Diversity on color and phenolic compounds in apricot fruits

Genome-wide association of dry (Tamar) date palm fruit color

Date palm (Phoenix dactylifera) fruit (dates) are an economically and culturally significant crop in the Middle East and North Africa. There are hundreds of different commercial cultivars producing dates with distinctive shapes, colors, and sizes. Genetic studies of some date palm traits have been performed, including sex determination, sugar content, and fresh fruit color. In this study, we used genome sequences and image data of 199 dry dates (Tamar) collected from 14 countries to identify genetic loci associated with the color of this fruit stage. Here, we find loci across multiple linkage groups (LG) associated with dry fruit color phenotype. We recover both the previously identified VIRESCENS (VIR) genotype associated with fresh fruit yellow or red color and new associations with the lightness and darkness of dry fruit. This study will add resolution to our understanding of date color phenotype, especially at the most commercially important Tamar stage.

Biochemical Characterization of Traditional Varieties of Apricots (Prunus armeniaca L.) of the Campania Region, Southern Italy

Campania is the most important region of Italy in the apricot cultivation, present mostly in the Vesuvio area. At least to the best of our knowledge, no studies are reporting the biochemical characterization of the considerable number of traditional apricot varieties present on this territory, including the qualitative and quantitative profile of the polyphenols present. Our work evaluated the content of β-carotene, total phenolics, phenolic profiles, ascorbic acid and antioxidant activity of 23 traditional varieties of apricots of the Campania region. Principal component analysis (PCA) highlighted that, in the two main groups, the antioxidant activity was strongly affected by the content of ascorbic acid (-0.89), or slightly affected by the content of total polyphenols (-0.67), respect to the content of ascorbic acid (-0.55), never by β-carotene. Chlorogenic acid (up to 55.07 μg g^-1) and catechin (up to 96.15 μg g^-1) resulted the most abundant polyphenols recognized through the chromatographic analysis. PCA, extended to the polyphenol profile, confirmed the distribution of the varieties in two large groups, evidencing once again the hierarchical distance of four varieties ("Panzona", "Paolona" "Baracca" and "Boccucia Eboli") compared to the others.

Optimization of extraction methods for characterization of phenolic compounds in apricot fruit (Prunus armeniaca)

Fruits are rich in phenolic compounds with health-promoting activities. However, phenolic profiles vary between fruits. Hence, specific extraction methods are required for accurate profiling of the functional compounds. This study aims to develop an optimised method by response surface methodology to extract phenolics from apricots (Prunus armeniaca) and correctly characterise apricots' phenolic profile. For this, the effects of the solid-to-liquid ratio, temperature, extraction solvent, extraction time and sequential extraction steps on the extraction of major phenolic families were investigated. Methanol- and ethanol-based extractions were suitable, although methanol was the optimal solvent. The optimised extraction conditions were 20 g mL-1, 38 °C and 72% methanol (1% formic acid). When this method was used in apricots, the characterisation of their phenolic profile by HPLC-ESI-MS/MS showed a higher extraction of phenolic compounds than other studies in the literature that use non-specific extraction methods. The developed method is fast and economically feasible for accurate characterisation of the phenolic profile of apricot fruits and thus can be routinely used to extract apricot phenolic compounds for their characterisation.