Volatile phenols, such as 4-ethylphenol, are responsible for a “horsey” smell in wine. Thus, the study of volatile phenol sorption in yeasts, and their subsequent elimination from wine, helps to ...optimize eco-friendly wine curative processes. Here, we compared the influences of spray drying, lyophilization and evaporative drying at low water activity on yeast, for improving the 4-ethylphenol sorption capacity in a synthetic model wine. The changes that occur in the physico-chemical characteristics of the yeast surface (surface hydrophobicity, electron-donor character and zeta potential) during these drying processes were determined to assess if any correlation exists between these factors and the 4-ethylphenol sorption capacities of the cells. Evaporative drying at low water activity, spray drying and lyophilization induced, respectively, 61.5%, 169% and 192% greater 4-ethylphenol sorption than biomass without drying treatment. Surface hydrophobicity of yeasts was also significantly greater, but the zeta potential of yeast cells was significantly lower after the drying processes. This is the first report investigating changes to the physico-chemical variables affected during yeast drying. These cell surface modifications were correlated with the 4-ethyphenol sorption value measured.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
For the first time, we report that enological yeasts or yeast cell walls can sorb (−)geosmin, an undesirable molecule that causes critical organoleptic defects in wine at low concentrations (around ...50
ng
l
−1). The wine is described as “earthy” or “mouldy”. The influence of various post-harvesting processes on yeast (−)geosmin sorption capacity was studied. The dried yeast biomass obtained by the different processes was analysed by FTIR spectroscopy in ATR mode: structural differences were detected between the samples depending on the strain and the treatment used. Surface proteins and mainly phospholipids from the plasma membrane appeared to induce significantly different signals which may explain the different sorption capacities. The possible involvement of phospholipids in (−)geosmin sorption by yeasts highlights the complexity of this phenomenon.
The post-harvesting processes were: spray-drying, mechanical cell disruption, autolysis and two methods of rehydration of dried yeast samples. The results show that, using the optimal combination of processes, the initial (−)geosmin concentration in model wine can be decreased by more than 50%.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Basal cell carcinomas (BCCs) are very frequent cutaneous cancers, often located on the face. Cure rates with surgery and radiotherapy are high, but these treatments have never been compared ...prospectively. A randomized trial was initiated in 1982 to compare surgery and radiotherapy in the treatment of primary BCC of the face measuring less than 4 cm. The primary end point was the failure rate (persistent or recurrent disease) after 4 years of follow-up. The secondary end point was the cosmetic results assessed by the patient, the dermatologist and three persons not involved in the trial. In the course of the trial, 347 patients were treated. Of the 174 patients in the surgery group, 71% had local anaesthesia and 91% frozen section examination. Of the 173 patients in the radiotherapy group, 55% were treated with interstitial brachytherapy, 33% with contactherapy and 12% with conventional radiotherapy. The 4-year actuarial failure rate (95% CI) was 0.7% (0.1-3.9%) in the surgery group compared with 7.5% (4.2-13.1%) in the radiotherapy group (log-rank P = 0.003). The cosmetic results assessed by four of the five judges were significantly better after surgery than after radiotherapy. Eighty-seven per cent of the surgery-treated patients and 69% of the radiation-treated patients considered the cosmetic result as good (P < 0.01). Thus, in the treatment of BCC of the face of less than 4 cm in diameter, surgery should be preferred to radiotherapy.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Aroma Compound Sorption by Oak Wood in a Model Wine Ramirez Ramirez, Gabriela; Lubbers, Samuel; Charpentier, Claudine ...
Journal of agricultural and food chemistry,
08/2001, Volume:
49, Issue:
8
Journal Article
Peer reviewed
Oak wood used for wine barrels was immersed into a model wine containing eight aroma compounds (e.g., aromatic and terpene alcohols, ethyl esters, and aldehyde), for which activity coefficients in ...water and model wine were determined using the mutual solubility measurement. A mass balance of these volatiles considering their reactivity in model wine was established. For most of the studied aroma compounds, and mainly for linalool and ethyl octanoate, a sorption behavior into wood was reported for the first time. This phenomenon was selective and could not be related to the solubilities in model wine and hydrophobicities of the studied aroma compounds, suggesting that acid−base and polar characteristics of wood were more involved in this sorption mechanism. This study has also shown that the level of sorption is a function of the ratio of wood surface area/solution volume. Keywords: Sorption; aroma compounds; solubility; oak wood; wine
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Basal cell carcinoma is the most frequent cutaneous carcinoma, and it is characterized by its local spreading and an exceptional tendency to metastasize. Radical excision or destruction ensures the ...highest chance of cure. The most frequent site of this tumor is the face, where radical excision is limited by the proximity of essential anatomic structures. The main difficulty is to avoid mutilation and to provide good cosmetic results despite the vicinity of the eyes, the nose, and the mouth. Surgery and radiotherapy are known to provide similar chances of cure, but results concerning cosmetic sequelae are controversial, depending sometimes on the specialty of the physician in charge of the treatment. A randomized trial was performed at the Gustave-Roussy Institute to compare basal cell carcinomas of the face treated either by surgery or by radiotherapy. In summary, a significant advantage was observed in favor of surgery, as has been published elsewhere. Looking at the details of the cosmetic results, we analyzed the specific methodology of the cosmetic evaluation set up to eradicate the usual bias owing to subjective judgments. We looked also to the evolution of the cosmetic results with time. A panel of five judges performed repeated evaluations during the follow-up, and standardized photographs were taken at each visit and rated later by three nonmedical judges. In total, 174 patients were treated by surgery and 173 by radiotherapy; the choice of the treatment was allocated by randomization. Postoperative complications were higher in the radiotherapy group. The final cosmetic results after 4 years of follow-up were rated significantly better with surgery than with radiotherapy (good in 87 percent versus 69 percent according to the patient, 79 percent versus 40 percent according to the dermatologist, and respectively for each of the observers). Evolution of the ratings during the follow-up demonstrated an improvement of the cosmesis after surgery and stable or deteriorated results after radiotherapy. The same trend was observed regardless of the site of the tumor on the face, except for the nose, where the difference--still in favor of the surgery--was not significant. Concordance of all assessments in our study was the main guarantee of reliability of our methodology for cosmetic evaluation.
Carbohydrate and aglycon moieties released, respectively, by acid and enzymatic hydrolysis of African mango pulp extracts containing glycosidically bound compounds were identified by TLC, GC, and ...GC/MS. Glucose was found to be the most important sugar constituent of the glycoside saccharidic moiety, while significant amounts of arabinose and trace amounts of rhamnose were detected. Several aglycons (Z)-hexen-3-ol, hexanol, hexanoic acid, 2,5-dimethyl-4-hydroxy-3-(2H)furanone (furaneol), linalool oxides, α-terpineol, carvacrol, vanillin, cis- and trans-6-p-menthen-2,8-diol, 1,8-p-menthadien-7-ol, 1-p-menthen-7,8-diol, and 9-hydroxymegastima-4-en-3-one were identified as additional mango bound volatile compounds. Fatty acids (myristic and stearic acids) were also found in glycosidically bound form. Ten glycosides (benzyl, 2-phenylethyl, and α-terpineyl glucosides and rutinosides, eugenyl, vanillyl and furaneyl glucosides and α-terpineyl arabinoglucoside were identified for the first time in mango by GC/MS of trifluoroacetylated derivatives and GC using reference compounds. Linalyl oxide glucosides (four isomers) and C13 norisoprenoid derivatives 9-hydroxymegastima-4,6-dien-3-one (two isomers), 9-hydroxymegastima-4,7-dien-3-one, and vomifoliol glucosides and arabinoglucosides were tentatively identified. Keywords: Mango; glycosidically bound compounds; TFA derivatives; GC/MS
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Reporting and scoring treatment complications in gynecological cancers is difficult because of the variety of normal tissues, anatomical structures and treatment disciplines involved, making it ...impossible to compare series of patients treated in different institutions even with the same strategy. An international group of experts (gynecologists, radiotherapists and surgeons) developed a multidisciplinary database to identify, score and report early and late normal tissue damage regardless of treatment strategy. The principles involve: (1) The identification of relevant organs and tissues; (2) An accurate definition of the type and score of each complication; (3) Reporting combinations of complications of various degrees; (4) A computerized format for data acquisition, update and retrieval. In the present version, the "Glossary" describes five degrees of increasing severity (0 to 4) in 14 organs and/or normal tissues. The rationale of the glossary leaves it open for as yet undescribed types of complications. This paper contains the definition and scoring for each type of complication, general guidelines for their use.
As important as the blend of base wines before bottling, one of the most important steps in the champagne-making process is the long ageing on lees. Two yeast strains of Saccharomyces cerevisiae ...MC001 and MC002, used in champagne wine production, were allowed to autolyse. After 8 days of autolysis, active dry yeasts adapted to wine released 1.7- to 1.8-fold more nitrogen compounds than nonadapted active dry yeast. The nitrogen content (total, proteins, peptides and amino) present in autolysates was measured for yeasts adapted to wine. The composition of free amino acids and amino acids constituting peptides showed no difference between the two strains of yeast used. Studies of intracellular proteolytic activity and release of peptides showed no correlation between these two phenomena. These results indicate that yeasts adapted to wine give results similar to those that occur in wine during ageing.
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CEKLJ, DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NUK, OBVAL, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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 reduction of organoleptic defects in wine due to phenols.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Five mandelonitrile glycosides have been detected in the glycosidic fraction isolated from several Passiflora fruits using GC/EI-MS or GC/NCI-MS of trifluoroacetylated derivatives. Reasons for the ...possible co-occurence of prunasin and sambunigrin in passion fruit juice and peel are given, and amygdalin is reported for the first time as a passion fruit component. Two mandelonitrile rhamnopyranosyl β-d-glucopyranosides have been tentatively identified by MS. The extraction of cyanoglycosides using Amberlite XAD-2 followed by GC analysis of TFA derivatives was found to be an efficient method for their rapid determination. Prunasin was found to be the most important cyanogenic glycoside in peel (285 mg/kg for P. edulis f. flavicarpa), whereas amygdalin (31 mg/kg for P. edulis) and the two compounds tentatively identified as mandelonitrile rhamnopyranosyl β-d-glucopyranosides were mostly found in the juice (99 mg/kg for P. edulis f. flavicarpa). Different amounts of sambunigrin were found in the juice and the peel (from 0.4 mg/kg in P. edulis juice to 15.5 mg/kg in P. edulis f. flavicarpa peel). Keywords: Passion fruit; cyanogenic glycosides; gas chromatography; mass spectrometry
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