It is well recognized that the aging process is a critical step in winemaking because it induces substantial chemical changes linked to the organoleptic properties and stability of the finished wines. Therefore, this study aimed to investigate the influence of different types, utilization times, and volumes of aging barrels on the metabolite profile of red wines, produced from Thai-grown Shiraz grapes, using a non-targeted proton nuclear magnetic resonance (H-NMR) metabolomics approach. As a result, 37 non-volatile polar metabolites including alcohols, amino acids, organic acids, carbohydrates and low-molecular-weight phenolics were identified.
View Article and Find Full Text PDFAutochthonous yeasts associated with pineapple fermentation were isolated and their fermentation behaviours were investigated for development of specific culture in pineapple winemaking. Autochthonous yeast isolates, Saccharomycodes ludwigii and Hanseniaspora uvarum, were selected due to their generated products of alcohol and 2-phenylethyl acetate, respectively. The fermentation kinetic parameters of selected autochthonous yeasts as single and co-cultures in chaptalized pineapple juice were investigated comparing to commercial Saccharomyces cerevisiae.
View Article and Find Full Text PDFBacterial diversity of the Thai traditional salt fermented fish with roasted rice bran (Pla-ra) was investigated using classical and molecular approaches. Bacterial population of Pla-ra ranged from 10-10 in solid-state (SSF) and 10-10 CFU/g in submerged (SMF) fermentation types. spp.
View Article and Find Full Text PDFBackground: Konjac glucomannan-based edible films formulated with Lactobacillus casei-01® and chicory-derived inulin Orafti®GR were studied for their properties, stability, and application as coatings on bread buns.
Results: Thickness and transparency were variable and dependent on the formulations. Alterations in color properties of all supplemented films were unnoticeable by unaided human eyes, with ΔE less than 3.
Background: Many fermented foods and beverages are produced through the action of complex microbial communities. Synthetic biology approaches offer the ability to genetically engineer these communities to improve the properties of these fermented foods. Soy sauce is a fermented condiment with a vast global market.
View Article and Find Full Text PDFThe aim of this research was to evaluate the feasibility of PCR-DGGE and Reverse Transcriptase-PCR-DGGE techniques for rapid detection of Vibrio species in foods. Primers GC567F and 680R were initially evaluated for amplifying DNA and cDNA of ten references Vibrio species by PCR method. The GC-clamp PCR amplicons were separated according to their sequences by the DGGE using 10% (w/v) polyacrylamide gel containing 45-70% urea and formamide denaturants.
View Article and Find Full Text PDFThe aim of this study was to evaluate the feasibility of Fe(III) ion reduction for the simple and rapid quantification of autoinducer-2 (AI-2) produced from bacteria using Salmonella Typhimurium as a model. Since the molecular structure of AI-2 is somewhat similar to ascorbic acid it was expected that AI-2 would also act as a reducing agent and reduce Fe(III) ions in the presence of 1,10-phenanthroline to form the colored [(o-phen)3 Fe(II)]SO4 ferroin complex that could be quantified colorimetrically. In support of this, colony rinses and cell free supernatants from cultures of all tested AI-2 producing strains, but not the AI-2 negative Sinorhizobium meliloti, formed a colored complex with a λmax of 510nm.
View Article and Find Full Text PDFThis study investigated autochthonous yeasts and their functions in the spontaneous fermentation of freshly crushed pineapple juice samples collected from two different areas of both Thailand and Australia. Hanseniaspora uvarum and Pichia guilliermondii were the main yeast species observed on the fruit skins of Thai samples, and also in the fresh juice and ferments of all samples from both countries. P.
View Article and Find Full Text PDFThe performance of denaturing gradient gel electrophoresis (DGGE) for analysing yeasts associated with wine grapes was compared with cultural isolation on malt extract agar (MEA). After optimisation of PCR and electrophoretic conditions, the lower limit of yeast detection by PCR-DGGE was 10(2) cfuml(-1), although this value was affected by culture age and the relative populations of the species in mixed culture. In mixed yeast populations, PCR-DGGE detected species present at 10-100-fold less than other species but not when the ratio exceeded 100-fold.
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