Sara R. Jaeger

Analysis of genetically modified red‐fleshed apples reveals effects on growth and consumer attributes

Consumers of whole foods, such as fruits, demand consistent high quality and seek varieties with enhanced health properties, convenience or novel taste. We have raised the polyphenolic content of apple by genetic engineering of the anthocyanin pathway using the apple transcription factor MYB10. These apples have very high concentrations of foliar, flower and fruit anthocyanins, especially in the fruit peel. Independent lines were examined for impacts on tree growth, photosynthesis and fruit characteristics. Fruit were analysed for changes in metabolite and transcript levels. Fruit were also used in taste trials to study the consumer perception of such a novel apple. No negative taste attributes were associated with the elevated anthocyanins. Modification with this one gene provides near isogenic material and allows us to examine the effects on an established cultivar, with a view to enhancing consumer appeal independently of other fruit qualities.

Comparison of TCATA and TDS for dynamic sensory characterization of food products

Temporal Check-All-That-Apply (TCATA) has been recently introduced as a method for temporal sensory product characterization. Building on the standard Check-All-That-Apply (CATA) question format, assessors select all the terms they consider applicable for describing the sensations they perceive, and they do so at each moment of the evaluation process. This research further investigates the TCATA method, through its application to products of varying complexity (yogurt, salami, cheese, orange juice, French bread, and marinated mussels) using consumers and trained panellists as assessors. More importantly, to deliver new methodological insights we compare TCATA to Temporal Dominance of Sensations (TDS). This comparison will aid researchers to select the temporal method best suited to their needs. Across three countries, six studies were conducted. Within-subjects experimental designs were used in Studies 1-3 and involved trained panellists using both TCATA and TDS on the same set of products. In Studies 4-6, between-subjects experimental designs were used, and the assessors, who were consumers, evaluated samples using either TCATA or TDS. The results confirmed that TCATA is suitable for measuring the temporal sensory characteristics of products. By enabling identification of several sensory characteristics that are concurrently perceived in products, the results from this research also suggest that TCATA may provide a more detailed description of the dynamics of the sensory characteristics of products. The TDS concept of dominance appears to decrease detailed description and discrimination of attributes that are simultaneously perceived, particularly when dealing with multiple sensory modalities. The practical implications of these differences are discussed.

Measurement of Consumer Product Emotions Using Questionnaires

Product emotion research is a burgeoning area of research within academia and industry. The explosion in the number of methods for measuring emotions and the rapidly growing range of applications for emotion research have created a situation filled with both important measurement and methodological issues. In this chapter we describe the measurement techniques that are currently available to capture emotional responses to products using self-report questionnaires. In addition, we address the fundamental issues related to the application of these measurement techniques, including scale issues, reliability of methods, temporal capture of self-reports, and issues related to stimulus formats, presenting the most relevant research that addresses these issues. In this way, it is our hope to provide actionable guidance and direction to new investigators coming into this area of research, as well as to stimulate thought and ideas for new avenues of research related to the self-report of emotions using questionnaires.

Relationships between food neophobia and food intake and preferences: Findings from a sample of New Zealand adults

Food neophobia (FN) has been shown to be a strong influence on food preferences using primarily small data sets. This has limited the explanatory power of FN and the extent to which it can be related to other factors that influence food choice. To address these limitations, we collected Food Neophobia Scale data from 1167 adults from New Zealand over a 45-month period. Participants also completed a 112-item food preference questionnaire and a self-report 24 h, a 145 item food intake recall survey, and the Food Choice Questionnaire (FCQ). As a way of providing a structure to the food intake and preference data, in each case the food items were condensed into patterns described in terms of the foods/beverages with highest factor loadings. We then determined the impact of season and participant age, gender, education and income on these factors, as well as the interaction of these variables with FN scores, divided into tertiles. FN was a strong influence on both intake frequency and preferences in the majority of the intake/preference factor patterns. When significant associations with FN were established, both frequency of intake and preference was lower among high FN individuals. Notably, the effect of FN on food preferences was evident on many commonplace foods making up the diet, suggesting that high FN individuals like food overall less than do those with lower degrees of FN. Seasonal effects in food intake were demonstrated, but with smaller impact for higher levels of FN. While associations between FN varied according to all demographic variables, these relationships varied as a function of the intake/preference patterns. Overall, the results suggest that FN is an important barrier to dietary change and addressing diet-related health problems.

Methodological Issues in Consumer Product Emotion Research Using Questionnaires

Abstract Within academia and industry product-focused emotion research is currently attracting considerable attention. In this chapter, focus is directed to the use of questionnaires for product emotion research and methodological issues are discussed. By creating awareness of important empirical considerations in product emotion research, we seek to provide guidance for existing/new investigators in this area of research.

Analysing conjoint data with OLS and PLS regression: a case study with wine

BACKGROUND This paper presents a case study with wine where two statistical methods for the analysis of rating-based conjoint analysis data were applied. Traditionally, ordinary least squares (OLS) regression is used to estimate the relative importance of the experimental factors and the part-worth utilities of factor levels. Partial least squares (PLS) regression, which is a popular tool in sensory and consumer science, can also be used for the analysis of interval-level conjoint data. RESULTS Using conjoint analysis, purchase intentions for Californian red and white wine were obtained from a convenience sample of young US adults (n ≈ 250). OLS and PLS regression uncovered the same systematic patterns in the data: negative utility associated with more expensive wine, and positive utility associated with famous wine regions. While OLS regression provided more accessible top-line results, an advantage of PLS regression was the graphical format of results. This provided easy insight to individual differences in the importance attached to the factors driving purchase intention. CONCLUSION OLS and PLS regression can complement each other in the analysis of interval-level conjoint data. Dual analysis can help to ensure that the right insights are drawn from the study and communicated to internal/external clients. It may also facilitate communication within project teams.

Characteristics of eating occasions that contain fruit

Purpose – This exploratory study seeks to examine self‐reported recall of eating occasions that contain fruit. The aim is to obtain insights around the use of fruit in a range of eating occasions, and to identify the ways that various fruit types are incorporated into the diet.Design/methodology/approach – A longitudinal study obtained detail about eating occasions using 24‐hour dietary recall over a three‐month period. A total of 25 women aged between 35‐66 years with a moderate to high annual household income took part. There were 5,791 eating occasions reported, of which 29 per cent contained fruit.Findings – Individual fruit types were integrated into the diet in varying ways. Diversity was observed within and between participants in terms of the foods and beverages that were typically consumed during eating occasions that contained fruit. The paper documents contextual characteristics of eating occasions that featured individual fruit types.Research limitations/implications – The study comprised a sm...

Fitting Psychometric Functions Using a Fixed-Slope Parameter: An Advanced Alternative for Estimating Odor Thresholds With Data Generated by ASTM E679

Psychometric functions are predominately used for estimating detection thresholds in vision and audition. However, the requirement of large data quantities for fitting psychometric functions (>30 replications) reduces their suitability in olfactory studies because olfactory response data are often limited (<4 replications) due to the susceptibility of human olfactory receptors to fatigue and adaptation. This article introduces a new method for fitting individual-judge psychometric functions to olfactory data obtained using the current standard protocol-American Society for Testing and Materials (ASTM) E679. The slope parameter of the individual-judge psychometric function is fixed to be the same as that of the group function; the same-shaped symmetrical sigmoid function is fitted only using the intercept. This study evaluated the proposed method by comparing it with 2 available methods. Comparison to conventional psychometric functions (fitted slope and intercept) indicated that the assumption of a fixed slope did not compromise precision of the threshold estimates. No systematic difference was obtained between the proposed method and the ASTM method in terms of group threshold estimates or threshold distributions, but there were changes in the rank, by threshold, of judges in the group. Overall, the fixed-slope psychometric function is recommended for obtaining relatively reliable individual threshold estimates when the quantity of data is limited.

Genetic variation in taste and odour perception: an emerging science to guide new product development

Abstract: The human genetic revolution is upon us, and while at this stage, it is restricted to providing fundamental insights on human traits, the notion underpinning the present chapter is that an understanding of human genetic variability, in the not too distant future, will be turned into insights that can systematically inform innovation of desirable products in the food and beverage, and personal care industries. Acceptability is a key driver of product consumption and use, and the extent to which products are liked/disliked is informed by liking/disliking for the sensory attributes of the product. Sensory perception, in turn, is a complex phenomenon controlled by genetic and environmental influences. To date more is known about the latter type of influences, but the human genetic revolution has presented the opportunity to identify the genetic determinants of sensory perception, and by proxy, the extent to which liking has a genetic basis. The purpose of the present chapter is to introduce this emerging science, by way of reviewing: what is currently known about the genetic determinants of sensory acuity (notably taste and odour), what is known about the impact of genetic variation for these traits on food preference and consumption, and finally what realistically is the ability of using this knowledge to inform new product development. In the chapter emphasis is placed on discussing industry opportunities, both in the food and beverage, and personal care sectors, and also on identifying barriers to industry application of this emerging science.

Molecular gastronomy, chefs and food innovation: an interview with Michael Bom Frøst

Abstract: Michael Bom Frost speaks about molecular gastronomy, and emerging science that integrates technological advances in food science with gastronomes’ visions for new dishes that go beyond tasting fantastic, to surprising and challenging our senses and food experiences. The conversation progresses to explore how collaboration between chefs and food scientists can be a route to new product development by industry. Michael also speaks about the MAYA principle – Most Advanced, Yet Acceptable – as a framework for guiding innovation.