70 research outputs found
Extra virgin olive oil bitterness evaluation by sensory and chemical analysis
An experimental investigation was performed on blend extra virgin olive oils (EVOO) from different cultivars and EVOO from different olive monovarieties (Coratina, Leccino, Maiatica, Ogliarola) with the aim to evaluate the possibility of estimating the perceived bitterness intensity by using chemical indexes, such as the total phenol content and the compounds responsible of oil bitterness measured spectrophotometrically at 225 nm (K225 value) as bitterness predictors in different EVOO. Therefore, a bitterness predictive model, based on the relationship between the perceived bitterness intensity of the selected stimuli and the chosen chemicals parameters has been built and validated. The results indicated that the oil bitterness intensity could be satisfactorily predicted by using the K225 values of oil samples
Application of ozone in fresh-cut iceberg lettuce refrigeration
Recently, technological innovations have been geared to supporting environmental sustainability, also in the fruit and vegetable industry. The application of ozone in the cold storage of fruits and vegetables is a sustainable technology used to improve product quality and its antimicrobial effect, simple use, and characteristic of not leaving any residue, makes this treatment suitable for many applications in this field. The aim of this work was to evaluate the effect of refrigeration at 4°C, associated with ozonization treatment at a concentration of 0.2 ppm on the shelf life of fresh-cut lettuce, compared to a lettuce control stored only at 4°C. Lettuce quality throughout the storage period (7 days) was determined by means of color and microbiological indexes, such as total bacterial count, total coliforms, Escherichia coli, Pseudomonadaceae, yeasts and molds. The lettuce used in the experiment was found to have a low microbiological load. Microbiological results obtained at different storage times have shown that the use of ozone is effective in containing microbial growth during chilling storage of the raw material compared to the refrigerated control. In particular, the positive effects of ozonation were appreciable after the third day of storage. Furthermore, the ozone treatment did not affect the color of the product
TRAP1 regulates stemness through Wnt/β-catenin pathway in human colorectal carcinoma
Colorectal carcinoma (CRC) is a common cause of cancer-related death worldwide. Indeed, treatment failures are triggered by cancer stem cells (CSCs) that give rise to tumor repopulation upon initial remission. Thus, the role of the heat shock protein TRAP1 in stemness was investigated in CRC cell lines and human specimens, based on its involvement in colorectal carcinogenesis, through regulation of apoptosis, protein homeostasis and bioenergetics. Strikingly, co-expression between TRAP1 and stem cell markers was observed in stem cells located at the bottom of intestinal crypts and in CSCs sorted from CRC cell lines. Noteworthy, TRAP1 knockdown reduced the expression of stem cell markers and impaired colony formation, being the CSC phenotype and the anchorage-independent growth conserved in TRAP1-rich cancer cells. Consistently, the gene expression profiling of HCT116 cells showed that TRAP1 silencing results in the loss of the stem-like signature with acquisition of a more-differentiated phenotype and the downregulation of genes encoding for activating ligands and target proteins of Wnt/β-catenin pathway. Mechanistically, TRAP1 maintenance of stemness is mediated by the regulation of Wnt/β-catenin signaling, through the modulation of the expression of frizzled receptor ligands and the control of β-catenin ubiquitination/phosphorylation. Remarkably, TRAP1 is associated with higher expression of β-catenin and several Wnt/β-catenin target genes in human CRCs, thus supporting the relevance of TRAP1 regulation of β-catenin in human pathology. This study is the first demonstration that TRAP1 regulates stemness and Wnt/β-catenin pathway in CRC and provides novel landmarks in cancer biology and therapeutics
The Reinforcing Therapist Performance (RTP) experiment: Study protocol for a cluster randomized trial
<p>Abstract</p> <p>Background</p> <p>Rewarding provider performance has been recommended by the Institute of Medicine as an approach to improve the quality of treatment, yet little empirical research currently exists that has examined the effectiveness and cost-effectiveness of such approaches. The aim of this study is to test the effectiveness and cost-effectiveness of providing monetary incentives directly to therapists as a method to improve substance abuse treatment service delivery and subsequent client treatment outcomes.</p> <p>Design</p> <p>Using a cluster randomized design, substance abuse treatment therapists from across 29 sites were assigned by site to either an implementation as usual (IAU) or pay-for-performance (P4P) condition.</p> <p>Participants</p> <p>Substance abuse treatment therapists participating in a large dissemination and implementation initiative funded by the Center for Substance Abuse Treatment.</p> <p>Intervention</p> <p>Therapists in both conditions received comprehensive training and ongoing monitoring, coaching, and feedback. However, those in the P4P condition also were given the opportunity to earn monetary incentives for achieving two sets of measurable behaviors related to quality implementation of the treatment.</p> <p>Outcomes</p> <p>Effectiveness outcomes will focus on the impact of the monetary incentives to increase the proportion of adolescents who receive a targeted threshold level of treatment, months that therapists demonstrate monthly competency, and adolescents who are in recovery following treatment. Similarly, cost-effectiveness outcomes will focus on cost per adolescent receiving targeted threshold level of treatment, cost per month of demonstrated competence, and cost per adolescent in recovery.</p> <p>Trial Registration</p> <p>Trial Registration Number: NCT01016704</p
Perceived astringency in wine: A predictive model
Sensations perceived in the act of tasting are important determinants of consumer response to red wine. Astringency is a tactile stimulus that strongly influences wine acceptability. Astringency descriptors account for more than a half of the total terms in the mouth-feel wheel proposed for describing the sensory properties of red wine. The physiological mechanism of the astringency perception in wine is based on the reaction of phenolic compounds with salivary proteins and the consequent formation of insoluble astringent/protein complexes. The availability of in vitro assays to estimate the strength of the sensation induced by different phenolic compounds became crucial in order to optimise the processing conditions in relation to this important driver of wine acceptability and sensory quality. In this work recent advancements in predicting astringency induced by phenolic compounds are discussed and new and promising methods are presented. Critical points in collecting both sensory and chemical data are reviewed. In particular, the application of the "Astringency Mucin Index" (AMI) in predicting the astringency induced by grape and wine phenol extracts is shown. The results of the use of the AMI on commercial phenolic extract, seed phenolic extracts from 'Aglianico' grape, 18 'Sangiovese' experimental wines and 20 commercial 'Aglianico del Vulture' wines are presented. Future developments of methods capable of predicting astringency are discussed
Focused Review: Agmatine in fermented foods
Polyamines(PAs)areubiquitoussubstancesconsideredtobebioregulatorsofnumerouscellfunctions;theytakepartincellgrowth,division,anddifferentiation.Thesebiogenicaminesarealsoinvolvedintissuerepairandinintracellularsignaling;infact,becauseoftheirpolycationiccharacter,theyinteracttoalargeextentwithmembranephospho-lipidsandmayplayanimportantroleintheregulationofmembrane-linkedenzymes.Theintracellularpolyaminecontentderivesfromthesimultaneousregulationofthesynthesis,catabolism,uptake,andeliminationofthepolyamines;furthermore,PAsarepresentinallcelltypesatdifferentconcentrations,butthehighestlevelsarefoundinrapid-turnovertissues.Inadditiontospermidine,spermine,andputrescine,alsoagmatine(AGM),deriv-ingfromarginineandidentifiedinmammalsinthe1990s,isapolyamineandseveralstudieshavereporteditspotentiallypositiveroleintheproductionofsecretagogues,andinneuronal,vascular,metabolic,andtherapeuticfunctions.Becauseofthelowargininedecarboxylase(ADC)activityinmammalians,theamountsofAGMfoundintheirtissuescanbeonlyminimallyascribedtoanendogenousdenovosynthesisbyADC,whileasub-stantialquantityofAGMmaybeofdietaryorigin.Severalfoodproductscontainonlysmallamountsofpolyamines,whilehigherconcentrationscanbefoundinfermentedfoods.PAscouldalsobeconsideredasindicatorsoffreshnessinfishandmeatproducts;asthesemoietiesareproducedduringfoodstorage,itwouldseemtoconfirmthemainroleofmicroorganismsintheirsynthesis.Inparticular,highlevelsofAGMarepresentinalcoholicbeverages,suchaswine,beer,sake,whichwouldseemtoconfirmtheroleofyeastsinAGMproduction.Althoughmanybiologicalfunctionshavebeenattributedtopolyamines,highlevelsofthesecompoundsinfoodstuffscanhavetoxicologicaleffects;however,nosafelevelfortheintakeofpolyaminesinadiethasyetbeenestablished.InthispaperthepresenceofAGMindifferentfoodstuffsisdiscussed,alsotakingintoaccountthevariousfactorsaffectingitspresenceandconcentration
Metataxonomic and metagenomic approaches for the study of undefined strain starters for cheese manufacture
Undefined strain starters are used for the production of many traditional and artisanal cheeses. Composition of undefined starters depends on several factors, and the diversity in strains and species significantly affects cheese quality and features. Culture-dependent approaches have long been used for the microbial profiling and functionalities of undefined cultures but underestimate their diversity due to culturability biases. Recently, culture-independent methods, based on high-throughput sequencing (HTS), have been preferred, with a significant boost in resolution power and sensitivity level. Amplicon targeted (AT) metagenomics, based on 16S rRNA sequencing, returned a larger microbiota diversity at genus and, sometimes, at species levels for artisanal starters of several PDO cheeses, but was inappropriate for populations with high strain diversity, and other gene targets were tested in AT approaches. Shotgun metagenomics (total DNA) and metatranscriptomics (total RNA), although are more powerful in depicting diversity and functionality of undefined cultures, have been rarely applied because of some limitations (e.g., high costs and laboriousness, need for bioinformatics skills). The advantages of HTS technologies are undoubted, but some hurdles need to be still overcame (e.g., resolution power, discrepancy between active and inactive cells, robust analytic pipelines, cost and time reduction for integrated approaches) so that HTS become routinary and convenient for defining complexity, microbial interactions (including host-phage relationships) and evolution in cheeses of undefined starters
Prediction of perceived astringency induced by phenolic compounds
A method which can be used to estimate perceived astringency due to polyphenolic compounds is presented here. Thirty subjects were selected on the basis of them having similar salivary flows and they were trained to rate the perceived astringency of tannic acid and grape seed extract solutions. A scale of phenolic compound concentrations ranging from 0 to 3.2 g/L was selected in order to obtain an experimental curve describing the perceived intensity of the sensation. The same astringent solutions were added to a mucin solution in conditions resembling those present in the oral cavity. The formation of polyphenol-protein complexes was measured on the basis of the increasing turbidity of the reaction mixture and was expressed in terms of nephelometric turbidity units (NTU). Experimental curves describing NTU vs polyphenol concentration were obtained. Predictive models of astringency intensity vs NTU were produced. The predictive capacity of the models was checked by comparing the measured and predicted intensities of a set of samples prepared at phenolic compound concentration level varying from 0.94 to 2.13 g/L. © 2004 Elsevier Ltd. All rights reserved
Prediction of perceived astringency induced by phenolic compounds II: Criteria for panel selection and preliminary application on wine samples
In the following work, subject saliva characteristics affecting panel astringency evaluation in phenolic mixtures were studied. Sixty subjects were selected on the basis of their salivary flow, haze developing capacity and protein concentration. Subjects rated the perceived astringency of tannic acid (TA), commercial procyanidin (PA) and grape seed extract (GSE) solutions with concentration values ranging from 0.42 to 1.4 g/L. Astringency intensity perception proved to be inversely related to saliva flow rate and haze developing capacity. No significant correlations were found between saliva protein concentration and intensity of astringency perception. A panel selected on the basis of subject similarity for flow rate and haze developing capacity rated the astringency intensity of set sample training solutions of TA, PA and GSE with concentrations ranging from 0.39 to 4.48 g/L. The reactivity of the same astringent solutions with mucin was measured in an in vitro assay and expressed in terms of Nephelometric Turbidity Units (NTU). Three predictive models described by a linear regression of astringency intensity vs. NTU were found. The possibility of a practical application of the proposed assay for optimization of wine production was evaluated on 18 experimental wines. A linear correlation was found between the intensity astringency ratings of wine samples and the in vitro assay response. © 2005 Elsevier Ltd. All rights reserved
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