Sugars and carotenoids are recognized as key quality compounds in vegetables due to their sensory and nutritional attributes. Ensuring a guaranteed content for these compounds in carrot crop is a major challenge for producers and breeders. Widely involved in plant acclimation mechanisms, the environment significantly influences their content. A multi-environment trial over two years was used in this study to identify the environmental determinism of carotenoid and sugar accumulation. After a fine characterization of cropping places in dissecting climatic variables, pedological conditions and cultural practices, PLSr models were used for predictive purposes to determine and prioritise pedoclimatic factors and cultural practices involvement. Interestingly, distinctive patterns are observed between sugars and carotenoids. Pedoclimatic factors and cultural practices effects are similar regardless studied carotenoid, with a differential effect in accumulation according to α-branch and β-branch carotenoids. For sugar metabolism, a reverse effect of leading factors is observed depending on sugars class. Our study brings to light the overall limiting effect of some climatic factors as time exposure to low temperature or atmospheric humidity. In contrast, pedological factors were shown to enhance sugar and carotenoid content in carrot, mainly phosphorus, potassium, iron and boron. This study provides useful information for carrot producers to adapt their cultural practice depending on crop place to reach a guaranteed quality in crops. Moreover, our work paves the way for a better understanding of the mechanisms underlying the major pedoclimatic factors and cultural practices effects on the accumulation of key compounds.

This chapter provides information on some organoleptic quality of carrots, such as appearance, texture, taste and flavour, and the factors affecting sensory quality. Consumer preference and behaviour for sensory characteristics of carrots are also discussed.

Consumer dissatisfaction with the flavor quality of many modern fresh market tomato varieties has fostered breeders’ interest in sensory quality improvement, and the demand for traditional varieties, which are generally associated with better flavor. To achieve further knowledge on the factors influencing the sensory quality and consumers’ preferences and perception, European traditional and modern fresh market tomato varieties were grown and evaluated in France, Italy, and Spain. Different growing conditions were tested in France (soilless vs. soil) and in Spain (open field vs. greenhouse), while in Italy fruits were evaluated at two ripening stages. Fruit quality was assessed by integrating physicochemical analyses, sensory profiles, and consumer tests. In all three countries, overall modern varieties were perceived as having more intense “tomato flavor” and “overall flavor” than traditional ones. In France and Spain, consumers’ preferences were more oriented towards modern varieties than traditional ones. Significant growing condition effects were found on sensory and physicochemical traits, while the effect on consumers’ overall liking was not significant, largely depending on the genotype. A fair agreement between product configurations from descriptive analysis by trained assessors and Check-All-That-Apply (CATA) questions by consumers was observed. Penalty-lift analysis based on CATA allowed identifying positive and negative drivers of liking.

Renewed consumer demand motivates the nutritional and sensory quality improvement of fruits and vegetables. Specialized metabolites being largely involved in nutritional and sensory quality of carrot, a better knowledge of their phenotypic variability is required. A metabolomic approach was used to evaluate phenotypic plasticity level of carrot commercial varieties, over three years and a wide range of cropping environments spread over several geographical areas in France. Seven groups of metabolites have been quantified by HPLC or GC methods: sugars, carotenoids, terpenes, phenolic compounds, phenylpropanoids and polyacetylenes. A large variation in root metabolic profiles was observed, in relation with environment, variety and variety by environment interaction effects in decreasing order of importance. Our results show a clear diversity structuration based on metabolite content. Polyacetylenes, β-pinene and α-carotene were identified mostly as relatively stable varietal markers, exhibiting static stability. Nevertheless, environment effect was substantial for a large part of carrot metabolic profile and various levels of phenotypic plasticity were observed depending on metabolites and varieties. A strong difference of environmental sensitivity between varieties was observed for several compounds, particularly myristicin, 6MM and D-germacrene, known to be involved in responses to biotic and abiotic stress. This work provides useful information about plasticity in the perspective of carrot breeding and production. A balance between constitutive content and environmental sensitivity for key metabolites should be reached for quality improvement in carrot and other vegetables.

Although tomato flavor has not been a major goal for breeders, nowadays it becomes important as it is a subject of consumer complaint. A better knowledge of tomato consumer preferences, at the European level, should provide the basis for improvement of fruit quality and for market segmentation. In the framework of a large European project, 806 consumers from 3 countries, The Netherlands, France, and Italy, were presented with a set of 16 varieties representing the diversity of fresh tomato offer in order to evaluate their preferences. In parallel, sensory profiles were constructed by expert panels in each country. Preference maps were then constructed in each country revealing the structure of consumer preferences and allowing identification of the most important characteristics. Then a global analysis revealed that preferences were quite homogeneous across countries. This study identified the overall flavor and firmness as the most important traits for improving tomato fruit quality. It showed that consumer preferences from different European countries, with different cultures and food practices, are segmented following similar patterns when projected onto a common referential plan. Moreover, the results clearly showed that diversification of taste and texture is required to satisfy all consumers' expectations as some consumers preferred firm tomatoes, while others preferred melting ones and were more or less demanding in terms of sweetness and flavor intensity. Detailed comparisons also showed the importance of the fruit appearance in consumer preference.

Sensory properties are important elements to evaluate the qualities of vegetable products and are also determinant factors in purchasing decision. Here we report the Italian results of a preference mapping study conducted within a larger European project with the aim of describing the preferences of European consumers in regard to the diversity of traditional and modern tomato varieties, available on the market. This study has allowed the assessment of fruit quality at 3 levels: objective description of sensory properties, consumer preference tests, and physicochemical measurements. A set of 16 tomato cultivars, with different fruit sizes and shapes, was described and classified according to 18 sensory attributes including flavor, appearance, and texture characteristics. The same cultivars were evaluated by 179 consumers in a "preference mapping" experiment with the goal of identifying the preferred varieties and the reasons for the choice. The consumer data are referred to hedonic ratings (aspect liking and overall liking), familiarity for the analyzed cultivars, and individual features collected by a questionnaire. A hierarchical analysis of the clusters allowed to distinguish, within the sampled Italian consumers, 4 segments with different preferences which represented 19%, 25%, 41%, and 15% of the population, respectively. A partial least square regression model allowed the identification of the sensory attributes that best described consumer cluster preferences for tomato cultivars. Both texture and flavor descriptors were important drivers of consumer preferences, but the relevance (predictive value) of individual descriptors to model tomato liking was different for each consumer segment. Information on demographic and behavioral characteristics, usage habits, and factors relevant for purchasing were also provided on the 4 groups of consumers.

The objective of this study was to determine the impact of lowering nitrogen supply from 12 to 6 or 4 mM NO(3)(-) on tomato fruit yield and quality during the growing season. Lowering nitrogen supply had a low impact on fruit commercial yield (-7.5%), but it reduced plant vegetative growth and increased fruit dry matter content, improving consequently fruit quality. Fruit quality was improved due to lower acid (10-16%) and increased soluble sugar content (5-17%). The content of some phenolic compounds (rutin, a caffeic acid glycoside, and a caffeic acid derivate) and total ascorbic acid tended to be higher in fruit with the lowest nitrogen supply, but differences were significant in only a few cases (trusses). With regard to carotenoids, data did not show significant and univocal differences related to different levels of nitrogen supply. Thus, reducing nitrogen fertilization limited environmental pollution, on the one hand, and may improve, on the other hand, both growers' profits, by limiting nitrogen inputs, and fruit quality for consumers, by increasing tomato sugars content. It was concluded that primary and secondary metabolites could be affected as a result of a specific response to low nitrogen, combined with a lower degree of vegetative development, increasing fruit irradiance, and therefore modifying fruit composition.

Mealiness, mechanical breakdown and cell wall chemical structure of a mealy (cv 'Cameron') and a juicy (cv 'Quest') tomato (Lycopersicon esculentum Mill.) variety were studied over several weeks during the harvest period.A set-up was designed to break tomato pericarp, tissue while measuring the rupture energy. For 'Cameron', the rupture energy was high and decreased over the harvest period. For 'Quest', the rupture energy was low and did not vary throughout the study. The particles in the pulp after breakdown were characterized by image analysis. For 'Cameron', intact cells were always recovered from the pulp. Many cell fragments were obtained in the case of 'Quest'. At the end of the harvest period, 'Quest' had a higher content of intact cells. The chemical composition and structure of cell walls in pericarp tissue were determined by biochemical analysis, mid-infrared and solid-state NMR spectroscopy. Cell walls of 'Cameron' pericarp tissue were richer in neutral sugars and uronic acid than those of 'Quest'. The pectin content of 'Cameron' samples decreased over the harvest week and was compensated for by protein. 'Quest' was richer in mobile arabinan pectic side-chains than 'Cameron'.Mealiness was correlated with rupture energy, size of recovered particles and mid-infrared data. The data are discussed with regard to cell adhesion and rigidity. (c) 2005 Elsevier B.V. All rights reserved.