Screening for Volatile α-Unsaturated Ester-Producing Yeasts from the Feces of Wild Animals in South Africa.

α-unsaturated esters are fruity-aromatic compounds which are largely spread in the volatilome of many different fruits, but they are rarely found in the volatilome of yeasts. The yeast has been recently shown to produce relatively high amounts of α-unsaturated esters and it appears to be an interesting model for the production of these compounds. This study aimed to isolate new α-unsaturated ester-producing yeasts by focusing on strains displaying a similar metabolism to .

Selection by UV Mutagenesis and Physiological Characterization of Mutant Strains of the Yeast (Former ) with Higher Capacity to Produce Flavor Compounds.

Yeast volatile organic compounds (VOCs), i.e. low molecular weight organic acids, alcohols and esters, are considered as potential and sustainable sources of natural aromas that can replace commonly used artificial flavors in food and other industrial sectors.

OVAT Analysis and Response Surface Methodology Based on Nutrient Sources for Optimization of Pigment Production in the Marine-Derived Fungus 30548 Submerged Fermentation.

Pigment production from filamentous fungi is gaining interest due to the diversity of fungal species, the variety of compounds synthesized, and the possibility of controlled massive productions. The species produce a large panel of metabolites, including azaphilone pigments, with potential use as natural colorants in industrial applications. Optimizing pigment production from fungal strains grown on different carbon and nitrogen sources, using statistical methods, is widespread nowadays.

Evaluation of mixed-fermentation of Saccharomyces cerevisiae with Saprochaete suaveolens to produce natural fruity beer from industrial wort.

Fruity beers can be promoted through production of flavoring compounds during fermentation by partial replacement of brewing yeast by non-conventional-yeasts with high aroma production abilities. We evaluated here the use of a wild Saprochaete suaveolens strain, producing atypical aroma compounds, to produce new natural fruity beer, while keeping classical production conditions used in brewing industry. S.

Evaluation of Filamentous Fungi and Yeasts for the Biodegradation of Sugarcane Distillery Wastewater.

Sugarcane Distillery Spent Wash (DSW) is among the most pollutant industrial effluents, generally characterized by high Chemical Oxygen Demand (COD), high mineral matters and acidic pH, causing strong environmental impacts. Bioremediation is considered to be a good and cheap alternative to DSW treatment. In this study, 37 strains of yeasts and filamentous fungi were performed to assess their potential to significantly reduce four parameters characterizing the organic load of vinasses (COD, pH, minerals and OD).

Statistical Optimization of the Physico-Chemical Parameters for Pigment Production in Submerged Fermentation of 30548.

30548 is a marine-derived pigment producing filamentous fungus, isolated from the La Réunion island, in the Indian Ocean. The objective of this study was to examine and optimize the submerged fermentation (SmF) process parameters such as initial pH (4-9), temperature (21-27 °C), agitation speed (100-200 rpm), and fermentation time (0-336 h), for maximum production of pigments (orange and red) and biomass, using the Box-Behnken Experimental Design and Response Surface Modeling (BBED and RSM). This methodology allowed consideration of multifactorial interactions between a set of parameters.

Production of biomass on sugarcane distillery wastewater: physiological aspects and potential for biodiesel production.

Background: Sugarcane distillery waste water (SDW) or vinasse is the residual liquid waste generated during sugarcane molasses fermentation and alcohol distillation. Worldwide, this effluent is responsible for serious environmental issues. In Reunion Island, between 100 and 200 thousand tons of SDW are produced each year by the three local distilleries.

Flavour production by Saprochaete and Geotrichum yeasts and their close relatives.

In this study, a total of 30 yeast strains belonging to the genera Dipodascus, Galactomyces, Geotrichum, Magnusiomyces and Saprochaete were investigated for volatile organic compound production using HS-SPME-GC/MS analysis. The resulting flavour profiles, including 36 esters and 6 alcohols compounds, were statistically evaluated by cluster and PCA analysis. Two main groups of strains were extracted from this analysis, namely a group with a low ability to produce flavour and a group producing mainly alcohols.

Contribution of trans-aconitic acid to DPPH scavenging ability in different media.

The antioxidant properties of trans-aconitic acid (TAA) alone or in the presence of usual antioxidants were assessed by DPPH assay. The IC50 value equal to 70mM was very high compared to usual antioxidants (vitamin C and trolox). A joint experimental/theoretical study suggested that hydrogen atom abstraction in TAA by DPPH was located on -CH2- methylene bridge because the corresponding radical was more stabilized than COO(·) and CC(·) radicals.

A comparative study on the potential of epiphytic yeasts isolated from tropical fruits to produce flavoring compounds.

In recent years, there has been an increasing interest in identifying and characterizing the yeast flora associated with diverse types of habitat because of the many potential desirable technological properties of these microorganisms, especially in food applications. In this study, a total of 101 yeast strains were isolated from the skins of tropical fruits collected in several locations in the South West Indian Ocean. Sequence analysis of the D1/D2 domains of the large subunit (LSU) ribosomal RNA gene identified 26 different species.

Physiological and biochemical characteristics of the ethyl tiglate production pathway in the yeast Saprochaete suaveolens.

A yeast identified as Saprochaete suaveolens was investigated for its capacity to produce a large panel of flavouring molecules. With a production of 32 compounds including 28 esters, S. suaveolens seems to be a good producer of fruity flavours and fragrances and especially of unsaturated esters, such as ethyl tiglate.

Comparison of the concentrations of phenolic constituents in cane sugar manufacturing products with their antioxidant activities.

Polyphenol content and free radical scavenging capacity of seven kinds of sugar manufacturing products (A sugars, clear juices, syrups, massecuite, and A, B, and C molasses) were studied. Seventy-two samples were collected at different stages of the process during two sugar harvests from a local sugar factory (Bois-Rouge, La Réunion). The total phenolic content of sugar products was determined according to the Folin-Ciocalteu assay.

Assessment of antioxidant activity of cane brown sugars by ABTS and DPPH radical scavenging assays: determination of their polyphenolic and volatile constituents.

Seven cane brown sugars (four from La Réunion, two from Mauritius, and one from France) were investigated for their polyphenol content and volatile composition in relation to their free radical scavenging capacity determined by ABTS and DPPH assays. The thin layer coated on the sugar crystal was extracted by Soxhlet extractor with dichloromethane. The volatile compounds of brown sugars were studied by GC-MS, and 43 compounds were identified.