Enzymatic modification of sesame seed protein,sourced from waste resource for nutraceutical application

The functional characteristics which include protein solubility at different pH, emulsifying and foaming properties, degree of hydrolysis, molecular weight distribution, antioxidant and ACE inhibitory activity of sesame protein hydrolysates prepared with pepsin, papain and alcalase enzymes were evaluated. The rate of degree of hydrolysis was found to reach maximum (25–30%) within the first time fragment i.e 10 min but 80% of hydrolysis was obtained in 120 min with alcalase. SDS-PAGE of hydrolysates with papain, pepsin and alcalase evinced bands of low molecular weight protein of 14.3 kDa and even lower for alcalase treatment of 120 min. Hydrolysates so formed were of improved functional properties as evident from emulsifying and foaming property. Hydrolysis with different proteases enhanced the protein solubility significantly at pH 7.0. Antioxidative assay revealed radical scavenging activity of the hydrolysates with papain hydrolysates showing maximum antioxidative efficacy. The ultra-filtered peptide fractions which showed comparable ACE inhibitory activity were sequenced by MALDI-TOF and matched to that of previously identified ACE inhibitory peptides. The results corroborate the ACE inhibitory effect of the peptides. Hence, these highly bioactive protein hydrolysates produced from waste sesame meals can be successfully employed in various functional food formulations.     

Functional and nutritional properties of modified proteins of sesame (Sesamum indicum, L.)

A study on the functional and nutritional properties of sesame (Sesamum indicum, L.) flour, concentrate and enzymatic hydrolysates, demonstrated that nitrogen solubility of the hydrolysates is improved, in water (85%) and at different pHs (91-95%), by the action of neutrasa 0.5L and alcalasa 0.6L, yielding a product with good emulsifying and improved foaming properties. Hydrolysates produced by the pH-stat method, then freeze-dried and spray-dried presented a PER of 1.1 and 0.9, respectively. The flour and the concentrate had PER values of 1.2. Supplementation of one of the hydrolysates with soya hydrolysate (1:1), improved the PER to a value similar to that of casein. Use of neutrasa 0.5L and alcalasa 0.6L enzymes, enhances the sesame protein solubility without modifying extensively the PER. Besides, it yields a dehydrated product with improved emulsifying and foaming properties.     

Antioxidative and Functional Properties of Pumpkin Oil Cake Globulin Hydrolysates

Cucurbitin extracted from pumpkin (Cucurbita pepo) oil cake was enzymatically hydrolysed with three different enzymes viz. alcalase, flavourzyme and pepsin. Antioxidative and functional properties of cucurbitin hydrolysates with different degrees of hydrolysis (DH) were investigated. The antioxidant activity of the hydrolysates was strongly dependent on the enzyme used. The hydrolysates obtained by alcalase and pepsin showed antioxidative potential whereas flavourzyme hydrolysates did not demonstrate these activities. Reducing power and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) scavenging activity of cucurbitin hydrolysate were positively related to DH. The highest antioxidant activity was found in the hydrolysate obtained by alcalase at DH 25.6 % [reducing power of 0.25 ± 0.01 A700 nm and ABTS scavenging activity of 3.34 ± 0.02 mmol/L Trolox equivalent antioxidant coefficients (TEAC)]. Hydrolysis by all enzymes increased the protein solubility within the studied pH range. The best emulsion activity and stability index (EAI = 143.28 ± 3.05 m²/g and ESI = 87.5 ± 1.96 min) have hydrolysates produced by flavourzyme (DH 9.2 %) whereas alcalase produced hydrolysates with the best foaming capacity (FC = 242 ± 3.21). The results demonstrate that hydrolysates produced in the present study have good functional properties as well as antioxidant activity indicating their possible use in different food systems.     

Analyzing molecular weight distribution of whey protein hydrolysates

Process parameters on enzymatic hydrolysis and molecular weight (MW) distribution of whey protein hydrolysates were investigated. Whey protein hydrolysates were first gained by the alkaline protease alcalase for 7 h at temperature (50 °C), pH (8.0) and E/S (3%). The diversification of the hydrolysis degree and dissociative amino acid content was investigated during the whey hydrolysis. The dissociative amino acid content was 56.09 μmol/mL with the hydrolysis degree of 20.04%. The results of Sephadex G25 washing and high performance liquid chromatography–electrospray ionization–mass spectrometry (HPLC–ESI–MS) indicated the molecular weight distribution of whey protein hydrolysates ranged from 300 to 1400 Da, and most of whey peptide was under 1000 Da.     

In Vitro Acetylcholinesterase-Inhibitory Properties of Enzymatic Hemp Seed Protein Hydrolysates

The aim of this work was to characterize the structural and functional properties of hemp seed protein‐derived acetylcholinesterase (AChE)‐inhibitory enzymatic hydrolysates. Hemp seed protein isolate hydrolysis was performed using six different proteases (pepsin, papain, thermoase, flavourzyme, alcalase and pepsin + pancreatin) at different concentrations (1–4 %). The degree of hydrolysis was directly related to the amount of protease used but had no relationship with AChE‐inhibitory activity. Amino acid composition results showed that the hemp seed protein hydrolysates (HPHs) had high levels of negatively charged amino acids (39.62–40.18 %) as well as arginine. The 1 % pepsin HPH was the most active AChE inhibitor with ~6 µg/mL IC₅₀ value when compared to 8–11.6 µg/mL for the other HPHs. Mass spectrometry analysis showed that most of the peptides in all the hydrolysates were less than 1000 Da in size. However, the pepsin HPHs contained larger‐sized peptides (244–1009 Da) than the papain HPHs (246–758 Da), which in turn was larger than the alcalase HPH (246–607 Da). The higher AChE‐inhibitory effects of the pepsin HPHs may be due to increased synergistic effects from a wider peptide size range when compared to the papain and alcalase HPHs that had narrower ranges. The narrow peptide size range in the alcalase HPH confirms the higher efficiency of this protease in releasing small‐sized peptides from food proteins.     

青霉素菌丝中蛋白质酶法水解工艺

采用碱热法溶解青霉素菌丝,研究酶法催化水解菌丝溶解液中蛋白质转化为氨基酸的过程.考察酶种类、溶解液pH值、酶与蛋白质质量比、反应温度和时间等因素对蛋白质水解度的影响,建立最佳水解工艺.结果 表明,酶种类、酶与蛋白质之比、pH、温度和时间均对蛋白质水解过程产生影响.以单酶为催化剂,碱性蛋白酶催化水解效果最好,蛋白质水解度...     

Hydrolysis and solubilization of corn gluten by Neutrase

Hydrolysis and solubilization of corn gluten were performed using a commercial protease preparation Neutrase. The effects of substrate concentration, enzyme concentration, temperature, pH and hydrolysate amount on the degree of hydrolysis and solubility of corn gluten were investigated depending on processing time. Trials were conducted in a batch reactor and degrees of hydrolysis were computed using a pH‐stat method. Results show that solubility and degree of hydrolysis were almost linearly related in all process conditions applied except in the case of hydrolysate addition. Optimum conditions for hydrolysis and solubilization were obtained as 10 g L^?1 protein concentration, 4 mL L^?1 enzyme concentration, 45 °C and pH 6.5. The mechanism of the kinetics was explained by taking into consideration association binding between the enzyme and substrate. The kinetics of hydrolysis and solubilization for all experiments performed were represented by exponential association equations that have not been used in the literature before. Also, to illustrate the effect of process variables on hydrolysis and solubilization, some modelling studies were performed. Copyright © 2007 Society of Chemical Industry     

碱性蛋白酶水解林蛙卵粕蛋白的工艺条件优化

研究了碱性蛋白酶水解林蛙卵粕蛋白制备混合氨基酸的工艺,分析了反应温度、酶加量、底物浓度和反应时间对蛋白水解度的影响.通过单因素实验和正交实验确定碱性蛋白酶水解林蛙卵粕蛋白的最佳工艺条件为:反应温度60℃、酶加量2000 U·g-1、底物浓度4％、反应时间120min,此时的蛋白水解度为10.18％.     

Functional properties of pea (Pisum sativum, L.) protein isolates modified with chymosin

In this paper, the effects of limited hydrolysis on functional properties, as well as on protein composition of laboratory-prepared pea protein isolates, were investigated. Pea protein isolates were hydrolyzed for either 15, 30 and 60 min with recombined chymosin (Maxiren). The effect of enzymatic action on solubility, emulsifying and foaming properties at different pH values (3.0; 5.0; 7.0 and 8.0) was monitored. Chymosin can be a very useful agent for improvement of functional properties of isolates. Action of this enzyme caused a low degree of hydrolysis (3.9-4.7%), but improved significantly functional properties of pea protein isolates (PPI), especially at lower pH values (3.0-5.0). At these pH values all hydrolysates had better solubility, emulsifying activity and foaming stability, while longer-treated samples (60 min) formed more stable emulsions at higher pH values (7.0, 8.0) than initial isolates. Also, regardless of pH value, all hydrolysates showed improved foaming ability. A moderate positive correlation between solubility and emulsifying activity index (EAI) (0.74) and negative correlation between solubility and foam stability (-0.60) as well as between foam stability (FS) and EAI (-0.77) were observed. Detected enhancement in functional properties was a result of partial hydrolysis of insoluble protein complexes.     

Sesame cake protein hydrolysis by alcalase: Effects of process parameters on hydrolysis, solubilisation, and enzyme inactivation

We investigated the effects of process parameters (substrate concentration, enzyme concentration, temperature and pH) on the hydrolysis and solubilization of sesame cake protein as well as enzyme stability. The sesame cake protein was hydrolyzed by Alcalase enzyme (a bacterial protease produced by a selected strain of Bacillus Licheniformis) that was chosen among five commercial enzymes examined. The optimum process conditions for hydrolysis and solubilization were obtained as 15 g L^?1 substrate concentration, 3 ml L^?1 enzyme concentration, 50 °C and pH 8.5. Under these conditions, the values of degree of hydrolysis and solubilization were found as 26.3% and 82.1%, respectively, and enzyme lost its activity by approx. 56% at the end of 120 min processing time. Modeling studies were performed to determine the kinetics of hydrolysis, solubilization and enzyme inactivation. The relationship between hydrolysis and solubilization was found linear for all experimental conditions examined. The inactivation energy of Alcalase at the temperature range of 45–55 °C was determined to be 25544 J mol^?1.     

Investigation of hydrolysis conditions and properties on protein hydrolysates from flatfish skin

Response surface method (RSM), based on Box-Behnken design, was used to optimize the enzymatic hydrolysis conditions of flatfish skin protein hydrolysates (FSPH). Among the tested proteases, the combination of nutrase and trypsin was selected. The optimal hydrolysis conditions were as follows: pH 7.3, temperature 51.8°C, and the enzyme/substrate (E/S) ratio 2.5; under these conditions, the maximum peptide yield (PY) was 69.41±0.43%. The physiochemical analysis showed that the amino acids (His, Asp and Glu) of FSPH accounted for 18.15%, and FSPH was a mixture of polypeptides mostly distributed among 900–2000 Da. FSPH could exhibit a 93% chelating effect on ferrous ion at a concentration of 400 μg/mL, and also a notable reducing power. This study showed bioprocess for the production of FSPH for the first time, which had a good potential for valuable ingredients in the food, cosmetic and medicine industries.     

An In-vitro Investigation of Selected Biological Activities of Hydrolysed Flaxseed (Linum usitatissimum L.) Proteins

A study was conducted to determine bioactivities of flaxseed (Linum usitatissimum L.; variety: Valour) proteins and their hydrolysates. Isolated flaxseed proteins were treated with Flavourzyme^® at different levels of enzyme to substrate ratio (E/S) and hydrolysis time. The unhydrolysed proteins and hydrolysates were studied for angiotensin I-converting enzyme inhibiting (ACEI) activity, hydroxyl radical (OH·) scavenging activity and bile acid binding ability. Flavourzyme catalysed hydrolysis generated hydrolysates with a 11.94–70.62% degree of hydrolysis (DH). The hydrolysates (0.67 mg/ml) had strong ACEI activity (71.59–88.29%). The maximum ACEI activity containing hydrolysate exhibited an IC₅₀ of 0.07 mg/ml (E/S: 1.5; Time: 12 h; DH: 11.94%). The OH· scavenging activity of the hydrolysates (0.5 mg/ml) was 12.48–22.08% with an IC₅₀ of 1.56 mg/ml in the sample possessing maximum activity (E/S: 47.5; Time 0.7 h; DH: 24.63%). Both these activities were greater in hydrolysates with lower DH and higher peptide chain length (PCL) than those with higher DH and lower PCL. Hydrolysed flaxseed proteins (0.67 mg/ml) had no bile acid binding ability. The unhydrolysed proteins had no ACEI or OH· scavenging activity but demonstrated bile acid binding ability.     

大豆蛋白酶解技术比较

以大豆蛋白粉和碱性2709蛋白酶为原料,进行了超声波功率对大豆蛋白水解度的影响,以及有、无超声波作用下大豆蛋白酶解的正交优化实验。结果表明,超声波作用效果与超声波功率有关,与无超声波作用下的大豆蛋白酶解相比,40kHz、128W的超声波处理,可使大豆蛋白的水解度提高6.48%～30.86%,平均提高21.18%,有效地促进了大豆蛋白酶解。超声波作用没有改变大豆蛋白酶解的优化工艺参数,均为温度55℃、pH=10.5、ρ(底物)=5g/L、w(酶)=5%,但使各因素对水解度影响的大小顺序发生了改变。有超声波作用下各因素影响大豆蛋白水解度的大小顺序为:酶质量分数>pH>底物质量浓度>温度;无超声波作用下各因素对大豆蛋白水解度影响的大小顺序为:酶质量分数>温度>底物质量浓度>pH。     

猪皮水解严物的吸湿保湿性能研究

研究猪皮水解产物的吸湿保湿性能。实验利用动物蛋白酶对猪皮进行酶解,以骨胶原为对照,对猪皮水解产物在26℃,相对湿度分别为20％、43％和81％的条件下的吸湿和保湿性能进行测定。在实验湿度环境范围内,猪皮在水煮45min后进行酶解,酶解条件为底物质量分数为4％、酶浓度为2％、酶解温度40％、酶解时间2h,pH值7．5的酶解条件下,酶解产物得率最高,酶解产物的吸湿和保湿性能和德国产的骨胶原相近。猪皮的动物蛋白酶水解产物用于开发吸湿保湿化妆品方面具有极大的开发前景。     

Peptide characteristics of sunflower protein hydrolysates

Protein isolate from sunflower seeds was used as the starting material for preparation of an extensively hydrolyzed peptide product. Protein was hydrolyzed using an endopeptidase (Alcalase), an exopeptidase (Flavourzyme), or both enzymes sequentially. Combined use of these proteases generated the highest degree of hydrolysis, 54.2%, and highest solubility, around 90%, between pH 2.5 and 7. Molecular weight profiles of the hydrolysates were characterized by gel filtration chromatography and denaturing electrophoresis. Amino acid compositions and solubilities of the different hydrolysates also were studied.     

Optimization of antioxidant hydrolysate production from flying squid muscle protein using response surface methodology

The squid muscle protein, extracted from by-products of flying squid (Ommastrephes bartrami) was hydrolyzed by five proteases (pepsin, trypsin, papain, alcalase and flavourzyme). DPPH radical scavenging power was used to evaluate antioxidative activity of hydrolysates. The hydrolysate obtained by papain exhibited the most excellent potential of antioxidative activity. Furthermore, response surface methodology (RSM) was employed to optimize hydrolysis conditions, including enzyme to substrate (E/S) ratio, reaction temperature, and hydrolysis time. The optimum conditions obtained were as follows: E/S ratio of 1.74%, temperature of 51 °C and time of 46 min, under which, DPPH radical scavenging activity of 74.25% was obtained. Moreover, it was found that the optimum hydrolysate of 8 mg/mL displayed relatively stronger inhibitory effect on lipid peroxidation compared with α-Tocopherol of 0.1 mg/mL.     

Aqueous enzymatic extraction of peanut oil and protein hydrolysates

The aqueous enzymatic process of simultaneously preparing oil and protein hydrolysates from peanut was investigated. The optimum parameters for hydrolysis using Alcalase 2.4L were established by the single-factor and orthogonal test. The optimal processing conditions were as follows: hydrolysis temperature 60 °C, pH 9.5, ratio of material to water 1:5 (w/w), alkaline extraction time 90 min, enzyme amount 1.5% (w/w) and hydrolysis time 5 h. Under these conditions, the free oil and protein hydrolysates yields were 79.32% and 71.38% respectively. In order to improve these yields, As1398 was chosen to hydrolyze the residue and emulsion. The total free oil and protein hydrolysates yields were increased to 91.98% and 88.21% respectively.     

碱性蛋白酶水解蚕蛹蛋白集总动力学

引言蚕蛹是养蚕业主要的副产物,蚕蛹蛋白质量占干蚕蛹质量的45%～50%。蚕蛹蛋白含有18种氨基酸,其中8种人体必需氨基酸含量占氨基酸总量40%以上,是一种优质蛋白源。文献报道蚕蛹蛋白酶解后的多肽具有抗氧化、降血压、抗疲劳、提高免疫力和抑制癌细胞扩散等作     

Optimization of glutamine Peptide production from soybean meal and analysis of molecular weight distribution of hydrolysates

The process parameters of enzymatic hydrolysis and molecular weight distribution of glutamine (Gln) peptides from soybean meal were investigated. The Protamex^® hydrolysis pH of 6.10, temperature of 56.78 °C, enzyme to substrate ratio (E/S) of 1.90 and hydrolysis time of 10.72 h were found to be the optimal conditions by response surface methodology (RSM) for a maximal degree of hydrolysis (DH) value of 16.63% and Gln peptides content at 5.95 mmol/L. The soybean meal was hydrolyzed by a combination of Protamex^® and trypsinase so that DH and Gln peptides would reach 22.02% and 6.05 mmol/mL, respectively. The results of size exclusion chromatography indicated that the relative proportion of the molecular weight <1000 Da fraction increased with DH values from 6.76%, 11.13%, 17.89% to 22.02%, most notably the 132–500 Da fractions of hydrolysates were 42.14%, 46.57%, 58.44% and 69.65%. High DH values did not lead to high Gln peptides content of the hydrolysate but to the low molecular weight Gln peptides.     

Optimization of the Aqueous Enzymatic Extraction of Rapeseed Oil and Protein Hydrolysates

An aqueous enzymatic extraction method was developed to obtain free oil and protein hydrolysates from dehulled rapeseeds. The rapeseed slurry was treated by the chosen combination of pectinase, cellulase, and β-glucanase (4:1:1, v/v/v) at concentration of 2.5% (v/w) for 4 h. This was followed by sequential treatments consisting of alkaline extraction and an alkaline protease (Alcalase 2.4L) hydrolysis to both produce a protein hydrolysate product and demulsify the oil. Response surface methodology (RSM) was used to study and optimize the effects of the pH of the alkaline extraction (9.0, 10.0 and 11.0), the concentration of the Alcalase 2.4L (0.5, 1.0 and 1.5%, v/w), and the duration of the hydrolysis (60, 120, and 180 min). Increasing the concentration of Alcalase 2.4L and the duration of the hydrolysis time significantly increased the yields of free oil and protein hydrolysates and the degree of protein hydrolysis (DH), while the alkaline extraction pH had a significant effect only on the yield of the protein hydrolysates. Following an alkaline extraction at pH 10 for 30 min, we defined a practical optimum protocol consisting of a concentration of 1.25–1.5% Alcalase 2.4L and a hydrolysis time between 150 and 180 min. Under these conditions, the yields of free oil and protein hydrolysates were 73–76% and 80–83%, respectively. The hydrolysates consisted of approximately 96% of peptides with a MW less than 1500, of which about 81% had a MW less than 600 Da.