Correction: study and characterization of an ancient European flint white maize rich in anthocyanins: Millo Corvo from Galicia

Polyphenols in Cereals: State of the Art of Available Information and Its Potential Use in Epidemiological Studies

Cereals are the basis of much of the world's daily diet. Recently, there has been considerable interest in the beneficial properties of wholegrains due to their content of phytochemicals, particularly polyphenols. Despite this, the existing data on polyphenolic composition of cereal-based foods reported in the most comprehensive databases are still not updated. Many cereal-based foods and phenolic compounds are missing, including pigmented ones. Observational epidemiological studies reporting the intake of polyphenols from cereals are limited and inconsistent, although experimental studies suggest a protective role for dietary polyphenols against cardiovascular disease, diabetes, and cancer. Estimating polyphenol intake is complex because of the large number of compounds present in foods and the many factors that affect their levels, such as plant variety, harvest season, food processing and cooking, making it difficult matching consumption data with data on food composition. Further, it should be taken into account that food composition tables and consumed foods are categorized in different ways. The present work provides an overview of the available data on polyphenols content reported in several existing databases, in terms of presence, missing and no data, and discusses the strengths and weaknesses of methods for assessing cereal polyphenol consumption. Furthermore, this review suggests a greater need for the inclusion of most up-to-date cereal food composition data and for the harmonization of standardized procedures in collecting cereal-based food data and adequate assessment tools for dietary intake.

Developing Germplasm and Promoting Consumption of Anthocyanin-Rich Grains for Health Benefits

Malnutrition, unhealthy diets, and lifestyle changes are the major risk factors for overweight and obesity-linked chronic diseases in humans adversely impact achieving sustainable development goals. Colored grains are a source of anthocyanins, a group of flavonoids, that contribute positively to human health. This review focuses on genetic variation harnessed through breeding and biotechnology tools for developing anthocyanin-rich grain crops. Agronomic practices, genotype × environment interactions, different stresses, seed development and seed maturity are factors that impact the content and composition of anthocyanins. Significant progress has been made in characterizing genes associated with anthocyanin biosynthesis in cereal and other crops. Breeding has led to the development and release of grain anthocyanin-rich crop cultivars in Europe, America and in some countries in Asia. Notably, genetic engineering utilizing specific transcription factors and gene editing has led to the development of anthocyanin-rich genetic variants without any significant yield penalty. A variety of food products derived from colored grains or flours are now available in grocery stores and supermarkets worldwide. The public perception about anthocyanin-rich food is positive, but availability, affordability, and willingness to pay a higher price than before limit consumption. Together with other seed nutrition traits in breeding programs the inclusion of anthocyanins can ensure the development of cultivars that meet nutrition needs of humans, especially in the developing world.

Back to beaked: Zea mays subsp. mays Rostrata Group in northern Italy, refugia and revival of open-pollinated maize landraces in an intensive cropping system

Crop landraces are fundamental resources to increase the eroded genepool of modern crops in order to adapt agriculture to future challenges; plus, they are of immeasurable heritage and cultural value. Between the 1940s and the 1960s open-pollinated varieties (OPVs) of flint and semi-flint maize in Europe were almost completely replaced by high-yielding hybrid dent cultivars selected in North America. No comprehensive assessment was performed after the 1950s to understand which maize genetic resources survived genetic erosion in northern Italy, an area characterized by a high degree of landraces extinction and introgression, intensive hybrid dent monocultures, as well as being one of the hotspots of maize cultivation at a continental level. Among these landraces, beaked maize represents a peculiar case study for assessing the survival of OPVs in intensive cropping systems. By means of ethnobotanical and literature surveys, the history of Zea mays subsp. mays Rostrata Group and its current distribution were reconstructed. It emerged that beaked maize originated in the study area and it is one of the oldest genepools available not subjected to formal crop improvement. We identified 28 landraces of beaked maize currently cultivated, 18 here recorded for the first time. The cultivation of more than half of the 28 landraces has continued throughout the last 80 years in a few fragmented localities that can be regarded as “refugia”. The survival of these landraces from substitution with high-yielding cultivars and unidirectional introgression has been mainly due to active on-farm conservation performed by custodian farmers and secondarily to cultivation in isolated areas (e.g., mountain valleys). After decades of genetic erosion, beaked maize has since the late 1990s experienced a revival, in terms of an increasing number of cultivation localities and the level of product commercialization. This process is mostly spontaneous and only occasionally mediated by governmental institutions; it is linked to the rediscovery of local food products, in this case mainly polenta, a dish made of corn flour, which used to be the staple food across northern Italy. The ex situ conservation of beaked maize and on-farm measures put in place by the farmers to prevent introgression are also assessed. Further research and collecting missions are needed to provide an inventory of open-pollinated landraces of other landrace groups that have survived genetic erosion in Europe. To meet this aim, extensive ethnobotanical surveys, such as the one performed here, are very powerful tools in detecting these genetic resources.