scholarly journals Yeast and Filamentous Fungi Microbial Communities in Organic Red Grape Juice: Effect of Vintage, Maturity Stage, SO2, and Bioprotection

2021 ◽  
Vol 12 ◽  
Author(s):  
Sara Windholtz ◽  
Emmanuel Vinsonneau ◽  
Laura Farris ◽  
Cécile Thibon ◽  
Isabelle Masneuf-Pomarède

Changes are currently being made to winemaking processes to reduce chemical inputs [particularly sulfur dioxide (SO2)] and adapt to consumer demand. In this study, yeast growth and fungal diversity were investigated in merlot during the prefermentary stages of a winemaking process without addition of SO2. Different factors were considered, in a two-year study: vintage, maturity level and bioprotection by the adding yeast as an alternative to SO2. The population of the target species was monitored by quantitative-PCR, and yeast and filamentous fungi diversity was determined by 18S rDNA metabarcoding. A gradual decrease of the α-diversity during the maceration process was highlighted. Maturity level played a significant role in yeast and fungal abundance, which was lower at advanced maturity, while vintage had a strong impact on Hanseniaspora spp. population level and abundance. The presence of SO2 altered the abundance of yeast and filamentous fungi, but not their nature. The absence of sulfiting led to an unexpected reduction in diversity compared to the presence of SO2, which might result from the occupation of the niche by certain dominant species, namely Hanseniaspora spp. Inoculation of the grape juice with non-Saccharomyces yeast resulted in a decrease in the abundance of filamentous fungi generally associated with a decline in grape must quality. Lower abundance and niche occupation by bioprotection agents were observed at the overripened stage, thus suggesting that doses applied should be reconsidered at advanced maturity. Our study confirmed the bioprotective role of Metschnikowia pulcherrima and Torulaspora delbrueckii in a context of vinification without sulfites.

Toxins ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 547
Author(s):  
Kai Zhang

Two methods for measuring ochratoxin A in corn, oat, and grape juice were developed and compared. Flow injection (FI) and on-line liquid chromatography (LC) performances were evaluated separately, with both methods using a triple quadrupole tandem mass spectrometer (MS/MS) for quantitation. Samples were fortified with 13C uniformly labeled ochratoxin A as the internal standard (13C-IS) and prepared by dilution and filtration, followed by FI- and LC-MS/MS analysis. For the LC-MS/MS method, which had a 10 min run time/sample, recoveries of ochratoxin A fortified at 1, 5, 20, and 100 ppb in corn, oat, red grape juice, and white grape juice ranged from 100% to 117% with RSDs < 9%. The analysis time of the FI-MS/MS method was <60 s/sample, however, the method could not detect ochratoxin A at the lowest fortification concentration, 1 ppb, in all tested matrix sources. At 5, 20, and 100 ppb, recoveries by FI-MS/MS ranged from 79 to 117% with RSDs < 15%. The FI-MS/MS method also had ~5× higher solvent and matrix-dependent instrument detection limits (0.12–0.35 ppb) compared to the LC-MS/MS method (0.02–0.06 ppb). In the analysis of incurred corn and oat samples, both methods generated comparable results within ±20% of reference values, however, the FI-MS/MS method failed to determine ochratoxin A in two incurred wheat flour samples due to co-eluted interferences due to the lack of chromatographic separation.


2002 ◽  
Vol 50 (23) ◽  
pp. 6935-6938 ◽  
Author(s):  
Francesca Boato ◽  
Gary M. Wortley ◽  
Rui Hai Liu ◽  
Raymond P. Glahn

2009 ◽  
Vol 102 (8) ◽  
pp. 1125-1135 ◽  
Author(s):  
Alberto Dávalos ◽  
Gema de la Peña ◽  
Carolina C. Sánchez-Martín ◽  
M. Teresa Guerra ◽  
Begoña Bartolomé ◽  
...  

The NADPH oxidase enzyme system is the main source of superoxide anions in phagocytic and vascular cells. NADPH oxidase-dependent superoxide generation has been found to be abnormally enhanced in several chronic diseases. Evidence is accumulating that polyphenols may have the potential to improve cardiovascular health, although the mechanism is not fully established. Consumption of concentrated red grape juice, rich in polyphenols, has been recently shown to reduce NADPH oxidase activity in circulating neutrophils from human subjects. In the present work we studied whether red grape juice polyphenols affected NADPH oxidase subunit expression at the transcription level. For this, we used human neutrophils and mononuclear cells from peripheral blood, HL-60-derived neutrophils and the endothelial cell line EA.hy926.Superoxide production was measured with 2′7′-dichlorofluorescein diacetate or lucigenin, mRNA expression by real-time RT-PCR and protein expression by Western blot. Each experiment was performed at least three times. In all cell types tested, red grape juice, dealcoholised red wine and pure polyphenols decreased superoxide anion production. Red grape juice and dealcoholised red wine selectively reduced p47phox, p22phox and gp91phox expression at both mRNA and protein levels, without affecting the expression of p67phox. Pure polyphenols, particularly quercetin, also reduced NADPH oxidase subunit expression, especially p47phox, in all cell types tested. The present results showing that red grape juice polyphenols reduce superoxide anion production provide an alternative mechanism by which consumption of grape derivatives may account for a reduction of oxidative stress associated with cardiovascular and/or inflammatory diseases related to NADPH oxidase superoxide overproduction.


Author(s):  
Gunawan Tarigan ◽  
I Wayan Arthana ◽  
Dewa Ayu Angga Pebriani

One of the nutrients that can be given to brood feed fish to improve reproductive performance and egg quality is vitamin E. Vitamin E has a very important role in increasing fish reproduction because vitamin E functions as an antioxidant that can maintain the presence of fatty acids and prevent fat oxidation in the fish cell membrane and can accelerate the secretion of reproductive hormones. This study aims to determine the effect of vitamin E in feed at different doses on the level of gonad maturity of tilapia. The research was conducted at the Fisheries Laboratory of the Faculty of Marine and Fisheries, Udayana University from July to August 2020. The samples of fish tested were tilapia (Oreochromis niloticus) obtained from the Teratai fishing pond, Sanur Bali. Vitamin E used was Ovagrow Vit E with a vitamin E content of 50%. The CRD method (completely randomized design) was used with four treatments and three replications. The doses of vitamin E that were mixed into the feed were 0, 100, 300, and 500 mg/kg of feed. The results showed that the administration of vitamin E mixed in the feed at different doses had a significant effect on the achievement of gonad maturity level, gonad somatic index (GSI), and Fecundity (P <0.05). Provision of vitamin E at a dose of 300 mg/kg of feed was the best dose for ripening tilapia gonads. The gonad maturity level developed up to maturity stage IV, the GSI value was (3.56 ± 0.46) and the fecundity value was (1379 ± 289).


2001 ◽  
Vol 40 (3) ◽  
pp. 113-120 ◽  
Author(s):  
Achim Bub ◽  
Bernhard Watzl ◽  
Daniel Heeb ◽  
Gerhard Rechkemmer ◽  
Karlis Briviba

2021 ◽  
Vol 02 ◽  
Author(s):  
Kirsten Berger ◽  
Johanna Josefine Ostberg-Potthoff ◽  
Tamara Bakuradze ◽  
Peter Winterhalter ◽  
Elke Richling

Background: The polyphenols from red fruits exhibit protective effects against degenerative diseases, including diabetes mellitus type 2, cardiovascular disease, etc. Objective: In this small pilot intervention study with only ten volunteers, we investigated the influence of phenolic extracts prepared from an Aronia juice and a red grape juice concentrate on peripheral glucose, blood glucose, and insulin after the intake of a drink containing these extracts plus maltodextrin and water. Method: Maltodextrin in water served as control; additionally, phenolic extracts from Aronia or grape juice were added. Blood samples were taken before ingestion of the bolus drink and 30, 60, 90, 120, 180, 240, and 360 min after. Additionally, continuously the peripheral glucose was measured using a commercially available sensor system. Results: In all ten volunteers, the intake of Aronia extract (100 mg) reduced both the peripheral glucose and the blood glucose levels significantly (p ≤ 0.05) in comparison to the control. Blood insulin levels were not affected. Whereas the intake of red grape extract (120 mg) did not reduce the glucose levels but increased the insulin levels significantly. Conclusion: Our pilot study showed that even low amounts of a phenolic Aronia extract could lower glucose absorption. Thus, due to the blood glucose-lowering effects of Aronia phenolics in healthy volunteers, these preliminary results warrant further investigation in the frame of a follow-up study with a larger number of volunteers.


2006 ◽  
Vol 84 (1) ◽  
pp. 252-262 ◽  
Author(s):  
Patricia Castilla ◽  
Rocío Echarri ◽  
Alberto Dávalos ◽  
Francisca Cerrato ◽  
Henar Ortega ◽  
...  

1994 ◽  
Vol 57 (12) ◽  
pp. 1080-1083 ◽  
Author(s):  
D. F. SPLlTTSTOESSER ◽  
J. J. CHUREY ◽  
C. Y. LEE

Two aciduric, aerobic, sporeforming bacteria were isolated from pasteurized juices. The gram-positive, catalase-positive rods produced spores that were located subterminally in a swollen sporangium. The cultures had an optimal pH of 3.5–4.0 for growth and preferred potato dextrose agar over many of the rich media usually used for cultivating sporeforming bacteria. Spore inocula grew well in apple juice and white grape juice. Red grape juice was inhibitory, perhaps because of the concentrations of certain phenolic compounds. The spores were sufficiently heat resistant (D90 values of 16 to 23 min and z-values of 7.2 to 7.7°C) to survive commercial pasteurization processes.


2010 ◽  
Vol 17 (3) ◽  
pp. 598-604 ◽  
Author(s):  
B.K. Tiwari ◽  
A. Patras ◽  
N. Brunton ◽  
P.J. Cullen ◽  
C.P. O’Donnell

2017 ◽  
Vol 39 (3) ◽  
Author(s):  
TAÍSA CERATTI TREPTOW ◽  
FERNANDA WOUTERS FRANCO ◽  
LAURA GIZELE MASCARIN ◽  
LUISA HELENA RYCHECKI HECKTHEUER ◽  
CLÁUDIA KAEHLER SAUTTER

ABSTRACT Grape juice has been widely studied due to the presence of phenolic compounds and its beneficial effects on human health. Ultraviolet irradiation C (UV-C) can increase the content of phenolic compounds and anthocyanins and contribute to sensory acceptability. The aim of this study was to evaluate the effect of different doses of ultraviolet irradiation C (UV-C) on ‘Trebbiano’, ‘Niagara Branca’, ‘Isabel’ and ‘Cabernet Sauvignon’ grapes, as well as effect of the storage period. Juices were elaborated and evaluated for physicochemical analyses, and for the sensorial analysis in irradiated samples. In ‘Niagara Branca’ and ‘Trebbiano’ cultivars, storage and irradiation promoted few physicochemical alterations, and sensorially, irradiation reduced the intensity of flavor and color attributes. In juices from ‘Isabel’ and ‘Cabernet Sauvignon’ cultivars, the storage period led to the concentration of sugars and irradiation influenced physicochemical parameters and increased the intensity of aroma attribute at dose of 2 kJ m-2. Thus, UV-C irradiation contributes little for the improvement of white grape juices; however, it favors some sensory attributes in red grape juice, requiring further studies to elucidate the influence of UV-C irradiation on the phenolic and volatile composition of grape juice.


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