Impact of Different Carbon Sources on Volatile Organic Compounds (VOCs) Produced during Fermentation by WLP672 Measured Using Proton Transfer Reaction Time-of-Flight Mass Spectrometry (PTR-ToF-MS).

Bacterial fermentation is considered to be a cost-effective means of generating desired flavour compounds from plant-based substrates. However, the wide range of substrates present in plants makes it challenging to understand how individual components impact on flavour volatile organic compound (VOC) production. To simplify this, a defined medium can be used to better understand VOCs production with regard to individual compounds.

Volatile Organic Compounds (VOCs) Produced by WLP672 Fermentation in Defined Media Supplemented with Different Amino Acids.

Fermentation by lactic acid bacteria (LAB) is a promising approach to meet the increasing demand for meat or dairy plant-based analogues with realistic flavours. However, a detailed understanding of the impact of the substrate, fermentation conditions, and bacterial strains on the volatile organic compounds (VOCs) produced during fermentation is lacking. As a first step, the current study used a defined medium (DM) supplemented with the amino acids L-leucine (Leu), L-isoleucine (Ile), L-phenylalanine (Phe), L-threonine (Thr), L-methionine (Met), or L-glutamic acid (Glu) separately or combined to determine their impact on the VOCs produced by WLP672 (LB672).

The Physical and Structural Effects of 1-MCP on Four Different Apple Cultivars during Storage.

The impact of the ethylene inhibitor, 1-methylcyclopropene (1-MCP), on four apple cultivars (Braeburn, Fuji, Jazz and Golden Delicious) over 150 days of storage at 2 °C was assessed. Proton transfer reaction quadrupole mass spectrometry (PTR-QUAD-MS) was used to monitor changes in VOC composition, while texture analysis and X-ray microcomputer tomography (µ-CT) scanning were used to study microstructural changes. The application of 1-MCP on apples reduced VOC emissions, concurrently maintaining a firmer texture compared to the untreated apples at each time point.

Online monitoring of higher alcohols and esters throughout beer fermentation by commercial Saccharomyces cerevisiae and Saccharomyces pastorianus yeast.

Higher alcohols and esters are among the predominant classes of volatile organic compounds (VOCs) that influence the quality of beer. The concentrations of these compounds are determined through a specific yeast strain selection and fermentation conditions. The effect of yeast strains on the formation of higher alcohols and esters throughout fermentations (at 20°C) was investigated.

Flavour Volatiles of Fermented Vegetable and Fruit Substrates: A Review.

Health, environmental and ethical concerns have resulted in a dramatic increase in demand for plant-based dairy analogues. While the volatile organic compounds (VOCs) responsible for the characteristic flavours of dairy-based products have been extensively studied, little is known about how to reproduce such flavours using only plant-based substrates. As a first step in their development, this review provides an overview of the VOCs associated with fermented (bacteria and/or fungi/yeast) vegetable and fruit substrates.