Lunde K.,Norwegian Meat Research Center |
Lunde K.,University of Life Science |
Skuterud E.,Norwegian Meat Research Center |
Skuterud E.,University of Life Science |
And 2 more authors.
Meat Science | Year: 2010
The aim of work was to study Norwegian consumers' acceptance of pork meat with different levels of skatole and androstenone. One group of androstenone sensitive consumers (N. = 46) and one group of non sensitive consumers (N. = 55) participated in a home test and evaluated 11 samples with different skatole (range 0-0.35 ppm) and androstenone (range 0-9.0 ppm) levels. Liking of odour during frying and odour and flavour of the fried meat were evaluated. Results showed that the non sensitive consumers accepted all levels of androstenone in the samples. Sensitive consumers gave a significantly lower liking score for androstenone samples containing 3 ppm (and more) than the reference sample when evaluating these samples above the frying pan, but no significant difference were found between 3 ppm samples and reference samples when liking of fried meat was evaluated. This indicated that the sensitive consumers accepted 3 ppm in fried meat, but not if 3 ppm was present in the sample during the frying process. The same consumer's differentiated skatole samples with regard to flavour at 0.15 ppm. The Norwegian established practise with a threshold value of 0.21 ppm skatole is higher than the value accepted by the consumers. © 2010 The American Meat Science Association.
Koch I.S.,Stellenbosch University |
Muller M.,Stellenbosch University |
Joubert E.,Stellenbosch University |
van der Rijst M.,ARC Infruitec Nietvoorbij |
Naes T.,430 As
Food Research International | Year: 2012
Rooibos samples were collected throughout the 2009 harvesting season from different geographic areas in the Western Cape, South Africa, and from different producers to capture as much potential variation in rooibos sensory characteristics as possible. The quality (i.e. the appearance of the leaves, and the color and flavor of the infusion) of 69 samples was evaluated by expert graders, and samples were grouped into four quality grades. Using descriptive analysis sensory profiles of the rooibos samples were developed and 121 aroma, flavor, taste, and mouthfeel descriptors were generated. A rooibos sensory wheel was created by selecting 27 flavor, taste and mouthfeel attributes and grouping these terms together to form a logical, convenient and user-friendly overview of the sensory descriptors associated with rooibos. The most frequently occurring descriptors were selected to compile a rooibos sensory lexicon of 14 flavor, taste and mouthfeel attributes along with a definition and reference standard for each term. It was found that the term "characteristic" rooibos flavor may be described as a combination of honey, woody and herbal-floral notes with a slightly sweet taste and subtle astringency. Also, differences in the sensory characteristics between and within different quality grades were established with low-quality tea often being associated with green, hay-like and musty flavors and a bitter or sour taste. High-quality tea was generally associated with pleasant rooibos attributes including honey, woody, floral and caramel notes and a sweet taste. This research is a first step towards the broader objective of standardizing the sensory terminology of rooibos tea. © 2011 Elsevier Ltd.
Naelig;s T.,430 As |
Tomic O.,430 As |
Mevik B.-H.,University of Oslo |
Martens H.,430 As
Journal of Chemometrics | Year: 2011
This paper presents a new approach to path modelling, based on a sequential multi-block modelling in latent variables. The approach is explorative and focused on interpretation. The method breaks with standard traditions of estimating all paths using one single modelling. Instead, one separate model is estimated for each endogenous block. Each separate model is constructed by stepwise use of the standard PLS regression on matrices that are orthogonalised with respect to each other. The advantages of the approach are that it can allow for different dimensionality within each block, it is invariant to relative weighting of the blocks and it is based on simple and standard methodology allowing for simple outlier detection, validation and interpretation. No convergence problems are involved and the method can be used for situations with many more variables than samples. An application based on sensory analysis of wines will be used to illustrate the method. This paper presents a new approach to path modelling, based on a sequential multi-block modelling in latent variables. Each separate model is constructed by stepwise use of the standard PLS regression on matrices that are orthogonalised with respect to each other. The advantage is that the method can allow for different dimensionality within each block, it is invariant to relative weighting of the blocks and is based on simple and standard methodology allowing for simple outlier detection, validation and interpretation. Copyright © 2010 John Wiley & Sons, Ltd.
Cellular damage as induced by high temperature is dependent on rate of temperature change - Investigating consequences of ramping rates on molecular and organismal phenotypes in Drosophila melanogaster
Sorensen J.G.,University of Aarhus |
Loeschcke V.,University of Aarhus |
Kristensen T.N.,University of Aarhus |
Kristensen T.N.,430 As
Journal of Experimental Biology | Year: 2013
Ecological relevance and repeatability of results obtained in different laboratories are key issues when assessing thermal tolerance of ectotherms. Traditionally, assays have used acute exposures to extreme temperatures. The outcomes of ecologically more relevant ramping experiments, however, are dependent on the rate of temperature change leading to uncertainty of the causal factor for loss of function. Here, we test the physiological consequences of exposing female Drosophila melanogaster to gradually increasing temperatures in so-called ramping assays. We exposed flies to ramping at rates of 0.06 and 0.1°Cmin-1, respectively. Flies were sampled from the two treatments at 28, 30, 32, 34, 36 and 38°C and tested for heat tolerance and expression levels of the heat shock genes hsp23 and hsp70, as well as Hsp70 protein. Heat shock genes were upregulated more with a slow compared with a faster ramping rate, and heat knock-down tolerance was higher in flies exposed to the faster rate. The fact that slow ramping induces a stronger stress response (Hsp expression) compared with faster ramping suggests that slow ramping induces more heat damage at the cellular level due to longer exposure time. This is supported by the observation that fast ramped flies have higher heat knock-down tolerance. Thus we observed both accumulation of thermal damage at the molecular level and heat hardening at the phenotypic level as a consequence of heat exposure. The balance between these processes is dependent on ramping rate leading to the observed variation in thermal tolerance when using different rates. © 2013. Published by The Company of Biologists Ltd.
Olsen N.V.,430 As |
Grunert K.G.,University of Aarhus |
Sonne A.-M.,University of Aarhus
Trends in Food Science and Technology | Year: 2010
The food industry continuously develops new products and new processing techniques. While food scientists may focus on the technical novelty and applaud the progress of science, consumers are often conservative and sceptical towards changes. The advantages that a new processing technology has to offer, do not necessarily guarantee the success of a product in the market place. Consumer acceptance depends on whether they perceive any specific benefits associated with the product. This review focuses specifically on how high-pressure processing (HPP) and pulsed-electric field (PEF) technologies and products produced by means of these novel technologies are perceived by consumers. © 2010 Elsevier Ltd.
Tomic O.,430 As |
Forde C.,Nestlé |
Delahunty C.,CSIRO |
Naes T.,430 As
Food Quality and Preference | Year: 2013
Many statistical methods exist for evaluation of different aspects of assessor and panel performance. In order to gain a realistic and exhaustive overview over each individual's performance in different areas a large number of statistical results or plots need to be considered. Such a process often can be time consuming, cumbersome and may lead to biased conclusions. The proposed performance indices framework aims to act as an effective and practical complementary screening tool for panel leaders to help them quickly detect off-performances by assessors. The framework provides performance indices in the three following areas: agreement, repeatability and discrimination. Performance indices for agreement and repeatability are based on computations of either RV or RV2 coefficients, while the discrimination index is based on results from one- and two-way ANOVA. The performance indices can be easily presented in tables or graphs. Results show that they effectively detect underperforming assessors, and in combination with influence plots, provide a useful first overall impression in a rapid manner. Detailed performance issues can then be studied further in more detail with established statistical methods for performance evaluation. © 2012 Elsevier Ltd.
Olsen N.V.,430 As |
Menichelli E.,430 As |
Sorheim O.,430 As |
Naes T.,430 As
Food Quality and Preference | Year: 2012
The aim of this study is to determine drivers of consumers' likelihood of buying healthy convenience meals. Convenience meals, like hamburger, pizza and other fast food meals are often perceived as unhealthy food choices, and previous studies have stated different drivers of convenience and healthy food choices. In this study, a new concept of a complete and healthy ready-to-heat (RTH) meal was developed and tested in an at-home study in Norway. Since previous at-home testing of meals has been conducted on products like soup and lasagne, we adapted a new procedure for at-home testing of more complex meals. Based on an extensive literature review of factors previously found to influence consumers' healthy food choice, a model was developed and tested by multifactor ANOVA and multiple regression. The results indicate that the likelihood of buying healthy convenience food is first of all affected by overall liking of the meal, which is affected by liking of sensory specific product attributes like appearance, flavour, and odour. Effects of socio-demographic factors are found to be product dependent. Gender, age, education, as well as the interaction between health orientation and age, education and age, and education and overall liking influence consumers' likelihood of buying the salmon meal, while no significant socio-demographic drivers are found for the chicken meal. © 2011 Elsevier Ltd.
Olsen N.V.,430 As |
Sijtsema S.J.,Wageningen University |
Hall G.,Swedish Institute for Food and Biotechnology
Appetite | Year: 2010
This study investigates the usefulness of integrating moral attitude into the Theory of Planned Behavior (TPB) model when predicting intention to consume ready-to-eat (RTE) meals. Questionnaire data were gathered in three countries: Norway (N=112), The Netherlands (N=99), and Finland (N=134) in spring 2009. A stepwise hierarchical regression was conducted, and the analyses showed that moral attitude is an important predictor of RTE-meal consumption. The feeling of moral obligation, operationalised as a negative feeling of guilt, had a negative effect on peoples' intention to consume ready meals in all the three countries tested, and the explained variance (R2) for TPB increased when moral was added as an explanatory factor. However, although the test showed significant results for the effect of attitude towards behavior and moral in all countries, non-significant results were observed for the effect of subjective norm in both The Netherlands and Norway when moral attitude was included to the TPB-model, indicating cultural differences in the social pressure towards ready meal consumption. © 2010 Elsevier Ltd.
Naes T.,430 As |
Lengard V.,430 As |
Bolling Johansen S.,430 As |
Hersleth M.,430 As
Food Quality and Preference | Year: 2010
This paper is about methods for combining design variables, consumer preference and additional information about consumers in conjoint analysis. Methods which are based on combination of ANOVA and PCA will be given main attention. Advantages and disadvantages of the methods will be analysed. The methods will be illustrated using an example from a conjoint study of dry cured ham. The methods tested give similar information about tendencies, but in different ways. © 2009 Elsevier Ltd. All rights reserved.
Naes T.,430 As |
Naes T.,Copenhagen University |
Tomic O.,430 As |
Afseth N.K.,430 As |
And 2 more authors.
Chemometrics and Intelligent Laboratory Systems | Year: 2013
This paper reviews the basic ideas underlying two new multi-block techniques, the SO-PLS and the PO-PLS regression methods. A discussion is given about how the two methods are related to each other and to standard regression and analysis of variance (ANOVA). In particular the relation between SO-PLS and Type I ANOVA is underlined. It is shown how the sums of squares can be split according to blocks introduced and also how two-way ANOVA applied to cross-validated residuals, can be utilised for testing significance of the blocks. Different ways of interpreting the results for both methods are considered and illustrated by examples. Relations to other proposed methods and ideas are discussed. © 2013 Elsevier B.V.