Ignazio Allegretta

Dr. Ignazio Allegretta

Department of Soil, Plant and Food Sciences, University of Bari, via Giovanni Amendola 165/A, 70126 Bari, Italy

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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9 October 2018 in Food & Function
Verified
Journal Article
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Vito ParadisoVito Paradiso
Vito Paradiso
MCMaria Castellino
Maria Castellino
Massimiliano RennaMassimiliano Renna
Massimiliano Renna
Concetta Eliana GattulloConcetta Eliana Gattullo
Concetta Eliana Gattullo
MCMaria Calasso
Maria Calasso
Pietro SantamariaPietro Santamaria
Pietro Santamaria
Besides the variety of colours and flavours, microgreens show interesting nutritional properties, mainly regarding their contents of mineral nutrients and bioactive compounds. To date, the literature has prevalently focused on the individual nutritional features of microgreens usually belonging to Brassicaceae. The present study reports an articulated nutritional profile of six genotypes of microgreens, belonging to three species and two families: chicory (Cichorium intybus L., Puglia's local variety ‘Molfetta’, CM, and cultivar ‘Italico a costa rossa’, CR) and lettuce (Lactuca sativa L. Group crispa, cultivar ‘Bionda da taglio’, LB, and ‘Trocadero’, LT), from Asteraceae; and broccoli (Brassica oleracea L. Group italica Plenk, Puglia's local variety ‘Mugnuli’, BM, and cultivar ‘Natalino’, BN) from Brassicaceae. All the microgreens, except LB, can be considered good sources of Ca, whilst LT and CM also showed considerable amounts of K. As regards bioactive compounds, Brassica microgreens were the richest in phenolic antioxidants. The microgreens also presented higher amounts of α-tocopherol and carotenoids compared to mature vegetables. In particular, broccoli microgreens and LB showed the highest amounts of vitamin E, while Asteraceae microgreens presented the highest levels of carotenoids. Due to their delicate tissues, fresh cut microgreens showed a shelf life not exceeding ten days at 5 °C. The results obtained highlight the possibility to exploit genetic biodiversity in order to obtain tailored microgreens with the desired nutritional profiles, with particular regard to mineral nutrients and bioactive compounds. Appropriate pre- and post-harvest strategies should be developed, so as to allow microgreens to retain as long as possible their nutritional value.


1 February 2021 in Heliyon
Verified
Journal Article
Open access
Davide De AngelisDavide De Angelis
Davide De Angelis
Antonella PasqualoneAntonella Pasqualone
Antonella Pasqualone
IAIgnazio Allegretta
Ignazio Allegretta
CPCarlo Porfido
Carlo Porfido
RTRoberto Terzano
Roberto Terzano
Carmine SummoCarmine Summo
Carmine Summo
Coarse (CF) and Fine (FF) fractions were obtained by dry fractionation (air classification) of raw micronized flour (RM) of kabuli chickpea, green pea, yellow and red lentil. Pea showed the highest phytate content in RM and CF. Stachyose was the main oligosaccharide in lentils, exceeding 50 mg g−1, whereas raffinose (39.9 mg g−1) was abundant in chickpea. Antinutritional factors were significantly enriched in FF, whereas decreased in CF. Total-reflection X-ray fluorescence identified potassium as the main macronutrient in pulses. Ca was highly variable, ranging from 0.92 to 0.28 g kg−1 in pea and yellow lentil, respectively. A significant shift of minerals was observed in FF, but despite the highest phytate content, phytate:Zn ratio of lentils was lower than RM, indicating that Zn was enriched more than phytates. Yellow lentil and pea FF showed a protein content higher than 55 g 100g−1. Dry fractionation significantly affected the physicochemical properties, indicating different potential use of fractions.

24 May 2022 in Nano Letters
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Journal Article
Open access
RGRoberto Grisorio
Roberto Grisorio
FFFrancesca Fasulo
Francesca Fasulo
AGAna Belén Muñoz García
Ana Belén Muñoz García
Michele PavoneMichele Pavone
Michele Pavone
DCDaniele Conelli
Daniele Conelli
GSGian Paolo Suranna
Gian Paolo Suranna
CsPbBr3 nanocrystals (NCs) passivated by conventional lipophilic capping ligands suffer from colloidal and optical instability under ambient conditions, commonly due to the surface rearrangements induced by the polar solvents used for the NC purification steps. To avoid onerous postsynthetic approaches, ascertained as the only viable stability-improvement strategy, the surface passivation paradigms of as-prepared CsPbBr3 NCs should be revisited. In this work, the addition of an extra halide source (8-bromooctanoic acid) to the typical CsPbBr3 synthesis precursors and surfactants leads to the in situ formation of a zwitterionic ligand already before cesium injection. As a result, CsPbBr3 NCs become insoluble in nonpolar hexane, with which they can be washed and purified, and form stable colloidal solutions in a relatively polar medium (dichloromethane), even when longly exposed to ambient conditions. The improved NC stability stems from the effective bidentate adsorption of the zwitterionic ligand on the perovskite surfaces, as supported by theoretical investigations. Furthermore, the bidentate functionalization of the zwitterionic ligand enables the obtainment of blue-emitting perovskite NCs with high PLQYs by UV-irradiation in dichloromethane, functioning as the photoinduced chlorine source.

1 October 2021 in Chemosphere
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Journal Article
Closed access
RTRoberto Terzano
Roberto Terzano
IRIda Rascio
Ida Rascio
IAIgnazio Allegretta
Ignazio Allegretta
CPCarlo Porfido
Carlo Porfido
Matteo SpagnuoloMatteo Spagnuolo
Matteo Spagnuolo
Concetta Eliana GattulloConcetta Eliana Gattullo
Concetta Eliana Gattullo

14 November 2019 in Nanoscale
Verified
Journal Article
Closed access
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RGRoberto Grisorio
Roberto Grisorio
Elisabetta FanizzaElisabetta Fanizza
Elisabetta Fanizza
IAIgnazio Allegretta
Ignazio Allegretta
DADAVIDE ALTAMURA
DAVIDE ALTAMURA
Marinella StriccoliMarinella Striccoli
Marinella Striccoli
GSGian Paolo Suranna
Gian Paolo Suranna
This study aims at rationalizing the effects of the lead/surfactant ratio on the structural evolution of cesium lead-bromide perovskite nanocrystals (NCs), ascertaining how their shape and surface composition can be modulated by suitably adjusting the ligand amount (an equivolumetric mixture of oleic acid and oleyl amine) relatively to lead bromide. The tailoring of the reaction conditions allows the obtainment of blue-emitting CsPbBr3 nanoplatelets in the presence of ligand excess, while green-emitting nanocubes are achieved under low-surfactant conditions. An insight into the NC's shape evolution dictated by the different reaction conditions suggests that the generation of CsPbBr3 nanoplatelets is controlled by the dimensions of [(RNH3)2(PbBr4)]n layers formed before the injection of cesium oleate. The growth step promoted by preformed layers is concomitant to (but independent from) the nucleation process of lead-based species, leading to centrosymmetric nanocubes (prevalent in low-surfactant regimes) or Cs4PbBr6 NCs (prevalent in high-surfactant regimes). The proposed NC growth is supported by the analysis of the optical properties of non-purified samples, which reveal the selective presence of structures endowed with four cell unit average thickness accompanying larger emissive nanocubes. By combining nuclear magnetic resonance (NMR) and UV-Vis spectroscopy techniques, it is ascertained that the lead/surfactant ratio also controls the relative proportion between lead-based species (PBr2, PbBr3 −, PbBr4 2− and plausibly PbBr5 3− or PbBr6 4−) formed before cesium injection, which regulate the size of [(RNH3)2(PbBr4)]n layers as well as the formation of Cs4PbBr6 NCs during the nucleation stage. The surface chemistry of the differently structured perovskite NCs is investigated by correlating the elemental composition of the nanoparticles with specific NMR signals ascribable to the surface ligands. This level of investigation also sheds light on the stability of the time-dependent fluorescence exhibited by differently composed perovskite NCs before the loss of their colloidal integrity. Our findings can bring about a fine tuning of the synthetic methods currently employed for controlling the shape and surface chemistry of perovskite NCs.