Creating a novel genetic diversity of Trichoderma afroharzianum by γ-radiation for xylanase-cellulase production.

Creating novel sources of a microbial strain using induced mutation can increase enzyme production for industrial use. According to this, we have developed a mutant strain of Trichoderma afroharzianum by Co60 gamma irradiation. Trichoderma mutants were isolated from an optimum dose of 250 Gy. The qualitative and quantitative screening were used for evaluating their enzyme production and the DNA barcoding method was used to identify the best Trichoderma mutant isolates. The highest cellulase (exo-glucanase, endoglucanase, ß-glucosidase, and total cellulase) and xylanase activities were observed in superior mutant isolates of Trichoderma afroharzianum NAS107-M44 and Trichoderma afroharzianum NAS107-M82, which is approximately 1.6-2.5 times higher than its parent strain, respectively. The electrophoretic pattern of proteins showed that the exo-glucanase I, endo-glucanase III, and the xylanase I enzymes hydrolyzed the corn bran, synergistically. Overall, gamma irradiation-induced mutation could be an expedient technique to access such superior mutants for the bioconversion of corn bran wastes.

Development and characterization of antioxidant bilayer film based on poly lactic acid-bitter vetch (Vicia ervilia) seed protein incorporated with Pistacia terebinthus extract for active food packaging.

This study focuses on designing an active bilayer food package film based on polylactic acid (PLA) and bitter vetch seed protein incorporated with Pistacia terebinthus extract (PTE). The effect of PTE on the physicochemical, barrier, structural, mechanical, and antioxidant properties of the active film was determined. Moisture content, water solubility, and water vapor permeability (WVP) of the active films indicated that the addition of PTE increased its suitability for food packaging. FE-SEM micrographs illustrated that the resulting films had a smooth and dense surface, describing a continuous network of protein molecules within the film structure. FTIR analysis displayed the physical interaction between PTE and the film polymer. XRD revealed an increase in the crystallinity of the active films. The resulting active film had a low migration rate (<7%) of phenolic compounds into fatty food simulant. Notably, the addition of PTE significantly (P ≤ 0.05) decreased the tensile strength and Young's modulus (from 15.13 and 315.98 MPa to 14.07 and 254.07 MPa, respectively). Concurrently, there was an increase in the elongation at break of the active films (from 23.19 to 75.60%), indicating higher flexibility compared to control films. Additionally, the incorporation of PTE improved the thermal properties of active films. The antioxidant capacity of the designed films was measured based on their DPPH radical scavenging activity, revealing that the antioxidant capacity of the control film increased from 44.65% to 59.72% in the active film containing 15% PTE. In conclusion, the prepared bilayer film can effectively be used as an active food package for sensitive foods to oxidation.

Cold plasma treatment to prepare active polylactic acid/ethyl cellulose film using wheat germ peptides and chitosan.

In this study, the surface of the polylactic acid/ethyl cellulose (PLA/EC) blend film was modified by dielectric barrier discharge (DBD) plasma treatment to facilitate the spin-coating of chitosan (CH) and wheat germ bioactive peptides (PEP) obtained from enzymatic hydrolysis of defatted wheat germ protein isolate on the surface of the film. The suitable plasma treatment condition was 5 min at 20 kV according to ATR-FTIR, AFM, SEM, water angle contact, and water solubility results. Increasing the surface roughness and oxygen-containing functional groups (CO and -OH) improved coating by PEP and CH. The PEP-coated film had better antioxidant activity than CH-PEP and CH-coated films. The results of antimicrobial activity demonstrated that PEP-coated film could reduce the growth of gram-negative bacteria (Escherichia coli) and gram-positive bacteria (Staphylococcus aureus). The PEP-coated film had competitive antibacterial properties with CH-coated. Hence, the obtained PEP-coated PLA/EC film could be a promising candidate for antioxidant and antibacterial food packaging.

Grain and flour quality of wheat genotypes grown under heat stress.

Heat stress during the grain-filling period is the main abiotic stress factor limiting grain yield and quality in wheat (Triticum aestivum L.). In this study, 64 wheat genotypes were exposed to heat stress during reproduction caused by delayed sowing in two growing seasons. Grain yield, 1000 grain weight (GW), grain hardness (GH), and grain-quality related traits were investigated. Heat stress caused a significant decrease in GW through reducing starch content (SC) and a non-compensating rise in protein content (PC), and thereby resulted in lower yield. In addition, significant increases in flour water absorption (WA), Zeleny sedimentation volume (ZT), ash content (AC), lipid content (LC), loaf volume (LV), wet gluten content (WG), dry gluten content (DG), gluten index (GI), and amylopectin content (APC) were found following heat stress. In contrast, decreases in grain moisture content (MC) and amylose content (AMC) induced by heat stress were observed. The heat-tolerant genotypes were superior in grain yield, GW, SC, AMC, and MC. While the sensitive genotypes contained higher PC, LV, GI and AMP. A group of wheat genotypes characterized with a higher yield, AMC, GW, and SC as well as lower PC, WA, GH, ZT, and LV; and was found to be the most heat tolerant by principal component analysis. Lighter weight and smaller grains produce a smaller starchy endosperm with lower quality (less amylose) and higher grain protein content in heat stress compared to normal conditions. Heat stress caused by delayed sowing improves some of the baking-quality related traits.

Relationships between grain, flour, and dough quality characteristics and solvent retention capacity tests of twelve triticale cultivars and parental species.

Relationships amongst solvent retention capacity (SRC) profiles and quality characteristics of triticale cultivars were investigated. Superior triticale grains resulted into flours with preferable quality attributes for baking bread. Standard and supplementary SRC-values exhibited significant correlation with grain, flour, and dough quality. Positive correlations among sucrose-SRC with ash, pentosan, and ferulic acid (FA) contents were significant. The standard SRC-profiles along with metabisulfite-SRC (MBS-SRC) and ethanol-SRC exhibited significant correlation with damaged starch (DS) content. The ethanol-SRC demonstrated strong correlations with water absorption capacity, FA, and Dmax-value alveolab parameter. Triticale flours containing a higher amount of anti-parallel ß-sheets and tyrosine exhibited higher lactic acid-SRC (LA-SRC) and gluten-performance-index (GPI). Positive correlations between sodium dodecylsulphate-SRC (SDS-SRC) and anti-parallel ß-sheets percentages were noticed. The LA-SRC, GPI, MBS-SRC, SDS-SRC, and SDS+MBS-SRC were positively correlated with SDS-sedimentation, gluten index and negatively to sulfhydryl-groups content. Triticales having higher LA-SRC and MBS-SRC resulted in dough with higher strength and tenacity.

Amaranth selective hydrolyzed protein influence on sourdough fermentation and wheat bread quality.

Amaranth selective hydrolyzed protein (ASPH) may improve sourdough properties and bread quality. In this regard, this study focused on investigating the influence of protein hydrolysates on sourdough fermentation and bread properties. Based on the findings, ASPH further increased Lactobacillus plantarum and Saccharomyces cerevisiae growth in sourdough compared with amaranth protein isolates and amaranth flour. ASPH at 5 g/kg resulted in sourdough with higher pH and total titratable acidity (TTA) after 20 h of fermentation at 30°C. The prepared sourdough using APH (S-ASPH) at 3 g/kg increased the specific volume (4.57 ml/g) and TTA (4.76 ml) while decreasing water activity, hardness, cohesiveness, and chewiness of the bread (S-ASPH-B) compared with the control. Moreover, transition temperature and enthalpy reduced whereas sensory properties and shelf life represented an increase with S-ASPH addition. Overall, the obtained data indicated the improvement of bread quality by S-ASPH sourdough.

Functional Properties of Rye Prolamin (Secalin) and Their Improvement by Protein Lipophilization through Capric Acid Covalent Binding.

Secalin (SCL), the prolamin fraction of rye protein, was chemically lipophilized using acylation reaction by treatment with different amounts of capric acid chloride (0, 2, 4, and 6 mmol/g) to enhance its functional properties. It was shown that SCL lipophilization increased the surface hydrophobicity and the hydrophobic interactions, leading to a reduction in protein solubility and water absorption capacity and to a greater oil absorption. In addition, SCL both emulsifying capacity and stability were improved when the protein was treated with low amount of capric acid chloride. Finally, the foaming capacity of SCL markedly increased after its treatment with increasing concentrations of the acylating agent, even though the foam of the modified protein was found to be more stable at the lower level of protein acylation. Technological application of lipophilized SCL as a protein additive in food preparations is suggested.

Pomegranate seed oil nanoemulsion enriched by α-tocopherol; the effect of environmental stresses and long-term storage on its physicochemical properties and oxidation stability.

In this study, pomegranate seed oil (PSO) nanoemulsions loading different amounts of α-tocopherol (0-40%) were produced. The nanoemulsions were fabricated by ultra-sonication method and the influence of thermal treatment (20-90 °C), pH (2-8) and ionic strength (0-500 mM NaCl) were investigated on physicochemical properties of all treatments. Moreover, the oxidative stability and α-tocopherol degradation were also assessed on optimal enriched nanoemulsion formulation during 50-day storage. The droplet diameter, viscosity, antioxidant activity, encapsulation efficiency and loading capacity of optimal formulation were 37.5 nm, 514 cp, 92%, 3.45% and 92.5%, respectively. The peroxide value changed in the range of 4.5-5.3 and 6.7-10.5 meq O2/kg in loaded and unloaded nanoemulsions, respectively. Transmission electron microscopy demonstrated spherical morphology of nanoemulsion droplets with diameter average of 40 nm. This study suggested that PSO nanoemulsion loading α-tocopherol could be introduced as delivery system with favorable features under severe environmental conditions.

Fabrication of nanostructured mesoporous starch encapsulating soy-derived phytoestrogen (genistein) by well-tuned solvent exchange method.

The present research was concerned with preparation of mesoporous starch (MPS) as a carrier for genistein, a model of poorly water-soluble phytoestrogen isoflavone; and exploration of the impact of different fabrication parameters on structural and loading properties. MPS is considered as a highly porous biomaterial which typically possesses nanometer-sized porous microstructure and low density, providing a large effective specific surface area (SSA) and hydrophilic surface to improve solubility, stability and bioavailability of poorly water-soluble active agents. To fabricate MPS, various concentrations (8-14% w/v) of starch from different sources (corn, potato and tapioca) was used for gel formation and the successive solvent exchange process was performed with use of various ethanol concentrations (40-70% v/v), which were then dried by different techniques (rotary vacuum evaporation, microwave and freeze drying). MPS quality attributes such as SSA, total porous volume, BJH pore diameter and swelling ratio were determined and effects of the fabrication parameters were investigated using L9-Taguchi orthogonal array design. The results indicate that second order polynomial regression models were well fitted for all response variables. Interestingly, the starch components greatly influenced physical properties of MPS. Also, the drying type and ethanol concentration altered significantly the model equations. The overall best fabrication condition (14% corn starch, 100% ethanol concentration in aging step and rotary vacuum drying) resulted in favorable MPS preparation with mean size of 105.4 nm and unimodal distribution. In the next step, genistein was encapsulated in MPS microstructure at different ratios, resulting in high loading capacity and efficiency (44.71% and 79.9%, respectively) at 1:1 weight ratio. Equilibrium adsorption isotherm of genistein was evaluated also by four different kinetics models including Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherms. The experimental data were found to be fitted well to the Langmuir model (R2 = 0.989). According to the electron microscopy and XRD analysis, the degree of genistein crystallinity lowered remarkably after the impregnation in to MPS, indicating improved solubility. In-vitro release profile of genistein from MPS in the simulated gastrointestinal buffer solutions (pH 1.2 and 6.8) demonstrated that incorporating genistein into the MPS enhanced the dissolution rate compared with genistein powder. Release kinetic data were fitted to the Higuchi model (R2 = 0.98), indicating diffusion-controlled release mechanism. Altogether, well-tuned MPS fabrication method can be utilized for an efficient encapsulation and dissolution enhancement of poorly soluble phytochemicals, such as genistein.

Production routing in perishable and quality degradable supply chains.

Generally, the major goal in perishable supply chains is preserving the product's quality along with improving its logistic performance. In this regard, temperature seems to be the most important and most sensitive factor, since uncontrolled temperature has shown to have great impact on reducing product quality. In this study, an integrated production routing model for a perishable product was developed; considering the production, inventory, storage temperature, routing and vehicle temperature. To solve the problem, a hybrid search algorithm combining the variable of neighborhood search algorithm and the mechanism of the simulated annealing algorithm was designed. In order to evaluate the validity of the proposed algorithm, its results were compared with that of the CPLEX solver in the GAMZ software environment. Comparison of the results of the two methods shows the efficiency of the proposed algorithm to solve this problem. As a case study, the proposed model was also applied in a real industrial case. According to the results, this company can greatly reduce its distribution and inventory costs and also avoid waste by using this program.

Capability of solvent retention capacity to quality of flat bread in three wheat cultivars.

Variations in levels and properties of flour constituents have an impact on the quality of its end products and a given application. While the solvent retention capacity test has been used to assess flour quality of pan breads and cookies, to date, this test for determination the suitability of flour for flat breads, where extensibility is the most desirable, has not been evaluated. In this study, three bread wheat cultivars were investigated for their major polymeric constituents, the number of disulfide bonds and SRC test values. The attained results revealed that in the gluten network, WRC and SuRC were affected by the gliadin, whereas SCRC and LaRC by gluten as a whole and glutenin content. These observed relationships are respectively owed to the solubility of gliadin in alcoholic solutions, and the solubility of glutenin in either acid or basic solutions. Also, consumers acceptability of flat-bread was observed at higher ratio of arabinose/xylose, which related to structural characteristics of arabinoxylan.

Production and characterization of hydrophilic and hydrophobic sunflower protein isolate nanofibers by electrospinning method.

In the present study, sunflower protein isolate (SPI) was extracted and applied for production of nanofiber using polyvinyl alcohol (PVA) in different SPI:PVA volume ratios (0:100, 20:80, 40:60, 60:40, 80:20 and 100:0) under two voltages (18 and 23 kV) and two flow rates (0.5 and 0.75 ml/h). Nanofibers with average diameters ranging from 304 to 400 nm were achieved. SPI:PVA volume ratio of 40:60 at voltage of 18 kV and flow rate of 0.75 ml/h were determined as the optimum conditions for electrospinning which produced bead-free and uniform nanofibers with average diameter of 398 nm. The effects of heating (150 °C, for 24 h) and calcium chloride (1% W/V) solution solely and together on nanofibers hydrophobicity were also examined. SEM images after 24 h soaking in lactate buffer (pH 5.5) showed that only heat treatment could make nanofibers hydrophobic, which was proved by contact angle data. FTIR analysis showed denaturation of protein and interactions between protein and PVA after heat treatment. Moreover, DSC and TGA results indicated miscibility of protein and PVA, and higher thermal stability of heat treated sample. This study showed the potential application of soy protein as a byproduct for production of both hydrophobic and hydrophilic nanofibers.

Reduction of acrylamide in whole-wheat bread by combining lactobacilli and yeast fermentation.

This study mainly focuses on a strategy for reducing acrylamide content in whole-wheat bread by combining lactobacilli and yeast in sourdough breadmaking. Combinations of sourdough (fermented dough using different Lactobacillus strains including Lactobacillus plantarum PTCC 1896 [probiotic], L. sakei DSM 20,017, L. rhamnosus DSM 20,021, and L. delbrueckii DSM 20,081) and yeast, in comparison with yeast alone, were used for breadmaking. The results showed that acrylamide levels in breads fermented using sourdough+yeast were in all cases much lower (6.9-20 µg/kg on a dry weight basis [d.b.]) than those in the yeast-only fermented bread (47.6 µg/kg d.b.). Significant (p < 0.05) correlations were also found between pH, total titratable acids (TTA) and lactic acid, and acrylamide content. Furthermore, the obtained results showed that the moisture content of dough directly influenced the formation of acrylamide in bread (r = 0.925, p < 0.0001). In addition, no significant correlations were observed between acrylamide content in breads and either the reducing sugar or free amino acid contents in dough samples. According to the different effects of Lactobacillus strains, it could be concluded that the acrylamide reducing potential of lactobacilli was strain-specific, with L. rhamnosus being the most effective. This suggests that sourdough fermentation with appropriate Lactobacillus strains can be used as an advantageous technology to reduce the acrylamide content of whole-wheat breads.

Multiplex-PCR As a Rapid and Sensitive Method for Identification of Meat Species in Halal-Meat Products.

BACKGROUND: Species identification and authentication in meat products are important subjects for ensuring the health of consumers. The multiplex-PCR amplification and species- specific primer set were used for the identification of horse, donkey, pig and other ruminants in raw and processed meat products. METHODS: Oligonucleotid primers were designed and patented for amplification of species-specific mitochondrial DNA sequences of each species and samples were prepared from binary meat mixtures. RESULTS: The results showed that meat species were accurately determined in all combinations by multiplex-PCR, and the sensitivity of this method was 0.001 ng, rendering this technique open to and suitable for use in industrial meat products. It is concluded that more fraud is seen in lower percentage industrial meat products than in higher percentage ones. There was also more fraud found in processed products than in raw ones. CONCLUSION: This rapid and useful test is recommended for quality control firms for applying more rigorous controls over industrial meat products, for the benefit of target consumers.

Encapsulation optimization of lemon balm antioxidants in calcium alginate hydrogels.

Calcium alginate hydrogel beads were used to encapsulate lemon balm extract. Chitosan layer was used to investigate the effect of hydrogel coating. To determine the interactions of antioxidant compounds of extract with encapsulation materials and its stability, microstructure of hydrogel beads was thoroughly monitored using scanning electron microscopy and Fourier transform infrared (FTIR). Total polyphenols content and antiradical activity of lemon balm extract were also evaluated before and after encapsulation. Three significant parameters (lemon balm extract, sodium alginate, and calcium chloride concentrations) were optimized by response surface methodology to obtain maximum encapsulation efficiency. The FTIR spectra showed no interactions between extract and polymers as there were no new band in spectra of alginate hydrogel after encapsulation of active compounds of lemon balm extract. The antioxidant activity of lemon balm extract did not change after encapsulation. Therefore, it was found that alginate is a suitable material for encapsulation of natural antioxidants. Sodium alginate solution concentration, 1.84%, lemon balm extract concentration, 0.4%, and calcium chloride concentration, 0.2% was determined to be the optimum condition to reach maximum encapsulation efficiency.

Properties of whey protein isolate nanocomposite films reinforced with nanocellulose isolated from oat husk.

Whey protein isolate (WPI)-based composite films with varying proportions of oat husk nanocellulose (ONC) obtained from acid sulfuric hydrolysis were prepared using a solution casting method. The obtained material after each step of the isolating cellulose, morphological and crystallinity of the ONC were studied by Fourier transform infrared (FTIR) spectroscopy, Scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The effect of ONC content (0, 2.5, 5 and 7.5wt% of WPI) on physical, mechanical and barrier properties of the nanocomposite were then evaluated. FTIR spectroscopy indicated the progressive removal of non-cellulosic components from the oat husk. SEM images showed the mean width of ONC was about 76nm and XRD analysis revealed the crystallinity increased after acid hydrolysis. The films prepared with up to 5wt% ONC showed the highest tensile strength, Young's modulus, solubility and the lowest elongation at break and moisture content. At high level (7.5wt%), tensile strength, Young's modulus and solubility of the films decreased and elongation at break and moisture content increased due to agglomeration of the fillers. Nevertheless, film transparency and water vapor permeability decreased with ONC incorporation.

Optimization of cocoa butter analog synthesis variables using neural networks and genetic algorithm.

Cocoa butter analog was prepared from camel hump fat and tristearin by enzymatic interesterification in supercritical carbon dioxide (SC-CO2) using immobilized Thermomyces lanuginosus lipase (Lipozyme TL IM) as a biocatalyst. Optimal process conditions were determined using neural networks and genetic algorithm optimization. Response surfaces methodology was used to design the experiments to collect data for the neural network modelling. A general regression neural network model was developed to predict the response of triacylglycerol (TAG) distribution of cocoa butter analog from the process pressure, temperature, tristearin/camel hump fat ratio, water content, and incubation time. A genetic algorithm was used to search for a combination of the process variables for production of most similar cocoa butter analog to the corresponding cocoa butter. The combinations of the process variables during genetic algorithm optimization were evaluated using the neural network model. The pressure of 10 MPa; temperature of 40 °C; SSS/CHF ratio of 0.6:1; water content of 13 % (w/w); and incubation time of 4.5 h were found to be the optimum conditions to achieve the most similar cocoa butter analog to the corresponding cocoa butter.

Nanomechanical characteristics of meat and its constituents postmortem: a review.

Tenderness/toughness are two important factors in meat evaluation and can be well explained by their mechanical and nanomechanical characteristics, which in turn are highly affected by the complex arrangement of meat numerous constituents and the influence of endogenous enzymes on this biological structure. It has been also revealed that post-slaughter variations in muscle characters that make muscle to transform to meat are a consequence of changes in the nanomechanical properties of myofibrillar proteins through linkage with each other or even through their breakdown. However, background toughness that is related to the connective tissues exists just at the time of slaughter and does not change over the time. The most famous instruments that measure the mechanical characters of myofibrils in pico/nano scale are atomic force microscopy, also known as scanning force microscope, optical tweezer, and glass microneedle. In this regard, mechanical terms such as torsional strength, rotational Brownian motion, elastic modulus, viscoelasticity, flexibility, etc. are generally used to show different behavior of meat ultrastructure and the changes that usually occur in postmortem muscle. It is expected that the evaluation of nanomechanical properties of muscle cells and connective tissues, particularly when the muscle undergoes different changes, be useful in order to justify many features of meat postmortem.

A study of lipid- and protein- bound sialic acids for the diagnosis of bladder cancer and their relationships with the severity of malignancy.

BACKGROUND: The gold standard for detection of bladder cancer is cystoscopy, which is an invasive and complicated procedure. Our study was conducted to find a tumor marker with high specificity, sensitivity, and accuracy for the diagnosis of bladder cancer. METHODS: Serum samples were collected from 58 bladder cancer patients and 60 healthy control subjects. Levels of lipid-bound sialic acid (LBSA), and protein-bound sialic acid (PBSA) were measured spectrophotometrically by Aminoff's method. RESULTS: Mean levels of both markers were found to be significantly higher in the patients than the healthy controls. Positive correlations were observed between serum levels of lipid- (r=0.283, p<0.05) and protein- bound (r=0.56, p<0.05) sialic acids and the grade of malignancy. To differentiate patients with bladder tumors from healthy controls, cut-offpoints were determined for each of the two parameters based on Receiver Operating Characteristic (ROC) curve analysis (LBSA=21.25 mg/dL, PBSA=6.15 mg/dL). The data showed good sensitivities (LBSA=89%, PBSA=79%), specificities (LBSA=70%, PBSA=70%) and accuracies (LBSA=83%, PBSA=81%) for both markers. CONCLUSION: Measuring serum LBSA and PBSA by this simple, reproducible, noninvasive, and inexpensive method can accurately discriminate cancer patients from healthy individuals.

Highly selective electrochemical biosensor for the determination of folic acid based on DNA modified-pencil graphite electrode using response surface methodology.

An electrochemical DNA biosensor was proposed as a screening device for the rapid analysis of folic acid using a pencil graphite electrode modified with salmon sperm ds-DNA. At first, immobilization of the ds-DNA on pencil graphite electrode was optimized using response surface methodology. Solution pH, DNA concentration, time of DNA deposition and potential of deposition was optimized each at three levels. The optimum combinations for the reaction were pH 4.8, DNA concentration of 24 µg mL(-1), deposition time of 304 s, and deposition potential of 0.60 V, by which the adenine signal was recorded as 3.04 µA. Secondly the binding of folic acid to DNA immobilized on a pencil graphite electrode was measured through the variation of the electrochemical signal of adenine. Folic acid could be measure in the range of 0.1-10.0 µmol L(-1) with a detection limit of 1.06×10(-8) µmol L(-1). The relative standard deviations for ten replicate differential pulse voltammetric measurements of 2.0 and 5.0 µmol L(-1) folic acid were 4.6% and 4.3%, respectively. The biosensor was successfully used to measure folic acid in different real samples.