Evaluation of indigenous non-Saccharomyces cider yeasts for use in brewing

Use of non-conventional yeasts for enhancing the sensory quality of craft beer

In recent years, craft beer production has grown significantly, sparking interest in using non-conventional yeasts to produce beers with distinctive flavors. This work investigated the impact of unconventional yeast strains, including Hanseniaspora uvarum YGA34 (EP1), Lachanchea thermotolerans MNF105 (EP2), Candida oleophila YS209 (EP3) and Starmerella lactis-condensi MN412 (EP4), as innovative co-starter cultures alongside the widely used Saccharomyces cerevisiae US-05 . The control trial was inoculated with S. cerevisiae US-05 (TC) alone. For the first time, C. oleophila and St. lactis-condensi have been applied for beer production and also result have been compared with H. uvarum and L. thermotolerans. These strains, selected from high-sugar matrices such as manna and fermented honey by-products, exhibited logarithmic growth cycles of 5-8 during fermentation. Starmerellalactis-condensi MN412 and L.thermotolerans MNF105 efficiently consumed fructose, glucose, and sucrose in beer must before the addition of S. cerevisiae US-05, with L.thermotolerans also effectively consuming maltose. The highest glycerol content (3.36 g/L) was observed in the EP4 trial with St. lactis-condensi MN412. Esters were the dominant volatile compounds in all samples (91.2-237.3 mg/L), with the EP2 trial showing the highest ester content (237.3 mg/L), primarily due to ethyl octanoate (125.5 mg/L). EP2 also had the most favourable sensory profile, excelling in 10 attributes, while other beers showed notable performances. These unconventional yeast strains exhibited significant differences compared to beers brewed with S. cerevisiae alone. Additionally, their application led to an increase in volatile organic compounds. In conclusion, novel yeast strains isolated from high-sugar matrices showed excellent technological properties, making them promising co-starters and starter in innovative craft beer production.

Exploring the potentials of indigenous Saccharomyces cerevisiae and Pichia kudriavzevii for enhancing flavour and aromatic characteristics in apricot wines

In this study, we investigated the oenological performance of key yeast populations previously identified from apricot wine fermentation, aiming to obtain indigenous starters suitable for apricot wine production. Twenty-one isolates were characterized physiologically, and two isolates each of Saccharomyces cerevisiae and Pichia kudriavzevii were selected for laboratory-scale fermentations. Results showed that S. cerevisiae S9 exhibited significantly higher sugar consumption than S2 and CECA strains, with the former demonstrating a fructophilic character. Mixed fermentations of P. kudriavzevii N11 and N12 resulted in lower citric acid content (decreasing by 12-25 %) and higher glycerol levels (increasing by 12-47 %) compared to pure fermentation. In the mixed fermentation, indigenous S. cerevisiae species supported the survival of P. kudriavzevii, effectively enhancing the fruity esters and terpenes content of apricot wine. This study provides technical support for screening specialized starters for apricot wine production.

Application of Non-Saccharomyces Yeast for the Production of Low-Alcohol Beer

In recent years, demand for low-alcohol and alcohol-free beers has been rising. Of the many methods of producing such beers, many have expensive implementation requirements or drawbacks in terms of beer quality. The exploration of non-Saccharomyces yeast species presents a promising opportunity to overcome these challenges. These yeasts, with their diverse metabolic capabilities and unique flavor profiles, offer the potential to create innovative and flavorful low-alcohol beers. The study investigates the feasibility of using selected non-Saccharomyces yeasts for brewing low-alcohol beers, focusing on fermentation kinetics, physicochemical parameters, and the sensory attributes of the final product. The evaluated yeast species were Kluyveromyces lactis MG971263, Metschnikowia pulcherrima MG971247 and MG971250, Torulaspora delbrueckii MG971248, Wickerhamomyces anomalus MG971261, and W. onychis MG971246. Two strains of Saccharomyces cerevisiae were used as a control. The results of the study show that selected non-Saccharomyces yeast species might be used to produce low-alcohol beers. The non-Saccharomyces yeast allowed the researchers to obtain beers with an alcohol content in the range of 0.5-1.05%, while the control beer brewed with US-05 had an alcohol content of 3.77%. Among the evaluated strains, the strains M. pulcherrima MG971250 and T. delbrueckii MG971248 were found to be rated better in a sensory evaluation than the brewed and low-alcohol strains of S. cerevisiae.

Unconventional raw materials used in beer and beer-like beverages production: Impact on metabolomics and sensory profile

Beer is the third most consumed beverage in the world, trailing only water and tea but ranking first among alcoholic beverages. In recent years, producers and researchers have shown a growing interest in brewing diversification and innovation, due to of the widespread consumption of beer. In order to create beers and beer-like products with unique and consumer-pleasing characteristics, the use of unconventional raw materials has become a subject of intensive research. The purpose of this paper is to identify, evaluate and summarize the findings of all relevant unconventional raw materials used in relevant scientific studies, as well as the effect on the metabolomics of beer and beer-like beverages.For the enhancement of beer characteristics, the production process may involve the use of an extremely diverse variety of unconventional raw materials that are not included on thelist of usual ingredients for the beer industry. However, the general trend is to use locally available ingredients as well as functional ingredients. Twoof the most studied functional characteristics involve phenolic compounds and antioxidant activity, which is why the fruit is by far the most commonly used adjunct category, as fruits are particularly important sources of polyphenols and antioxidants. Other uncommon adjuncts used in brewing includeplants, starch sources, spices or even propolis. Moreover, unconventional raw materials are used to enhance the sensory profile by create new characteristics such as new tastes and flavors, accentuation of the cooling sensation or even increasing acceptability among potential consumers, who do not appreciate traditional beers due to their specific characteristics.

Exploring future applications of the apiculate yeast Hanseniaspora

As a metaphor, lemons get a bad rap; however the proverb 'if life gives you lemons, make lemonade' is often used in a motivational context. The same could be said of Hanseniaspora in winemaking. Despite its predominance in vineyards and grape must, this lemon-shaped yeast is underappreciated in terms of its contribution to the overall sensory profile of fine wine. Species belonging to this apiculate yeast are known for being common isolates not just on grape berries, but on many other fruits. They play a critical role in the early stages of a fermentation and can influence the quality of the final product. Their deliberate addition within mixed-culture fermentations shows promise in adding to the complexity of a wine and thus provide sensorial benefits. Hanseniaspora species are also key participants in the fermentations of a variety of other foodstuffs ranging from chocolate to apple cider. Outside of their role in fermentation, Hanseniaspora species have attractive biotechnological possibilities as revealed through studies on biocontrol potential, use as a whole-cell biocatalyst and important interactions with Drosophila flies. The growing amount of 'omics data on Hanseniaspora is revealing interesting features of the genus that sets it apart from the other Ascomycetes. This review collates the fields of research conducted on this apiculate yeast genus.

Contaminated Perry in Patagonia Argentina: A Case Study

Perry is a beverage obtained by fermentation of pear juice, popular in the North Hemisphere. In Argentina it is an emerging market, particularly in the Patagonian region. The aim of this work is to describe and to evaluate the spoilage yeasts associated to six perry samples showing signs of microbiological contamination from a local craft perry company in North Patagonian region. Eighteen yeasts were isolated from four of the six perry samples where Brettanomyces custersianus, Brettanomyces bruxellensis and Zygosaccharomyces parabailii were identified. The growth capacity of these isolates in the presence of antimicrobial agents (sulfite and potassium sorbate) was analyzed in solid media. Growth parameters in sterile perry must was evaluated and the production of undesirable compounds were evaluated, products were characterized in terms of their aromatic and physicochemical features. The yeasts Z. parabailii NPCC1791 was able to grow on plates containing sulfite concentrations of up to 4 mM and produced high methanol concentrations in perry. Additionally, B. bruxellensis NPPC1792 was able to produce methanol as well as high concentrations of volatile phenols including 4-ethylphenol and 4-ethylguaiacol. These results demonstrate the potential of these species as perry contaminants. Given the lack of studies describing the contaminating yeasts in perry production, this work represents the first report about perry spoilage yeasts in Argentina, with this knowledge, control strategies can be developed to prevent microbiological contamination and minimize product loss.

A comparative study of the effect of bacteria and yeasts communities on inoculated and spontaneously fermented apple cider

Understanding bacteria and yeasts communities can reduce unpredictable changes of apple cider. In this study, apple juice inoculated with Saccharomyces cerevisiae WET 136 and fermented spontaneously were compared, the relationships of bacteria, yeasts, organic acids, and volatiles were analyzed. Results showed that microbial diversity affected the fermentation, organic acids and volatiles in apple ciders. In the first four spontaneous fermentation days, LAB (lactic acid bacteria) multiplied and reached 7.89 lg CFU/mL, and then triggered malolactic fermentation (MLF), leading to malic acid decreased by 3880.52 mg/L and lactic acid increased by 4787.55 mg/L. The citric, succinic and fumaric acids content was 2171.14, 701.51 and 8.06 mg/L lower than that in inoculated cider, respectively. Although the yeasts multiplied during spontaneous fermentation, it did not reach 7.50 lg CFU/mL until the 5th day, which led to a long lag period, as well as later and lower production of acetaldehyde and higher alcohols. The inoculated yeast inhibited LAB, acetic acid bacteria, Rahnella, and non-Saccharomyces. Yeasts were the key to produce citric acid, acetaldehyde and 3-methyl-1-butanol in apple cider; while bacteria were closely related to the formation of lactic acid, acetic acid and ethyl acetate. It suggested that low higher alcohols and acetaldehyde can be realized by selecting yeasts, and Leuconostoc pseudomesenteroides can work as candidate to reduce L-malic and citric acids in apple cider.

The Role of Emergent Processing Technologies in Beer Production

The brewing industry is regarded as a fiercely competitive and insatiable sector of activity, driven by the significant technological improvements observed in recent years and the most recent consumer trends pointing to a sharp demand for sensory enhanced beers. Some emergent and sustainable technologies regarding food processing such as pulsed electric fields (PEF), ultrasound (US), thermosonication (TS), high-pressure processing (HPP), and ohmic heating (OH) have shown the potential to contribute to the development of currently employed brewing methodologies by both enhancing the quality of beer and contributing to processing efficiency with a promise of being more environmentally friendly. Some of these technologies have not yet found their way into the industrial brewing process but already show potential to be embedded in continuous thermal and non-thermal unit operations such as pasteurization, boiling and sterilization, resulting in beer with improved organoleptic properties. This review article aims to explore the potential of different advanced processing technologies for industrial application in several key stages of brewing, with particular emphasis on continuous beer production.

Indigenous Yeasts from Rose Oil Distillation Wastewater and Their Capacity for Biotransformation of Phenolics

The indigenous yeasts associated with the spontaneous fermentation of phenolic-rich rose oil distillation wastewater (RODW) generated after the industrial distillation of rose oil were studied. The ITS-rDNA sequence analysis of the samples collected from RODW fermented at semi-sterile conditions, a waste deposition lagoon and endophytic yeasts isolated from industrially cultivated Rosa damascena suggests that the spontaneous RODW fermentation is caused by yeasts from the genus Cyberlindnera found also as endophytes in the rose flowers. Phylogenetic analysis based on the nucleotide sequences of the translation elongation factor (TEF1α) and 18S- and 26S- rRNA genes further confirmed the taxonomic affiliation of the RODW yeast isolates with the genus Cyberlindnera. The RODW fermentation capacity of a selected set of indigenous yeast isolates was studied and compared with those of common yeast strains. The indigenous yeast isolates demonstrated a superior growth rate, resulting in a nearly double reduction in the phenolic content in the fermented RODW. The indigenous yeasts' fermentation changed the RODW phenolics' composition. The levels of some particular phenolic glycosides decreased through the depletion and fermentation of their sugar moiety. Hence, the relative abundance of the corresponding aglycons and other phenolic compounds increased. The capacity for the biotransformation of RODW phenolics by indigenous yeasts is discussed.

Beer fermentation performance and sugar uptake of Saccharomycopsis fibuligera–A novel option for low-alcohol beer

There is a growing trend for beers with novel flavor profiles, as consumers demand a more diversified product range. Such beers can be produced by using non-Saccharomyces yeasts. The yeast species Saccharomycopsis fibuligera is known to produce exceptionally pleasant plum and berry flavors during brewer’s wort fermentation while its mycelia growth is most likely a technological challenge in industrial-scale brewing. To better understand and optimize the physiological properties of this yeast species during the brewing process, maltose and maltotriose uptake activity trials were performed. These revealed the existence of active transmembrane transporters for maltose in addition to the known extracellular amylase system. Furthermore, a single cell isolate of S. fibuligera was cultured, which showed significantly less mycelial growth during propagation and fermentation compared to the mother culture and would therefore be much more suitable for application on an industrial scale due to its better flocculation and clarification properties. Genetic differences between the two cultures could not be detected in a (GTG)₅ rep-PCR fingerprint and there was hardly any difference in the fermentation process, sugar utilization and flavor profiles of the beers. Accordingly, the characteristic plum and berry flavor could also be perceived by using the culture from the single cell isolate, which was complemented by a dried fruit flavor. A fermentation temperature of 20°C at an original gravity of 10 °P proved to be optimal for producing a low-alcohol beer at around 0.8% (v/v) by applying the S. fibuligera yeast culture from the single cell isolate.

Metabolomics of Non-Saccharomyces Yeasts in Fermented Beverages

Fermented beverages have been consumed for millennia and today support a global industry producing diverse products. Saccharomyces yeasts currently dominate the fermented beverage industry, but consumer demands for alternative products with a variety of sensory profiles and actual or perceived health benefits are driving the diversification and use of non-Saccharomyces yeasts. The diversity of flavours, aromas, and other sensory characteristics that can be obtained by using non-Saccharomyces yeasts in fermentation is, in large part, due to the diverse secondary metabolites they produce compared to conventional Saccharomyces yeast. Here, we review the use of metabolomic analyses of non-Saccharomyces yeasts to explore their impact on the sensory characteristics of fermented beverages. We highlight several key species currently used in the industry, including Brettanomyces, Torulaspora, Lachancea, and Saccharomycodes, and emphasize the future potential for the use of non-Saccharomyces yeasts in the production of diverse fermented beverages.

New Approaches for the Fermentation of Beer: Non-Saccharomyces Yeasts from Wine

Non-Saccharomyces yeasts represent a very attractive alternative for the production of beers with superior sensory quality since they are able to enhance the flavour of beer. Furthermore, they can produce beers with low ethanol content due to the weak fermentative capacity of a large percentage of non-Saccharomyces species. The objective of this study was to evaluate the ability of 34 non-Saccharomyces yeast strains isolated from Madrilenian agriculture to produce a novel ale beer. The non-Saccharomyces yeast strains were screened at two scales in the laboratory. In the first screening, those with undesirable aromas were discarded and the selected strains were analysed. Thirty-three volatile compounds were analysed by GC, as well as melatonin production by HPLC, for the selected strains. Thirteen strains were then fermented at a higher scale in the laboratory for sensory evaluation. Only yeast strains of the species Schizosaccharomyces pombe and Lachancea thermotolerans were able to complete fermentation. Species such as Torulaspora delbrueckii, Metschnikowia pulcherrima, Wickerhamomyces anomalus, Hanseniaspora vineae, and Hanseniaspora guilliermondii could be used both for production of low ethanol beers and co-fermentation with a Saccharomyces yeast to improve the organoleptic characteristics of the beer. In addition, for these strains, the levels of melatonin obtained were higher than the concentrations found for Saccharomyces strains subjected to the same study conditions. The selected strains can be used in future trials to further determine their viability under different conditions and for different purposes.

Maltose-Negative Yeast in Non-Alcoholic and Low-Alcoholic Beer Production

Although beer is a widely used beverage in many cultures, there is a need for a new drinking alternative in the face of rising issues such as health concerns or weight problems. However, non-alcoholic and low-alcoholic beers (NABLAB) still have some sensory problems that have not been fully remedied today, such as “wort-like”/”potato-like” flavours or a lack of aroma. These defects are due to the lack of alcohol (and the lack of the aldehyde-reducing effect of alcohol fermentation), as well as production techniques. The use of new yeast strains that cannot ferment maltose—the foremost sugar in the wort—is highly promising to produce a more palatable and sustainable NABLAB product because production with these yeast strains can be performed with standard brewery equipment. In the scientific literature, it is clear that interest in the production of NABLAB has increased recently, and experiments have been carried out with maltose-negative yeast strains isolated from many different environments. This study describes maltose-negative yeasts and their aromatic potential for the production of NABLAB by comprehensively examining recent academic studies.