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

Soil salinity is destroying several hectares of arable land every minute. Because remedial land management cannot completely solve the problem, salt tolerant crops or plant species able to remove excessive salt from the soil could contribute significantly to managing the salinity problem. The key to engineering crops for salt tolerance lies in a thorough understanding of the physiological mechanisms underlying the adaptive responses of plants to salinity. Plant Salt Tolerance: Methods and Protocols describes recent advances and techniques employed by researchers to understand the molecular and ionic basis of salinity tolerance and to investigate the mechanisms of salt stress perception and signalling in plants. With chapters written by leading international scientists, this book covers nearly 30 different methods, such as microelectrode and molecular methods, imaging techniques, as well as various biochemical assays. Written in the highly successful Methods in Molecular BiologyTM series format, chapters contain introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and notes on troubleshooting and avoiding known pitfalls. Authoritative and easily accessible, Plant Salt Tolerance: Methods and Protocols serves as an essential read for every student or researcher tackling various aspects of the salinity problem.

Plant Salt Tolerance

Mechanisms of oxidative stress in plants: From classical chemistry to cell biology

Sugars play important roles as both nutrients and regulatory molecules throughout plant life. Sugar metabolism and signalling function in an intricate network with numerous hormones and reactive oxygen species (ROS) production, signalling and scavenging systems. Although hexokinase is well known to fulfil a crucial role in glucose sensing processes, a scenario is emerging in which the catalytic activity of mitochondria-associated hexokinase regulates glucose-6-phosphate and ROS levels, stimulating antioxidant defence mechanisms and the synthesis of phenolic compounds. As a new concept, it can be hypothesized that the synergistic interaction of sugars (or sugar-like compounds) and phenolic compounds forms part of an integrated redox system, quenching ROS and contributing to stress tolerance, especially in tissues or organelles with high soluble sugar concentrations.

https://febs.onlinelibrary.wiley.com/doi/epdf/10.1111/j.1742-4658.2010.07633.x

Sugar signalling and antioxidant network connections in plant cells.

Effect of thermal and non thermal processing technologies on the bioactive content of exotic fruits and their products: Review of recent advances

Effect of fruit blanching on phenolics and radical scavenging activity of highbush blueberry juice

The antioxidant properties of simple carbohydrates were studied in a chemical system. Hydroxyl radicals generated by a Fenton reaction induce damage on simple carbohydrates with a consequent free radical scavenging activity. Carbohydrate activities were measured by different methods as spin-trapping of hydroxyl radical and electron paramagnetic resonance detection and 1,1-diphenyl-2-picrylhydrazyl quenching. Carbohydrate damage was evaluated in a Fenton system by measuring the reactive substances to thiobarbituric acid, by their decreased detection with an HPLC test, and by a gas chromatographic determination of formic acid from sugar oxidation. Different intensities of damage and scavenging were found according to molecular structure, and some hyphotheses on the carbohydrate action against free radicals were attempted. The assayed disaccharides were shown to be more active toward and less damaged by hydroxyl radical than monosaccharides.

Fenton-dependent damage to carbohydrates: free radical scavenging activity of some simple sugars.

Phytochemical content in organic and conventionally grown Italian cauliflower

Organic acids influence on DPPH scavenging by ascorbic acid

Eggplant berries are a source of health-promoting metabolites including antioxidant and nutraceutical compounds, mainly anthocyanins and chlorogenic acid; however, they also contain some anti-nutritional compounds such as steroidal glycoalkaloids (SGA) and saponins, which are responsible for the bitter taste of the flesh and with potential toxic effects on humans. Up to now, Quantitative Trait Loci (QTL) for the metabolic content are far from being characterized in eggplant, thus hampering the application of breeding programs aimed at improving its fruit quality. Here we report on the identification of some QTL for the fruit metabolic content in an F2 intraspecific mapping population of 156 individuals, obtained by crossing the eggplant breeding lines "305E40" × "67/3." The same population was previously employed for the development of a RAD-tag based linkage map and the identification of QTL associated to morphological and physiological traits. The mapping population was biochemically characterized for both fruit basic qualitative data, like dry matter, °Brix, sugars, and organic acids, as well as for health-related compounds such chlorogenic acid, (the main flesh monomeric phenol), the two peel anthocyanins [i.e., delphinidin-3-rutinoside (D3R) and delphinidin-3-(p- coumaroylrutinoside)-5-glucoside (nasunin)] and the two main steroidal glycoalkaloids, solasonine, and solamargine. For most of the traits, one major QTL (PVE ≥10%) was spotted and putative orthologies with other Solanaceae crops are discussed. The present results supply valuable information to eggplant breeders on the inheritance of key fruit quality traits, thus providing potential tools to assist future breeding programs.

/pdf/mapping-quantitative-trait-loci-affecting-biochemical-and-18ndkho8gn.pdf

Roberto Lo Scalzo

Papers

Effect of fruit blanching on phenolics and radical scavenging activity of highbush blueberry juice

Fenton-dependent damage to carbohydrates: free radical scavenging activity of some simple sugars.

Phytochemical content in organic and conventionally grown Italian cauliflower

Organic acids influence on DPPH scavenging by ascorbic acid

Mapping Quantitative Trait Loci Affecting Biochemical and Morphological Fruit Properties in Eggplant (Solanum melongena L.)