Search results for "engineer"
showing 10 items of 44296 documents
Anti-Bacterial Activity and Online HPLC-DPPH Based Antiradical Kinetics of Medicinal Plant Extracts of High Relevance for Cosmetics Production
2018
The present study provides an assessment of extracts of six medicinal plants for their applicability in cosmetic formulations aimed at anti-UV protection and anti-acne treatment. Ethanol extracts of Chelidonium majus L., Myrtus communis L., Hamamelis virginiana L., Juniperus communis L., Alchemilla vulgaris and Ilex paraguariensis are analysed for the phytochemical content, antimicrobial activity, antiradical activity and antiradical kinetics. The phytochemical composition of the plants is investigated by LC-MS analysis and the most active antioxidants in plant extracts are determined by online HPLC-DPPH assay. The kinetic parameters of the antiradical reaction are determined both for the s…
Improvement of resveratrol production from waste residue of grape seed by biotransformation of edible immobilized Aspergillus oryzae cells and negati…
2017
Abstract A biotransformation method of producing resveratrol with immobilized Aspergillus oryzae negative pressure cavitation bioreactor (ICNPCB) with biphasic ionic liquid aqueous system pretreatment was investigated. Subsequently, the biotransformation conditions were optimized for the resveratrol production under types of ILs [C4MIM]Br, concentration of ILs 0.75 M, temperature 31 °C, ratios of solid to liquid 1:15 (mg/L), time 60 h and pH 6.0, the yield of resveratrol reached 224.61 ± 0.35 μg/g, which increased 4.36-fold to that of untreated one. The conversion rate of piceid reached 85.21%. The residual activity of immobilized microorganism was 82.26% after used for 15 runs. The develop…
Pulsed electric field and pH assisted selective extraction of intracellular components from microalgae Nannochloropsis
2015
Abstract The study was aimed at investigation of the potential of pulsed electric field (PEF) pre-treatment as a preliminary step of pH-assisted aqueous extraction of algae components from microalgae Nannochloropsis suspensions. The PEF and sonication (S) were compared as pretreatment methods. They were applied at normal (pH = 8.5) and basic (pH = 11) conditions, and supplementary basic extraction (at pH = 11) was done. The extracts were analyzed for content of pigments, proteins, carbohydrates, total phenolic compounds and antioxidant capacity. The colloidal stability of PEF- and S-pretreated suspensions was also evaluated. The data evidence that PEF technique allows selective extraction o…
Optimization of the Hydrolysis of Safflower Oil for the Production of Linoleic Acid, Used as Flavor Precursor
2015
Commercial lipases, from porcine pancreas (PPL),Candida rugosa(CRL), andThermomyces lanuginosus(Lipozyme TL IM), were investigated in terms of their efficiency for the hydrolysis of safflower oil (SO) for the liberation of free linoleic acid (LA), used as a flavor precursor. Although PPL, under the optimized conditions, showed a high degree of hydrolysis (91.6%), its low tolerance towards higher substrate concentrations could limit its use for SO hydrolysis. In comparison to the other investigated lipases, Lipozyme TL IM required higher amount of enzyme and an additional 3 h of reaction time to achieve its maximum degree of SO hydrolysis (90.2%). On the basis of the experimental findings, C…
Postharvest Application of Aloe vera Gel-Based Edible Coating to Improve the Quality and Storage Stability of Fresh-Cut Papaya
2020
Ready-to-eat products are damaged by various factors, including exposure to O2 and CO2, extreme temperatures, and rapid decay, due to trauma during processing. The use of natural antimicrobial agents and antioxidants might extend the shelf-life of the fruits. The aim of this work is to investigate the effects of four different antibrowning and gelling agents added into the Aloe vera gel-based edible coatings and applied to fresh-cut papaya. EC1 treatment consists of Aloe vera gel (30% v/v), EC2 contains CaCl2 (5% v/v), EC3 contains K carrageenan (0.5% v/v), and EC4 contains sodium alginate (1.5% v/v) and K carrageenan (0.5% v/v). The fruits treated with EC2 showed the best results while mai…
Primary production calculations for sea ice from bio-optical observations in the Baltic Sea
2016
Abstract Bio-optics is a powerful approach for estimating photosynthesis rates, but has seldom been applied to sea ice, where measuring photosynthesis is a challenge. We measured absorption coefficients of chromophoric dissolved organic matter (CDOM), algae, and non-algal particles along with solar radiation, albedo and transmittance at four sea-ice stations in the Gulf of Finland, Baltic Sea. This unique compilation of optical and biological data for Baltic Sea ice was used to build a radiative transfer model describing the light field and the light absorption by algae in 1-cm increments. The maximum quantum yields and photoadaptation of photosynthesis were determined from 14C-incorporatio…
A Knowledge-Based System as a Sustainable Software Application for the Supervision and Intelligent Control of an Alcoholic Fermentation Process
2020
One goal of specialists in food processing is to increase production efficiency in accordance with sustainability by optimising the consumption of raw food materials, water, and energy. One way to achieve this purpose is to develop new methods for process monitoring and control. In the winemaking industry, there is a lack of procedures regarding the common work based on knowledge acquisition and intelligent control. In the present article, we developed and tested a knowledge-based system for the alcoholic fermentation process of white winemaking while considering the main phases: the latent phase, exponential growth phase, and decay phase. The automatic control of the white wine&rsquo
A simple modelling of crop water balance for agrometeorological applications
1991
Abstract A simple agrometeorological model of crop water balance is presented. It aims at the best estimate possible of the water balance components with the simplest formulation and the minimum set of input data. The model works with a time step of one day and uses rainfall and the calculated evapotranspiration as the climatic inputs. Some soil and crop characteristics, such as the maximum available moisture and crop coefficients are required as input parameters. The model is tested using experimental data obtained on wheat and lucerne crops in the Paris region. The sensitivity of the model is discussed and some possible applications to rainfed crop management are presented.
Systems Approach to Eastern Baltic Coastal Zone Management
2020
Relying on the results of multivariate analysis of the re-analysis case studies from the BaltCoast project, specific features of integrated coastal management (ICM) approaches in Estonia, Latvia, Lithuania, and the Kaliningrad Oblast of the Russian Federation are highlighted in this paper. Eleven Eastern Baltic ICM case studies have been re-analyzed in-depth, which was the main focus of the present paper, covering a wide range of coastal landscapes, themes, policy issues, and ICM approaches. Five principal components explaining 84.86% of the total variance of ICM factor scores have been elicited by calculating rotation sums of squared loadings: (1) Stakeholder Involvement
Stability Studies of Bioactive Compounds from Birch Outer Bark Ethanolic Extracts
2018
The literature survey summarizes information about birch outer bark phytochemical composition and details major components: betulin, betulinic acid, lupeol and ursolic acid. In the practical part of research birch outer bark major component stability against chemical and physical degradation was tested; total phenolic content and the antiradical activity of the degraded and nondegraded ethanolic extracts was studied using UV/VIS spectroscopy; the phytochemical composition of the birch outer bark ethanolic extract was investigated by HPLC-TOF/MS. The study of stability experiments has been carried out, which found that birch outer bark ethanolic extract compounds can be exposed to thermal an…