Combination Of Enzymatic Hydrolysis Research Articles

Impact of pre-treatments and bioprocessing on the carbohydrate and polyphenol profile of brewers’ spent grain

Brewers’ spent grain (BSG), the solid waste of the brewing industry, is high in fibres, proteins and health-beneficial compounds such as polyphenols. This research investigated bioprocessing with enzymes and microbes to modify the properties of BSG for its utilisation as a food ingredient. Pre-treatment studies showed that wet milling performed better than dry milling, and heat and homogenisation either before or after the enzyme hydrolysis did not significantly influence the release of reducing sugars and free amino nitrogen (FAN). Four treatments were applied to wet-milled BSG: fermentation with Lactiplantibacillus plantarum POM1 with or without the enzyme Ondea pro and enzymatic bioprocessing without any fermentation. Control was the condition without enzyme and starter. Without the enzyme, there was negligible free sugar and FAN, and the starter had limited growth and organic acid production. Only the combination of enzymatic hydrolysis and fermentation reached a pH of 4 and 10 mg/g DW lactic acid. The microbial preference for monosaccharides was evident, and the enzyme influenced the release of oligosaccharides that can have a prebiotic effect. Bioprocessing impacted the phenolic acid composition and microbial consumption, with a significant release of ferulic acid during enzyme hydrolysis.

Oat Dietary Fiber Delays the Progression of Chronic Kidney Disease in Mice by Modulating the Gut Microbiota and Reducing Uremic Toxin Levels.

Chronic kidney disease (CKD) has emerged as a significant public health concern. In this article, we investigated the mechanism of oat dietary fiber in regulating CKD. Our findings indicated that the gut microbiota of CKD patients promoted gut microbiota dysbiosis and kidney injury in CKD mice. Intervention with oat-resistant starch prepared by ultrasonic combined enzymatic hydrolysis (ORSU) and oat β-glucan with a molecular weight of 5 × 104 Da (OBGM) elevated the levels of short-chain fatty acids (SCFAs) and regulated gut dysbiosis in the gut-humanized CKD mice. ORSU and OBGM also reduced CKD-related uremic toxins such as creatinine, indoxyl sulfate (IS), and p-cresol sulfate (PCS) levels; reinforced the intestinal barrier function of the gut-humanized CKD mice; and mitigated renal inflammation and fibrosis via the NF-κB/TGF-β pathway. Therefore, ORSU and OBGM might delay the progression of CKD by modulating the gut microbiota to reduce uremic toxins levels. Our results explain the mechanism of oat dietary fiber aimed at mitigating CKD.

Co-enzymatic hydrolysis enhanced thermal stability of mayonnaise

With the accelerated pace of life, frozen bakery products and ready-to-eat hot food are gradually emerging. Mayonnaise, a commonly used flavor sauce, is also applied to these products. However, with the large amount of oil and fat precipitation of mayonnaise in the reheating process of the product, which affects its application in the food industry, the thermal stability of mayonnaise has been gradually paid attention to. In this study, the thermal stability of mayonnaise was effectively improved by the combined enzymatic hydrolysis of liquid egg yolk (LEY) with phospholipase A2 (PLA2) and flavor protease. It was found that the moderate addition of flavor protease could effectively reduce the surface hydrophobicity and interfacial tension of egg yolk protein and improve its emulsification stability. Moreover, the hydrolysis reduced the molecular weight of yolk protein, thus reducing the thermal aggregation effect of yolk protein due to heating, which in turn reduced the loss of protein at the O/W interface and improved the thermal stability of mayonnaise.

Treatment and mechanism for hot melting starch by reducing the molecular chain winding and crystallinity

Unlike thermoplastic petroleum-based materials, starch-based materials rely on aqueous systems but are incapable of hot melting, resulting in low processing efficiency and limited large-scale industrial applications. In this study, the combination of α-amylase liquefaction and urea plasticization was used for the first time to obtain enzymatic thermoplastic starch (ETPS) for hot melting by changing the molecular chain of starch. ETPS showed an apparent hot melting phenomenon when heated below 200 °C. Differential scanning calorimetry revealed that heat absorption peaks were obviously reduced, and the hot melting phenomenon occurred easily depending on the combination of enzymatic hydrolysis and plasticization. Dynamic mechanical analysis indicated that the combined modification effectively increased the number of freely movable chains. The red shift of -OH stretching vibration peaks indicated the formation of strengthened hydrogen bonds in ETPS. X-ray diffraction showed that the crystallinity of ETPS was reduced to 5.68 %, effectively reducing the regenerative phenomenon. Gel permeation chromatography revealed that the molecular weight of ETPS decreased, and the entanglements between molecular chains were reduced. A tensile test showed that the elongation at break of ETPS was as high as 235.29 %, which was much higher than those of enzymatic hydrolysis starch and thermoplastic starch.

Efficient production of ferulic acid and p-coumaric acid from reed straws via combined enzymatic hydrolysis and hydrothermal pretreatment

The present study aimed to evaluate an available process for production of ferulic acid (FA) and p-coumaric acid (pCA) that could be potentially used as functional agents in food processing. The hydrothermal pretreatment combined with enzymatic hydrolysis (HP-CEH) was explored for efficient production of phenolic acids from reed straws. The results indicated that HP-CEH significantly increased production of phenolic acids. The recovery yield of ferulic acid and p-coumaric acid was respectively found to be 0.69 and 0.81 mg/g dry reed straw when performed by HP-CEH for 16 h. The degradation of hemicellulose, lignocellulose and lignin, and disruption of cell walls or cellulose fibers contributed to phenolic acids production from reed straws. Moreover, the scavenging activity of hydroxyl radical and DPPH radical of the phenolic acids extracted by HP-CEH was respectively obtained to be 77.32% and 86.77%.

Different multi-scale structural features of oat resistant starch prepared by ultrasound combined enzymatic hydrolysis affect its digestive properties

In this research, oat resistant starch (ORS) was prepared by autoclaving-retrogradation cycle (ORS-A), enzymatic hydrolysis (ORS-B), and ultrasound combined enzymatic hydrolysis (ORS-C). Differences in their structural features, physicochemical properties and digestive properties were studied. Results of particle size distribution, XRD, DSC, FTIR, SEM and in vitro digestion showed that ORS-C was a B + C-crystal, and ORS-C had a larger particle size, the smallest span value, the highest relative crystallinity, the most ordered and stable double helix structure, the roughest surface shape and strongest digestion resistance compared to ORS-A and ORS-B. Correlation analysis revealed that the digestion resistance of ORS-C was strongly positively correlated with RS content, amylose content, relative crystallinity and absorption peak intensity ratio of 1047/1022 cm−1 (R1047/1022), and weakly positively correlated with average particle size. These results provided theoretical support for the application of ORS-C with strong digestion resistance prepared by ultrasound combined enzymatic hydrolysis in the low GI food application.

Investigation of Chinese Herbal Decoctions with Enzymatic Hydrolysis and Sequential Fermentation as Potential Nutrient Supplements

Chinese herbal medicine has attracted increasing attention due to its therapeutic effects. It demands increasing understanding of the processing methods and the generated changes to control quality and offer better final products. In this study, extraction differences were compared among direct plant extracts (DE), standard decoction (SD), spontaneous fermentation (SF) and inoculated sequential fermentation (IF). Results showed that the extraction with the transformation of probiotics positively contributed to the release of functional compounds from Chinese herbs. It provided the strongest antioxidant capacity and the best amino acid profile. The flavor and the compositions of the herbal decoctions were further characterized. Distinctive volatile differences were found, indicating that the different treatments profoundly altered the spectrum of volatile components. The most aromatic changes were in the IF group, which corresponded with the greatest number of upregulated and the lowest number of downregulated differential compounds. Beneficial intestinal microbiota with voluntary intake of herbal tea suggested a possible positive metabolism shift in the healthy host. In conclusion, the combination of enzymatic hydrolysis and sequential fermentation provided better extraction efficiency than direct plant extraction and traditional herbal decoction. It may enable a broader utilization of traditional Chinese herbs as potential nutrient supplements, such as antibiotic alternatives in animal husbandry.

Effects of combined enzymatic hydrolysis and fed-batch operation on efficient improvement of ferulic acid and p-coumaric acid production from pretreated corn straws

In the present work, the effects of combined enzymatic hydrolysis by cellulase and xylanase (CXEH), fed-batch enzymatic hydrolysis (FBEH) operation and kinetics on production of ferulic acid (FA) and p-coumaric acid (pCA) from pretreated corn straws were investigated. The results showed that CXEH could efficiently increase production of FA and pCA. When performed the FBEH operation by feeding 150 mL enzymatic hydrolysis solution (1.5 % enzyme concentration, 5:4 (v/v) ratio of cellulase to xylanase and 2.0 % substrate loading) to 250 mL batch enzymatic hydrolysis solution at 36 h, the maximum production (2178.58 and 2710.17 mg/L) and production rate (590.95 and 727.89 mg/L.h) of FA and pCA were respectively obtained. Moreover, the disruption of fiber tissues, enhancement of crystallinity and accelerated degradation of hemicelluloses and lignocelluloses caused by CXEH contributed to effectively improving production of FA and pCA in corn straws.

Optimisation of pre-harvest sago frond sap for the production of l-lactic acid using Lactococcus lactis IO-1

The major restriction of sago palm plantation is the long maturation period for the starch extraction. As such, alternative commodity has to be identified to increase commercial value of sago palm especially from the by-product. Sago frond has been harvested to have numerous advantages as an alternative substrate for the production of biomaterial and biofuel such as lactic acid and bioethanol. This study focuses on effective approach to maximise the concentration of sugar in the substrate and to identify the ideal concentration of sago frond sap (SFSp) as sole media to produce l-lactic acid and grow L. lactis IO-1. Result shows that SFSp extracted from sago rachis using a roller press machine contained glucose (43.8 g/L), xylose (17.3 g/L) as free sugars and starch (5.55 g/L). Combination of enzymatic hydrolysis and sterilisation pre-treatment was found to maximise the concentration of total carbon source (68 g/L) and sterilised sago frond sap suitable to be used for fermentation process. The ideal concentration of SFSp that was determined at 50% dilution produces the highest amount of l-lactic acid (24.02 g/L) synergist by most efficient sugar consumption (89.93%). The use of SFSp as fermentation medium for l-lactic acid production generated maximum biomass concentration of 14.53 g/L. The utilisation of SFSp extracted from pre-harvest sago frond as substrate promote efficiency of l-lactic acid production associated to exceptional growth performance of L. lactis IO-1. In conclusion, the concept of utilizing by-product from sago palm as novel raw material promise reliable resources and superiority of L. lactis IO-1 to metabolise sugar in SFSp promote lucrative and ethical production of l-lactic acid.

Effect of cell wall‐disruption processes on wall disruption, antioxidant activity and nutrients in tea pollen

AbstractTea pollen is rich in nutritional and bioactive compounds; however, the pollen wall limits their release. In this study, we explored the effects of freeze–thaw processing (FT), a combination of enzymatic hydrolysis and ultrasonication (EHUS) and superfine grinding (SG) on the wall disruption, antioxidant activity, sensory qualities and nutrients in tea pollen. SG‐treated pollen had the highest broken‐wall ratio (100%), followed by EHUS (79.14%), while FT‐treated pollen displayed the lowest ratio (59.86%). Release of nutrient compounds, including polyphenols, flavonoids, carbohydrates, total free amino acids, proteins and theanine, increased after treatment with the three wall‐disruption methods compared with untreated samples. Moreover, levels of epigallocatechin gallate (EGCG), epigallocatechin (EGC), catechin gallate (CG) and gallocatechin gallate (GCG) were higher following EHUS or SG than in untreated or FT‐treated tea pollen. EGCG was the most potent catechin involved in antioxidant activity of tea pollen, making major contributions to the significant improvement of antioxidant activity in SG‐ and EHUS‐treated groups. Additionally, the overall sensory qualities of tea were lower after treatment with the three wall‐disruption methods compared with untreated samples. In summary, SG and EHUS treatment had greater effects on cell wall disruption, nutrient release and antioxidant activity in tea pollen.

Enzymatic Hydrolysis and Fermentation of Pea Protein Isolate and Its Effects on Antigenic Proteins, Functional Properties, and Sensory Profile.

Combinations of enzymatic hydrolysis using different proteolytic enzymes (papain, Esperase®, trypsin) and lactic fermentation with Lactobacillus plantarum were used to alter potential pea allergens, the functional properties and sensory profile of pea protein isolate (PPI). The order in which the treatments were performed had a major impact on the changes in the properties of the pea protein isolate; the highest changes were seen with the combination of fermentation followed by enzymatic hydrolysis. SDS-PAGE, gel filtration, and ELISA results showed changes in the protein molecular weight and a reduced immunogenicity of treated samples. Treated samples showed significantly increased protein solubility at pH 4.5 (31.19–66.55%) and at pH 7.0 (47.37–74.95%), compared to the untreated PPI (6.98% and 40.26%, respectively). The foaming capacity was significantly increased (1190–2575%) compared to the untreated PPI (840%). The treated PPI showed reduced pea characteristic off-flavors, where only the treatment with Esperase® significantly increased the bitterness. The results from this study suggest that the combination of enzymatic hydrolysis and lactic fermentation is a promising method to be used in the food industry to produce pea protein ingredients with higher functionality and a highly neutral taste. A reduced detection signal of polyclonal rabbit anti-pea-antibodies against the processed protein preparations in ELISA furthermore might indicate a decreased immunological reaction after consumption.

A wholly biological method for galactaric acid production from pectin by the combination of enzymatic hydrolysis and resting-cell catalysis

An eco-friendly wholly biological method for galactaric acid preparation from pectin with three steps including enzymolysis, purification and catalysis.

Production of ACE Inhibitory Peptides from Whey Proteins Modified by High Intensity Ultrasound Using Bromelain.

High Intensity Ultrasound (HIUS) can induce modification of the protein structure. The combination of enzymatic hydrolysis and ultrasound is an interesting strategy to improve the release of the Angiotensin-Converting Enzyme (ACE) inhibitory peptides. In this study, whey proteins were pretreated with HIUS at two levels of amplitude (30 and 50%) for 10 min, followed by hydrolysis using the vegetable protease bromelain. The hydrolysates obtained were ultrafiltrated and their fractions were submitted to a simulated gastrointestinal digestion. The conformational changes induced by HIUS on whey proteins were analyzed using Fourier-transform infrared spectroscopy by attenuated total reflectance (FTIR-ATR) and intrinsic spectroscopy. It was found that both levels of ultrasound pretreatment significantly decreased the IC50 value (50% Inhibitory Concentration) of the hydrolysates in comparison with the control (α = 0.05). After this treatment, HIUS-treated fractions were shown as smaller in size and fractions between 1 and 3 kDa displayed the highest ACE inhibition activity. HIUS promoted significant changes in whey protein structure, inducing, unfolding, and aggregation, decreasing the content of α-helix, and increasing β-sheets structures. These findings prove that ultrasound treatment before enzymatic hydrolysis is an innovative and useful strategy that modifies the peptide profile of whey protein hydrolysates and enhances the production of ACE inhibitory peptides.

D-Galacturonic acid reduction by S. cerevisiae for L-galactonate production from extracted sugar beet press pulp hydrolysate

Pectin-rich residues are considered as promising feedstocks for sustainable production of platform chemicals. Enzymatic hydrolysis of extracted sugar beet press pulp (SBPP) releases the main constituent of pectin, d-galacturonic acid (d-GalA). Using engineered Saccharomyces cerevisiae, d-GalA is then reduced to l-galactonate (l-GalOA) with sorbitol as co-substrate. The current work addresses the combination of enzymatic hydrolysis of pectin in SBPP with a consecutive optimized biotransformation of the released d-GalA to l-GalOA in simple batch processes in stirred-tank bioreactors. Process conditions were first identified with synthetic media, where a product concentration of 9.9 g L-1 L-GalOA was obtained with a product selectivity of 99% (L-GalOA D-GalA-1) at pH 5 with 4% (w/v) sorbitol within 48 h. A very similar batch process performance with a product selectivity of 97% was achieved with potassium citrate buffered SBPP hydrolysate, demonstrating for the first time direct production of L-GalOA from hydrolyzed biomass using engineered S. cerevisiae. Combining the hydrolysis process of extracted SBPP and the biotransformation process with engineered S. cerevisiae paves the way towards repurposing pectin-rich residues as substrates for value-added chemicals.Key points• Efficient bioreduction of D-GalA with S. cerevisiae in stirred-tank reactors• Batch production of L-GalOA by engineered S. cerevisiae with high selectivity• Direct L-GalOA production from hydrolyzed sugar beet press pulpGraphical abstractBioreduction of D-galacturonic acid to L-galactonate with recombinant Saccharomyces cerevisiae enables for the first time the valorization of hydrolysates from extracted sugar beet press pulp for the sustainable production of value-added chemicals.

Evaluation of using a combination of enzymatic hydrolysis and lactic acid fermentation for γ-aminobutyric acid production from soymilk

The production of fermented foods enriched with γ-aminobutyric acid (GABA) is a current trend in the food industry. In this study, the release of free glutamic acid (Glu) and its conversion to GABA in soymilk were conducted through enzymatic hydrolysis using Alcalase (Al) and Flavourzyme (Fl), following by the fermentation using Lb. plantarum LMG6907 (at 30 °C for 96 h). Results showed that a degree of hydrolysis of 90% was achieved when soymilk was treated with a mixture of Al:Fl in a ratio 1:1 (final enzyme concentration of 2 mL/100 mL). Both the free Glu and the GABA content were significantly increased in soymilk hydrolysate, which is a product obtained after enzymatic hydrolysis of soymilk. After 72 h of fermentation, the GABA content in soymilk hydrolysate reached 859 mg/L while the remaining Glu was 2467 mg/L. Fermentation of soymilk hydrolysate at the optimal conditions for glutamate decarboxylase activity (initial pH 4.7, 50 °C), the enzyme catalyzing the conversion of Glu to GABA, also did not show a higher GABA production.

Fermentation of Lupin Protein Hydrolysates-Effects on Their Functional Properties, Sensory Profile and the Allergenic Potential of the Major Lupin Allergen Lup an 1.

Lupin protein isolate was treated using the combination of enzymatic hydrolysis (Papain, Alcalase 2.4 L and Pepsin) and lactic acid fermentation (Lactobacillus sakei ssp. carnosus, Lactobacillus amylolyticus and Lactobacillus helveticus) to investigate the effect on functional properties, sensory profile and protein integrity. The results showed increased foaming activity (2466–3481%) and solubility at pH 4.0 (19.7–36.7%) of all fermented hydrolysates compared to the untreated lupin protein isolate with 1613% of foaming activity and a solubility of 7.3 (pH 4.0). Results of the SDS-PAGE and Bead-Assay showed that the combination of enzymatic hydrolysis and fermentation of LPI was effective in reducing L. angustifolius major allergen Lup an 1 to a residual level of <0.5%. The combination of enzymatic hydrolysis and fermentation enables the production of food ingredients with good functional properties in terms of protein solubility and foam formation, with a balanced aroma and taste profile.

Preparation and antioxidant activities of polysaccharides obtained from abalone viscera by combination of enzymolysis and multiple separation methods.

Abalone viscera were byproducts of the abalone processing and usually discarded as wastes. In this study, we tried to obtain functional polysaccharides from abalone viscera by a combination of enzymatic hydrolysis, membrane separation, anion exchange chromatography, and gel filtration techniques. Abalone viscera underwent successive hydrolyzation with alcalase and flavourzyme. Each enzymolysis was followed by deproteinization via membrane separation. The final yield of crude abalone viscera polysaccharide (CAVP) was 19.72%; the polysaccharide content of CAVP was 51.75%. Furthermore, three fractions of polysaccharides (AVP1, AVP2, and AVP3) were isolated from the CAVP by anion exchange chromatography and gel filtration. The molecular weights of each AVP were 14.99kDa, 58.48kDa, and 39.63kDa, with a carbohydrate content of 62.75, 23.09, and 44.67%, respectively. These AVPs showed excellent antioxidant activities in vitro. Our results provide a scientific basis for the further utilization of polysaccharides from abalone viscera. PRACTICAL APPLICATION: This study demonstrated an eco-friendly approach for industrial production of high purity animal-derived polysaccharides without any environmental pollution caused by the viscera waste of abalone and promoting the comprehensive utilization of abalone resources.

Synthesis of Bioethanol from Oat Husk via Enzyme-Substrate Feeding

A promising way of utilizing oat husks is its bioconversion into technical bioethanol. Ways of increasing the concentration of bioethanol in the mash must be found to increase the economic efficiency of the process. A combination of enzymatic hydrolysis and alcoholic fermentation (combined biocatalytic stages, or CBS) can be used to obtain bioethanol. In addition, delayed introduction of the inoculum can be used when combining stages. In this work, a comparative study is performed of the CBS processes with an initial substrate concentration of 60 g/L (one-time substrate loading) and an increased substrate concentration of 120 g/L after enzyme–substrate feeding (loading the substrate at a concentration of 60 g/L at the beginning of the process and feeding 30 g/L of the substrate after 4 and 8 hours. The substrate is oat husks treated with 4 wt % nitric acid in a pilot plant; a multi-enzyme composition of industrial preparations Cellolux-A and Ultraflo Core is used for enzymatic hydrolysis. Alcohol is fermented using the yeast Saccharomyces сerevisiae Y-1693 (VKPM). The equipment is a fermenter with a capacity of 11 L. Feeding with a doubled concentration of the substrate raises the concentration of bioethanol by 1.7 times (from 2.4 to 4.0 vol %) but lowers its yield by 11.4%. Make-up regimes are being developed that ensure higher concentrations of bioethanol in the mash without reducing its yield.

Characterization of salted egg yolk flavoring prepared by enzyme hydrolysis and microwave irradiation

The salted egg yolk (SEY) is very popular in China for its pleasant flavor and texture. However, the long production cycle of traditional pickling and the waste of salted egg white had limited its industrialization. To solve these problems, a salted egg yolk flavoring was generated through enzymatic hydrolysis and microwave irradiation from fresh egg yolk in this study. The combination of enzymatic hydrolysis and microwave irradiation could force water and lipids in egg yolk to migrate out, and lead to lipid oxidation in high temperature. Lipid oxidation and Strecker degradation were defined as the major pathways of flavor generation. Among the generated volatile compounds, Hexanal, Heptanal, Benzaldehyde and 2-Pentyl-furan were supposed closely related to SEY flavor. This method could be used as an alternative method for the production of salted egg yolk. Furthermore, it could provide a foundation for further investigation of egg yolk containing flavor system.

Enzymatically Treated Spent Cellulose Sausage Casings as an Ingredient in Beef Emulsion Systems

The objective of this research was to incorporate an ingredient obtained from spent cellulose casings in beef emulsion modeling systems. The test ingredient (residual sausage casing, RSC) was procured from cellulose sausage casings following thermal processing of the sausages. The casings were cleaned of contaminants before a combination of enzymatic hydrolysis and high-speed homogenization was conducted in an effort to improve the functional attributes of the cellulose casing residue (i.e. recycling/upcycling of the spent casings). The beef emulsion modeling systems used in this study consisted of 57.30% beef, 20% water, 15% olive oil, 6% of the combination of RSC and an all-purpose binder, 1.45% NaCl, 0.40% sodium tri-polyphosphate, 0.15% sodium nitrite cure, and 0.0035% sodium erythorbate. The overlying goal here was to test the ability of the RSC ingredient for partial or full replacement of binder ingredients in a beef emulsion system. Therefore, the beef emulsion model systems were prepared with five different levels of the RSC ingredient as a substitution to an all-purpose binder ingredient (0% RSC, 25% RSC, 50% RSC, 75% RSC, and 100% RSC). This study was independently replicated in its entirety three times in a completely randomized design and data were analyzed using a generalized linear mixed statistical model. Emulsion samples were tested for proximate composition, cooking loss, emulsion stability, texture profile analysis, and instrumental color. Overall, technological properties and emulsion stability were lost as the level of the RSC ingredient increased, but low inclusion levels of the RSC ingredient (25% RSC) may help maintain acceptable levels of yield and emulsion stability, while improving the sustainability of the sausage production system.