Overview of the Metabolite Composition and Antioxidant Capacity of Seven Major and Minor Cereal Crops and Their Milling Fractions.

Cereal grains play an important role in human health as a source of macro- and micronutrients, besides phytochemicals. The metabolite diversity was investigated in cereal crops and their milling fractions by untargeted metabolomics ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) of 69 samples: 7 species (barley, oat, pearl millet, rye, sorghum, triticale, and wheat), 23 genotypes, and 4 milling fractions (husk, bran, flour, and wholegrain). Samples were also analyzed by in vitro antioxidant activity. UHPLC-MS/MS signals were processed using XCMS, and metabolite annotation was based on SIRIUS and GNPS libraries. Bran and husk showed the highest antioxidant capacity and phenolic content/diversity. The major metabolite classes were phenolic acids, flavonoids, fatty acyls, and organic acids. Sorghum, millet, barley, and oats showed distinct metabolite profiles, especially related to the bran fraction. Molecular networking and chemometrics provided a comprehensive insight into the metabolic profiling of cereal crops, unveiling the potential of coproducts and super cereals such as sorghum and millet as sources of polyphenols.

Untargeted metabolomics analysis reveals improved phenolic profile in whole wheat bread with yerba mate and the effects of the bread-making process.

Untargeted metabolomics analysis was applied to evaluate the phenolic profile of whole wheat bread with yerba mate (YM) during the bread-making process (flour, dough and bread). The free, bound and total phenolic contents of the samples evaluated by the Folin-Ciocalteu method showed the highest values for the flour, dough and bread samples prepared with 4.5% YM in fine and medium particle sizes (flour 181.48 - 175.26 mg GAE/g; dough 149.62 - 141.40 mg GAE/g; and bread 148.32 - 147.00 mg GAE/g). Globally, 104 phenolic compounds were tentatively identified, belonging to the five subclasses: flavonoids (35), phenolic acids (32), other polyphenols (10), stilbenes (2) and lignan (1). Of these compounds, 24 had the same m/z but showed different fragmentation profiles. A higher number of polyphenols was identified in the bound extracts (77%) than in the free extracts (59%). The addition of 4.5% of YM promoted an improved and more abundant profile of phenolic compounds in the dough and bread. The major compounds found in the samples containing YM were 5-caffeoylquinic acid and caffeic acid. The baking process did not adversely affect the abundance of phenolic compounds. The bread-making process positively affected the phenolic profile due to the release of bound phenolic compounds. At the same time, the addition of YM as a natural ingredient promoted an increase in the polyphenols in the bread.

Evaluation of the antioxidant capacity, volatile composition and phenolic content of hybrid Vitis vinifera L. varieties sweet sapphire and sweet surprise.

Bioactive compounds were extracted using two different extraction solvents (acetone and water) from pulp and whole grape berries derived from hybrid Vitis vinifera L. varieties Sweet sapphire (SP) and Sweet surprise (SU) and were characterised based on a comprehensive metabolomic approach by chromatography coupled with mass spectrometry (UPLC-QTOF-MSE and GC-FID/MS). GC-FID/MS analysis was performed with two different extraction methods (solvent extraction method and solid-phase extraction). Anthocyanins were characterised and quantified by HPLC-UV. The antioxidant potential was assessed by different assays. SP acetone extract from grape skin had the highest mean to DPPH, FRAP, ORAC and phenolic content SP samples, also showed higher anthocyanin content. Globally, 87 phenolic compounds were identified. The relative quantification by UPLC-MSE showed flavonoids the most abundant class. Forty two compounds were found in the volatile fraction of SU, while only thirty one volatile compounds were found in the SP samples.

Production of bioactive films of carboxymethyl cellulose enriched with green coffee oil and its residues.

Carboxymethyl cellulose (CMC)-based films were developed by incorporating green coffee oil (GCO) obtained by cold pressing and hydroalcoholic extracts of its residues. The effect of cake (CE) and sediment extracts (SE) in different proportions (20-40%) and GCO on chemical, morphological, physical, mechanical, optical, and antioxidant properties of the films was investigated. Eight fatty acids and four major phenolic compounds were identified by High-Resolution Direct-Infusion Mass Spectrometry in GCO and residue extracts. FTIR indicated interactions among CMC, phenolic compounds, and fatty acids. Films enriched with residue extracts presented heterogeneous microstructure. The tensile strength of the films decreased from 58 to 3 MPa with the extracts concentration, while elongation increased from 28 to 156% (p < 0.05). The water vapor permeability (averaging 3.94 × 10-8 g mm/cm2 h Pa) was not significantly affected by the extracts and GCO. The surface color was influenced by the type and concentration of extracts (p < 0.05), the film with SE40% had remarkable UV-vis barrier properties. The incorporation of GCO residue extracts imparted high antioxidant capacity to the CMC-based films, especially with CE40% (643.8 µmol Trolox eq./g dried film; 51.3 mg GAE/g dried film). General observations indicated the potential of these films, mainly the ones containing CE, like active packaging material for food applications.

Effects of cooking on the phytochemical profile of breadfruit as revealed by high-resolution UPLC-MSE.

BACKGROUND: This study evaluated the impact of cooking on the profile of bioactive compounds in unripe breadfruit. To this end, the accessibility of bioactive compounds by various solvents was assessed through total phenolic content and antioxidant capacity analyses. The most efficient solvent was applied to extract the metabolites, which were evaluated by ultra-performance liquid chromatography coupled with high-resolution quadrupole time-of-flight mass spectrometry in MSE mode. RESULTS: Cooked and raw breadfruit presented total phenolic content and antioxidant capacities in almost all extracts, and pure water proved to be the best extractor. Globally, 146 bioactive compounds have been identified for both raw and cooked fruits' aqueous extracts. Most of these compounds were stable to the heat treatment applied (121 °C/10 min). However, results revealed that 22 metabolites contributed to significantly distinguishing the raw from the cooked samples. Among those, 15 compounds, such as pyrogallol, 1-acetoxypinoresinol, and scopolin, evidenced higher relative abundance in the cooked extracts. On the other hand, only seven metabolites, such as 4-hydroxyhippuric acid, epicatechin, and leptodactylone, decreased post-heating. CONCLUSIONS: Cooking promoted little alteration in the bioactive compounds profile of immature breadfruit and thus appears to be an exploitation alternative for this perishable fruit, which seems to be a source of a large range of bioactive compounds. © 2019 Society of Chemical Industry.

Metabolomic approach for characterization of phenolic compounds in different wheat genotypes during grain development.

The phenolic-profiling of seven different wheat (Triticum aestivum) genotypes was investigated for the first time during different stages of grain development (milky, softy, physiological maturity and mature). Free and bound phenolic compounds were extracted separately and analyzed by UPLC-QTOF-MSE. Total phenolic content significantly decreased, up to 50% depending on the genotype, towards the maturation of grain. The highest content (free and bound) was observed in the most immature grains, while the lowest level was found in mature grains (408.0 and 165.0 GAE mg/100 g, respectively). Globally, 237 phenolic compounds were identified, divided into 5 classes: flavonoids (85), phenolic acids (77), other polyphenols (51), lignans (16) and stilbenes (8). UPLC-MS results showed a progressively decrease of the number of phenolic identification (ID) all along grain development, milky (213), softy (192), physiological maturity (169) and mature (144). The proportion bound to free phenolic progressively increased, reaching the maximum at physiological maturity, indicating a possible enzymatic reactions and complexation during grain growth. Ferulic acid, diphyllin, 4-hydroxybenzoic acid, ferulic acid isomer, apigenin 7-O-apiosyl-glucoside isomer and myricetin isomer were the most abundant compounds. Chemometric tools showed a clear separation between immature and mature grain for all genotypes. Phenolic profile varied significantly among genotypes, this result can help the selection of varieties towards a higher retention of bioactive compounds. Noteworthy, immature wheat grains can be considered a rich source of phenolic compounds and as an attractive ingredient to incorporate to functional foods.

Dataset on phenolic profile of seven wheat genotypes along maturation.

This article contains data on phenolic-profiling of seven wheat genotypes along maturation (softy, milky, physiological maturity and mature). This supplementary data is related to research "Metabolomic approach for characterization of phenolic compounds in different wheat genotypes during grain development" (Santos et al., 2018). Briefly, free and bound phenolic compounds were extracted with 80% ethanol (v/v) and hydrolysis processes, respectively. The aliquots resultants were separated by ultra-performance liquid chromatography (UPLC) and analyzed by quadrupole time-of-flight mass spectrometry (QTOF). Data were acquired using a multiplexed MS/MS acquisition with alternating low and high energy acquisition (MSE). The phenolic compounds with their respective abundances are showed here through characterization table and multivariate analysis (hierarchical cluster analysis-HCA-and principal component analysis-PCA).