Relationship between proportion and composition of albumins,and in vitro protein digestibility of raw and cooked pea seeds (Pisum sativum L.)

BACKGROUND: Peas provide an excellent plant protein resource for human diets, but their proteins are less readily digestible than animal proteins. To identify the relationship between composition and in vitro digestibility of pea protein, eight pea varieties with a wide range of protein content (157.3–272.7 g kg^?1) were determined for the proportion of albumins and globulins, their compositions using sodium dodecyl sulfate–polyacrylamide gel electrophoresis, and in vitro protein digestibility (IVPD) before and after heat treatment using a multi‐enzyme (trypsin, chymotrypsin and peptidase) method. RESULTS: The proportion of albumins based on total seed protein content decreased from 229 to 147 g kg^?1 as seed protein content increased from 157.3 to 272.7 g kg^?1, while the proportion of globulins increased from 483 to 590 g kg^?1. The IVPDs of eight raw pea seeds were 79.9–83.5%, with significant varietal variations, and those were improved to 85.9–86.8% by cooking. Albumins, including (pea albumins 2) PA2, trypsin inhibitor, lectin and lipoxygenase, were identified as proteolytic resistant proteins. Globulins were mostly digested by protease treatment after heating. CONCLUSION: The quantitative ratio of albumins and globulins, and the quantitative variations of albumin protein components, including lipoxygenase, PA2, lectins and trypsin inhibitors, appear to influence the protein digestibility of both raw and cooked pea seeds. Copyright © 2010 Society of Chemical Industry     

Artificial intelligence in predicting extraction of anti-cancer compounds

Saponins from the particulate Saponaria vaccaria L. seeds (0.29–0.84 mm, 15.35–61.40 g H₂O/100 g dry mass) were extracted for methanol concentrations (MeOH) of 30, 50, 70, and 90 mL/100 mL H₂O and temperatures (T) of, 30, 45, and 60 °C at ten extraction intervals (t) between 1 and 180 min. A calibration equation was developed from the liquid-chromatogram–mass spectroscopy peaks to quantify the extract yields (mg mL⁻¹) for various types of saponins. An artificial neural network (ANN) with three inputs, MeOH, T, and t predicted the extraction kinetics and the yields with less than ca. 12% error. The ANN model not only slightly outperformed the numerical diffusional model, but it also made the prediction simple and faster eliminating the use of the partition coefficient and the effective diffusivity. Therefore an ANN model can be a right approach to predict the yields of saponins and similar products.     

Enhanced biodegradation of carbamazepine after UV/H2O2 advanced oxidation

Carbamazepine is one of the most persistent pharmaceutical compounds in wastewater effluents due to its resistance to biodegradation-based conventional treatment. Advanced oxidation can efficiently degrade carbamazepine, but the toxicity and persistence of the oxidation products may be more relevant than the parent. This study sets out to determine whether the products of advanced oxidation of carbamazepine can be biotransformed and ultimately mineralized by developing a novel methodology to assess these sequential treatment processes. The methodology traces the transformation products of the (14)C-labeled carbamazepine during UV/hydrogen peroxide advanced oxidation and subsequent biotransformation by mixed, undefined cultures using liquid scintillation counting and liquid chromatography with radioactivity, mass spectrometry, and UV detectors. The results show that the oxidation byproducts of carbamazepine containing a hydroxyl or carbonyl group can be fully mineralized by a mixed bacterial inoculum. A tertiary treatment approach that includes oxidation and biotransformation has the potential to synergistically mineralize persistent pharmaceutical compounds in wastewater treatment plant effluents. The methodology developed for this study can be applied to assess the mineralization potential of other persistent organic contaminants.     

Manufacture and quality evaluation of purple sweet potato Makgeolli vinegar using a 2-stage fermentation

Purple sweet potato makgeolli vinegar made using a 2-stage fermentation method was evaluated. The highest alcohol concentration was 4% in a growth medium containing Acetobacter aceti ATCC 15973. Purple sweet potato makgeolli vinegar (PMV) had higher pH and lower acidity values than rice makgeolli vinegar (RMV). The total polyphenol content was 327.14 mg of GAE/L and the DPPH radical scavenging activity was 67.63% for PMV. Both values were much higher than for RMV. The total polyphenol and the DPPH radical scavenging activities of PMV decreased slowly during storage for 20 days, showing that stability of the antioxidant effect during storage was maintained.     

Experimental study on mitigating the cathode flooding at low temperature by adding hydrogen to the cathode reactant gas in PEM fuel cell

Severe flooding can be critical in a fuel cell vehicle operating at a high current density, and in a fuel cell vehicle at the initial stage of start up. It is often difficult to remove the condensed water from the cathode gas diffusion layer (GDL) of the fuel cell because of the surface tension between the water and the GDL. In this research, in order to remove the condensed water from the cathode GDL, a small amount of hydrogen was injected into the cathode reactant gases. The results showed that the hydrogen addition method successfully removed the liquid water from the cathode GDL. Water removal was verified for various hydrogen flow rates and hydrogen addition durations. Furthermore, the dew point temperature of the outlet gas at the cathode was observed to determine the amount of water removed from the cathode GDL. In addition, the water droplet in the cathode gas flow channel was visualized by using a transparent cell. Furthermore, degradation tests are also performed. Considering the degradation test, the hydrogen addition method is expected to be effective in mitigating cathode flooding.     

Hydrogen production by hybrid system and its conversion by fuel cell in Algeria; Djanet

In this work we present a scenario of wind and solar energy production and seasonal energy storage producing Hydrogen in Djanet (East-South of Algeria). In addition we suppose assume the use of a set of fuel cells which are connected to the grid to provide a supply of energy when needed afterwards. The aim of this primary study is giving an alternative solution for the electric production in Djanet, which is mainly based on diesel generator. For that we made an investigation to highlight the potential of renewable energy production in this region. To ascertain feasibility of one hybrid system, we made energetic assessment considering the real climatic conditions of Djanet.     

Retrogradation kinetics of chestnut starches cultivated in three regions of Korea

Retrogradation kinetics of chestnut starches from three different regions of Korea were investigated during storage at 4 °C. The retrogradation properties were determined using four DSC characteristics: glass transition temperature (\( {\text{T}}_{\text{g}}^{\prime } \)), ice melting enthalpy (ΔH_i), amylopectin melting enthalpy (?H_r) and degree of retrogradation (DR). The Gongju (GJ) starch showed the highest gelatinization enthalpy (?H_g) value, followed by Gwangyang (GY) and Hadong (HD). \( {\text{T}}_{\text{g}}^{\prime } \) of all samples gradually increased with increasing storage time, while ?H_i decreased as the storage time increased. ?H_r of all samples significantly increased after 2 days of storage. DR, calculated based on ?H_g and ?H_r, showed a similar tendency with ?H_r. The retrogradation rates of three chestnut starches were analyzed using the Avrami equation, and the time constants (1/k) were obtained. GY, GJ and HD showed the fastest retrogradation rate in \( {\text{T}}_{\text{g}}^{\prime } \), ?H_i, and ?H_r, respectively suggesting that each sample experienced different retrogradation kinetics in different region.     

Molecular cloning and high-level expression in Escherichia coli of fungal alpha-galactosidase from Absidia corymbifera IFO 8084

A cDNA encoding the alpha-galactosidase of Absidia corymbifera IFO 8084 was cloned and sequenced. The cloned DNA has a single open-reading frame consisting of 2190 base pairs, and the deduced amino acid sequence revealed that the mature enzyme consisted of 730 amino acid residues with a molecular mass of 82,712 Da. The native structure of the alpha-galactosidase of A. corymbifera IFO 8084 was determined to be a tetramer. Comparison with amino acid sequences of other alpha-galactosidase showed high homology with sequences of members of family 36. An expression vector, pET32Trx/galalpha, was constructed by introducing the cDNA coding region into a thioredoxin fusion system, pET32-Ek/LIC. The resulting transformant, pET32Trx/galalpha, overproduced the active enzyme as a thioredoxin fused form in the host Escherichia coli. By using His-binding metal affinity chromatography, recombinant alpha-galactosidase was purified to homogeneity in a single step. The purified recombinant fusion alpha-galactosidase showed properties very similar to the native alpha-galactosidase from A. corymbifera IFO 8084.     

Ni@Ru and NiCo@Ru Core–Shell Hexagonal Nanosandwiches with a Compositionally Tunable Core and a Regioselectively Grown Shell

The development of highly active electrocatalysts is crucial for the advancement of renewable energy conversion devices. The design of core–shell nanoparticle catalysts represents a promising approach to boost catalytic activity as well as save the use of expensive precious metals. Here, a simple, one‐step synthetic route is reported to prepare hexagonal nanosandwich‐shaped Ni@Ru core–shell nanoparticles (Ni@Ru HNS), in which Ru shell layers are overgrown in a regioselective manner on the top and bottom, and around the center section of a hexagonal Ni nanoplate core. Notably, the synthesis can be extended to NiCo@Ru core–shell nanoparticles with tunable core compositions (Ni₃Co_x@Ru HNS). Core–shell HNS structures show superior electrocatalytic activity for the oxygen evolution reaction (OER) to a commercial RuO₂ black catalyst, with their OER activity being dependent on their core compositions. The observed trend in OER activity is correlated to the population of Ru oxide (Ru⁴⁺) species, which can be modulated by the core compositions.