ethanol concentration during vinegar fermentation is a desirable in producing high acetic acid for vinegar production.