Publications by authors named "G T Backes"

51 Publications

Toxicity and larvicidal activity on Aedes aegypti of citronella essential oil submitted to enzymatic esterification.

Braz J Biol 2021 28;83:e244647. Epub 2021 Jun 28.

Programa de Pós-Graduação em Engenharia de Alimentos, Universidade Regional Integrada do Alto Uruguai e das Missões - URI Erechim, Erechim, RS, Brasil.

The essential oil of citronella (Cymbopogon winterianus) has several biological activities, among them the insect repellent action. Some studies showed that cinnamic acid esters can be applied as natural pesticides, insecticides and fungicides. In this context, the objective of the present work was to evaluate the production of esters from citronella essential oil with cinnamic acid via enzymatic esterification. Besides, the essential oil toxicity before and after esterification against Artemia salina and larvicidal action on Aedes aegypti was investigated. Esters were produced using cinnamic acid as the acylating agent and citronella essential oil (3:1) in heptane and 15 wt% NS 88011 enzyme as biocatalysts, at 70 °C and 150 rpm. Conversion rates of citronellyl and geranyl cinnamates were 58.7 and 69.0% for NS 88011, respectively. For the toxicity to Artemia salina LC50 results of 5.29 μg mL-1 were obtained for the essential oil and 4.36 μg mL-1 for the esterified oils obtained with NS 88011. In the insecticidal activity against Aedes aegypti larvae, was obtained LC50 of 111.84 μg mL-1 for the essential oil of citronella and 86.30 μg mL-1 for the esterified oils obtained with the enzyme NS 88011, indicating high toxicity of the esters. The results demonstrated that the evaluated samples present potential of application as bioinsecticide.
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http://dx.doi.org/10.1590/1519-6984.244647DOI Listing
July 2021

[Transition between gainful employment and retirement].

Z Gerontol Geriatr 2021 May 18. Epub 2021 May 18.

, Berlin, Deutschland.

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http://dx.doi.org/10.1007/s00391-021-01903-wDOI Listing
May 2021

Structural and Techno-Functional Properties of Bovine
Collagen and Its Application in Hamburgers.

Food Technol Biotechnol 2019 Sep;57(3):369-377

Department of Food Engineering, URI Erechim, Av. Sete de Setembro 1621, Erechim, RS, 99709910, Brazil.

The objective of this work is to characterize two types of bovine collagen (fibre and powder), evaluating its application in mixed hamburger formulations, as well as the quality characteristics of the products. The collagen fibre had a fibrillar structure, molecular mass 100 kDa and greater gel strength (146 315 Pa) and protein content (97.81%) than the powdered collagen, which had molecular mass from 50 to 100 kDa, greater hydroxyproline content, and a morphological structure with spherical microparticles more amorphous than the collagen fibre. In this study we found that the addition of 1.5% powdered collagen and 2.5% flocculated soybean flour and/or 0.75% powdered collagen and 3.5% flocculated soybean flour did not deteriorate the technological properties or the sensory attributes of hamburgers. The use of collagen is a promising alternative, since it has functional properties, improves the texture characteristics of a product, and is of low cost.
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http://dx.doi.org/10.17113/ftb.57.03.19.5896DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6902288PMC
September 2019

High pressure extraction of olive leaves (): bioactive compounds, bioactivity and kinetic modelling.

J Food Sci Technol 2019 Aug 10;56(8):3864-3876. Epub 2019 Jun 10.

Department of Food Engineering, URI Erechim, Av. Sete de Setembro, 1621, Erechim, RS 99700-000 Brazil.

In this study, the extraction yield, the mathematical modeling of pressurized liquid extraction (PLE) kinetics with sub- and supercritical carbon dioxide (SC-CO) of olive leaves () and the biological activity of the extracts were evaluated. The extraction with PLE was conducted isobarically (10.3 MPa), varying the temperature (20, 40 and 60 °C) and the solvent (ethyl acetate, acetone, ethanol, ethanol:water-80:20, v:v), solvent flow (2 mL min) and time (110 min) and the extractions with SC-CO, varying the temperature between 20 and 60 °C and the pressure between 8 and 25 MPa, keeping the time constant (210 min) and the CO flow of 2 mL min. In the extracts, antioxidant activity, total phenolic and flavonoid contents and oleuropein were evaluated. The highest total extract yield in the PLE was 30.91% at 60 °C, 10.3 MPa using ethanol:water (80:20, v:v). The yield obtained using the supercritical fluid was 0.68% at 60 °C and 25 MPa. The PLE extract obtained with ethanol at 60 °C presented the highest concentration of total phenolic content (386.42 mg GAE g extract), total flavonoids content (33.43 mg CAT g extract), oleuropein (73.65 mg g extract) and antioxidant activity (82.87%). The overall extraction curves were modeled using the well-established Sovová model and kinetic extraction model based on the Brunauer-Emmett-Teller theory of adsorption. Both kinetic models used were able to correlate well with the experimental data with slightly better results obtained by the former. The alternative PLE extraction technique investigated in this work was found to be suitable for the extraction of olive leaves after short times of extraction obtaining an extract with high biological activities.
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http://dx.doi.org/10.1007/s13197-019-03856-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6675833PMC
August 2019

Identification of Ideal Allele Combinations for the Adaptation of Spring Barley to Northern Latitudes.

Front Plant Sci 2019 3;10:542. Epub 2019 May 3.

Department of Plant Breeding, The Swedish University of Agricultural Sciences, Alnarp, Sweden.

The northwards expansion of barley production requires adaptation to longer days, lower temperatures and stronger winds during the growing season. We have screened 169 lines of the current barley breeding gene pool in the Nordic region with regards to heading, maturity, height, and lodging under different environmental conditions in nineteen field trials over 3 years at eight locations in northern and central Europe. Through a genome-wide association scan we have linked phenotypic differences observed in multi-environment field trials (MET) to single nucleotide polymorphisms (SNP). We have identified an allele combination, only occurring among a few Icelandic lines, that affects heat sum to maturity and requires 214 growing degree days (GDD) less heat sum to maturity than the most common allele combination in the Nordic spring barley gene pool. This allele combination is beneficial in a cold environment, where autumn frost can destroy a late maturing harvest. Despite decades of intense breeding efforts relying heavily on the same germplasm, our results show that there still exists considerable variation within the current breeding gene pool and we identify ideal allele combinations for regional adaptation, which can facilitate the expansion of cereal cultivation even further northwards.
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http://dx.doi.org/10.3389/fpls.2019.00542DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6510284PMC
May 2019
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