scholarly journals Adaptive Laboratory Evolution of Native Torulaspora delbrueckii YCPUC10 With Enhanced Ethanol Resistance and Evaluation in Co-inoculated Fermentation

2020 ◽  
Vol 11 ◽  
Author(s):  
Daniela Catrileo ◽  
Andrea Acuña-Fontecilla ◽  
Liliana Godoy

Torulaspora delbrueckii is a yeast species typically present in the early stages of the fermentation process. T. delbrueckii positively modifies the aromatic properties of wines. However, its contribution to the final quality of the wine is restricted by its low tolerance to ethanol. T. delbrueckii is capable of fermenting and tolerating an ethanol concentration ranging from 7.4% (v/v) to slightly higher than 9% (v/v). For this reason, it cannot complete fermentation, when alcohol reach levels higher than 12% (v/v), limiting their use in the industry. The objective of this work was to obtain new variants of T. delbrueckii with improved resistance to ethanol through adaptive laboratory evolution. Variants capable of tolerating ethanol levels of 11.5% (v/v) were obtained. These presented improved kinetic parameters, and additionally showed an increase in resistance to SO2 in ethanol compared to the original strain. Co-inoculated fermentations were performed with the original strain (FTd/Sc) and with the evolved strain (FTdF/Sc), in addition to a control fermentation using only Saccharomyces cerevisiae EC1118 (FSc). The results obtained show that FTdF/Sc present higher levels of 2-Ethylhexanol, compared to FTd/Sc and FSc. Furthermore, FTdF/Sc presents higher levels of total alcohols, total aldehydes, total phenolic derivatives, and total sulfur compounds with significant differences with FSc. These results provide a T. delbrueckii YCPUC10-F yeast with higher resistance to ethanol, which can be present throughout the fermentation process and be used in co-inoculated fermentations. This would positively impact the performance of T. delbrueckii by allowing it to be present not only in the early stages of fermentation but to remain until the end of fermentation.

2010 ◽  
Vol 67 (5) ◽  
pp. 555-561 ◽  
Author(s):  
Débora Branquinho Garcia ◽  
Gisele Cristina Ravaneli ◽  
Leonardo Lucas Madaleno ◽  
Miguel Angelo Mutton ◽  
Márcia Justino Rossini Mutton

The quality of the raw material defines the industrial potential production. The harvest of raw sugarcane promoted a favorable environment for the increase of Mahanarva fimbriolata (Stål, 1854) pest that affects the plant development. This research was undertaken to evaluate the effects of M. fimbriolata on sugarcane quality and fermentation process. For the technological analysis, four damage levels and two evaluation periods were evaluated, while four fermentation cycles and two evaluation periods were tested for microbiological analysis, with three replications. The determined parameters were Brix (soluble solids), Pol (apparent sucrose), Purity, reducing sugars (RS), total reducing sugars (TRS), Total Acidity, pH and Total Phenolic Compounds in juice. In the fermentation process cellular viability analysis, yeast sprout and bacterial concentration were carried out. The wine was submitted to alcohol content, TRRS (total residual reducing sugars) and fermentation efficiency. The treatment with 60% of damage steams exhibited the lowest averages of Brix, Pol, Purity and TRS of the juice. An increase of the RS% of the juice and content of total phenolic compounds was observed. The cellular and sprouts viability were reduced with the increase in the damages caused by M. fimbriolata. The fermentation process exhibited larger quantities of contaminators. With the damages, the wine TRRS quantity was superior and, consequently there was a decrease of the alcoholic content and fermentation efficiency. The damages caused by M. fimbriolata affected the quality of the raw material, compromising the fermentative process, and increase the production of phenolic compounds and contaminators.


Author(s):  
Nguyễn Thị Hồng Thu ◽  
Đặng Minh Nhật ◽  
Nguyễn Hoàng Dung

Sugar palm (Arenga pinnata) is a feather palm native to tropical Asia. In Vietnam, it is named Búng Báng or Đoác and grown only on the highlands in the central or northern part of Vietnam. It is utilized for many purposes, especially for Ta Vat wine production - a characteristic and unique product of Co Tu ethnic minority. However, because of the natural fermentation used in the production, the product quality is inconsistent. The purpose of this study was to examine a new procedure of using palm sap for making Ta Vat wine. Some characteristics of the sap, which was collected at Nam Giang district, Quang Nam province are determined, proving the potential of the sap for making wine product. The quality of sap changes quickly at room temperature. At low temperature (4 - 60C), the changes in sap quality are apparently slower. Examining some factors affecting its quality during the wine fermentation process, we determined the best parameters for the fermentation process as follows: inoculum size of 3% with cell density of about 1x108 cells/ml, the addition of the extract from the bark of Ceylon ironwood (Mesua ferrea L.) 4%. Keywords: Arenga pinnata, sap, Ceylon ironwood bark, Mesua ferrea L., wine fermentation.


Author(s):  
Sophie Vaud ◽  
Nicole Pearcy ◽  
Marko Hanževački ◽  
Alexander M.W. Van Hagen ◽  
Salah Abdelrazig ◽  
...  

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 300
Author(s):  
Jhih-Ying Ciou ◽  
Hsin-Chun Chen ◽  
Chih-Wei Chen ◽  
Kai-Min Yang

The study sought to investigate the effect of roasting temperatures on antioxidant components and oxidative stability of peanut oils. The total phenolic content, total flavonoid content, α–tocopherol content, and phytosterol content in peanut oils was influenced by roasting at temperatures of 120 °C, 140 °C, and 160 °C, while those roasting temperatures had no effect on the fatty acid profile and γ–tocopherol content of peanut oils. Roasting promotes the quality of peanut oil aroma via the Maillard reaction, particularly when it is derived from N–heterocyclic compounds (such as pyrazine and pyrrole). The oxidative stability of peanut oils was investigated using the Rancimat method, and the results show that there is a linear relationship between roasting and natural logarithm of the induction period (R2: 0.959~0.998). This was determined based on the Arrhenius equation, which indicated the activation energy (Ea) was in the range of 82.08~108.61 kJ/mol. In principal component analysis (PCA) analysis, the antioxidant stability of the increase levels of phenols released in the peanut oils was found to rise with the increment of roasting temperatures. The data obtained in this study should be confirmed as the nutritional benefits of peanut oils that will be most appealing to consumers.


Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1095
Author(s):  
Ke Jiang ◽  
Yong Kuang ◽  
Liying Feng ◽  
Yuhao Liu ◽  
Shu Wang ◽  
...  

Chinese chive usually becomes decayed after a short storage time, which was closely observed with the redox imbalance. To cope with this practical problem, in this report, molecular hydrogen (H2) was used to evaluate its influence in maintaining storage quality of Chinese chive, and the changes in antioxidant capacity were also analyzed. Chives were treated with 1%, 2%, or 3% H2, and with air as the control, and then were stored at 4 ± 1 °C. We observed that, compared with other treatment groups, the application of 3% H2 could significantly prolong the shelf life of Chinese chive, which was also confirmed by the obvious mitigation of decreased decay index, the loss ratio of weight, and the reduction in soluble protein content. Meanwhile, the decreasing tendency in total phenolic, flavonoid, and vitamin C contents was obviously impaired or slowed down by H2. Results of antioxidant capacity revealed that the accumulation of reactive oxygen species (ROS) and hydrogen peroxide (H2O2) was differentially alleviated, which positively matched with 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and the improved activities of antioxidant enzymes, including superoxide dismutase (SOD), guaiacol peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX). Above results clearly suggest that postharvest molecular hydrogen application might be a potential useful approach to improve the storage quality of Chinese chive, which is partially achieved through the alleviation of oxidative damage happening during the storage periods. These findings also provide potential theoretical and practical significance for transportation and consumption of perishable vegetables.


Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 69
Author(s):  
Alberto Martínez ◽  
Rocío Velázquez ◽  
Emiliano Zamora ◽  
María L. Franco ◽  
Camille Garzo ◽  
...  

The killer strains of Torulaspora delbrueckii can be used to improve the dominance of this yeast during must fermentation. The present work analyzes its usefulness for traditional sparkling wine making. T. delbrueckii killer strain dominated base wine fermentation better than non-killer strains and produced dried wines. The foam ability of T. delbrueckii base wines was very low compared to that of Saccharomyces cerevisiae. Significant positive correlations of foam parameters were found with some amounts of C4–C16 ethyl esters and proteins, and negative correlations with some antifoam alcohols. The organoleptic quality of T. delbrueckii base wines was considered unusual for cava making. While S. cerevisiae (single or mixed with T. delbrueckii) completed the second fermentation to produce dry sparkling wines with high CO2 pressure, single T. delbrueckii did not complete this fermentation, leaving sweet wines with low CO2 pressure. Death due to CO2 pressure was much higher in T. delbrueckii than in S. cerevisiae, making any killer effect of S. cerevisiae on T. delbrueckii irrelevant. However, the organoleptic quality of cava inoculated with mixtures of the two yeast species was better than that of wine inoculated exclusively with S. cerevisiae, and no deterioration in the quality of the foam was observed.


Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 226
Author(s):  
Katarzyna Rybak ◽  
Artur Wiktor ◽  
Dorota Witrowa-Rajchert ◽  
Oleksii Parniakov ◽  
Małgorzata Nowacka

It has been demonstrated previously in the literature that utilization of PEF or a combination of a pulsed electric field (PEF) and ultrasounds (US) can facilitate dehydration processes and improve the quality of dried products even better than the application of thermal methods such as blanching. The aim of the study was to evaluate the quality of red bell pepper subjected to freeze-drying preceded by blanching or PEF or US treatment applied in a single and combined mode. Furthermore, the freeze-drying was preceded by shock freezing or vacuum freezing performed inside the freeze-dryer as a result of pressure drop during the first stage of freeze-drying. All of the analyzed technological variants enhanced the drying kinetics when compared to the intact material. Freeze-dried bell pepper subjected to non-thermal pretreatment exhibited higher vitamin C, total phenolic and carotenoids content than blanched material despite the fact that blanching reduced drying time the most compared to all other analyzed methods.


Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 478
Author(s):  
Stefania Toscano ◽  
Valeria Rizzo ◽  
Fabio Licciardello ◽  
Daniela Romano ◽  
Giuseppe Muratore

The aim of the study was to assess, through a comparative shelf-life test, the suitability of two packaging materials, namely macro-perforated polypropylene (PP MA) and micro-perforated coextruded polypropylene (PP C), for the quality preservation of green asparagus (Asparagus officinalis L. ‘Vegalim’). Quality of spears was evaluated during 30 days at refrigerated storage by monitoring chemical, physical, and enzymatic parameters as well as sensory descriptors. PP C kept headspace composition close to suggested values for fresh green asparagus. Total color difference increased during the storage and it was highly correlated with chlorophyll-a and carotenoids, however, sensory color perception did not change significantly until 22 days of storage. PP C maintained ascorbic acid concentrations close to the initial levels, limited total phenolic compound loss to 24% (45% in PP MA), determined an increase of 72% in fiber content and small changes in lignin value; enzymatic changes were significantly inhibited. Significant sensorial differences were detected after 22 days of storage, with PP C performing better than PP MA. PP C film was confirmed as the best choice, limiting weight loss and maintaining a fresh-like appearance during 30 days of storage, thus allowing an extension in postharvest life.


Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1764
Author(s):  
Alejandra Rodríguez-Tadeo ◽  
Julio C del Hierro-Ochoa ◽  
Jesús O. Moreno-Escamilla ◽  
Joaquín Rodrigo-García ◽  
Laura A. de la Rosa ◽  
...  

Physiological changes in elderly individuals (EI) can contribute to nutritional deterioration and comorbidities that reduce their quality of life. Factors such as diet can modulate some of these effects. The aim was to evaluate the functionality of foods added with Brosimum alicastrum Sw. seed flour in EI. EI (n = 23) living in nursing home conditions agreed to participate. A control stage was carried out (30 days) and subsequently, an intervention stage (30 days) was realized in which a muffin and a beverage, designed for EI, were added to the participants’ their usual diet. In both stages, anthropometric parameters, body composition, nutritional status, dietary intake, sarcopenic status, cognitive and affective states, biometric parameters, and total phenolic compounds (TPC), and antioxidant capacity in foods and plasma of EI were determined. The results showed that the consumption of the foods improved the energy intake and preserved the muscle reserves of the EI. The EI gained body weight (+1.1 kg), increased their protein (+18.6 g/day; 1.5 g/kg BW/day), dietary fiber (+13.4 g/day), iron (+4.4 mg/day), zinc (+1.8 mg/day), folic acid (+83.4 µg/day) consumption while reducing their cholesterol (−66 mg/day) and sodium (−319.5 mg/day) consumption. LDL-C lipoproteins reduced (14.8%) and urea (33.1%) and BUN (33.3%) increased. The TPC increased (7.8%) in the plasma, particularly in women (10.7%). The foods improve the EI nutritional status, and this has a cardiovascular protective effect that can benefit the health of the EI.


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