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- Characterization of triacylglycerols in Madeira laurel oil by HPLC-atmospheric pressure chemical ionization-MSPublication . Castilho, Paula C.; Costa, Maria do Céu; Rodrigues, Ana; Branco, Pedro Costa; Costa, MafalaaMadeira laurel oil was fractionated by liquid ex traction combined with TLC, and TAGs were analyzed by HPLC coupled with atmospheric pressure chemical ionization-MS (APCI-MS). Eluted molecular species compositions of the eluted TAG in the complex natural mixture were determined by GC identification of FAME and by LC-atmospheric pressure chemi cal ionization (APCI)-MS analysis of the lipid. The APCI-MS spectra of most TAG exhibited [M + H]+ and [M − RCOO]+ ions, which defined the M.W. and the molecular association of fatty acyl residues, respectively. Despite the relatively high de gree of saturation, with a saturated/unsaturated ratio of 0.70, no totally saturated TAG nor mixed asymmetric TAG with two sat urated FA (SSM or SSU, where S is saturated, M is monounsatu rated, and U is unsaturated) were found. This type of molecular structure provides a possible explanation for the relatively low m.p. (12–15°C) and also the high oxidative resistance observed.
- Autohydrolysis of Annona cherimola Mill. seeds: optimization, modeling and products characterizationPublication . Branco, P. C.; Dionísio, A.M.; Torrado, I.; Carvalheiro, F.; Castilho, P. C.; Duarte, L.C.Annona cherimola Mill. seeds are a residue of the industrial processing of this fruit, for which, presently, there is no industrial application. They have a considerable amount of oil, which can be converted into biodiesel, but the remaining lignocellulosic fraction still needs relevant added-value valorization routes. Inthis work,the selectivehemicelluloses removal by autohydrolysis was optimizedaiming tomaximize the yield of oligosaccharides with potential applications in food, pharmaceutical and cosmetic industries. A maximum of 10.4 g L−1 of oligosaccharides was obtained, for a severity factor of 3.6, where 74.5% of the original hemicellulose was solubilized. The process kinetics is presented, modeled (based on the Arrhenius equation) and its scale-up is dis cussed. The hydrolyzate shelf-life was evaluated and the produced oligosaccharides are stable at room temperature for, at least, 3 weeks. Furthermore, all oligosaccharides are also stable at 100 ◦C for 1 h, in pH values between 1 and 11, enabling their industrial processing, and at 37 ◦C for 3 h, in pH values between 1 and 3, thus indicating its potential classification as non-digestible oligosaccharides. The remaining cel lulose enriched solids presented an increased enzymatic digestibility (as a function of the autohydrolysis severity) that assures its efficient use in subsequent processes (e.g., bioethanol production). The upgrade route developed in this work in combination to the previously reported use of A. cherimola seed oil for biodiesel production can lead to an integrated zero-waste valorization strategy within the biorefinery framework.
- Integrated valorization of Anona Cherimola Mill. seedsPublication . Branco, Pedro Miguel Sena da Costa; Castilho, Paula Cristina Machado Ferreira; Duarte, Luís Jorge Abreu Chorão de QuelhasAgricultural and agro-industrial residues are often considered both an environmental and an economical problem. Therefore, a paradigm shift is needed, assuming residues as biorefinery feedstocks. In this work cherimoya (Annona cherimola Mill.) seeds, which are lipid-rich (ca. 30%) and have a significant lignocellulosic fraction, were used as an example of a residue without any current valorization. Firstly, the lipid fraction was obtained by solvent extraction. Extraction yield varied from 13% to 28%, according to the extraction method and time, and solvent purity. This oil was converted into biodiesel (by base-catalyzed transesterification), yielding 76 g FAME/100 g oil. The obtained biodiesel is likely to be incorporated in the commercial chain, according to the EN14214 standard. The remaining lignocellulosic fraction was subjected to two alternative fractionation processes for the selective recovery of hemicellulose, aiming different products. Empirical mathematical models were developed for both processes, aiming future scale-up. Autohydrolysis rendered essentially oligosaccharides (10 gL-1) with properties indicating potential food/feed/pharmacological applications. The remaining solid was enzymatically saccharified, reaching a saccharification yield of 83%. The hydrolyzate obtained by dilute acid hydrolysis contained mostly monosaccharides, mainly xylose (26 gL-1), glucose (10 gL-1) and arabinose (3 gL-1), and had low content of microbial growth inhibitors. This hydrolyzate has proven to be appropriate to be used as culture media for exopolisaccharide production, using bacteria or microbial consortia. The maximum conversion of monosaccharides into xanthan gum was 0.87 g/g and kefiran maximum productivity was 0.07 g.(Lh)-1. This work shows the technical feasibility of using cherimoya seeds, and materials as such, as potential feedstocks, opening new perspectives for upgrading them in the biorefinery framework.
- Characterization of Annona cherimola mill. Seed oil from Madeira Island: a possible biodiesel feedstockPublication . Branco, Pedro Costa; Castilho, Paula C.; Rosa, Maria Fernanda; Ferreira, JuanThe possibility of using Annona seed oil as an added value product, namely as a source of biodiesel, is explored. Milled Annona seeds were extracted with hexane at room temperature (72 h) and at solvent boiling point (6 h). Oil content was found to be 25 and 22.4% respec tively. The oil was characterized in terms of lipid compo sition (HPLC–APCI–MS and 13C NMR), resistance to oxidation and acidity index. FAME composition was determined by GC–MS and five major peaks were identi fied. Production of biodiesel from Annona’s seed oil was achieved by base-catalyzed transesterification. Density, viscosity, refraction coefficient, acid value, cold filter plugging point, cloud point and oxidation stability were measured. The iodine value and the ‘‘apparent cetane number’’ were calculated. Density, viscosity, acid value, iodine value, cold filter plugging point and cloud point were within EN14214 specifications and the calculated ‘‘apparent cetane number’’ was also indicative of a suitable product.