A market-driven algorithm for the assessment of promising bio-based chemicals

Actors willing to participate in biomass-based value chains need to screen through a vast number of product options to identify the most promising ones. This is challenging as (a) processes for biomass-based chemicals/materials are still in development stage, thus do not perform well in techno-economic evaluations, (b) factors as which and how many links of the value chain should be uptaken, are not fully addressed by techno-economic analysis. Inspired by the Five Forces framework for industry analysis, this work presents an algorithm-like approach for assessing the attractiveness of biomass-based products. The algorithm relies on market data to classify the different sources as posing a low, medium, or high threat to the profit of a company that is considering production of a certain chemical/material. The approach is exemplified by analyzing the attractiveness of the biomass-lactic acid-polylactic acid route in the context of defining pathways for development of a biomass-based industry in Uruguay.     

Quaternized chitosan as support for the assembly of gold nanoparticles and glucose oxidase: Physicochemical characterization of the platform and evaluation of its biocatalytic activity

We report for the first time the use of quaternized chitosan (QCHI) for the immobilization of gold nanoparticles (NP) and glucose oxidase (GOD), the characterization of the resulting platform and its biocatalytic activity using glucose as substrate. The chemical substitution of chitosan has allowed us to work at physiologic pH to build up self-assembled layers of QCHI-NP as platform for the enzyme immobilization. The adsorption of GOD was analyzed by surface plasmon resonance (SPR) to compare the surface coverage of GOD in absence and presence of the QCHI-NP platform. The results obtained with cyclic voltammetry and scanning electrochemical microscopy (SECM) revealed that the adsorption of NP improves the conductivity of the structure and its electrochemical reactivity, facilitating the oxidation of the hydrogen peroxide produced by GOD. The electrodes modified with NP present higher amperometric response demonstrating the efficient transduction of the enzymatic activity in this structure.     

Vitamin C and sugar levels as simple markers for discriminating Spanish honey sources

In this work, 7 Spanish honeys with different botanical origins were studied. The honey origins were rosemary, chestnut, lavender, echium, thyme, multifloral, and honeydew. The chemical compounds determined were ascorbic acid (vitamin C), hydroxymethylfurfural, and major sugar contents (glucose and fructose). The physicochemical parameters, pH, conductivity, moisture, free acidity, and color, were also measured. Vitamin C is an important antioxidant in food, and the possibility to use it as discriminate parameter among different honeys was studied. The determination of vitamin C in honey samples was carried out by 2 different methods, volumetric and chromatographic comparing the results by both statistically. Vitamin C content was higher in thyme honeys than in the other types; however a wide dispersion in the values was found. Through a linear discriminant analysis (LDA), conductivity, glucose, fructose, and vitamin C content were the most important discriminant parameters. PRACTICAL APPLICATION: Vitamin C content in different honey sources has been determined by a simple and rapid chromatographic method (less than 3 min) in honeys from 6 botanical origins. The results together with glucose and fructose content and some physicochemical parameters have been studied in order to discriminate the botanical origin of honeys and in the future certified their quality. A statistical LDA was applied to the data, and differentiation of honey sources was possible with very good agreement. The vitamin C content found in thymus honeys was significantly higher than in other types. This fact makes vitamin C a special marker for thymus honeys that have a higher antioxidant effect than the others giving it special properties. The identification of honey sources is essential for beekeepers in order to certify honeys for consumers.     

Physical Properties and Oxidative Status of Concentrated-from-Fish Oils Microencapsulated in Trehalose/Sodium Caseinate Matrix

Foods supplemented with omega-3 fatty acids have attracted much attention in the past decade. However, it is difficult to protect polyunsaturated fatty acids from oxidation. Microencapsulation is a technological process used with the aim to protect oils against oxidation or chemical deterioration, to mask unpleasant flavors or retain aromas, and/or to powder polyunsaturated fatty acids for food fortification purposes. The objective of this study was to analyze physical properties and oxidation status of microencapsulated concentrated-from-fish oils. Powders were prepared from emulsions formulated with 10 wt.% of concentrated-from-fish oils as fat phase and 20 or 30 wt.% trehalose solution that also contained 0.5, 2.0, or 5.0 wt.% sodium caseinate as aqueous phase. Encapsulation efficiency was higher for powders coming from 20 wt.% trehalose emulsions, and the percentage of retention of core material increased with increasing sodium caseinate concentration. The powder prepared from 20 wt.% trehalose and 5 wt.% sodium caseinate showed the highest retention of core material. This powder had lower water content and an amorphous matrix. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry method, used for this new application, allowed proving that trehalose/sodium caseinate matrix was efficient for microencapsulation of polyunsaturated oils and that concentrated-from-fish oils was protected from oxidation in powder form. Spectra were very similar to the original oil without any treatments. Most likely, the oxidation products found when core material was extracted were formed during extraction steps.     

Fabrication of aerogels from cellulose nanofibril grafted with β-cyclodextrin for capture of water pollutants

Journal of Porous Materials - Interactions at the molecular and surface chemistry are some of the key factors that determine the adsorption capacity of pollutants and emerging contaminants in...     

Energy management in solar cells powered wireless sensor networks for quality of service optimization

Sensor nodes equipped with solar cells and rechargeable batteries are useful in many outdoor, long-lasting applications. In these sensor nodes, the cycles of energy harvesting and battery recharge need to be managed appropriately in order to avoid sensor node unavailability due to energy shortages. To this purpose, we suggest sensor nodes to be programmed with alternative scheduling plans, each corresponding to a given energy requirement and meeting a given quality level. Thus, sensor nodes can select the scheduling plan that best suits to the expected energy production and the residual battery charge, in order to avoid sensor nodes' unavailability. We then propose an algorithm for the selection of the scheduling plan that aims at keeping the overall energy consumption neutral and that can sustain the sensor nodes’ activities uninterruptedly.     

Micro-oxygenation and oak chip treatments of red wines: Effects on colour-related phenolics,volatile composition and sensory characteristics. Part II: Merlot wines

The character of Merlot wines after the treatments of micro-oxygenation and subsequent chips addition, as regards the colour-related phenolics, volatile composition and sensory characteristics, was studied. An increase in the degree of polymerisation of red pigments and a decrease in the value of the red component of the colour (a^*) and the degree of co-pigmentation were observed. The concentrations of monomeric anthocyanins and anthocyanin-derived pigments, such as hydroxyphenyl-pyranoanthocyanins and anthocyanin-ethyl-flavan-3-ol adducts, significantly decreased. With regard to the wine aroma, the micro-oxygenation produced a decrease of some esters, alcohols and benzenic compounds and increased some terpenes and C₁₃-norisoprenoids. With regard to sensorial analysis, micro-oxygenation treatment resulted in higher scores for the red fruit and spicy attributes and caused the presence of new attributes (nutty and sweet fruit). This technique produces a lower level of the typical oak chip aromas (vanilla and woody) in Merlot wines.