Anthocyanins are the most abundant flavonoid constituents of fruits and vegetables. The conjugated bonds in their structures, which absorb light at about 500 nm, are the basis for the red, blue and purple colours of fruits, vegetables and their products. Anthocyanin pigments readily degrade during thermal processing which can have a dramatic impact on colour quality and may also affect nutritional properties. This review attempts to summarize some important aspects of anthocyanin degradation during thermal processing. Conclusions regarding the mechanisms and kinetics of anthocyanin degradation during heat treatment are postulated based on current findings.

Effect of thermal processing on anthocyanin stability in foods; mechanisms and kinetics of degradation

Anthocyanins, synthesized via the flavonoid pathway, are a class of crucial phenolic compounds which are fundamentally responsible for the red color of grapes and wines. As the most important natural colorants in grapes and their products, anthocyanins are also widely studied for their numerous beneficial effects on human health. In recent years, the biosynthetic pathway of anthocyanins in grapes has been thoroughly investigated. Their intracellular transportation and accumulation have also been further clarified. Additionally, the genetic mechanism regulating their biosynthesis and the phytohormone influences on them are better understood. Furthermore, due to their importance in the quality of wine grapes, the effects of the environmental factors and viticulture practices on anthocyanin accumulation are being investigated increasingly. The present paper summarizes both the basic information and the most recent advances in the study of the anthocyanin biosynthesis in red grapes, emphasizing their gene structure, the transcriptional factors and the diverse exterior regulation factors.

http://disciplinas.stoa.usp.br/pluginfile.php/91135/mod_resource/content/1/molecules15%282010%299057.pdf

Biosynthesis of Anthocyanins and Their Regulation in Colored Grapes

Flavonoids and their glycosides, including anthocyanins

Natural Product Isolation: An Overview Satyajit D. Sarker, Zahid Latif, and Alexander I. Gray Initial and Bulk Extraction Veronique Seidel Supercritical Fluid Extraction Lutfun Nahar and Satyajit D. Sarker An Introduction to Planar Chromatography Simon Gibbons Isolation of Natural Products by Low-Pressure Column Chromatography Raymond G. Reid and Satyajit D. Sarker Isolation by Ion-Exchange Methods David G. Durham Separation by High-Speed Countercurrent Chromatography James B. McAlpine and Patrick Morris Isolation by Preparative High-Performance Liquid Chromatography Zahid Latif Hyphenated Techniques Satyajit D. Sarker and Lutfun Nahar Purification by Solvent Extraction Using Partition Coefficient Hideaki Otsuka Crystallization in Final Stages of Purification Alastair J. Florence, Norman Shankland, and Andrea Johnston Dereplication and Partial Identification of Compounds Laurence Dinan Extraction of Plant Secondary Metabolites William P. Jones and A. Douglas Kinghorn Isolation of Marine Natural Products Wael E. Houssen and Marcel Jaspars Isolation of Microbial Natural Products Russell A. Barrow Purification of Water-Soluble Natural Products Yuzuru Shimizu and Bo Li Scale-Up of Natural Product Isolation Steven M. Martin, David A. Kau, and Stephen K. Wrigley Follow-Up of Natural Product Isolation Richard J. P. Cannell Index

Natural products isolation

The color of food is often associated with the flavor, safety, and nutritional value of the product. Synthetic food colorants have been used because of their high stability and low cost. However, consumer perception and demand have driven the replacement of synthetic colorants with naturally derived alternatives. Natural pigment applications can be limited by lower stability, weaker tinctorial strength, interactions with food ingredients, and inability to match desired hues. Therefore, no single naturally derived colorant can serve as a universal alternative for a specified synthetic colorant in all applications. This review summarizes major environmental and biological sources for natural colorants as well as nature-identical counterparts. Chemical characteristics of prevalent pigments, including anthocyanins, carotenoids, betalains, and chlorophylls, are described. The possible applications and hues (warm, cool, and achromatic) of currently used natural pigments, such as anthocyanins as red and blue colorants, and possible future alternatives, such as purple violacein and red pyranoanthocyanins, are also discussed.

Natural Colorants: Food Colorants from Natural Sources

Since the identification of a new class of anthocyanin-derived pigments in red wine, the so-called pyranoanthocyanins, a lot of scientific information have been published dealing with different aspects of these pigments. Depending on their origin as well as different pathways of formation in foodstuff, the pyranoanthocyanins possess varying chemical structures. This report presents an overview of different classes of pyranoanthocyanins, their formation, occurrence, and their relevance for the color and analysis of aged fruit juices and wines.

Pyranoanthocyanins – an overview on structures, occurrence, and pathways of formation

Grenache red wines were produced following three different winemaking techniques, that is, small-scale standard experimental wines and industrial-scale wines by both double-mash fermentation and fermentation in Ganimede vats. Wines were analyzed for their color properties, as well as the anthocyanin, flavonol, hydroxycinnamic acid, and pyranoanthocyanin profiles following alcoholic and malolactic fermentation. The evolution of pyranoanthocyanins and their corresponding precursors in the experimental wines was monitored at 6 and 10 months of aging. Wines produced by double-mash fermentation exhibited superior color properties compared to Ganimede wines and the experimental red wines, due to better extraction of flavonols and anthocyanins as well as a lower degree of polymerization. Pyranoanthocyanin formation varied within the different classes of pigments. Vitisins A and B were formed only during alcoholic fermentation. Pinotin A (i.e., the reaction product from malvidin 3-glucoside and caffeic acid) formation took place only during the aging process, whereas formation of hydroxyphenyl-pyranoanthocyanins derived from p-coumaric and ferulic acid followed two different pathways, that is, an enzymatically assisted production during fermentation and a pure chemical formation during aging.

Formation of hydroxyphenyl-pyranoanthocyanins in Grenache wines: precursor levels and evolution during aging.

As the most visible role of anthocyanins is to impart colors, the adaptive significance of anthocyanins in plant reproductive organs is invariably attributed to the attraction of seed dispersers an

https://journals.sagepub.com/doi/pdf/10.1177/1934578X0800300808

Michael Rentzsch

Papers

Pyranoanthocyanins – an overview on structures, occurrence, and pathways of formation

Formation of hydroxyphenyl-pyranoanthocyanins in Grenache wines: precursor levels and evolution during aging.

Anthocyanins Reduce Fungal Growth in Fruits

Non-flavonoid Phenolic Compounds

Survey on the content of vitisin A and hydroxyphenyl-pyranoanthocyanins in Tempranillo wines.