Production Of Volatile Flavour Compounds Research Articles

Quality and Flavor Difference in Dry-Cured Meat Treated with Low-Sodium Salts: An Emphasis on Magnesium.

The present study aimed to develop low-sodium curing agents for dry-cured meat products. Four low-sodium formulations (SPMA, SPM, SP, and SM) were used for dry-curing meat. The physicochemical properties and flavor of the dry-cured meat were investigated. The presence of Mg2+ ions hindered the penetration of Na+ into the meat. The weight loss, moisture content, and pH of all low-sodium salt groups were lower than those of S. Mg2+ addition increased the water activity (Aw) of SPMA, SPM, and SM. Dry-curing meat with low-sodium salts promoted the production of volatile flavor compounds, with Mg2+ playing a more prominent role. Furthermore, low-sodium salts also promoted protein degradation and increased the content of free amino acids in dry-cured meat, especially in SM. Principal component analysis (PCA) showed that the low-sodium salts containing Mg2+ were conducive to improving the quality of dry-cured meat products. Therefore, low-sodium salts enriched with Mg2+ become a desirable low-sodium curing agent for achieving salt reduction in dry-cured meat products.

Exploring core microbiota responsible for the production of volatile flavor compounds during the traditional fermentation of Koumiss

This study aimed to explore the core microbiota involved in the production of volatile flavor compounds during the fermentation of traditional Koumiss. Microbiological analysis based on high-throughput sequencing (HTS) demonstrated that Lactobacillus, Lactococcus, Acetobacter, Streptococcus, Serratia, and Leuconostoc bacteria as well as Kazachstania, Kluyveromyces, Trichosporonaceae, Pichia, and Candida fungus were the predominant genera during the traditional fermentation process. A total of 112 volatile compounds were identified in fresh mare's milk and during the simulation of the traditional brewing process. Heatmaps and Cluster Analysis revealed that the flavor formation of Koumiss is largely determined by the types and contents of acids, esters, and alcohols. Furthermore, the correlations between microbiota succession and volatile flavor dynamics were explored through bidirectional orthogonal partial least squares (O2PLS) based correlation analysis. Four bacterial genera (Lactobacillus, Acetobacter, Lactococcus, Pseudomonas), and two fungal genera (Kazachstania, and Candida) were determined as the core microbiota for production of the main volatile flavor compounds of Koumiss. The information provided in this study is beneficial in understanding the fermentation mechanism of traditional Koumiss, and to provide a theoretical basis and quality control guidance for the semi-industrial or industrial production of Koumiss.

Can Interspecies Hybrid Zygosaccharomyces rouxii Produce an Allohaploid Gamete?

In soy sauce manufacturing, Candida versatilis plays a role in the production of volatile flavor compounds, such as volatile phenols, but limited accessible information on its genome has prevented further investigation regarding aroma production and breeding. Although the draft genome sequence data of two strains of C. versatilis have recently been reported, these strains are not similar to each other. Here, we reassess the draft genome sequence data for strain t-1, which was originally reported to be C. versatilis, and conclude that strain t-1 is most probably not C. versatilis but a gamete of hybrid Zygosaccharomyces rouxii Phylogenetic analysis of the D1/D2 region of the 26S ribosomal DNA (rDNA) sequence indicated that strain t-1 is more similar to the genus Zygosaccharomyces than to C. versatilis Moreover, we found that the genome of strain t-1 is composed of haploid genome content and divided into two regions that show approximately 100% identity with the T or P subgenome derived from the natural hybrid Zygosaccharomyces rouxii, such as NBRC110957 and NBRC1876. We also found a chromosome crossing-over signature in the scaffolds of strain t-1. These results suggest that strain t-1 is a gamete of the hybrid Z. rouxii, generated by either meiosis or chromosome loss following reciprocal translocation between the T and P subgenomes. Although it is unclear why strain t-1 was misidentified as C. versatilis, the genome of strain t-1 has broad implications for considering the evolutionary fate of an allodiploid.IMPORTANCE In yeast, crossing between different species sometimes leads to interspecies hybrids. The hybrid generally cannot produce viable spores because dissimilarity of parental genomes prevents normal chromosome segregation during meiotic division, leading to a dead end. Thus, only a few natural cases of homoploid hybrid speciation, which requires mating between 1n gametes of hybrids, have been described. However, a recent study provided strong evidence that homoploid hybrid speciation is initiated in natural populations of the budding yeast, suggesting the potential presence of viable 1n gametes of hybrids. The significance of our study is finding that the strain t-1, which had been misidentified as Candida versatilis, is a viable 1n gamete derived from hybrid Zygosaccharomyces rouxii.

Control of oxidation-reduction potential during Cheddar cheese ripening and its effect on the production of volatile flavour compounds.

In cheese, a negative oxidation-reduction (redox) potential is required for the stability of aroma, especially that associated with volatile sulphur compounds. To control the redox potential during ripening, redox agents were added to the salted curd of Cheddar cheese before pressing. The control cheese contained only salt, while different oxidising or reducing agents were added with the NaCl to the experimental cheeses. KIO3 (at 0·05, 0·1 and 1%, w/w) was used as the oxidising agent while cysteine (at 2%, w/w) and Na2S2O4 (at 0·05 and 0·1%, w/w) were used as reducing agents. During ripening the redox potential of the cheeses made with the reducing agents did not differ significantly from the control cheese (E h ≈ -120 mV) while the cheeses made with 0·1 and 0·05% KIO3 had a significantly higher and positive redox potential in the first month of ripening. Cheese made with 1% KIO3 had positive values of redox potential throughout ripening but no starter lactic acid bacteria survived in this cheese; however, numbers of starter organisms in all other cheeses were similar. Principal component analysis (PCA) of the volatile compounds clearly separated the cheeses made with the reducing agents from cheeses made with the oxidising agents at 2 month of ripening. Cheeses with reducing agents were characterized by the presence of sulphur compounds whereas cheeses made with KIO3 were characterized mainly by aldehydes. At 6 month of ripening, separation by PCA was less evident. These findings support the hypothesis that redox potential could be controlled during ripening and that this parameter has an influence on the development of cheese flavour.

Co-culturing of Pichia guilliermondii enhanced volatile flavor compound formation by Zygosaccharomyces rouxii in the model system of Thai soy sauce fermentation

The roles of salt-tolerant yeasts such as Zygosaccharomyces rouxii, Candida versatilis, and Candida etchellsii in the production of volatile flavor compounds (VFCs) in soy sauce fermentation have been well documented. However, the knowledge of VFC production by other salt-tolerant yeasts is still limited. In this work, the roles of Z. rouxii and Pichia guilliermondii strains in VFC production were investigated in moromi medium as a model system for soy sauce fermentation. Inoculation of a single culture of either Z. rouxii or P. guilliermondii as well as co-cultures of these two yeasts into moromi medium showed increased numbers of viable yeast at around 0.7 to 1.9 log CFU/mL after 7days of cultivation at 30°C. During cultivation, both single and co-cultures displayed survival over a 7-day time period, compared with the controls (no culture added). Overall, yeast inoculation enhanced the production of VFCs in the moromi media with higher amounts of ethanol, alcohols, furanones, esters, aldehyde, acid, pyrone and phenols, known as important characteristic flavor compounds in soy sauce. Moreover, the co-culture produced more alcohols, furanones, esters, maltol and benzoic acid than the single culture of Z. rouxii.

Biochemistry of cheese ripening

Rennet‐coagulated cheeses are ripened for periods ranging from about two weeks to two or more years depending on variety. During ripening, microbiological and biochemical changes occur that result in the development of the flavour and texture characteristic of the variety. Biochemical changes in cheese during ripening may be grouped into primary (lipolysis, proteolysis and metabolism of residual lactose and of lactate and citrate) or secondary (metabolism of fatty acids and of amino acids) events. Residual lactose is metabolized rapidly to lactate during the early stages of ripening. Lactate is an important precursor for a series of reactions including racemization, oxidation or microbial metabolism. Citrate metabolism is of great importance in certain varieties. Lipolysis in cheese is catalysed by lipases from various source, particularly the milk and cheese microflora, and, in varieties where this coagulant is used, by enzymes from rennet paste. Proteolysis is the most complex biochemical event that occurs during ripening and is catalysed by enzymes from residual coagulant, the milk (particularly plasmin) and proteinases and peptidases from lactic acid bacteria and, in certain varieties, other microorganisms that are encouraged to grow in or on the cheese. Secondary reactions lead to the production of volatile flavour compounds and pathways for the production of flavour compounds from fatty acids and amino acids are also reviewed.

Volatile flavour compounds in suspension culture of Agastache rugosa Kuntze (Korean mint)

AbstractFor the production of volatile flavour compounds from Agastache rugosa Kuntze (Korean mint) suspension culture, callus was obtained from the leaves of A rugosa. Cell growth of A rugosa suspension culture was improved when cells were cultivated in Murashige and Skoog medium supplemented with 50 g l−1 sucrose and 1 mg l−1 2,4‐dichlorophenoxyacetic acid. Volatiles were isolated from a 15‐day‐old suspension culture by liquid–liquid continuous extraction and identified by gas chromatography/mass spectrometry. 3‐Hydroxy‐2‐butanone was the most abundant compound, followed by 2,4,5‐trimethyl‐3‐oxazoline, 1,2,4‐trimethylbenzene and 1,3‐butanediol. However, the volatile profile of the suspension culture was totally different from that of the intact plant. Fourteen aroma‐active compounds were detected by aroma extract dilution analysis. The most potent aroma‐active compounds representing characteristic aroma of A rugosa suspension culture were 2,3‐butanedione (buttery/cheese), (E,Z)‐2,6‐nonadienal (cucumber/melon) and (E,Z)‐2,6‐nonadien‐1‐ol (cucumber/sweet). Some alcohols and unknown compounds are thought to contribute to the wine‐like aroma characteristics of A rugosa suspension culture. Through a time course study, A rugosa suspension culture was revealed to have an inverse relationship between cell growth and flavour production.© 2001 Society of Chemical Industry

Volatile flavour compounds from oyster mushroom (Pleurotus florida) in submerged culture

The flavour extract from the mycelial pellets of oyster mushroom (Pleurotus florida) grown in submerged culture was isolated by simultaneous distillation and solvent extraction under reduced pressure. Nineteen volatile flavour compounds were identified after analysing the extract by capillary gas chromatography. Among the most abundant compounds were anisaldehyde, 3-methyl-1-butanol, 3-methyl-1-propanol, benzaldehyde and 1-octen-3-one. The flavour profile from P. florida in submerged culture was found to be significantly different from that of mushrooms grown on natural substrate. The effect of addition of precursors like phenylalanine, linoleic acid and linolenic acid on production of volatile flavour compounds by oyster mushroom in submerged culture is discussed. Copyright © 2000 John Wiley & Sons, Ltd.

Effect of processing on flavor precursor amino acids and volatiles of sesame paste (tehina)

AbstractThe content of flavor precursor free amino acids in dehulled sesame seeds, subjected to roasting (R), steaming (S), roasting plus steaming (RS) and microwaving (M), was determined and compared with those of the raw (RW) seeds. R, RS, and S had major effects in reducing the content of free amino acids from 2360 µg/g to 582, 795 and 884 µg/g, respectively; M had no effect on the content of free amino acids. Meanwhile, flavor volatiles of the raw and processed seeds were compared by means of a dynamic headspace analyzer/gas chromatograph‐mass spectrometer. Volatiles of RW seeds contained 85 compounds, whereas under the analytical conditions employed, seeds subjected to R, RS, S, and M had 117, 97, 93 and 87 compounds, respectively. Among volatiles identified in the RW seeds were 36 hydrocarbons, 8 aldehydes, 4 ketones, 8 alcohols, 2 acids, 2 esters, and 1 pyrazine. The only pyrazine identified in the RW seeds was 2,5‐dimethylpyrazine. Pyrazines, generally recognized as contributors to the roasted aroma of foods, were more numerous (10 in R, 6 in RS, 2 in S, and 2 in M) and prevalent (8.71% in R, 2.97% in RS, 2.04% in S, 0.53% in M, and 0.25% in RW) in the volatiles of processed sesame seeds. The chemical nature of pyrazines also depended on the process employed. Multivariant analysis indicated a highly negative correlation between the loss of free amino acids and production of volatile flavor compounds in the R and RS samples, while the M sample remained unchanged. Furthermore, both R and RS seeds contained dimethyl sulfide and dimethyl disulfide, whereas no sulfur‐containing compounds were present in other samples. Of the processed seeds, the flavors of R and RS samples were considered as acceptable, and the flavor intensity of the former was deemed stronger than that of the latter by the experimenters.

Influence of Wheat Flour Type on the Production of Flavour Compounds in Wheat Sourdoughs

Abstract The influence of wheat flour type on the production of flavour compounds in wheat sourdoughs was investigated in sourdoughs fermented with four strains of lactic acid bacteria. The acidification of the sourdoughs and the production of lactic acid were influenced mainly by the flour type, with most lactic acid produced in sourdoughs made from low-grade flour and wholemeal flours. The production of volatile flavour compounds, including acetic acid, in the sourdoughs depended primarily on the starter culture used. An interaction between the starter culture and the flour type was observed for some of the flavour compounds, however. The flour type had a significant effect on the production of ethyl acetate and ethanol in sourdoughs fermented with heterofermentative cultures, with the highest amounts detected in sourdoughs made from wholemeal flour and low-grade flour.

Headspace flavour compounds produced by yeasts and lactobacilli during fermentation of preferments and bread doughs

Production of volatile flavour compounds during fermentation with pure cultures of Saccharomyces cerevisiae and Candida guilliermondii, Lactobacillus plantarum have been investigated, using wheat doughs and several preferments as substrates. For yeast, preferments consisted of 10% (w/v) glucose, maltose and sucrose solutions, whereas for lactobacilli they consisted of supplemented and unsupplemented (3% and 10% (w/v)) glucose solutions, and a 10% (w/v) wheat flour slurry. Seven volatile compounds (acetaldehyde, acetone, ethyl acetate, ethanol, hexanal + isobutyl alcohol, and propanol) were detected when using yeasts. All these compounds, except propanol, appeared for all the substrates assayed, with ethanol as the predominant component. Generally, S. cerevisiae produced higher amounts of the different components than C. guilliermondii. Both yeasts produced larger amounts of volatile flavour compounds during fermentation in glucose and sucrose solutions than in maltose or wheat dough. In general the yeasts examined produced more flavour components than the lactobacilli. For the lactobacilli the highest number of volatile compounds were observed for substrates containing flour.

Production of Monoterpenes in Liquid Cultures by the YeastAmbrosiozyma monospora1

The production of volatile flavour compounds was studied during liquid culture cultivation of two Ambrosiozyma monospora v. d. Walt strains in defined medium containing glucose as carbon source. Linalool, α-terpineol, citronellol, and geraniol are the main constituents of the aroma concentrate, which have been identified by GC and GC/MS.

Production of volatile flavor compounds in ultrahigh-temperature processed milk during aseptic storage

Production of volatile flavor compounds in ultrahigh-temperature processed milk during aseptic storage