Enzymatic treatment of peanut kernels to reduce allergen levels

This study investigated the use of enzymatic treatment to reduce peanut allergens in peanut kernels as affected by processing conditions. Two major peanut allergens, Ara h 1 and Ara h 2, were used as indicators of process effectiveness. Enzymatic treatment effectively reduced Ara h 1 and Ara h 2 in roasted peanut kernels by up to 100% under optimal conditions. For instance, treatment of roasted peanut kernels with α-chymotrypsin and trypsin for 1–3 h significantly increased the solubility of peanut protein while reducing Ara h 1 and Ara h 2 in peanut kernel extracts by 100% and 98%, respectively, based on ELISA readings. Ara h 1 and Ara h 2 levels in peanut protein extracts were inversely correlated with protein solubility in roasted peanut. Blanching of kernels enhanced the effectiveness of enzyme treatment in roasted peanuts but not in raw peanuts. The optimal concentration of enzyme was determined by response surface to be in the range of 0.1–0.2%. No consistent results were obtained for raw peanut kernels since Ara h 1 and Ara h 2 increased in peanut protein extracts under some treatment conditions and decreased in others.     

Potential of peanut skin phenolic extract as antioxidative and antibacterial agent in cooked and raw ground beef

This study investigated the potential of peanut skin extract (PSE) as inhibitor of lipid oxidation in cooked and raw ground beef (GB) and as antimicrobial agent in raw GB. Results show that addition of PSE to raw GB before cooking significantly inhibited the formation of peroxides and TBARS in cooked GB during the refrigerated storage. PSE at concentration ≥0.06% was as effective as BHA/BHT at 0.02% in inhibiting lipid oxidation. PSE also inhibited the oxidation of meat pigments thereby preserving the fresh redness of treated meat when used at 0.02–0.10%. Microplate assay showed complete inhibition of test bacteria (Bacillus subtilis, Salmonella typhimurium, Staphylococcus aureus, Streptococcus faecalis and Escherichia coli) in the presence of PSE at 0.4% or higher. However, the antimicrobial effect of PSE in GB was less potent. Hence, PSE can primarily serve the dual purposes of preserving the colour of raw GB and preventing lipid oxidation in cooked products.     

Role of Learning Algorithm in Neural Network-Based Backcalculation of Flexible Pavements

Nondestructive testing (NDT) methods are widely used for the performance evaluation of flexible pavements. Falling weight deflectometer (FWD), which measures time-domain deflections resulting from applied impulse loads, is the most popular technique among all NDT methods. The evaluation of the FWD data requires the inversion of mechanical pavement properties using a backcalculation tool that includes both a forward pavement response model and an optimization algorithm. Neural networks (NNs) have also emerged as alternative tools that can be employed for pavement backcalculation problems relative to their real-time processing abilities. However, there have been no comprehensive analyses in previous studies that focus on the learning algorithm and the architecture of a NN model, which considerably affect backcalculation results. In this study, 284 different NN models were developed using synthetic training and testing databases obtained by layered elastic theory. Results indicated that both the learning algorithm and network architecture play important roles in the performance of the NN based backcalculation process.     

Role of sex, gender roles, and attraction in predicting emergent leaders.

Examined the influence of sex, gender role characteristics, and interpersonal attractiveness on the selection of emergent leaders. Data were collected on 2 occasions from 122 subjects in 28 task groups performing "sex neutral" tasks for valued rewards over many weeks of interaction. Results showed no significant difference in the proportion of men and women to emerge as leaders through intragroup sociometric choice. Regardless of sex, group members with masculine gender role characteristics emerged as leaders significantly more than those with feminine, androgynous, or undifferentiated gender role characteristics. Emergent leaders received significantly higher interpersonal attractiveness ratings than nonleaders within groups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Degradation of aflatoxins in peanut kernels/flour by gaseous ozonation and mild heat treatment

Aflatoxins occur naturally in many agricultural crops causing health hazards and economic losses. Despite improved handling, processing and storage, they remain a problem in the peanut industry. Therefore, new ways to detoxify contaminated products are needed to limit economic/health impacts and add value to the peanut industry. The study was conducted (1) to evaluate the effectiveness of ozonation and mild heat in breaking down aflatoxins in peanut kernels and flour, and (2) to quantify aflatoxin destruction compared with untreated samples. Peanut samples were inoculated with known concentrations of aflatoxins B1, B2, G1 and G2. Samples were subjected to gaseous ozonation and under various temperatures (25, 50, 75°C) and exposure times (5, 10, 15 min). Ozonated and non-ozonated samples were extracted in acetonitrile/water, derivatized in a Kobra cell and quantified by high-performance liquid chromatography. Ozonation efficiency increased with higher temperatures and longer treatment times. Regardless of treatment combinations, aflatoxins B1 and G1 exhibited the highest degradation levels. Higher levels of toxin degradation were achieved in peanut kernels than in flour. The temperature effect lessened as the exposure time increased, suggesting that ozonation at room temperature for 10-15 min could yield degradation levels similar to those achieved at higher temperatures while being more economical.     

Evaluation of Pyrite in a Tailings Dam by Flotation

Pyrite is presented as a gangue mineral in most of complex sulphide ores and most of time it is removed as a tailing. However, beneficiation of pyrite from railings could be important because of its economical value and the environmental concern. This paper presents a research for the enrichment of pyrite from copper plant tailings, Siirt-Madenkoy/Turkey, by flotation. Siirt-Madenkoy copper mine is operated by Park Electric Production Mining and Industry since 2005. In order to obtain the pyrite from Siirt-Madenkoy copper plant tailings, laboratory test work has to be done to determine the type of reagents, the flowsheet and the size of plant. The objective of the company is to develop a pyrite flotation circuit for concentration of pyrite from tailing dam to obtain 750,000 tons/year pyrite concentrate. There are about 4 million tons tailings that containing pyrite in the railings dam. Experiments were carried out with three different types of tailings from the plant and the pyrite concentrate with 46%Fe and 90% recovery has been obtained. Therefore, this study shows that high grade pyrite with high recovery can be recovered from the tailings.     

pH‐ and temperature‐induced release of doxorubicin from multilayers of poly(2‐isopropyl‐2‐oxazoline) and tannic acid

We present a simple strategy to prepare doxorubicin (DOX) containing hydrogen‐bonded films of poly(2‐isopropyl‐2‐oxazoline) (PIPOX) and tannic acid (TA) which release DOX in acidic conditions while releasing a minimal amount of DOX at physiological pH. Water soluble complexes of TA and DOX (TA ? DOX) were prepared prior to film construction. PIPOX and TA ? DOX were deposited at the surface at pH 6.5 using the layer‐by‐layer (LbL) technique. We found that multilayers released a minimal amount of DOX at physiological pH due to further ionization of TA with increasing pH and enhanced electrostatic interactions between TA and DOX. In contrast, pH‐induced release of DOX was observed in moderately acidic conditions due to protonation of TA as the acidity increased and electrostatic interactions between TA and DOX decreased. Moreover, we found that raising the temperature from 25 °C to 37.5 °C increased the amount of DOX released from the surface. This can be rationalized with the conformational changes within the multilayers correlated with the lower critical solution temperature behaviour of PIPOX and increased kinetic energy of DOX molecules. Considering the acidic nature of tumour tissues and important biological properties of PIPOX and TA, these multilayers are promising for pH‐ and temperature‐triggered release of DOX from surfaces. © 2017 Society of Chemical Industry     

Reduction of major peanut allergens Ara h 1 and Ara h 2, in roasted peanuts by ultrasound assisted enzymatic treatment

This study investigated the effects of ultrasound, enzyme concentration and enzyme treatment time on soluble protein and major allergenic proteins (Ara h 1 and Ara h 2) of roasted peanut kernels. A 3-factor, five-level orthogonal experimental design was implemented with various ultrasonication times, concentrations of trypsin or α-chymotrypsin and treatment times. The total soluble proteins were determined by the Bicinchoninic acid (BCA) method, Ara h 1 and Ara h 2 were evaluated by SDS–PAGE and sandwich ELISA. The IgE-binding of peanut extracts was analysed by a competitive inhibition ELISA. Results indicate that ultrasound treatment, followed by protease digestion of peanuts, significantly increased the solubility of peanut protein and decreased the concentrations of Ara h 1 and Ara h 2. The sequential treatment of peanuts by ultrasonication–trypsin–alpha chymotrypsin, resulted in maximum reductions of Ara h 1/Ara h 2, and lowest IgE-binding. This study provides an approach to significantly reduce allergenic proteins in peanut product.     

Extrusion parameters and consumer acceptability of a peanut-based meat analogue

Despite its high protein content and low cost, defatted peanut flour (DPF) remains underutilised in human foods. The objectives of this study were to: (1) determine the best extrusion parameters for a peanut-based textured meat analogue (TMA); (2) develop new TMA products from DPF and (3) evaluate their consumer acceptability. Preliminary runs using a wide range of extrusion parameters were conducted. A central composite RSM design was used to determine the optimal extrusion conditions within the best ranges revealed by the preliminary runs. Three levels of moisture, screw-speed and barrel temperature were used in 31 runs. Expansion ratio, bulk density, texture profile, water absorption/solubility indexes of the extrudates were determined and used as indicators of product quality. Peanut-based TMAs produced at optimal extrusion conditions were flavoured with beef flavour and evaluated by a 60-member sensory panel for flavour, texture, and overall liking, using a 9-point hedonic scale. Optimisation studies revealed that the most important extrusion conditions are in descending order: protein content, temperature, moisture and screw-speed. Extrusion conditions that produced the best TMA were 60–65% protein, 50–55% moisture, 160–165 °C and 80–90 r.p.m. Sensory acceptability of snacks incorporating peanut-based TMAs was similar or better than those containing soya-based TMAs in terms of flavour, texture, off-flavour and overall liking. TMA produced from inexpensive DPF has the potential to compete with commercial meat analogues, thereby adding value to the peanut industry.     

The use of nutshell carbons in drinking water filters for removal of chlorination by‐products

Chlorination of drinking water is a common practice, used by numerous municipalities in the United States (US) to safeguard their water supplies. However, the chlorine used can chemically react with organic components in the drinking water to produce unwanted chlorination by‐products. The objective of this investigation was to evaluate the use of granular activated carbon produced from nutshells (almond, English walnut, pecan) in a point‐of‐use (POU) water filtration system designated ‘Envirofilter’ and to determine its efficacy in removing select, potentially carcinogenic chlorination by‐products, namely the trihalomethanes (THMs) bromodichloromethane, bromoform and dibromochloromethane. The POU water filtration system that contained the nutshell‐based carbons was designated ‘Envirofilter’ and adsorption efficiencies of this system were compared to that of four commercially available POU home water filter systems, namely, BRITA, Omni Filter, PūR and Teledyne Water Pik. Eight different ‘Envirofilters’ were constructed of individual or binary mixtures of carbons produced from acid‐activated almond or pecan shells and steam‐activated pecan or walnut shells and evaluated for adsorption of the three chlorination by‐products. The results indicate that only two of the eight ‘Envirofilters’ failed to remove more THMs than the commercial POU systems. In both cases, these filters contained carbons with either 100% acid‐activated almond shells or 100% acid‐activated pecan shells. All six of the other filters contained carbons with either 50% or 100% steam‐activated pecan shells or steam‐activated walnut shells. Therefore, ‘Envirofilters’ appeared to depend on the presence of steam‐activated nutshell carbons for their success. The six effective ‘Envirofilters’ reduced THM levels to below the Maximum Contaminant Levels (MCL) required by the US Environmental Protection Agency (US EPA). Based on these results, these six ‘Envirofilters’ may be considered as a replacement for existing commercial filter systems because of their efficacy and projected cost. Copyright © 2004 Society of Chemical Industry