Search results for "Autolysis"
showing 10 items of 18 documents
Bedeutung der Autolyse f�r die Ur�miediagnostik durch Kreatininbestimmung am Leichenherzen
1968
Die Kreatininkonzentrationen im Herzmuskel wurden untersucht in Abhangigkeit von der Lagerungstemperatur und dem zeitlichen Intervall zwischen Todeseintritt und chemischer Bestimmung. Fur die Bestimmung der Todesursache und der Todeszeit ergaben sich folgende Konsequenzen: 1. Eine Beurteilung der intravitalen Nierenfunktion ist bis zu 3 Tagen post mortem moglich. 2. Werte unter 5 und uber 20 mg/100 g schliesen ein Leichenalter von mehr als 5 Tagen aus. 3. Verlaufsbeobachtungen der Kreatininkonzentration am obduzierten Herzen erlauben Ruckschlusse auf eine renale Todesursache und die Todeszeit. 4. Mit geringen Erniedrigungen der Kreatininwerte 1–4 Tage post mortem bei niedrigen Ausentemperat…
Sorption of wine volatile phenols by yeast lees
2005
The capacity of Saccharomyces cerevisiae yeast lees to sorb 4-ethylguaiacol and 4-ethylphenol was investigated in a synthetic medium and in wine. Active dried yeast was more effective when volatile phenols were diluted in red wine. Partition coefficients between wine model solution and wine yeast lees were determined and compared with those measured for dried active yeast. They showed a larger affinity of volatile phenols for wine yeast lees than for dried active yeast. The effect of yeast lees on volatile phenol sorption was sensitive to yeast autolysis level and to physicochemical parameters, such as ethanol content, temperature and pH. These results could be applied in the technology of …
Proteolytic capacity in mouse cardiac muscle following strenuous exercise
1981
Proteolytic capacity in mouse cardiac muscle was analyzed 1, 3, and 6 days after exhaustive intermittent or submaximal prolonged running. No significant changes were recorded in the activities of acid or alkaline proteases, β-glucuronidase or trypsin inhibitor. Similarly, no changes were found in the rates of acid or neutral autolysis.
Yeast autolysis in sparkling wine – a review
2006
Sparkling wine produced by the traditional methode champenoise requires a second in-bottle alcoholic fermentation of a base wine, leading to the sparkling wine. This second fermentation is followed by prolonged ageing in contact with yeast cells (lees). The autolysis of yeast occurs during the ageing of sparkling wines. During this process, the yeast releases different compounds that modify the organoleptic properties of the wine. The ageing period is required to give these wines their roundness and characteristic aroma and flavour. Autolysis products also influence the foaming properties of sparkling wine. Yeast autolysis is characterised by the hydrolysis of intracellular biopolymers by y…
Release of macromolecules by Saccharomyces cerevisiae during ageing of French flor sherry wine “Vin jaune”
2003
The French flor sherry wine "Vin jaune" spends 6 years and 3 months in the same barrel under a yeast velum. Because of temperature variations in the cellars, this velum sinks partially into the wine and a deposit of dead yeasts cells accumulates in the bottom of the barrels, favouring the formation of new velum. Growth and autolysis occur simultaneously. This study investigated the evolution of macromolecules released by yeasts during the ageing of "Vin jaune" in a model system closely simulating winemaking. It was observed that the release of macromolecules during the formation of the velums by living yeasts was low but greatly increased when the velums fell and yeast viability decreased. …
Ultrastructural changes of sparkling wine lees during long-term aging in real enological conditions.
2012
Ultrastructural changes of lees of three series of sparkling wines produced using the traditional method during long-term aging (4 years) were assessed by high-pressure freezing in combination with transmission electron microscopy. The stratified structure of the cell wall disappeared throughout aging. After 18 months, the microfibrous material of the cell wall appeared more diffuse and the amorphous midzone of the inner wall layer was progressively degraded. From 30 months onward, the cell wall consisted of a tangled structure of fibers. In spite of these changes, the cell wall of yeasts remained unbroken at 48 months of wine aging. Cell membrane breakage was observed for the first time in…
Acute change of titin at mid-sarcomere remains despite 8 wk of plyometric training
2014
Purpose: The purpose of this study was to investigate skeletal muscle changes induced by an acute bout of plyometric exercise (PlyEx) both before and after PlyEx training, to understand if titin is affected differently after PlyEx training. Methods: Healthy untrained individuals (N=11) completed the 1stPlyEx (10x10 squat-jumps, 1min rest). Thereafter, 6 subjects completed 8 weeks of PlyEx, while 5 controls abstained from any jumping activity. Seven days after the last training session all subjects completed the 2ndPlyEx. Blood samples were collected before, 6 hours and 1, 2, 3 and 4 days after each acute bout of PlyEx, and muscle biopsies 4 days before and 3 days after each acute bout of Pl…
Animal rennets as sources of dairy lactic acid bacteria
2014
ABSTRACT The microbial composition of artisan and industrial animal rennet pastes was studied by using both culture-dependent and -independent approaches. Pyrosequencing targeting the 16S rRNA gene allowed to identify 361 operational taxonomic units (OTUs) to the genus/species level. Among lactic acid bacteria (LAB), Streptococcus thermophilus and some lactobacilli, mainly Lactobacillus crispatus and Lactobacillus reuteri , were the most abundant species, with differences among the samples. Twelve groups of microorganisms were targeted by viable plate counts revealing a dominance of mesophilic cocci. All rennets were able to acidify ultrahigh-temperature-processed (UHT) milk as shown by pH …
Yeasts and Sparkling Wine Production
2019
Sparkling wines are produced in many different countries. Among sparkling wines, some are produced from Charmat or bottle fermentation. In this chapter, the practical methods and principles of producing quality sparkling wine is given in details including each step of the production from viticultural parameters, base wine production up to secondary fermentation. After the second fermentation in bottle, the wine is aged on lees. During aging, yeast autolysis occurred. The mechanisms of yeast autolysis and the compounds released are presented. The consequences of yeast autolysis on wine quality are detailed. Finally the riddling and disgorging operation are presented
Protease A activity and nitrogen fractions released during alcoholic fermentation and autolysis in enological conditions
2000
Determination of protease A activity during alcoholic fermentation of a synthetic must (pH 3.5 at 25 degrees C) and during autolysis showed that a sixfold induction of protease A activity occurred after sugar exhaustion, well before 100% cell death occurred. A decrease in protease A activity was observed when yeast cell autolysis started. Extracellular protease A activity was detected late in the autolysis process, which suggests that protease A is not easily released. Evolution of amino acids and peptides was determined during alcoholic fermentation and during autolysis. Amino acids were released in early stationary phase. These amino acids were subsequently assimilated during the fermenta…