Part of the book: Plants and Environment
Grape metabolites can be affected by many extrinsic and intrinsic factors, such as grape variety, ripening stage, growing regions, vineyard management practices, and edaphoclimatic conditions. However, there is still much about the in vivo formation of grape metabolites that need to be investigated. The winemaking process also can create distinct wines. Nowadays, wine fermentations are driven mostly by single-strain inoculations, allowing greater control of fermentation. Pure cultures of selected yeast strains, mostly Saccharomyces cerevisiae, are added to grape must, leading to more predictable outcomes and decreasing the risk of spoilage. Besides yeasts, lactic acid bacteria also play an important role, in the final wine quality. Thus, this chapter attempts to present an overview of grape berry physiology and metabolome to provide a deep understanding of the primary and secondary metabolites accumulated in the grape berries and their potential impact in wine quality. In addition, biotechnological approaches for wine quality practiced during wine alcoholic and malolactic fermentation will also be discussed.
Part of the book: Grape and Wine Biotechnology
Phenolic compounds are secondary metabolites abundant in our diet. These compounds may affect positively or negatively the sensory characteristics of food with important impacts on color, flavor, and astringency. An adequate consumption of phenolic compounds may also offer health benefits. After the consumption of fruits, the colon is the main site of microbial fermentation, where high molecular weight phenolic compounds are transformed into low molecular weight phenolic compounds such as phenolic acids or lactone structures by intestinal microbiota, which produce metabolites with biological and antioxidant activity, with evidence on health benefits for humans. A large amount of different phenolic compounds are responsible for physicochemical and sensory characteristics of table grapes and wines. Also, sweet cherry (Prunus avium L.) is one of the most popular temperate table fruits; they contain flavonoids, flavan‐3‐ols, and flavonols in addition to non‐flavonoid compounds. Anthocyanins are the major polyphenols in blueberries, and this group of phytochemicals is thought to be responsible for many of the health benefits of berry consumption. Therefore, considering the importance of red/dark‐colored fruits phenolic composition, the purpose of this chapter is to make a review of the most recent publications about these fruits’ phenolic composition and their impact on sensorial properties as well as the effect of microorganisms on fruit phenolic composition.
Part of the book: Phenolic Compounds
Aromas and flavours play an important role in horticultural crops’ quality, namely in fruits. Plant breeders have made considerable advances producing cultivars with higher yields, resistant to pests and diseases, or with high nutritional quality, without paying enough attention to flavour quality. Indeed, consumers have the perception that fruit aromas and flavours have declined in the last years. Attention is given nowadays not only to flavoured compounds but also to compounds with antioxidant activity such as phenolic compounds. Fruit flavour is a combination of aroma and taste sensations. Conjugation of sugars, acids, phenolics, and hundreds of volatile compounds contribute to the fruit flavour. However, flavour and aroma depend on the variety, edaphoclimatic conditions, agronomical practices and postharvest handling. This chapter reviews the aromas and flavours of the most important fruits and discusses the most recent advances in the genomics, biochemistry and biotechnology of aromas and flavours.
Part of the book: Generation of Aromas and Flavours