scholarly journals Screening of Indigenous Yeast From Different Ecological Region of Kathmandu Valley and Its Application in Wine Production

2020 ◽  
Vol 7 ◽  
pp. 104-114
Author(s):  
Bipanab Rajopadhyaya ◽  
Bipana Maharjan ◽  
Roshani Maharjan ◽  
Amrit Acharya
Keyword(s):  
Ethanol Fermentation ◽  
Grape Juice ◽  
Titratable Acidity ◽  
Wine Yeast ◽  
Kathmandu Valley ◽  
Wine Quality ◽  
Wine Production ◽  
Microscopic Appearance ◽  
Fermentative Capacity ◽  
New Yeast

Objectives: The aim of the study was to isolate and screen the potent yeast from the air for implementing new yeast in wine fermentation. Methods: In this study, 35 air samples collected in sterile grape juice in glass jar and left over for four days exposure for the growth of yeast from different locations around the Kathmandu Valley. Yeasts were screened by culturing on selective Ethanol Sulfite Agar (ESA) media at 30°C for 2-3 days in Microbiology Lab of Pinnacle College. Yeast isolates were characterized based on colony morphology, microscopic characteristics, Fermentative capacity, Hydrogen sulfide production. Selected yeast isolates were subjected to ethanol fermentation and tested for alcohol tolerance capacity. Wine quality was assessed by sensory evaluation. Results: Of 35 samples, only 20 yeast isolates were isolated. Among these isolates, the variation in colony characteristics along with oval and ellipsoidal microscopic appearance was observed. All the isolates were able to ferment major sugars such as glucose, fructose and sucrose, but few could not ferment galactose and maltose, while none-fermented lactose and xylose. Here, isolates showing no H2S (L29, L34) and mild H2S producer (isolate L31) were subjected to ethanol fermentation. Also, Comparative analysis was made by using commercial standard wine yeast (STAN). Rapid fermentation of grape juice with initial 21 0Brix was observed in L31 isolate, which produced 12.99% v/v alcohol with titratable acidity (TA) 5.25 g/L, followed by L29 strain with 11.99%v/v alcohol and 4.5 g/L TA which were higher than STAN (10.99% alcohol). These isolates specified as Ethanol tolerance up to 13%v/v, while none of them were able to grow at 15% v/v ethanol concentration and 45°C temperature. However, significant growth was observed at pH 3 along with sugar tolerance capacity at 30 0Brix. The wine produced by these isolates was found to be remarkably different among each other. While the sensory analysis of wine led to isolate L31 being congenial to tasters. Conclusion: L31 isolate was found to be efficient and advantageous for wine production indicating its industrial application.  

scholarly journals Wine Yeast Terroir: Separating the Wheat from the Chaff—for an Open Debate

2020 ◽  
Vol 8 (5) ◽  
pp. 787 ◽  
Author(s):  
Hervé Alexandre
Keyword(s):  
Microbial Communities ◽  
High Throughput Sequencing ◽  
Abiotic Factors ◽  
Soil Microbial Communities ◽  
Consumer Preference ◽  
Wine Yeast ◽  
Wine Quality ◽  
Critical Feature ◽  
Wine Production ◽  
Sequencing Technologies

Wine terroir is characterized by a specific taste and style influenced by the cultivar of the fermented grapes, geographical factors such as the vineyard, mesoclimate, topoclimate, and microclimate, soil geology and pedology, and the agronomic approach used. These characteristics together define the concept of “terroir”. Thus, regional distinctive flavors in wine have been the subject of many studies aimed at better understanding the link between the wine and the vineyard. Indeed, the identification of key environmental elements involved in the regional variation of grape and wine quality characteristics is a critical feature for improving wine production in terms of consumer preference and economic appreciation. Many studies have demonstrated the role of abiotic factors in grape composition and consequently in wine style. Biotic factors are also involved such as grape microbial communities. However, the occurrence and effects of region-specific microbiota in defining wine characteristics are more controversial issues. Indeed, several studies using high throughput sequencing technologies have made it possible to describe microbial communities and revealed a link between grape must and soil microbial communities, and the geography of the territory. Based on these observations, the concept of “microbial terroir” emerged. However, this concept has been subject to contradictory studies. The aim of this opinion article is to take a step back and examine in perspective the concept of microbial terroir, by comparing numerous data from different studies and providing arguments in favor of or against this concept to stimulate discussion and point out that experimental research is still needed to study the contribution of this assembly of microorganisms to the final product and to support or refute the concept.

scholarly journals Chemical and Physical Implications of the Use of Alternative Vessels to Oak Barrels during the Production of White Wines

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 554
Author(s):  
Mariona Gil i Cortiella ◽  
Cristina Ubeda ◽  
José Ignacio Covarrubias ◽  
V. Felipe Laurie ◽  
Álvaro Peña-Neira
Keyword(s):  
Stainless Steel ◽  
Inorganic Compounds ◽  
Grape Juice ◽  
Titratable Acidity ◽  
White Wine ◽  
Wine Production ◽  
Concrete Walls ◽  
Sauvignon Blanc ◽  
Steel Tanks ◽  
Oak Barrels

Recently, the use of alternative vessels to oak barrels during winemaking has become increasingly popular, but little is known about their impact on the chemical composition of the resulting wines. To address this issue, a Sauvignon Blanc wine was elaborated from the same grape juice by using cylindrical stainless-steel tanks, oval-shaped concrete vessels, oval-shaped polyethylene vessels, and clay jars in triplicate. Each vessel was used for alcoholic fermentation and the aging of wines over its own lees. Wines elaborated in concrete vessels showed the highest pH and the lowest titratable acidity, most likely related to the observed release of inorganic compounds from the concrete walls. Little effect of the vessels was seen on the wine color and phenolic composition. Wines elaborated in clay jars showed the highest turbidity and the highest content of soluble polysaccharides, while those made using cylindrical stainless-steel tanks showed the highest content of volatile compounds. Despite the observed differences, all of the vessels tested seem suitable for white wine production since every wine showed chemical features that corresponded with the quality standards of Sauvignon Blanc wines.

scholarly journals An Overview of CRISPR-Based Technologies in Wine Yeasts to Improve Wine Flavor and Safety

Fermentation ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 5
Author(s):  
Alice Vilela
Keyword(s):  
Genetic Engineering ◽  
Wine Yeast ◽  
Wine Yeasts ◽  
Wine Quality ◽  
Yeast Strains ◽  
Off Flavors ◽  
Natural Isolates ◽  
The Stability ◽  
Wine Flavor ◽  
New Yeast

Modern industrial winemaking is based on the use of specific starters of wine strains. Commercial wine strains present several advantages over natural isolates, and it is their use that guarantees the stability and reproducibility of industrial winemaking technologies. For the highly competitive wine market with new demands for improved wine quality and wine safety, it has become increasingly critical to develop new yeast strains. In the last decades, new possibilities arose for creating upgraded wine yeasts in the laboratory, resulting in the development of strains with better fermentation abilities, able to improve the sensory quality of wines and produce wines targeted to specific consumers, considering their health and nutrition requirements. However, only two genetically modified (GM) wine yeast strains are officially registered and approved for commercial use. Compared with traditional genetic engineering methods, CRISPR/Cas9 is described as efficient, versatile, cheap, easy-to-use, and able to target multiple sites. This genetic engineering technique has been applied to Saccharomyces cerevisiae since 2013. In this review, we aimed to overview the use of CRISPR/Cas9 editing technique in wine yeasts to combine develop phenotypes able to increase flavor compounds in wine without the development of off-flavors and aiding in the creation of “safer wines.”

scholarly journals Nitrogen Preferences during Alcoholic Fermentation of Different Non-Saccharomyces Yeasts of Oenological Interest

2020 ◽  
Vol 8 (2) ◽  
pp. 157 ◽  
Author(s):  
Helena Roca-Mesa ◽  
Sonia Sendra ◽  
Albert Mas ◽  
Gemma Beltran ◽  
María-Jesús Torija
Keyword(s):  
Amino Acids ◽  
Inorganic Nitrogen ◽  
Wine Yeast ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Positive Contribution ◽  
Wine Quality ◽  
Fermentative Capacity ◽  
Nitrogen Consumption ◽  
Saccharomyces Yeasts

Non-Saccharomyces yeasts have long been considered spoilage microorganisms. Currently, oenological interest in those species is increasing, mostly due to their positive contribution to wine quality. In this work, the fermentative capacity and nitrogen consumption of several non-Saccharomyces wine yeast (Torulaspora delbrueckii, Lachancea thermotolerans, Starmerella bacillaris, Hanseniaspora uvarum, and Metschnikowia pulcherrima) were analyzed. For this purpose, synthetic must with three different nitrogen compositions was used: a mixture of amino acids and ammonium, only organic or inorganic nitrogen. The fermentation kinetics, nitrogen consumption, and yeast growth were measured over time. Our results showed that the good fermentative strains, T. delbrueckii and L. thermotolerans, had high similarities with Saccharomyces cerevisiae in terms of growth, fermentation profile, and nitrogen assimilation preferences, although L. thermotolerans presented an impaired behavior when only amino acids or ammonia were used, being strain-specific. M. pulcherrima was the non-Saccharomyces strain least affected by the nitrogen composition of the medium. The other two poor fermentative strains, H. uvarum and S. bacillaris, behaved similarly regarding amino acid uptake, which occurred earlier than that of the good fermentative species in the absence of ammonia. The results obtained in single non-Saccharomyces fermentations highlighted the importance of controlling nitrogen requirements of the wine yeasts, mainly in sequential fermentations, in order to manage a proper nitrogen supplementation, when needed.

scholarly journals Potentials of Saccharomyces cerevisiae Y10 as a Starter Culture for Wine Production from Date Palm (Phoenix dactylifera) Fruits

2021 ◽  
Vol 6 (1) ◽  
pp. 227-232
Author(s):  
A. J. Adeleke ◽  
◽  
J. U. Ewansiha ◽  
B. T. Thomas ◽  
A. S. Shitu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Sugarcane Bagasse ◽  
Proximate Composition ◽  
Date Palm ◽  
Starter Culture ◽  
Titratable Acidity ◽  
Wine Yeast ◽  
Wine Production ◽  
Palm Fruit ◽  
Agricultural Produce

A considerable quantity of agricultural produce in Nigeria gets spoilt due to lack of storage facilities and poor storage conditions. An example of such agricultural produce is date palm which is readily available in the northern parts of Nigeria. This study aimed at evaluating the potential of Saccharomyces cerevisiae Y10 isolated from decomposed sugarcane bagasse to produce wine using date palm fruits. The yeast was isolated using yeast extract peptone dextrose agar and was identified by molecular methods. Fermentation of date palm fruit juice was carried out anaerobically for 20 days during which physicochemical parameters and proximate composition were determined using standard methods. The yeast was identified as Saccharomyces cerevisiae Y10 with accession number MG321589. Analysis of physicochemical properties showed that pH dropped from 5.4 to 3.6, titratable acidity increased from 0.25 to 0.71% and specific gravity decreased from 1.1 to 1.01. Proximate composition of produced wine gave low total reducing sugar and low protein of 0.11 and 0.44% respectively and the final alcohol content was 10.4% at the 20th day of fermentation. This study has shown that Saccharomyces cerevisiae Y10 which was isolated from decaying sugarcane bagasse sample has the potential to be used as starter culture for fermentation of date palm for wine production. Keywords: Date palm, Saccharomyces cerevisiae Y10, wine, yeast, alcoholic fermentation

scholarly journals Effect of Pure Culture of Yeast on the Characteristics of Wine Quality

2021 ◽  
Author(s):  
Ketevan Zakaidze ◽  
Elene Salia ◽  
Nino Vephkhishvili
Keyword(s):  
Pure Culture ◽  
Alcoholic Fermentation ◽  
Grape Juice ◽  
Wine Yeast ◽  
Biologically Active ◽  
Chemical Transformations ◽  
Active Components ◽  
Wine Quality ◽  
High Quality ◽  
Distinguished Varieties

Saperavi is one of the most distinguished varieties of wine among the grape varieties widely spread in Georgia. Along with the grapevine variety, the pure culture of yeast also plays a crucial role in producing high quality wine material, because wine is the product of the viability of yeast. All chemical transformations that take place during the alcoholic fermentation, as a result of which the grape juice is turned into a qualitatively new product, i.e. wine, are carried out by direct involvement of the ferment system of the yeast. In addition, in the process of viability, the yeast produces not only the primary products of fermentation (ethanol and carbon dioxide), but also a number of organic substances (secondary and by -products) that play a big role in forming the wine taste and aroma, as well as the antioxidants, which provide its sustainability, and some biologically active components. Therefore, selecting the pure culture of wine yeast and directing the alcoholic fermentation correctly with the use of it, will guarantee to obtain a high quality product.

Fermentative capacity of residual wine yeast

2005 ◽  
Vol 34 (2) ◽  
pp. 187-191 ◽  
Author(s):  
L. Oprean ◽  
N. Darie ◽  
E. Gaspar
Keyword(s):  
Wine Yeast ◽  
Fermentative Capacity

scholarly journals How can remote sensing techniques help monitoring the vine and maximize the terroir potential?

2018 ◽  
Vol 50 ◽  
pp. 02007
Author(s):  
Cecile Tondriaux ◽  
Anne Costard ◽  
Corinne Bertin ◽  
Sylvie Duthoit ◽  
Jérôme Hourdel ◽  
...  
Keyword(s):  
Remote Sensing ◽  
High Resolution ◽  
Satellite Images ◽  
Sampling Strategy ◽  
Wine Quality ◽  
Wine Production ◽  
Spectral Bands ◽  
High Resolution Satellite Images ◽  
Remote Sensing Techniques ◽  
Set Up

In each winegrowing region, the winegrower tries to value its terroir and the oenologists do their best to produce the best wine. Thanks to new remote sensing techniques, it is possible to implement a segmentation of the vineyard according to the qualitative potential of the vine stocks and make the most of each terroir to improve wine quality. High resolution satellite images are processed in several spectral bands and algorithms set-up specifically for the Oenoview service allow to estimate vine vigour and a heterogeneity index that, used together, directly reflect the vineyard oenological potential. This service is used in different terroirs in France (Burgundy, Languedoc, Bordeaux, Anjou) and in other countries (Chile, Spain, Hungary and China). From this experience, we will show how remote sensing can help managing vine and wine production in all covered terroirs. Depending on the winegrowing region and its specificities, its use and results present some differences and similarities that we will highlight. We will give an overview of the method used, the advantage of implementing field intra-or inter-selection and how to optimize the use of amendment and sampling strategy as well as how to anticipate the whole vineyard management.

scholarly journals THE ROLE OF MINERAL NUTRITION ON YIELDS AND FRUIT QUALITY IN GRAPEVINE, PEAR AND APPLE

2015 ◽  
Vol 37 (4) ◽  
pp. 1089-1104 ◽  
Author(s):  
GUSTAVO BRUNETTO ◽  
GEORGE WELLINGTON BASTOS DE MELO ◽  
MORENO TOSELLI ◽  
MAURIZIO QUARTIERI ◽  
MASSIMO TAGLIAVINI
Keyword(s):  
Fruit Quality ◽  
Skin Color ◽  
N Uptake ◽  
Maximum Yield ◽  
Grape Juice ◽  
Fruit Trees ◽  
N Availability ◽  
Wine Quality ◽  
Fruit Skin ◽  
Soluble Solid

ABSTRACT Fertilization of temperate fruit trees, such as grapevine ( Vitis spp.), apple ( Malus domestica), and pear ( Pyrus communis) is an important tool to achive maximum yield and fruit quality. Fertilizers are provided when soil fertility does not allow trees to express their genetic potential, and time and rate of application should be scheduled to promote fruit quality. Grapevine berries, must and wine quality are affected principally by N, that regulate the synthesis of some important compounds, such as anthocyanins, which are responsible for coloring of the must and the wine. Fermenation of the must may stop in grapes with low concentration of N because N is requested in high amount by yeasts. An N excess may increase the pulp to peel ratio, diluting the concentration of anthocyanins and promoting the migration of anthocyanins from berries to the growing plant organs; a decrease of grape juice soluble solid concentration is also expected because of an increase in vegetative growth. Potassium is also important for wine quality contributing to adequate berry maturation, concentration of sugars, synthesis of phenols and the regulation of pH and acidity. In apple and pear, Ca and K are important for fruit quality and storage. Potassium is the most important component of fruit, however, any excess should be avoided and an adequate K:Ca balance should be achieved. Adequate concentration of Ca in the fruit prevents pre- and post-harvest fruit disorders and, at the same time, increases tolerance to pathogens. Although N promotes adequate growth soil N availability should be monitored to avoid excessive N uptake that may decrease fruit skin color and storability.

scholarly journals Physical, Chemical-physical and chemical characterization of must and integral juice in grape cultivars

2017 ◽  
Vol 10 (3) ◽  
pp. 1 ◽  
Author(s):  
I. T. S. Viana ◽  
G. V. A. Fonseca ◽  
G. H. Bueno ◽  
J. O. F. Melo
Keyword(s):  
Chemical Characterization ◽  
Grape Juice ◽  
Titratable Acidity ◽  
Mineral Elements ◽  
Flame Emission ◽  
Level Of Significance ◽  
Physical And Chemical ◽  
Grape Cultivars

In recent years there has been an important increase in the production of grape derivatives such as integral grape juice. Thus, it was intended with the accomplishment of this study to evaluate the composition of the grape juice of the grape cultivars: Bordô, Concord e Isabel in the composition of integral grape juice from the Bento Gonçalves-RS. The samples were evaluated for classical analysis:°Brix, pH, titratable acidity, ratio Brix / titratable acidity made through methods, physics, physical chemistry and chemistry. The mineral elements sodium and potassium analyzed by flame emission and color intensity by colorimetry. For the statistical analysis of the data, the Tukey test was applied at the 5% level of significance. The contents of integral grape juice evaluated, SS, A Tand minerals presented according to the legislation, the pH was within the comparative average with other works. The determination of the color demonstrated the need to make cuts.

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