Characterization of Nanovesicles Isolated from Olive Vegetation Water.

Edible plant and fruit-derived nanovesicles (NVs) are membrane-enclosed particles with round-shape morphology and signaling functions, which resemble mammalian cell-derived extracellular vesicles. These NVs can transmit cross-kingdom signals as they contain bioactive molecules and exert biological effects on mammalian cells. Their properties and stability in the gastrointestinal tract suggest NVs as a promising nutraceutical tool. In this study, we have demonstrated for the first time the presence of NVs in olive vegetation water (OVW), a waste by-product generated during olive oil production. Biophysical characterization by scanning electron microscopy, cryo-transmission electron microscopy, and nanoparticle tracking analysis revealed the presence in OVW of NVs having size and morphology similar to that of vesicles isolated from edible plants. Integrated lipidomic, metabolomic, and proteomic analyses showed that OVW-NVs carry a set of lipids, metabolites and proteins which have recognized antioxidant and anti-inflammatory activities. The nature of biomolecules identified in OVW-NVs suggests that these vesicles could exert beneficial effects on mammalian cells and could be used in the nutraceutical and food industries. The successful isolation of OVW-NVs and the characterization of their features strengthen the idea that agricultural waste might represent a source of NVs having features similar to NVs isolated from edible plants/fruits.

Investigating phenotypic relationships in persimmon accessions through integrated proteomic and metabolomic analysis of corresponding fruits.

Together with phenological and genomic approaches, gel-based and label-free proteomic as well metabolomic procedures were separately applied to plants to highlight differences between ecotypes, to estimate genetic variability within/between organism populations, or to characterize specific mutants/genetically modified lines at metabolic level. To investigate the possible use of tandem mass tag (TMT)-based quantitative proteomics in the above-mentioned contexts and based on the absence of combined proteo-metabolomic studies on Diospyros kaki cultivars, we here applied integrated proteomic and metabolomic approaches to fruits from Italian persimmon ecotypes with the aim to characterize plant phenotypic diversity at molecular level. We identified 2255 proteins in fruits, assigning 102 differentially represented components between cultivars, including some related to pomological, nutritional and allergenic characteristics. Thirty-three polyphenols were also identified and quantified, which belong to hydroxybenzoic acid, flavanol, hydroxycinnamic acid, flavonol, flavanone and dihydrochalcone sub-classes. Heat-map representation of quantitative proteomic and metabolomic results highlighted compound representation differences in various accessions, whose elaboration through Euclidean distance functions and other linkage methods defined dendrograms establishing phenotypic relationships between cultivars. Principal component analysis of proteomic and metabolomic data provided clear information on phenotypic differences/similarities between persimmon accessions. Coherent cultivar association results were observed between proteomic and metabolomic data, emphasizing the utility of integrating combined omic approaches to identify and validate phenotypic relationships between ecotypes, and to estimate corresponding variability and distance. Accordingly, this study describes an original, combined approach to outline phenotypic signatures in persimmon cultivars, which may be used for a further characterization of other ecotypes of the same species and an improved description of nutritional characteristics of corresponding fruits.

In vivo absorptomics: Identification of bovine milk-derived peptides in human plasma after milk intake.

A dedicated two-step purification procedure prior to nanoliquid chromatography-electrospray-tandem mass spectrometry analysis enabled the identification of bovine milk-derived peptides absorbed and circulating in the plasma of three healthy volunteers who received 250 mL of pasteurized milk after a 10-days washout. The appearance and clearance of milk peptides in plasma were monitored at various time points. Overall, 758, 273 and 212 unique peptides derived from 15, 15 and 18 bovine milk proteins, respectively, were identified in the plasma of these volunteers, evidencing a substantial inter-individual variability. Peptides encrypting possible bioactive and/or immunogenic molecules originating from caseins, ß-lactoglobulin and minor milk proteins were detected. Peptide representation data revealed the combined action of endoproteases involved in primary hydrolysis during gastroduodenal digestion and exopeptidases that hydrolyse peptides in the small intestine. It remains to be established whether the half-life and concentration ranges of circulating milk-derived peptides may have any impacts on human health.

Polyphenol Profiling of Chestnut Pericarp, Integument and Curing Water Extracts to Qualify These Food By-Products as a Source of Antioxidants.

Plant polyphenols have beneficial antioxidant effects on human health; practices aimed at preserving their content in foods and/or reusing food by-products are encouraged. The impact of the traditional practice of the water curing procedure of chestnuts, which prevents insect/mould damage during storage, was studied to assess the release of polyphenols from the fruit. Metabolites extracted from pericarp and integument tissues or released in the medium from the water curing process were analyzed by matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) and electrospray-quadrupole-time of flight-mass spectrometry (ESI-qTOF-MS). This identified: (i) condensed and hydrolyzable tannins made of (epi)catechin (procyanidins) and acid ellagic units in pericarp tissues; (ii) polyphenols made of gallocatechin and catechin units condensed with gallate (prodelphinidins) in integument counterparts; (iii) metabolites resembling those reported above in the wastewater from the chestnut curing process. Comparative experiments were also performed on aqueous media recovered from fruits treated with processes involving: (i) tap water; (ii) tap water containing an antifungal Lb. pentosus strain; (iii) wastewater from a previous curing treatment. These analyses indicated that the former treatment determines a 6-7-fold higher release of polyphenols in the curing water with respect to the other ones. This event has a negative impact on the luster of treated fruits but qualifies the corresponding wastes as a source of antioxidants. Such a phenomenon does not occur in wastewater from the other curing processes, where the release of polyphenols was reduced, thus preserving the chestnut's appearance. Polyphenol profiling measurements demonstrated that bacterial presence in water hampered the release of pericarp metabolites. This study provides a rationale to traditional processing practices on fruit appearance and qualifies the corresponding wastes as a source of bioactive compounds for other nutraceutical applications.

The occurrence of genetic polymorphism and related non-allelic proteins increases the compositional complexity of goat α((s1)) -CN.

A genetic survey on three autochthonous goat breeds reared in Italy was carried out by a proteomic approach. This methodology, further to providing the phenotypic frequency of identified α(s1) genetic variants, allowed to determine (i) the additional constitutive presence of a non-allelic 'α(s1) -casein (CN) F like' protein in goat 'strong' α(s1) variants; (ii) an α(s1) -CN B(2) like protein, expressed at very low quantitative level, in goat 'weak' α(s1) -CN variants, and, as main focus; (iii) the occurrence of a new α(s1) -CN D(1) variant characterised by the lack of α(s1) (f59-69) sequence otherwise encoded by exon 9 in goat α(s1) B(2) reference. The same exon skipping event had been identified since 1990, as responsible of the 'weak quantitative class' of α(s1) -CN D variant (0.6 g/L), while the new α(s1) -CN D(1,) has been 'quantitatively' classified as an 'intermediate' variant, since 1.8 g/L per allele was assessed in the milk.