Utility of Metabolomics toward Assessing the Metabolic Basis of Quality Traits in Apple Fruit with an Emphasis on Antioxidants

A gas chromatography–mass spectrometry approach was employed to evaluate the use of metabolite patterns to differentiate fruit from six commercially grown apple cultivars harvested in 2008. Principal component analysis (PCA) of apple fruit peel and flesh data indicated that individual cultivar replicates clustered together and were separated from all other cultivar samples. An independent metabolomics investigation with fruit harvested in 2003 confirmed the separate clustering of fruit from different cultivars. Further evidence for cultivar separation was obtained using a hierarchical clustering analysis. An evaluation of PCA component loadings revealed specific metabolite classes that contributed the most to each principal component, whereas a correlation analysis demonstrated that specific metabolites correlate directly with quality traits such as antioxidant activity, total phenolics, and total anthocyanins, which are important parameters in the selection of breeding germplasm. These data sets lay the foundation for elucidating the metabolic basis of commercially important fruit quality traits

Recent trends in the analysis of amino acids in fruits and derived foodstuffs

The amino acid content of fruit and fruit-derived foods is intensely studied, because of their contribution to nutritional value, aroma, taste and health-promoting effects and their possible use as markers of origin and authenticity. In this review, based on 101 references, the most recent trends in the analysis of amino acids are presented: the most important techniques, the different sample treatment procedures (including derivatisation) and the most frequent applications are described and compared. Pertinent publications were retrieved from Scopus and Web of Knowledge database searches lastly performed in February 2012 with the keywords "amino acid", "analysis", "liquid chromatography", "gas chromatography", "electrophoresis", "fruit", "vegetables"; the time limit was set from the year 2000 onwards. Although amino acids have been analysed in foods for decades, new technical possibilities and advancements have allowed ever increasing accuracy and targeting of the methods, in order to overcome the challenges posed by the complex plant matrices and by their high intrinsic variability

Factors influencing sweet taste in apple

Sweet taste is a major determinant of apple fruit as driving a large part of consumer preferences. As a consequence, increase in sweetness is very frequently one of the targets in breeding programs and is a key parameter for evaluating apple quality. Its perception can be modulated by several factors, and it is important to understand the individual impact of each of them and the processes involved in order to interpret it better. This chapter reviews the studies of the past two decades dealing with apple and specifically its composition and the related sweet perception. It proposes an overview of the different aspects influencing sweet taste perception. First, global and sugar compositions of apple fruit are characterized followed by the definition of the principal relative methods of measurements. Then, a part is dedicated to the input brought by sensory analysis in apple sweet taste perception. Finally, the influences of volatile compounds and then texture on sweet taste perception are expose