Late glacial and Holocene landscape change and rapid climate and coastal impacts in the Canal Beagle, southernmost Patagonia

Palaeoenvironmental data for the Late Glacial and Holocene periods are provided from Caleta Eugenia, in the eastern sector of Canal Beagle, southernmost Patagonia. The record commences at c. 16 200 cal a bp following glacier retreat in response to climatic warming. However, cooler conditions persisted during the Late Glacial period. The onset of more temperate conditions after c. 12 390 cal a bp is indicated by the arrival of southern beech forest and later establishment at c. 10 640 cal a bp, but the woodland growth was restricted by lower levels of effective moisture. The climate signal is then truncated by a rapid marine incursion at c. 8640 cal a bp which lasted until a more gradual emergence of the coast at c. 6600 cal a bp. During this period the pollen record appears to be dominated by the southern beech woodland. A punctuated hydroseral succession follows the isolation of the site from the sea leading to the re‐establishment of a peat bog. Between c. 5770 cal a bp and the present there were several periods of short rapid climatic change leading to drier conditions, probably as a result of late Holocene periods of climatic warming

Late glacial and Holocene landscape change and rapid climate and coastal impacts in the Canal Beagle, southernmost Patagonia

Palaeoenvironmental data for the Late Glacial and Holocene periods are provided from Caleta Eugenia, in the eastern sector of Canal Beagle, southernmost Patagonia. The record commences at c. 16 200 cal a bp following glacier retreat in response to climatic warming. However, cooler conditions persisted during the Late Glacial period. The onset of more temperate conditions after c. 12 390 cal a bp is indicated by the arrival of southern beech forest and later establishment at c. 10 640 cal a bp, but the woodland growth was restricted by lower levels of effective moisture. The climate signal is then truncated by a rapid marine incursion at c. 8640 cal a bp which lasted until a more gradual emergence of the coast at c. 6600 cal a bp. During this period the pollen record appears to be dominated by the southern beech woodland. A punctuated hydroseral succession follows the isolation of the site from the sea leading to the re‐establishment of a peat bog. Between c. 5770 cal a bp and the present there were several periods of short rapid climatic change leading to drier conditions, probably as a result of late Holocene periods of climatic warming

Production of fructo-oligosaccharides by Aspergillus ibericus and their chemical characterization

A great demand for prebiotics is driving the search for new sources of fructo-oligosaccharides (FOS) producers and for FOS with differentiated functionalities. In the present work, FOS production by a new isolated strain of Aspergillus ibericus was evaluated. The temperature of fermentation and initial pH were optimized in shaken flask to yield a maximal FOS production, through a central composite experimental design. FOS were produced in a one-step bioprocess using the whole cells of the microorganism. The model (R2 = 0.918) predicted a yield of 0.56, experimentally 0.53 ± 0.03 gFOS.ginitial sucrose1 was obtained (37.0 °C and a pH of 6.2). A yield of 0.64 ± 0.02 gFOS.ginitial sucrose1 was obtained in the bioreactor, at 38 h, with a content of 118 ± 4 g.L1 in FOS and a purity of 56 ± 3%. The chemical structure of the FOS produced by A. ibericus was determined by HPLC and NMR. FOS were identified as 1-kestose, nystose, and 1F-fructofuranosylnystose. In conclusion, A. ibericus was found to be a good alternative FOS producer.Clarisse Nobre acknowledges the Portuguese Foundation forScience and Technology (FCT) for her Post-Doc Grant [ref. SFRH/BPD/87498/ 2012] and the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124FEDER-027462), the strategic funding of UID/BIO/04469/2013 unit, COMPETE 2020 (POCI-01-0145-FEDER-006684), BioTecNorte operation(NORTE-01-0145-FEDER-000004) and the project MultiBiorefinery (POCI-01-0145-FEDER-016403) funded by European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Characterization and quantitation of short chain fructooligosaccharides and inulooligosaccharides in fermented milks by high-performance anion-exchange chromatography with pulsed amperometric detection

With the increased interest in the possible link between fructooligosaccharides (FOS) intake from functional foods and health, the need for reliable data on the individual FOS content of those foods has become very important. In this study a new high-performance anion-exchange chromatography coupled to pulsed amperometric detection (HPAEC-PAD) method is described for the selective determination of short-chain FOS and inulooligosaccharides (IOS) present in the investigated prebiotic food ingredients. Response factor of PAD was investigated in relationship with degree of polymerization and isomers. The developed HPAEC-PAD method has been applied to characterize short-chain oligosaccharides of the inulin series with DP ranging from DP3 to DP7 and IOS from DP2 to DP7. Their quantification in commercial water-soluble fibers of relevant importance as prebiotic food ingredient added in fermented milks has been performed. in order to evaluate the reliability of the proposed method, results have been compared with those obtained by the official enzymatic method. Furthermore, this new HPAEC-PAD method may contribute to clarify the real importance, prebiotic effectiveness and biological role of these carbohydrates

Determination of nitrates, nitrites and oxalates in food products by capillary electrophoresis with pH-dependent electroosmotic flow reversal.

This paper describes an innovative and rapid capillary electrophoretic method for the simultaneous analysis of nitrates. nitrites and oxalates, which are anions of food interest. The novelty of our method is based on reversing the electroosmotic flow without using any buffer additive nor performing a capillary coating, but simply employing a buffer at low pH values. The analytical conditions have been optimised and the proposed method has been fully validated following the EURACHEM guidelines. The method has been successfully applied to the analysis of different vegetable samples: furthermore nitrates' content has been evaluated for the first time in table sugars and dietary fibres. A comparison of our results with those obtained by a common HPLC method has also been carried out

Determination of flavanones in citrus byproducts and nutraceutical products by a validated RP-HPLC method

The aim of this work was to develop and validate a specific reversed phase high performance liquid chromatographic method (HPLC) using diode array detection (DAD) for the determination of flavanones, which is the dominant flavonoid class in the genus citrus. The procedures and criteria used for validation of the method including sensitivity, linearity, repeatability, recovery, and robustness were carried out following the EURACHEM guidelines. The validated RP-HPLC-DAD method was applied for the determination of the mainly flavanone glycosides contained in dried blood orange peel and dried lemon peel, and for the quantitation of flavanone glycosides and hesperetin in nutraceutical products