Enzymatic Hydrolysis Treatment Research Articles

Changes in allergenicity characteristics of bovine casein by enzymatic hydrolysis treatment

Changes in allergenicity characteristics of bovine casein by enzymatic hydrolysis treatment

Hemoglobin Hydrolyzate Promotes Iron Absorption in the Small Intestine through Iron Binding Peptides.

Hemoglobin is an excellent source of iron supplements, and its hydrolyzate spontaneously binds iron during digestion and promotes iron absorption in vivo. However, the underlying mechanisms of what peptides bind and how they bind iron ions remain unclear. This study prepared the porcine hemoglobin hydrolyzate through enzymatic hydrolysis and acid treatment and investigated the mechanisms of hemoglobin hydrolyzate on iron absorption through the determination of iron levels in dietary intervention mice, iron binding site analyses, peptide digestion analyses, molecular simulation docking, and INT407 cell validation. The results showed that ingestion of the hemoglobin hydrolyzate diets increased iron levels in the blood of mice, accompanied by the upregulation of duodenal iron circulation-related genes such as ferritin, PCBP1, and HP. Carboxyl, imidazole groups, and aromatic amino acid residues were iron binding sites of hemoglobin hydrolyzate during digestion. VDEVGGEA and VDEVGGE were found to involve the spontaneous and efficient binding of hemoglobin hydrolyzate to iron ions in the intestinal cavity. In particular, the DEVGGE peptide was the typical sequence for hemoglobin hydrolytic peptides to exert iron binding activity.

Characterization, Antioxidant Capacity and Protective Effect of Peptides from Cordyceps militaris Cultivated with Tussah Pupa on Oxidative Injured HepG2 Cells.

The antioxidant capacity and protective effect of peptides from protein hydrolysate of Cordyceps militaris cultivated with tussah pupa (ECPs) on H2O2-injured HepG2 cells were studied. Results indicated ECP1 (<3 kDa) presented the strongest antioxidant activity compared with other molecular weight peptides. Pretreated with ECPs observably enhanced survival rates and reduced apoptosis rates of HepG2 cells. ECPs treatment decreased the ROS level, MDA content and increased CAT and GSH-Px activities of HepG2 cells. Besides, the morphologies of natural peptides from C. militaris cultivated with tussah pupa (NCP1) and ECP1 were observed by scanning electron microscopy (SEM). Characterization results suggested the structure of NCP1 was changed by enzymatic hydrolysis treatment. Most of hydrophobic and acidic amino acids contents (ACC) in ECP1 were also observably improved by enzymatic hydrolysis. In conclusion, low molecular weight peptides had potential value in the development of cosmetics and health food.

The Effect of Enzymatic Hydrolysis and Maillard Reaction on the Flavor of Chicken Osteopontin.

To reveal the changes in the flavor quality of chicken osteopontin (CO) before and after enzymatic hydrolysis and a thermal reaction, the present study was carried out to evaluate the volatile compounds and non-volatile compounds in CO. The results show that the chicken boneset enzymatic solution (CBES) presented a notably richer aroma after the enzymatic hydrolysis treatment. At the same time, the concentrations of the total free amino acids (FAAs) and 5'-nucleotides in the CBES increased dramatically. The ERP (enzymatic reaction paste) scores and the ORC (osteopontin reactive cream) scores were exceptionally high in terms of the umami and salty flavor profiles. As precursors, FAAs and 5'-nucleotides also boosted the Maillard reaction, leading to the generation of wide volatile compounds. Compared to CO, CBES, and ORC, the sensory evaluation showed that ERP scored the highest. In summary, the enzymatic hydrolysis treatment coupled with the Maillard reaction significantly enhanced the flavor profile of CO. These findings offer valuable insights into the high-value utilization of bone by-products, making a significant advancement in the field.

Production of derivatives from wheat straw as reinforcement material for paper produced from secondary fibers

Nowadays, a high percentage (> 50%) of the paper produced in Europe uses recovered paper (secondary fibers) as raw material. In order to improve the mechanical properties of the paper produced, different kinds of additives are usually incorporated into the paper. Emerging renewable materials based on agricultural or forest residues, such as cellulose nanomaterials, have recently proved good capacities as reinforcing agents for different applications. In this work, pulp from wheat straw with a content of cellulose nanomaterial has been produced and tested as a mechanical reinforcing agent for paper production. A soda semi-chemical process was applied for the delignification of straw, to produce pulp with high cellulose content. Posteriorly, pulps with cellulose nanofibers were obtained in a high-pressure homogenizer, applying three different pretreatments to the cellulose pulp (acid hydrolysis, enzymatic hydrolysis and thermal treatment with glycerol) in order to facilitate the obtention of cellulose nanomaterial. Handsheets of paper were prepared from two sources of secondary fiber (fluting paper and old corrugated containers), adding different percentages of wheat straw derivatives (0, 3.5, 5 and 7%). The fibers' morphology and the papers' mechanical properties were investigated. Noticeable improvement rates (up to 25%) were observed for some mechanical properties of paper containing nanocellulose produced after the enzymatic and acid pretreatments. The quality of the secondary fibers source also affected the improvement rates achieved, with higher percentage changes for the lower-quality recycled paper.

Enzymatic hydrolysis and extensive heat treatment induce distinct modifications of cow's and camel milk proteins of relevance for production of infant formula

Camel milk is an alternative to cow's milk as protein source for infant formula. Reduced allergenicity is usually obtained through enzymatic hydrolysis of milk proteins. Heat treatment is another route to modify allergenicity. This study investigated the effect of enzyme hydrolysis and extensive heat treatment on the size, aggregation mechanisms, and modifications of camel milk proteins in comparison to the effect on cow's milk proteins. Disulphide bonds stabilized casein micelles in cow's milk but not in camel milk. The formation of large stable complexes by extensive heat treatment was prominent in cow's milk and not in camel milk. In both milks heat treatment led to equal levels of Maillard reaction, whereas sugar independent cross-linking was less pronounced in camel milk. Low sequence identity, different relative composition, and complete absence of β-lactoglobulin in camel milk are likely explanations for the different properties of cow's and camel milk. Production of infant formula based on camel milk should accordingly employ process parameters specifically adapted to this type of milk.

Exploration of the Linkages between Lignin and Carbohydrates in Kraft Pulp from Wheat Straw Using a 13C/2H Isotopic Tracer.

To further our understanding of the change in association between lignin and carbohydrates after kraft pulping, isotope-labeled kraft pulp (KP) was prepared using 13C and D double-isotope-labeled wheat straw, and it was subjected to enzymatic hydrolysis and ionic liquid treatment to explore the linkages between lignin and carbohydrate complexes in wheat straw. Isotope abundance determination showed that 13C and D abundances in the experimental groups were substantially higher than those in the control group, indicating that the injected exogenous coniferin-[α-13C], coniferin-[γ-13C], and d-glucose-[6-D2] were effectively absorbed and metabolized during wheat internode growth. Solid-state CP/MAS 13C-NMR spectroscopy showed that lignin was mainly linked to polysaccharides via acetal, benzyl ether, and benzyl ester bonds. Kraft pulp (KP) from the labeled wheat straw was degraded by cellulase. The obtained residue was fractionated using the ionic liquid DMSO/TBAH to separate the cellulose-lignin complex (KP-CLC) and xylan-lignin complex (KP-XLC). X-ray diffractometer determination showed that the KP-CLC regenerated cellulose type II from type I after the ionic liquid conversion. The 13C-NMR spectrum of Ac-En-KP-CLC showed that the cellulose-lignin complex structure was chemically bonded between the lignin and cellulose through acetal and benzyl ether bonds. The 13C-NMR spectrum of En-KP-XLC showed a lignin-hemicellulose complex structure, wherein lignin and xylan were chemically bonded by benzyl ether and acetal bonds. These results indicate that the cross-linking between lignin and carbohydrates exists in lignocellulosic fibers even after kraft pulping.

Quality of purula (rice seasoning for anemia from soy protein hydrolysate and seaweed) during pilot plant scale development using drum drying process

Purula is a new rice seasoning product made from soy protein hydrolysate and seaweed. It contains low molecular weight (&lt;20 kDa) biopeptide from soybean that can enhance iron absorption and fortified with vitamin and mineral to prevent anemia. This research aimed to monitor the quality of purula and its main ingredient during pilot plant scale process. The two main ingredients of purula are soy protein hydrolysate flour and seaweed slurry. Steam flash explosion and enzymatic hydrolysis treatment were applied to the soybean, followed by drum drying to produce soy protein hydrolysate flour. Brown and green algae were blanched and grinded to make seaweed slurry. Then, they were mixed with flour mix, drum dried, and added with vitamin and mineral to produce purula. Proximate, microbiological, and heavy chemical analysis were conducted on samples taken during stages of purula processing. Moisture content and thickness of Purula flakes were examined during pilot plant process. Molecular weight of protein analysis was also conducted on raw soybean, soy protein hydrolysate, and purula. Microbiological and chemical quality of soy protein hydrolysate flour, seaweed slurry, and purula conform with the food safety requirement. This indicates that Purula is safe for human consumption. Purula flakes produced by drum drying process also share consistent results of moisture content and thickness of Purula flake within 5 days of production. Low molecular weight of protein (&lt;20 kDa) was produced on soy protein hydrolysate and still intact on purula finished product. This study concluded that purula is able to be properly produced on pilot plant scale.

Bacterial cellulose biomass aerogels for oil-water separation and thermal insulation

The use of environment-friendly biomass for the preparation of functional materials has attracted increasing attention. In this study, bacterial cellulose (BC) was prepared from fruit waste via kombucha fermentation without involving any secondary enzymatic hydrolysis treatments. A three-dimensional network of bacterial cellulose aerogels (BCAs) with ultralow density (5.693 mg/cm3), high porosity (98–99%), and low thermal conductivity (23.4 mW/(m·K)) were obtained using two directional freeze-drying techniques. Here, the proposed freezing method can not only control the concentration of BC but make access to fibres reassembly by extremely low temperature freezing (−196 °C), which can further form a multi-stage pore structure. To increase their compressive resistance and optimise their ability to adsorb organic solvents and oils, the aerogels were subjected to chemical vapour deposition using methyltrimethoxysilane. The modified biomass aerogel exhibits a compression resilience exceeding 90% and achieves a hydrophobic angle of approximately 146.4°. This cost-effective, environmentally friendly, and highly efficient BCAs can be employed to treat oil spills and industrial waste.

Evaluation of IgG/IgE-binding capacity and functional properties of enzymatic hydrolysis in skimmed cow milk system.

Cow's milk (CM) allergy is a common food allergy that seriously impacts the growth and development of infants and children. However, CM is an important source of nutrients, and few studies focus on the effects of enzymatic hydrolysis treatment on the whole skimmed CM system. In this study, the IgG/IgE-binding and functional properties of Alcalase-, Protamex-, and Flavourzyme-treated skimmed CM (AT, PT, and FT, respectively) were systematically evaluated. The results showed that the treatment groups were mainly composed of low molecular weight (MW) peptides (<3kDa), accounting for 94.85%-97.90%. Additionally, the IgG reactivity of these peptides was significantly lower (p<0.05) than those of higher MW peptides (10-30kDa and >30kDa). The IgE reactivity of FT with higher MW peptides was the lowest among these groups, with the OD value reaching 0.089. Moreover, the total amino acid content of hydrolysates of skimmed CM (HM) increased significantly (skimmed CM, 5.94µg/mL; AT, 123.70 µg/mL; PT: 136.20µg/mL; FT, 988.72µg/mL) compared to that in skimmed CM. A total of 10, 10, and 7 flavor compounds were increased in AT, PT, and FT, respectively. Furthermore, the solubility, foamability, and emulsifying ability of HM were significantly improved, being 2.17-fold, 1.52-fold, and 1.96-fold higher in PT than in skimmed CM. These results lay a theoretical foundation for the development of hypoallergenic dairy products.

Improving the Sustainability of Processing By-Products: Extraction and Recent Biological Activities of Collagen Peptides.

Society and consumers are increasingly concerned about food safety and the sustainability of food production systems. A significant amount of by-products and discards are generated during the processing of aquatic animals, which still needs to be fully utilized by the food industry. The management and sustainable use of these resources are essential to avoiding environmental pollution and resource waste. These by-products are rich in biologically active proteins, which can be converted into peptides by enzymatic hydrolysis or fermentation treatment. Therefore, exploring the extraction of collagen peptides from these by-products using an enzymatic hydrolysis technology has attracted a wide range of attention from numerous researchers. Collagen peptides have been found to possess multiple biological activities, including antioxidant, anticancer, antitumor, hypotensive, hypoglycemic, and anti-inflammatory properties. These properties can enhance the physiological functions of organisms and make collagen peptides useful as ingredients in food, pharmaceuticals, or cosmetics. This paper reviews the general methods for extracting collagen peptides from various processing by-products of aquatic animals, including fish skin, scales, bones, and offal. It also summarizes the functional activities of collagen peptides as well as their applications.

Microplastic isolation method for wastewater and sludge samples by removal of excess organic and inorganic interferences

The isolation of microplastics from other organic and inorganic contents is a major hurdle to the effective quantification and characterization of microplastics in wastewater and biosolids samples. As a result, a well-established and standardized isolation method is vital for the analysis of microplastics. In this study, we evaluated biological hydrolysis, enzymatic hydrolysis, wet peroxidation and ethylenediaminetetraacetic acid treatment for microplastics isolation and demonstrated that the integration of these processes can effectively remove organic and inorganic contents to provide a clear microscope view for microplastics identification from wastewater and sludge samples. To the best of our knowledge, this study is the first to introduce biological hydrolysis and ethylenediaminetetraacetic acid treatment for the isolation of microplastics from environmental samples. The results reported could facilitate the establishment of a standardized procedure for microplastic isolation from wastewater and biosolid samples.

Cellulosic Fiber Waste Feedstock for Bioethanol Production via Bioreactor-Dependent Fermentation

The bioconversion of environmental wastes into energy is gaining much interest in most developing and developed countries. The current study is concerned with the proper exploitation of some industrial wastes. Cellulosic fiber waste was selected as a raw material for producing bioethanol as an alternative energy source. A combination of physical, chemical, and enzymatic hydrolysis treatments was applied to maximize the concentration of glucose that could be fermented with yeast into bioethanol. The results showed that the maximum production of 13.9 mg/mL of glucose was achieved when 5% cellulosic fiber waste was treated with 40% HCl, autoclaved, and followed with enzymatic hydrolysis. Using SEM and FTIR analysis, the instrumental characterization of the waste fiber treatment confirmed the effectiveness of the degradation by turning the long threads of the fibers into small pieces, in addition to the appearance of new functional groups and peak shifting. A potent yeast strain isolated from rotten grapes was identified as Starmerella bacillaris STDF-G4 (accession number OP872748), which was used to ferment the obtained glucose units into bioethanol under optimized conditions. The maximum production of 3.16 mg/mL of bioethanol was recorded when 7% of the yeast strain was anaerobically incubated at 30 °C in a broth culture with the pH adjusted to 5. The optimized conditions were scaled up from flasks to a fermentation bioreactor to maximize the bioethanol concentration. The obtained data showed the ability of the yeast strain to produce 4.13 mg/mL of bioethanol after the first 6 h of incubation and double the amount after 36 h of incubation to reach 8.6 mg/mL, indicating the efficiency of the bioreactor in reducing the time and significantly increasing the product.

Potential Anti-Sarcopenia Effect and Physicochemical and Functional Properties of Rice Protein Hydrolysate Prepared through High-Pressure Processing

Rice protein is a suitable alternative protein source for dairy protein in infant formulas on account of its unique nutrition and hypoallergenicity. Rice protein was isolated through enzymatic hydrolysis (Alcalase, papain, bromelain, Flavourzyme®) in combination with high-pressure processing (HPP) (400 MPa for 15 min at 25 °C) to enhance its functional properties and broaden its food processing applications. The effect of the HPP-treated rice protein hydrolysate on dexamethasone (DEX)-induced atrophy in C2C12 myotubes was also studied. The length of myotubes was observed under a light microscope, and periodic acid Schiff staining. The results showed that even though enzymatic hydrolysis and HPP treatment affected the color of the resulting rice protein, the protein content (3120.31 ± 42.15), branched chain amino acid (BCAA) content (15.12 ± 1.03), peptide content (31.25 ± 0.55), and amino acid composition of the rice protein were significantly increased. Moreover, the combined enzymatic and HPP treatment effectively overcame the problem of limited solubility and water-holding capacity. Rice protein produced through enzymatic and HPP treatment exhibited a higher free radical scavenging activity and oxygen radical absorbance capacity. It also alleviated DEX-induced muscle atrophy in C2C12 myotubes as indicated by the increase in myotube length. In short, the enzymatic and HPP treatment of rice protein not only overcame limitations, but also produced rice protein with high functionality in terms of antioxidant and therapeutic effects on muscle atrophy. The rice protein hydrolysate produced through enzymatic hydrolysis and HPP treatment showed the potential for use as an ingredient for functional foods in the nutraceutical industry.

Preparation and Taste Profiling of the Enzymatic Protein Hydrolysate from a by-Product of Red Snow Crab Processing as a Natural Seasoning Compound.

The red snow crab (Chionoecetes japonicus) is the most industrially processed in the Republic of Korea, and the meat is very popular, owing to its savory taste and flavor. Its body meat production comprises a two-step separation to increase meat yield. However, during the secondary separation, broken shell debris is occasionally entrained in the meat products, which is a concern for manufacturers. As the residues from first separation contain 39.9% protein, it can be utilized as an enzymatic protein hydrolysate (FPH) rich in free amino acids (FAAs). A combination of flavourzyme and alcalase (1:1) superiorly hydrolyzed the protein of the residues, and the best hydrolysis condition was suggested at 60 °C for 15 h with fourfold water and 2% enzyme addition, achieving a 57.4% degree of hydrolysis. The EPH was mostly composed of FAAs containing most essential amino acids; however, bitter-tasting amino acids accounted for 46.4% of the FAAs. To reduce the bitter taste, different nonvolatile organic acids were considered as masking agents, and citric and malic acids were effective, though the umami taste is slightly decreased. In conclusion, the crab processing residues can be utilized as an FAA-based natural seasoning compound through enzymatic hydrolysis and organic acid treatment.

Selection of Enzymatic Treatments for Upcycling Lentil Hulls into Ingredients Rich in Oligosaccharides and Free Phenolics

In this study, the comprehensive chemical characterization of red lentil hulls obtained from the industrial production of football and split lentils was described. The lentil hulls were rich in dietary fiber (78.43 g/100 g dry weight with an insoluble to soluble fiber ratio of 4:1) and polyphenols (49.3 mg GAE/g dry weight, of which 55% was bound phenolics), which revealed the suitability of this lentil by-product as a source of bioactive compounds with recognized antioxidant and prebiotic properties. The release of oligosaccharides and phenolic compounds was accomplished by enzymatic hydrolysis, microwave treatment and a combination of both technologies. The key role played by the selection of a suitable enzymatic preparation was highlighted to maximize the yield of bioactive compounds and the functional properties of the lentil hull hydrolysates. Out of seven commercial preparations, the one with the most potential for use in a commercial context was Pectinex® Ultra Tropical, which produced the highest yields of oligosaccharides (14 g/100 g lentil hull weight) and free phenolics (45.5 mg GAE/100 g lentil hull weight) and delivered a four-fold increase in terms of the original antioxidant activity. Finally, this enzyme was selected to analyze the effect of a microwave-assisted extraction pretreatment on the yield of enzymatic hydrolysis and the content of free phenolic compounds and oligosaccharides. The integrated microwave and enzymatic hydrolysis method, although it increased the solubilization yield of the lentil hulls (from 25% to 34%), it slightly decreased the content of oligosaccharides and proanthocyanidins and reduced the antioxidant activity. Therefore, the enzymatic hydrolysis treatment alone was more suitable for producing a lentil hull hydrolysate enriched in potential prebiotics and antioxidant compounds.

Bioconversion of Starch Base Food Waste into Bioethanol

The global demand for fuel keeps increasing daily. The massive depletion of fossil fuels and their influence on the environment as pollution is a severe problem. Meanwhile, food waste disposal is also a complex problem in solid-waste management since one-third of every food consumed is discarded as waste. The standard waste management methods, including food waste incineration and landfilling, are considered hazardous to the environment. Food waste constituents are majorly starch-based and contain various biomolecules, including sugar, lipids, proteins, vitamins, cellulose, etc. These polysaccharides can be hydrolysed into monosaccharides such as glucose, which can then be fermented using microorganisms to produce ethanol through the fermenting of sugars derived from enzymatic hydrolysis treatment of food wastes. The human food system is rich in starch, which can be a potential resource for bioethanol production.

Intracellular and extracellular sources, transformation process and resource recovery value of proteins extracted from wastewater treatment sludge via alkaline thermal hydrolysis and enzymatic hydrolysis

Excess sludge contains a large amount of protein and can be recycled to prepare industrial foaming agents, foliar fertilizers and other high value-added products. The optimization and effects of sludge protein extraction using the common processes of alkaline thermal hydrolysis (ATH) and enzymatic hydrolysis (EH) have been widely studied. This study focused on the protein extraction mechanisms of ATH and EH by comparing the ratio of intracellular to extracellular proteins extracted and the transformation of protein during the hydrolysis process. The extracellular protein content was 82.6 ± 5.07 mg/g VSS, and the content of intracellular protein extracted using ATH and EH was 376.9 mg/g VSS and 127.9 mg/g VSS, respectively. The ratio of intracellular to extracellular proteins extracted by ATH and EH was 4.5 and 1.5, respectively, indicating that ATH had a much better wall-breaking effect that allowed it to extract abundant intracellular proteins. The protein content obtained from ATH continuously increased over time, and approximately 38 % of proteins were further hydrolyzed to polypeptides. In contrast, the relatively low protein content extracted by EH possibly limited subsequent polypeptide hydrolysis, but subsequent hydrolysis to amino acids was not noticeably affected and was linearly correlated with the amount of protein extracted. An analysis of the recycling convenience and value of extracted proteins showed that the sludge dewatering performance increased by 86.7 % and 45.5 % after ATH and EH treatment, respectively, which was conducive to the subsequent separation of the protein solution. The protein extracted by ATH, with a large amount of peptides, would be beneficial to prepare industrial foaming agents, while the protein extracted by EH was rich in free amino acids and could be used to prepare foliar fertilizer.

Study on functional improvement of freeze-thaw egg yolk pellet by enzymatic hydrolysis.

Freeze-thaw egg yolk pellet (FYP) could be produced as a by-product in the process of egg yolk immunoglobulin (IgY) extraction. The FYP contained many superior nutritional components like fresh egg yolk, but it has poor functionalities because of protein denaturation resulted from freezing treatment during IgY extraction. For the purpose of comprehensive utilization of egg yolk resources, FYP was subjected to enzymatic hydrolysis with alcalase to produce FYP hydrolysates (FYPh) with four enzyme concentrations of 250, 500, 1000 and 2000U/g for improved functional properties. And then FYPh was spray dried to obtain hydrolyzed egg yolk pellet powder (HYP). Solubility, emulsifying property and surface hydrophobicity of HYP were investigated. The results showed that enzymatic hydrolysis could lead to noticeable changes in surface hydrophobicity, microstructure, solubility and emulsifying properties of HYP compared with the control group without enzymatic hydrolysis treatment. Solubility and emulsification stability index generally increased from 19g/100g, 12.33 to 87g/100g, 76.63 with increasing degree of hydrolyze, respectively. This study demonstrated that the functional properties of FYP could be effectively improved when the enzyme addition amount reached 1000U/g. HYP prepared under this condition owes desirable solubility and emulsification, and has the potential of application in food industry.

Combined effects of limited enzymatic hydrolysis and high hydrostatic pressure on the structural and emulsifying properties of rice proteins

The combined effects of limited enzymatic hydrolysis and high hydrostatic pressure (HHP) treatment on the structural and emulsifying properties of rice proteins (RPs) were investigated. Alcalase exhibited higher hydrolysis efficiency than papain. Through alcalase-catalyzed hydrolysis and HHP treatment, emulsifying activity index (EAI) and emulsifying stability index (ESI) of RPs were improved from 14.58 m2/g and 22.54 min to 29.93 m2/g and 43.35 min, respectively. The content of random coil in RPs increased, while the content of α-helix decreased. HHP at 300 MPa led to the highest surface hydrophobicity (H0) and fluorescence intensity. The enzymatic hydrolysis-HHP (300 MPa) modified RPs could form an oil-in-water emulsion with a d4,3 of 0.347 nm, ζ-potential of −36.4 mV, and creaming index of 10.5% after 7 days storage. This work sheds light on employing limited enzymatic hydrolysis and HHP to modify RPs for better application in emulsion-based food products.