Are bacterial spores activated by High Pressure treatment at 20°C ?

International audience

Multidimensional extension of the mixed assessor model

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Multiplicative decomposition of the scaling effect in the Mixed Assessor Model into a descriptor-specific and an overall coefficients

Abstract In 1994, Brockhoff and Skovgaard presented the so-called assessor model, including a “scaling coefficient” expressing the predisposition of a panelist to spread more or less his scores than the panel on a given sensory descriptor. This paper discusses potential scaling causes, and then proposes a decomposition of the scaling coefficient into two components: (i) an overall scaling coefficient, independent of the descriptors, expressing a psychological trend of the panelist towards the scoring task in general; (ii) a corrected scaling coefficient for each descriptor, expressing specific sensitivity of the panelist to the descriptor. Applied to 187 sensory datasets, this decomposition…

Characterization of key aroma compounds in Burgundy truffle

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Monitoring panel performances with the Mixed Assessor Model. Meta-analysis of the SensoBase

Monitoring panel performances with the Mixed Assessor Model. Meta-analysis of the SensoBase. The 11. Sensometrics meeting

Monitoring sensory panel performances with the mamcap R-package

Monitoring sensory panel performances with the mamcap R-package. AgroStat 2016 Congress - 14. Symposium on Statistical Methods for the Food Industry

The effect of gender, age and smoking status on use of scale, repeatability, product discrimination and agreement with the panel investigated in 177 descriptive sensory studies

The effect of gender, age and smoking status on use of scale, repeatability, product discrimination and agreement with the panel investigated in 177 descriptive sensory studies. 11. Pangborn sensory science symposium

Exploratory multiblock data: do they lead to the same results?

Should I replace replicates by additional subjects in my trained descriptive sensory panel?

Should I replace replicates by additional subjects in my trained descriptive sensory panel?. 11. Pangborn sensory science symposium

The subject effect in descriptive analysis: fixed or random? An old question revisited thanks to 697 datasets from the sensobase

The subject effect in descriptive analysis: fixed or random? An old question revisited thanks to 697 datasets from the sensobase. 11. Pangborn sensory science symposium

Cellular Injuries in Cronobacter sakazakii CIP 103183T and Salmonella enterica Exposed to Drying and Subsequent Heat Treatment in Milk Powder

International audience; Because of the ability of foodborne pathogens to survive in low-moisture foods, their decontamination is an important issue in food protection. This study aimed to clarify some of the cellular mechanisms involved in inactivation of foodborne pathogens after drying and subsequent heating. Individual strains of Salmonella Typhimurium, Salmonella Senftenberg, and Cronobacter sakazakii were mixed into whole milk powder and dried to different water activity levels (0.25 and 0.58); the number of surviving cells was determined after drying and subsequent thermal treatments in closed vessels at 90 and 100 degrees C, for 30 and 120 s. For each condition, the percentage of unc…

L'analyse statistique du profil sensoriel revisitée par une approche base de données

During a sensory evaluation, trained subjects taste and score products on differentdescriptors in order to obtain a descriptive profile of these products. The data are thenanalyzed by several statistical methods (PCA, ANOVA…) in order to monitor the subjectperformances and map the product space.This work aims to revisit these statistical methods thanks to the analysis of a large number ofdatasets of sensory profiling data from the SensoBase (a database containing more than athousand of datasets). Different statistical methods of mapping and analysis ofperformances were compared, then improved. We mainly focused on the so-called scalingeffect (tendency of the subject to spread his scores mor…

Influence of cheese composition on the aroma content, release and perception

Characterization of the aromatic potential of grape berry

IntroductionProbe is a research infrastructure gathering 4 analytical platforms of INRAE and allowing multi-approach and multi-complementarity to be explored and exploited. As a proof of concept, a common study was conducted around the structure and the evolution of the skin of the grape berry and the diffusion of compounds of interest during the winemaking process.Materials and methodsIn this context, the aromatic potential on two Vitis vinifera grape varieties (Carignan and Grenache,) were studied. Berries were harvested at an average potential alcohol of 12% vol. in the vineyard of the Pech Rouge experimental unit (INRAE, Gruissan, France) and separated according to their natural heterog…

Comparison of canonical variate analysis and principal component analysis on 422 descriptive sensory studies

International audience; Although Principal Component Analysis (PCA) of product mean scores is most often used to generate a product map from sensory profiling data, it does not take into account variance of product mean scores due to individual variability. Canonical Variate Analysis (CVA) of the product effect in the two-way (product and subject) multivariate ANOVA model is the natural extension of the classical univariate approach consisting of ANOVAs of every attribute. CVA generates successive components maximizing the ANOVA F-criterion. Thus, CVA is theoretically more adapted than PCA to represent sensory data. However, CVA requires a matrix inversion which can result in computing inst…

The MAM-CAP table: A new tool for monitoring panel performances

Abstract Assessor performances in sensory analysis are usually represented by three indicators: repeatability, discrimination and agreement. However, assessors can also differ on the range of their scores, the so-called “scaling effect”. Brockhoff, Schlich, and Skovgaard (2013) proposed the mixed assessor model (MAM) which, as the original assessor model ( Brockhoff & Skovgaard, 1994 ), takes this effect into account, but also allows for the product effect to be tested against a new interaction free of the scaling effect. The present paper proposes a unified system for monitoring assessor and panel performances based on the MAM. In addition to the product effect (tested at panel and individ…

Canonical Variate Analysis of Sensory Profiling Data

Principal Component Analysis (PCA) of product mean scores is generally used to obtain a product map from sensory profiling data. However, this approach does not take into account the variance of the product mean scores due to the individual panelist variability. Therefore, Canonical Variate Analysis (CVA) of the product effect in the two-way multivariate analysis of variance (MANOVA) should be considered as a natural alternative analysis to PCA. Indeed, it is the extension of the classical univariate approach used for the analysis of each descriptor separately. This analysis generates successive components maximizing product discrimination as measured by the usual Fisher statistics in analy…

Understanding the Effects of High Pressure on Bacterial Spores Using Synchrotron Infrared Spectroscopy

International audience; Bacterial spores are extremely resistant life-forms that play an important role in food spoilage and foodborne disease. The return of spores to a vegetative cell state is a three-step process, these being activation, germination, and emergence. High-pressure (HP) processing is known to induce germination in part of the spore population and even to inactivate a high number of Bacillus spores when combined with other mild treatments such as the addition of nisin. The aim of the present work was to investigate the mechanisms involved in the sensitization of spores to nisin following HP treatment at ambient temperature or with moderate heating leading to a heterogeneous …

Underdetermination in PCA: towards a psychometric approach of sensory data analysis

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