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The production of bioethanol from lignocellulosic biomass could be considered as an appropriate and economic option to remove environmental disasters and improve energy security. In fact, lignocellulosic material is mainly composed of cellulose, hemicellulose and lignin. Lignin works as the adhering prevents the bioconversion of cellulose into sugars and ultimately to ethanol. To address the problem, various chemical, physical, physicochemical and biological methods have been suggested. Enjoying convenient operating conditions, production of non-hazardous wastes, and having no harmful side effects, make the biological methods a potentially proper option. Unfortunately, the biological methods are slower and less efficient in comparison with the other processes. In the present study, an attempt is made to resolve this problem in an enzymatic degradation of lignin of a rice straw sample. Several peroxidase enzymes were produced by a white rot fungus, and their effects on lignin removal from the biomass samples were investigated in shaking flasks. Lignin concentration and enzymes' activity were measured by the acetyl bromide-soluble lignin spectrophotometric method and optical density method using special reagents, respectively. The results revealed that the enzymatic treatment could remove at least 30% of the lignin content of the lignocellulosic biomass. To achieve the maximum activity of the enzymes, The chemical composition of the culturing medium was optimized for the concentration of important metal ions including Cu2+, Mn2+ and Zn2+ through Box Behnken response surface methodology. The enzymes' activity at the obtained optimal conditions increased four times for Manganese peroxidase, and lignin peroxidase.

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Abstract The aim of this study was to hydrolysis of rainbow trout viscera by application of flavourzyme, papain and pepsin enzymes and compare the functional and antioxidant properties of these three types of proteins. At the same time, the maximum degree of hydrolysis and nitrogen recovery was recorded for the hydrolysate produced by flavourzyme (23.12 ± 1.05% and 55.64 ± 0.68% respectively). In all pH values tested (apart pH 8 and 10), hydrolysate produced by flavourzyme showed the highest solubility compared to other proteins (p<0.05). In addition, emulsion activity (apart from pH 4) and emulsion stability index (apart from pH 8) in this protein were higher in comparison with two other proteins (p<0.05). To compare the antioxidant properties of hydrolysate, the inhibition capability of scavenging of 2,2 diphynyl-1-picrylhydrazyl (DPPH) free radicals and reduction capacity of iron (III), were measured. As a result, hydrolysate produced by pepsin showed highest DPPH scavenging power (83.59 ± 2.27 %) and iron (III) reduction power (0.886 ± 0.013 absorbtion in 700 nm).This study showed that the proteins produced from the substrate has favorable properties and various factors, including the type of enzyme used greatly affect these properties.

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Lipid oxidation is one of the major processes in deterioration of food quality and nutritional value. In this study, antioxidative activity of peptide was determined from hydrolysate of protein isolate from common kilka (Clupeonella cultriventris caspia) muscle using trypsin enzyme of pyloric caeca extraction. The optimum pH and temperature of trypsin enzyme for BAPNA (Nα –benzoyl -DL- argentine – ρ – nitroanilide -HCL) hydrolysis were measured 8.0 and 60 °C, respectively. The finding showed that antioxidative activities determined by DPPH, ABTS radical scavenging activities and ferric reducing antioxidant power (FRAP) increased significantly with variation of degree of hydrolysates from 20 to 40% (p<0.05). The results suggest that trypsin enzyme from pyloric caeca extraction could be a useful tool for peptide production from protein isolate with antioxidant activity and used as an alternative for commercial enzymes such as microbial enzymes in production of protein hydrolysates.

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Aims: Skipjack tuna has the highest level of catch rate among tuna all over the world. Its head contains about 64% protein. Many Protein Hydrolysates and peptides obtained from various marine sources have a high antioxidant power. The aim of this study was to investigate the antioxidant activity of Protein Hydrolysate in Skipjack tuna head.
Materials & Methods: In this experimental study, 30 Skipjack tunas were investigated. At first, the amount of different compounds (protein, fat, ash, and moisture) was evaluated in the raw material; then, the hydrolysis process was performed by Alcalase enzyme and the hydrolysis degree of the protein hydrolysate was evaluated at different times. The antioxidant activity of the protein hydrolysate mixture was measured by DPPH radical scavenging activity, iron revival power, and ABTS radical inhibitory activity. For data analysis, the analytical tests were used.
Findings: The main part of the fish head was protein and it had high levels of ash. The degree of hydrolysis increased with increasing time and was it significant at 15, 60, and 120 minutes (p<0.05), but not significant at 120 and 240 minutes (p<0.05). DPPH radical scavenging activity increased with increasing hydrolysis time and there was a significant difference in all samples obtained from different times (p<0.05). The iron reduction capacity of the protein hydrolysate samples increased with increasing the hydrolysis time, and the highest amount was at 240 minute. The samples obtained from different times had a significant difference in iron reduction capacity (p<0.05). Increasing the concentration of protein hydrolysate increased inhibitory activity (p<0.05).
Conclusion: Protein hydrolysate in Skipjack tuna head has a high antioxidant activity and can be used in food products to increase oxidation stability.

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In this experiment, head wastes were prepared and enzymatically hydrolyzed using alcalase (2.4 L) enzyme. The hydrolysate was fractionated by ultrafiltration with 10 kDa molecular weight cut-offs and the desired fraction was encapsulated following ion coagulation method (chitosan and triphosphate (TPP)) in nanochitosan capsules. Encapsulation process was optimized based on different ratios of chitosan:TPP and different concentrations (1, 5 and 10 mg/ml) of peptidic fraction. Finally, the degree of hydrolysis and the length of the peptides obtained from enzymatic hydrolysis were determined. The nanocapsules were examined for size, zeta potential and polydispersity index (PDI) using dynamic light scattering (Malvern, England). Structural and surface morphology studies including scanning electron microscopy (SEM) and infrared spectroscopy (FTIR) of capsules produced under favorable conditions were also performed. Particle size was measured in various concentrations and treatments in the range of 30 to 150 nm. The best results were obtained in the treatment of 2: 1 ratio of chitosan to polyphosphate and concentration of 10 mg / ml. The size, dispersion index, zeta potential and size of nanocapsules in the optimal conditions were 0.375, 2020 and 30.13 nm, respectively, and storage conditions at -20 °C had no effect on the quality of nanocapsules. Based on the efficiency study, it was found that fraction with a concentration of 10 mg/ml is well encapsulated by chitosan with an efficiency of 91.04 ± 0.18 percent. The results showed that chitosan-TPP could be used for nanocapsulation of bioactive peptides with an approximate molecular weight of less than 10 kDa.

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Diabetes mellitus is a major health problem in the worldwide. Inhibition of DPP-IV is one of the methods to control diabetes type 2. Inhibition of this enzyme may improve glycemic control in diabetics by preventing the rapid breakdown and there by prolonging the physiological action of incretin hormones. Furthermore, improving the antioxidant system in diabetic patients can prevent the occurrence of secondary disease caused by oxidative stress. Therefore, the head of skipjack tuna was hydrolyzed with alcalase enzyme (1/5% of raw material weight) for 4 hours, in order to produce a product with antidiabetic and antioxidant activities. The DPP-IV inhibition activity, DPPH radical scavenging activity and reducing power of hydrolysate were measured. The results showed that the skipjack tuna head protein hydrolysate possess bioactive properties in a concentration dependent manner and increasing the protein concentration leads to a significant increase in bioactive properties of hydrolyzed product (p≤0.05). The IC50 of protein hydrolysate in DPP-IV inhibition and DPPH radical scavenging activities were obtained 1.016±0.02 mg/ml and 0.297±0.015 mg/ml, respectively. Also the reducing power of hydrolysate was 0.176±0.002 in 2.5 mg/ml protein concentration. Overall, according to the obtained results, it can be concluded that protein hydrolysate of skipjack tuna head possess high antioxidant and antidiabetic activities in vitro, and can be used as a food additive to enhance health level if additional research be conducted.

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Polysaccharides possess diverse biological properties, mostly owed to their structural complexity and molecular heterogeneity, that could be improved through engineering methods and application of structural modifications. The objective of the present study was the assessment of antioxidant properties of hydrolyzed fucoidan from seaweed Nizamuddinia zanardinii and the correlation of molecular weight with biological function. After the removal of pigments and low molecular weight compounds, crude extracted polysaccharide was hydrolyzed at 100 C for 10, 20, 40 and 60 minutes using 0.01N HCl. The average molecular weight of crude fucoidan 1254.4 × 10³ g/mol and for hydrolysates FH10, FH20, FH40 and FH60 was 974.5, 891.8, 806.5 and 705.5 × 10³ g/mol, respectively. With the decrease of molecular weight, hydrolysates, compared with the crude fucoidan, exerted considerable DPPH (61.27-84.54%) and ABTS (40.1-88.5%) radical scavenging and Fe³⁺ reducing power (0.49-0.81 Abs) activities. Among different samples, hydrolysate FH20 showed the greatest capacity for DPPH radical scavenging activity (70.45-84.54%) and Fe³⁺ reducing power (0.49-0.81 Abs). Overall, the results of the current study showed that hydrolysis and reduction of molecular weight significantly improved the antioxidant activities of the fucoidan while time did not result any significant differences in antioxidant properties of hydrolysates which could be due to alterations in functional groups. Hence, fucoidan isolated from the examined species could be utilized as antioxidant agents in forms of native or hydrolysates.
 

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In this study, the orangefin ponyfish (Leiognathus bindus) was hydrolyzed by alcalase in an enzyme to substrate ratio of 1: 100 for 300 minutes, and the degree of hydrolysis was measured for 5 hours. Also, the hydrolysate was fractionated by centrifugal having molecular mass cutoffs of 3, 10, and 30 kDa, and four peptide fractions were obtained. Then, the antioxidant activity (DPPH and ABTS free radicals scavenging activity) of peptide fractions, as well as hydrolysate, were measured at different hydrolysis times. The degree of hydrolysis was the highest (55.43 ± 2.11%) at a hydrolysis time of 240 minutes. The hydrolysate had a high amount of hydrophobic amino acids (50.6%) which cause antioxidant properties. The results of DPPH radical scavenging activity showed that the highest scavenging activity was obtained at a hydrolysis time of 240 minutes (75.59 ± 1.46). Also, among all the fractions, the 3-10 kDa fraction exhibited the highest scavenging activity compared to other fractions (80.58 ± 2.96% at a concentration of 5mg /ml). Based on the result of ABTS radical scavenging, the highest activity was reported at 240 minutes after hydrolysis (50.54 ± 0.63). Also, among all peptide fractions, the 3-10 kDa fraction had significantly higher scavenging activity than other fractions (84.58 ± 0.44 at a concentration of 5 mg /ml). The results of this study showed that the peptides obtained by enzymatic hydrolysis of orangefin ponyfish are a good candidate for providing antioxidant properties.

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Proper conditions for producing crude beta-galactosidase from waste materials were de-termined. This enzyme is to be used in the production of lactose-hydrolyzed milk. Whey permeate was used as a basic medium. Twenty seven treatments were developed by 3 vary-ing factors of: yeast extract (1, 2, and 3 %), wheat steep liquor (1, 2, and 3 %), and whey powder (0.5, 1, and 1.5 %). Crude enzyme extract was obtained by sonication of the cells collected from cultivation of Lactobacillus delbrueckii ssp. bulgaricus in various media at 43oC. The beta-galactosidase activity was assessed using Ortho-Nitro-Phenyl-beta-D-galactopyranoside (ONPG). Yeast extract and whey powder had both significant effects (P< 0.01), while wheat steep liquor proved to be ineffective. Yeast extract had the most pro-nounced effect on the production of beta-galactosidase. The effect of the interactions of yeast extract-whey powder and wheat steep liquor-whey powder were significant at 5 % level (P< 0.05), while the effect of the interaction of yeast extract-wheat steep liquor was sig-nificant at 1% level (P< 0.01). Interaction effect of the 3 factors on the production of beta-galactosidae was significant (P< 0.01). The best combination for production of beta-galactosidase (4.924 U ml-1) was 3% yeast extract, 1.5% whey powder and 2% wheat steep liquor.

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In this study, the effect of different hydrolysis times (45, 90, 135, 180, and 225 minutes) by alcalase enzyme on the yield and quality of oil extracted from common kilka fish (Clupeonella cultriventris caspia) was investigated. The results showed that the highest extraction yield (40.41%) was in the hydrolyzed treatment for 135 minutes, which was not significantly different from other treatments. The qualitative indices of TBA, FFA, and CD of the extracted oils increased by increasing hydrolysis time, so the highest value of the mentioned indices was at 225 minutes, while the highest value of the PV index was at 180 minutes. Because the treatment of oil extracted in 45 minutes had lower values in the investigated oxidative spoilage indicators, it was selected as the treatment. The composition of its fatty acids was investigated, and it was found that monounsaturated fatty acids were the predominant fatty acids. Also, the amounts of saturated and polyunsaturated fatty acids did not show significant differences (p < 0.05). According to the obtained results, it was found that different hydrolysis times have different effects on the yield and quality of the obtained oil. Therefore, more research and studies are needed to fully investigate the effect of hydrolysis time on the quality characteristics of the oil extracted from Kilka fish.
 

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Studies on the production of protein supplements for phenylketonuria (PKU) patients indicate that whey protein is one of the most important protein sources for production of these compounds, owning to its specific combination of amino acids.Whey is considered as one of the most polluting by-product in environment, otherwise, it is an excellent source of functional proteins that can be used in medicine and special diet products. In this study, three different concentrations of whey protein concentrate (WPC) were used as a substrate for three enzymes Flavourzyme^®, Neutrase^®and Protamex^®. Effect of substrate concentration and hydrolysis time were studied on the separation efficiency of phenylalanine using response surface methodology (RSM) design. Phenylalanine was removed from hydrolyzed samples using ultra filtration (UF) and its concentration was measured using HPLC technique. Results of this study showed that samples hydrolyzed by Flavourzyme^® contain the lowest level of phenylalanine. Also, process optimization was done in order to predict the best conditions of hydrolyzing .The best condition in order to remove the maximum phenylalanine from whey proteins was found for the minimum hydrolyzing time and the lowest substrate concentration for all three enzymes.

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In the present study Protein hydrolysate was prepared from the sheep visceral (stomach and intestine) using Alcalase 2.4 L. The effect of temperature (40, 45, 50 and 55 °C), time ( in six levels) and enzyme/substrate ratio (30, 60 and 90 Anson unit), on degree of hydrolysis and antioxidant activity were investigated using factorial experiment. The highest degree of hydrolysis was observed at 45 °C, after 180 min and enzyme/substrate ratio of 90 Anson unit/ Kg substrate (p< 0.05). Under these conditions, degree of hydrolysis was 36/92%. To study the antioxidant activity of protein hydrolysate, DPPH radical scavenging activity, ferric reducing power and effect of protein hydrolysate on stability of soybean oil were measured. All antioxidant activity experiments were performed at constant temperature (45°C). The highest DPPH radical scavenging activity and ferric reducing power were achieved after 150 min at enzyme/substrate ratio of 90 Anson unit/ Kg substrate (p< 0.05) and after 180 min at 90 Anson unit/ Kg substrate (p< 0.05), respectively. Results show that protein hydrolysate can be used as a natural antioxidant source instead of synthetic antioxidants.    

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Sometimes, the spray solution must be stored for some time. This study aimed to answer the following questions: how long can an aryloxyphenoxypropionate herbicide be kept in the tank without losing efficacy? Is it dependent on pH? The experiment was designed as a completely randomized design with three factors including the labeled dose of herbicides (clodinafop, cyhalofop, diclofop, fenoxaprop, fluazifop, haloxyfop, propaquizafop, and quizalofop), the pH of spray solution (5, 7, and 8), and the storage time of spray solution (0, 12, 24, 36, 48, 60, and 72 h). The efficacy of herbicides on winter wild oat Avena sterilis subsp. ludoviciana Durieu. was not affected by changing the pH of the spray solution when the spray solution was applied immediately after preparation. When the spray solutions were stored, the herbicides' highest and lowest efficacy were generally observed at pH 5 and 9, respectively. At pH 9, except for fluazifop and haloxyfop, the effectiveness of other herbicides was reduced after 12-h storage of spray solution. The efficacy of all herbicides was reduced with 24-h spray solution storage. At pH 7, the efficacy of cyhalofop and fluazifop remained stable with 72-h storage of their spray solution. In contrast, at pH 5, the efficacy of clodinafop, cyhalofop, diclofop, fluazifop, haloxyfop, and quizalofop remained stable with 72-h storage of their spray solution. Therefore, if it is necessary to keep the spray solution of aryloxyphenoxypropionate herbicides for a short time, it is recommended to use a lower pH to avoid reducing their efficacy.


 

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Crude Enzyme (beta-galactosidase) Extract (CEE) was produced by Lactobacillus ssp. bulgaricus CHR Hansen Lb-12 and was applied in sterile milk which had been processed through Ultra High Temperature method (UHT milk), for hydrolyzing lactose. Lactosehydrolyzed milk was also produced by a pure and commercially available betagalactosidase (Maxilact). Optimum quantities of CEE and Maxilact enzyme, for producing lactose-hydrolyzed milk, during 6 hours of processing, were 0.418 and 0.512 U ml-1, respectively. Using more than 0.418 U ml-1 CEE resulted in unacceptable acidity. Acidity of lactose-hydrolyzed milk produced through 0.418 U ml-1 of CEE was significantly increased from 15 to 17 ºD, while enhancement of acidity in lactosehydrolyzed milk produced through Maxilact enzyme was not significant. Total count of lactose-hydrolyzed milk by 0.418 U ml-1 CEE, after 6 hours of processing was significantly increased from 5 to 30 CFU (Colony Forming Unit). Sensory evaluation of lactosehydrolyzed milk and ordinary UHT milk (as control) did not show any significant differences with respect to acceptability of sweetness, taste, aftertaste and color.

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This study suggests a new effective chemical pretreatment to hydrolyze rice straw for efficient ethanol production. It introduces a new yeast strain that ferments rice straw hydrolyzate more efficiently than Saccharomyces cerevisiae. The results proved the effectiveness of alkali application before HCl to delignify rice straw and to make it more appropriate for hydrolysis. The application of the hydrolyzing enzymes (cellulase and pectinase) resulted in hydrolysis of pretreated rice straw up to 94.3%. The total sugars released due to pretreatment-enzyme system was about 624 mg g^–1 dry mass and the glucose fraction was 198 mg g^–1. The results indicated that Pichia guilliermondii is more effective to ferment rice straw hydrolyzate than S. cerevisiae. P. guilliermondii produced larger amounts of bioethanol (7.72 g L^–1) than S. cerevisiae (6.13 g L^–1)under the same conditions. Our results suggest an appropriate pretreatment system (the cold dilute alkali-acid) and a new effective yeast strain to ferment the rice straw hydrolyzate to produce large amounts of bioethanol.