Correlation between color parameters and bioactive compound content during cocoa seed transformation under controlled process conditions

The quality demanded by consumers in the cocoa sector has led to carrying out the postharvest transformation of cocoa,directing efforts to highlight properties of cocoa beans,such as the content of bioactive compounds,due to its beneficial effects on health,as well as its color,which varies from the typical brown color to the recently developed red-pink hues.This work aims to establish a correlation between the color parameters of a cocoa matrix obtained during the transformation of cocoa seeds under controlled process conditions(temperature,organic acid,and its concentration,and time)and the flavan-3-ols content(catechin,epicatechin,and epigallocatechin),methylxanthines content(theobromine,caffeine),and total phenolic content(TPC)through image analysis of color.The results showed that the content of flavan-3-ols and methylxanthines decreased as the controlled transformation advanced.However,the content of these bioactive compounds is retained by applying mild temperature conditions(30℃)and low concentrations of organic acid(1 g/L)to transform cocoa seeds.Furthermore,the color parameters respond to changes in the internal pH of the seeds,and the red-pink hues are favored when using high concentrations of organic acid(30 g/L).Based on these findings,it was possible to establish a correlation between epigallocatechin content and four color parameters(a^(∗),b^(∗),h_(ab)^(∗) and C_(ab)^(∗))through a multiple linear regression model.In this way,color image analysis could be an appropriate alternative to predict the concentration of quality-related compounds in cocoa matrices.

Genetic differentiation of grain, fodder and pod vegetable type cowpeas (Vigna unguiculata L.) identified through single nucleotide polymorphisms from genotyping-by-sequencing

The species Vigna unguiculata L.(Walp),commonly known as cowpea,is a multi-purpose legume that has been selected into three subspecies that are divided into grain,fodder and pod(yardlong bean)types.However,genetic bases for distinctions are not well understood.The purpose of this study was to apply genotyping-by-sequencing(GBS)and current reference genome for V.unguiculata to distinguish three subspecies and identify signatures of divergence.The collection of 130 accessions included 128 cultivated from:1)ssp.cylindrica,fodder type;2)ssp.sesquipedalis,pod vegetable type;and 3)ssp.unguiculata,grain type.Two wilds genotypes from spp.dekindtiana and spp.pubescens,were used to anchor phylogeny.A total of 11,083 highly informative single nucleotide polymorphisms(SNPs)were discovered.Wild accessions showed distinct genetic fingerprints and were separated from cultivated subspecies.Principal component analysis showed closer relationship between ssp.unguiculata and ssp.cylindrica compared to ssp.sesquipedalis.Relative differentiation of cultivated subspecies(with Fixation Index,FST)indicated the existence of discrete signatures of selection.This work clarifies the population structure,phylogeny,and domestication of cultivated cowpeas.Furthermore,significant genetic differences between grain and pod vegetable types can provide valuable information for future breeding in three cowpea groups.