Enzyme-assisted Aqueous Extraction Processing Research Articles

Effects of sucrase enzymatic hydrolysis combined with Maillard reaction on soy protein hydrolysates: Bitterness and functional properties

In this study, sucrase was added to convert non-reducing sugars into reducing sugars in skim obtained by enzyme-assisted aqueous extraction processing (EAEP), then the variation of soy protein hydrolysates (SPH) from the skim under different Maillard reaction times were studied. We conducted one-factor experiment and selected 2 mg/mL sucrase for enzymatic hydrolysis for 2 h. The structure of SPH was investigated by Fourier transform infrared spectroscopy, intrinsic fluorescence spectroscopy, and amino acid composition. Results showed that the Maillard reaction loosened the SPH structure and produced new functional groups. Sensory evaluation, electronic tongue, electronic nose and GC–MS were used to study the sensory characteristics of SPH, we found that the bitterness value was significantly reduced to 1.71 from 4.63 after 2 h of the Maillard reaction. The change of bitterness was related to amino acid composition and the production of pyrazine. Additionally, the iron reduction ability, DPPH free radical scavenging ability, and emulsifying activity reached the highest at 2 h of reaction with 0.80, 73.94 %, and 56.09 %. The solubility, emulsifying stability, and foaming capacity increased and gradually stabilized with the increasing reaction time. Therefore, this paper presents an effective method for generating SPH with low bitterness and high functional properties.

One positive part of copper ion on biocatalysts: CNPs@Cu-Trypsin-assisted aqueous extraction technique for simultaneous exploration of edible insect oil and protein

Edible insects are rich in oil and protein resources, and has it become increasingly important to develop them reasonably when resources are increasingly scarce. However, due to the challenges in recovering enzymes in the enzyme-assisted aqueous extraction technique and the remaining organic solvents in the extraction process based on organic solvent, it is difficult to achieve simultaneous utilization of oil and protein from edible insects. Hence, an improved enzyme-assisted aqueous extraction process based on the assistance of chitosan cross-linked Fe3O4 nanoparticles (CNPs) immobilized enzymes and divalent copper ions chelation, CNPs@Cu-Trypsin-assisted aqueous extraction technique, was first proposed. The hydrolysis activity was significantly increased by 6.16 times, and the value of Kcat/Km was increased by 1.7 times for the results of the formation of the hydrophilic microenvironment. Furthermore, the extraction ratio of silkworm pupae oil extracted via CNPs@Cu-Trypsin-assisted aqueous extraction technique could be increased to 93%, and the oil extraction rate could be maintained above 65% after 10 times reused. Improvement of enzyme-assisted aqueous extraction under the addition of divalent copper ions could achieve an ideal effect of oil extracted from silkworm pupae with less time. Additionally, the quality of silkworm pupae oil was significantly improved and the silkworm pupae protein hydrolysate also showed improved biological activity. Therefore, the enzyme-assisted aqueous extraction enhancement by trypsin immobilization and divalent copper ion chelation is a promising strategy for the green and sustainable exploration of edible insect oil and protein without the use of organic solvents.

A STUDY ON CHARACTERIZATION OF PECTINASE ASSISTED AQUEOUS EXTRACTION OF RICE BRAN OIL

The Rice bran oil is known as wonder oil because of its numerous health benefits. It has a number of advantages over other edible oils because of the presence of antioxidant known as oryzanol. The rice bran contains 10-26% oil depending on the factors like variety, milling process, and other conditions. Various solvents are currently used for rice bran oil extraction process at industrial sectors. These solvents are carcinogenic and also cause adverse effects to the environment. The enzyme-assisted aqueous extraction process has been regarded as an eco-friendly process. Pectinase enzyme is used to break down complex carbohydrates like pectin present in rice bran and allows easy oil extraction in aqueous solution. The present study aims to perform the aqueous extraction of rice bran oil using crude pectinase enzyme extracted from the pectinase producing bacteria Bacillus paramycoides and to study the oil characteristics. Out of the various solvents used in the study, hexane yielded highest percentage of oil. The oil yield was found to be 49.8% in 6 h. The total activity of enzyme was found to be 11 U/mL/min. 500 Units of enzyme was taken for rice bran oil extraction. The Average yield of oil was found to be 80.5% in 3 h and 76.9% in 6 h. The acid value, saponification value, iodine value and oryzanol content of the oil was found to be11.22, 84.15, 5.0 and 0.05 percentage respectively. The percentage of radical scavenging activity of the extracted rice bran oil was found to be 49.51%. The fatty acids present in the oil sample were analyzed by GC MS analysis.

Techno-Economic Analysis of Integrating Soybean Biorefinery Products into Corn-Based Ethanol Fermentation Operations

With the development of agricultural biorefineries and bioprocessing operations, understanding the economic efficiencies and environmental impacts for these have gradually become popular for the deployment of these industrial processes. The corn-based ethanol and soybean oil refining industries have been examined extensively over the years, especially details of processing technologies, including materials, reaction controls, equipment, and industrial applications. The study focused on examining the production efficiency changes and economic impacts of integrating products from the enzyme-assisted aqueous extraction processing (EAEP) of soybeans into corn-based ethanol fermentation processing. Using SuperPro Designer to simulate production of corn-based ethanol at either 40 million gallons per year (MGY) or 120 MGY, with either oil separation or no oil removal, we found that indeed integrating soy products into corn ethanol fermentation may be slightly more expensive in terms of production costs, but economic returns justify this integration due to substantially greater quantities of ethanol, distillers corn oil, and distillers dried grains with solubles being produced.

Enzyme-Assisted Aqueous Extraction of Cobia Liver Oil and Protein Hydrolysates with Antioxidant Activity

Cobia, Rachycentron canadum, is a medium-size marine fish with emerging global potential for offshore aquaculture. The processing waste, cobia liver, is a raw material rich in polyunsaturated fatty acid oils. In this study, an environmentally friendly green process, aqueous extraction (AE), was used to extract the cobia liver oil. The effect of cooking time and substrate water ratio on the oil extractability was investigated herein. The cooking time of 15 min, and substrate water ratio of 1:2 obtained the highest extraction efficiency. However, the oil extractability was only 18.8%. Thus, enzyme-assisted aqueous extraction (EAAE) was used to increase oil extractability and recovery of protein hydrolysates. The commercial proteases—including alcalase, papain, trypsin, and pepsin—were employed in pretreated cobia liver in order to increase oil release during AE. The EAAE results showed that maximum oil extractability was 38% by papain pretreatment. EAAE greatly improved the extraction efficiency; the oil extractability was double than that of AE (18.8%). The fatty acid profiles revealed that ω-3 polyunsaturated fatty acid contents of extracted oil obtained from AE and EAAE were 21.3% and 19.5%, respectively. Besides, the cobia liver hydrolysates obtained from EAAE by alcalase, papain, pepsin, and trypsin pretreatment showed scavenge DPPH radical activity with EC50 values of 0.92, 1.03, 0.83, and 0.53 mg, respectively. After in vitro simulated gastrointestinal digestion, the protein hydrolysates exhibited scavenge DPPH radical activity with EC50 values of 1.15, 1.55, 0.98, and 0.76 mg for alcalase, papain, pepsin, and trypsin, respectively. The study showed that the EAAE process can be used for extracting fish oil from fish waste while simultaneously obtaining the protein hydrolysates with antioxidant activity.

Effects of Processing Conditions on the Simultaneous Extraction and Distribution of Oil and Protein from Almond Flour

The enzyme-assisted aqueous extraction process (EAEP) is an environmentally friendly strategy that simultaneously extracts oil and protein from several food matrices. The aim of this study was to investigate the effects of pH (6.5–9.5), temperature (45–55 °C), solids-to-liquid ratio (SLR) (1:12–1:8), and amount of enzyme (0.5–1.0%) on the extraction and separation of oil and protein from almond flour using a fractional factorial design. Oil and protein extraction yields from 61 to 75% and 64 to 79% were achieved, respectively. Experimental conditions resulting in higher extractability were subsequently replicated for validation of the observed effects. Oil and protein extraction yields of 75 and 72% were achieved under optimized extraction conditions (pH 9.0, 50 °C, 1:10 SLR, 0.5% (w/w) of enzyme, 60 min). Although the use of enzyme during the extraction did not lead to significant increase in extraction yields, it did impact the extracted protein functionality. The use of enzyme and alkaline pH (9.0) during the extraction resulted in the production of more soluble peptides at low pH (5.0), highlighting possible uses of the EAEP skim protein in food applications involving acidic pH. The implications of the use of enzyme during the extraction regarding the de-emulsification of the EAEP cream warrant further investigation.

Aqueous and Enzymatic Extraction of Oil and Protein from Almond Cake: A Comparative Study

The almond cake is a protein- and oil-rich by-product of the mechanical expression of almond oil that has the potential to be used as a source of valuable proteins and lipids for food applications. The objectives of this study were to evaluate the individual and combined effects of solids-to-liquid ratio (SLR), reaction time, and enzyme use on oil and protein extraction yields from almond cake. A central composite rotatable design was employed to maximize the overall extractability and distribution of extracted components among the fractions generated by the aqueous (AEP) and enzyme-assisted aqueous extraction process (EAEP). Simultaneous extraction of oil and protein by the AEP was favored by the use of low SLR (1:12.82) and longer reaction times (2 h), where extraction yields of 48.2% and 70% were achieved, respectively. Increased use of enzyme (0.85%) in the EAEP resulted in higher oil (50%) and protein (75%) extraction yields in a shorter reaction time (1 h), compared with the AEP at the same reaction time (41.6% oil and 70% protein extraction). Overall, extraction conditions that favored oil and protein extraction also favored oil yield in the cream and protein yield in the skim. However, increased oil yield in the skim was observed at conditions where higher oil extraction was achieved. In addition to improving oil and protein extractability, the use of enzyme during the extraction resulted in the production of skim fractions with smaller and more soluble peptides at low pH (5.0), highlighting possible uses of the EAEP skim in food applications involving acidic pH. The implications of the use of enzyme during the extraction regarding the de-emulsification of the EAEP cream warrant further investigation.

Enzyme-assisted aqueous extraction of oil and protein hydrolysate from sesame seed

In this work, sesame oil and protein hydrolysates were extracted via the enzyme-assisted aqueous extraction (EAAE) process using Neutrase (a commercial protease), Pectinex (a commercial carbohydrate-hydrolyzing enzyme) and a 1:1 mix of Neutrase and Pectinex. All the extractions were performed at 50 °C and the optimum pH of the enzymes for 6 h, and the water to sesame ratio was raged between 1:1 and 6:1. The highest oil recoveries were obtained at 2:1 water to sesame ratio for each treatment and the Neutrase-Pectinex treatment gave the max recovery (89.7%, p 0.05). Protein hydrolysates obtained using Neutrase-Pectinex treatment (NPPH) had lower protein and higher carbohydrate content than that obtained using Neutrase treatment (NPH). The lowest solubility, emulsifying activity and stability indices, foam capacity and foam stability of NPPH and NPH was found to be at pH 4.0. The solubility of NPPH was higher than the NPH, but the emulsification properties of the NPH was better than NPPH at pH 2–10 (p 0.05).

Effect of the condition of spray-drying on the properties of the polypeptide-rich powders from enzyme-assisted aqueous extraction processing

Enzyme-assisted aqueous extraction processing (EAEP) is an environmentally friendly technology that simultaneously extracts both oil and protein. It has shown to be commercial feasibility for high oil recovery (∼97%) and favorable protein functionality properties. The present study used soy skim, the liquid co-products obtained using EAEP to produce a polypeptide-rich spray-dried powder. The effects of inlet drying air temperature (140 °C, 160 °C, 180 °C and 200 °C), feed flow rate (3, 6, 9, and 12 mL/min), and solids concentration (25%, 30%, 35%, and 40%) on the properties of the polypeptide-rich powders were investigated. Water activity (aw), color characteristics, bulk density, Carl Index (CI), Water Solubility Index (WSI), micro-morphology, peptide distribution, and antioxidant capacity were significantly affected by different spray-drying parameters. The results of antioxidant capacity test showed that the spray drying conditions significantly affected the antioxidant capacity of the polypeptide-rich powders. The polypeptide molecular weight size and distribution, the composition of the peptide chain, and the cross-linking with other substances could all affect its antioxidant capacity. Overall, good quality polypeptide-rich powders in terms of physicochemical characteristics, micro-morphology, and functional properties can be produced by spray-drying at an inlet temperature of 160 °C, a feed flow rate of 6 mL/min, and solids concentration of 35%.

Economic Feasibility of Soybean Oil Production by Enzyme-Assisted Aqueous Extraction Processing

Aqueous oil extraction is an approach that could replace organic solvent extraction with water. Compared to typical solvent extraction and mechanical pressing processes, aqueous extraction has higher oil recovery (over 80%) than the mechanical pressing process, and resolve issues resulted from chemical loading and remaining in the hexane extraction. Proteases are used to assist free oil release from oil bodies by hydrolyzing cotyledon cell walls in aqueous extraction process. The resulting enzyme-assisted aqueous extraction process (EAEP) includes dehulling, flaking, extruding, enzymatic extraction, and enzymatic demulsification processes. SuperPro Designer was used to conduct a techno-economic analysis (TEA) of the extraction process. The total capital investment, operation cost, and profits were evaluated. During EAEP, insolubility of water and oil allows the simultaneous extraction of protein and oil. This decreases operation costs, especially the oil purification process, and therefore increases profits made from the main product (soybean oil). This simultaneous extraction also increases the profit towards the coproduct, i.e., protein in skim. Additionally, the absence of chemical and enzyme recycling contribute to the better economic value of EAEP. Despite the increase in facility costs due to extraction and demulsification units, the value-added coproduct extraction and high free oil yield contribute to the economic feasibility of EAEP in industrial- and commercial-scale productions when skim and insoluble fiber are used as water and carbohydrate supplies for integrated soy/corn ethanol biorefinery processing.

Enzyme-Assisted Aqueous Oil Extraction from High Oleic Sunflower Seeds in a Scalable Prototype Reactor

Enzyme assisted aqueous extraction processing (EAEP) facilitates the production of high quality oils without the need for chemical refining. However, up to date, oil recovery remains remarkably below that found in mechanical and solvent extraction. In this study, response surface methodology (RSM) was applied, to optimize oil extraction from high oleic sunflower seeds via EAEP in a prototype automatic continuous stirred-tank extractor. Temperature, enzyme mass, water mass and proton concentration were varied for the exploration of optimum process conditions. The fit of a full second-order model was significant (p = 0.003), while the lack of fit was non-significant (p = 0.111). A local maximum was found at an extraction efficiency of 82.18%. A subsequent mass balance succeeded in reproducing the results from the RSM optimization. 93.03 ± 2.80% of the initial total mass was recovered, of which 90.90 ± 4.3% could be related to the components of the fractions.

Physical-Chemical Properties of Edible Film Made from Soybean Residue and Citric Acid

The effect of citric acid on the properties of soybean enzyme-assisted aqueous extraction processing (EAEP) residue edible film was studied. The washed soybean EAEP residue was produced by the process of EAEP. It was determined that the washed soybean EAEP residue is rich in fibers (76.10 ± 1.03%) and has lower oil and protein contents (7.74 ± 0.11% and 3.50 ± 0.20%, resp.). Edible films intended for food packaging have been produced from the washed EAEP residue combined with glycerol, different concentrations of citric acid (0%, 10%, 15%, 20%, 25%, and 30%), and sodium hypophosphite. The spectra have evidenced that the cross-linking reaction of citric acid and fibers has taken place in the residue. 30-CA films showed the highest tensile strength (17.52 MPa) and the lowest water vapor permeability (7.21 g·cm−1·s−1·Pa−1). Also, it indicated that citric acid can cross-link with the hydroxyls of polysaccharide and improve the compatibilization between the polymeric molecules to improve the intermolecular interaction between polysaccharide molecules, so that the water uptake is reduced. The smooth surface and better translucency of the films suggest that the EAEP residue films treated with citric acid are suitable for application in food packaging.

Effect of co-products of enzyme-assisted aqueous extraction of soybeans, enzymes, and surfactant on oil recovery from integrated corn-soy fermentation

Integrated corn-soy fermentation, utilizing co-products of soybean enzyme-assisted aqueous extraction process (EAEP) of soybeans in corn fermentation, has shown potential for enhancing bioethanol production compared to corn only fermentation. To maximize economic returns, oil may be recovered. In the present study, the effect of skim and insoluble fiber, and oil extraction aids on ethanol yield, oil partition, and oil recovery, and quality of Distillers Dried Grains (DDG) was investigated. Two fiber hydrolyzing enzymes (pectinase and cellulase), an acid protease (Fermgen®), and a surfactant (Tween 80) were evaluated. Addition of skim, mixture of skim and insoluble fiber, or Fermgen® to corn fermentation resulted in a ∼32 h decrease in fermentation time. Addition of soy co-products also resulted in ∼10–28% increase in oil partition in thin stillage with no additional enzyme or surfactant treatment. Addition of insoluble fiber alone resulted in ∼19% decrease in solids partition in thin stillage. Maximum free oil recovery, 22.5 ± 4.5%, was achieved from corn-insoluble fiber thin stillage with a combined treatment of enzymes (pectinase, cellulase, and Fermgen®) and surfactant (Tween 80). Maximum extractable oil recovery, 67 ± 3.2%, was achieved with the enzyme treatment alone. Corn-soy DDG has ∼11% higher protein, ∼2% lower fiber, and ∼2% lower fat contents compared to corn DDG. The fiber content was further reduced to ∼2% after enzyme treatment. This study demonstrates an efficient use of soy EAEP co-products and enzymes to maximize oil partition in thin stillage, and produce a high quality corn-soy DDG.

Ethanol Production by Soy Fiber Treatment and Simultaneous Saccharification and Co-Fermentation in an Integrated Corn-Soy Biorefinery

Insoluble fiber (IF) recovered from the enzyme-assisted aqueous extraction process (EAEP) of soybeans is a fraction rich in carbohydrates and proteins. It can be used to enhance ethanol production in an integrated corn-soy biorefinery, which combines EAEP with traditional corn-based ethanol processing. The present study evaluated IF as a substrate for ethanol production. The effects of treatment of IF (soaking in aqueous ammonia (SAA), liquid hot water (LHW), and enzymatic hydrolysis), primarily simultaneous saccharification and co-fermentation (SSCF), as well as scaling up (250 mL to 60 L) on ethanol production from IF alone or a corn and IF slurry were investigated. Enzymatic hydrolysis (pectinase, cellulase, and xylanase, each added at 5% soy solids during simultaneous saccharification and fermentation/SSCF) was the best treatment to maximize ethanol production from IF. Ethanol yield almost doubled when SSCF of IF was performed with Saccharomyces cerevisiae and Escherichia coli KO11. Addition of IF in dry-grind corn fermentation increased the ethanol production rate (~31%), but low ethanol tolerance of E. coli KO11 was a limiting factor for employing SSCF in combination corn and IF fermentation. Nonlinear Monod modeling accurately predicted the effect of ethanol concentration on E. coli KO11 growth kinetics by Hanes-Woolf linearization. Collectively, the results from this study suggest a potential of IF as a substrate, alone or in dry-grind corn fermentation, where it enhances the ethanol production rate. IF can be incorporated in the current bioethanol industry with no added capital investment, except enzymes.

Environmental impact assessment of soybean oil production: Extruding-expelling process, hexane extraction and aqueous extraction

Expelling and hexane extraction are two typical processes for soybean oil production used in industry. The main issues for these two processes are the low efficiency and hazardous chemical problems respectively. Enzyme assisted aqueous extraction process (EAEP) was proposed to increase the efficiency without using organic solvent, which is replaced by water. The environmental impact analysis of these three processes are based on their mass flows, energy consumption and global warming potential. For mass flows, the environmental impact indices were calculated based on material flow of input and output components. Energy consumption was used to evaluate the carbon dioxide, other greenhouse gas (GHG), and criteria pollutants emissions by GREET models. According to our results, hexane extraction has the highest environmental impact due to the application of organic solvent. Expelling has the highest GHG and criteria pollutants emissions because of the high energy requirement for heat pressing processes. EAEP has similar environmental impacts to the expelling process, but it also lowers GHG and criteria pollutants emissions. EAEP has the potential to be a green process adopted by industry although a high energy intense pretreatment to produce finer soybean flakes for increasing oil recovery is still a challenge.

Using Short‐Wave Infrared Radiation to Improve Aqueous Enzymatic Extraction of Peanut Oil: Evaluation of Peanut Cotyledon Microstructure and Oil Quality

In this study, the effects of short‐wave infrared radiation (SIR) on enzyme‐assisted aqueous extraction process (EAEP) of peanut oil (PO) are investigated, including peanuts cotyledon cells mircrostructure and yield as well as quality of extracted PO. GC‐flash electronic nose (EN) combined with principal components analysis (PCA) is applied to select conditions for SIR process. The appropriate roasting condition based on the overall flavor is determined as 150 °C for 55 min. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are used to investigate the effects of SIR on cotyledon microstructure. The results demonstrated that SIR damaged the cell microstructure and oil body membrane, and the extraction of oil is facilitated. Accordingly, the oil yield increased significantly by 8.74% compared to that of the control (p < 0.05). Further analysis on the quality properties of PO revealed that the content of polyphenols of oil extracted from SIR roasted peanuts (2.79 ± 0.05 mg GAE kg−1) is 62.21% higher than that from the control. It is in consistent with the significantly enhanced oxidation stability of oil in the present study (p < 0.05). Furthermore, the variety and relative content of volatile compounds which contributed to a better overall flavor are greatly increased.Practical Applications: SIR as a mild and efficient roasting method could enhance the oil extraction yield in EAEP and improve the oxidation stability of the extracted oil. With the appropriate pre‐roasting of peanuts by SIR, the overall flavor of EAEP extracted peanut oil was improved. Its volatiles pattern was close to that of the commercial hot‐pressed PO. It was confirmed that SIR is a novel choice for roasting processing, as well as a potential and available pre‐roasting method of peanuts to improve the EAEP technology.In order to improve the enzyme‐assisted aqueous extraction process (EAEP) of peanut oil, short‐wave infrared radiation (SIR) to roast peanuts before the extraction process is used. SEM and TEM are employed to evaluate the roasting effects on cotyledon microstructure. Some chemical properties, the content of antioxidant compounds, and the flavor of extracted oil are assessed to show the effects on oil quality. The oil yield is also evaluated to explain the roasting effects together with the changes of the microstructure.

Profitability Analysis of Soybean Oil Processes.

Soybean oil production is the basic process for soybean applications. Cash flow analysis is used to estimate the profitability of a manufacturing venture. Besides capital investments, operating costs, and revenues, the interest rate is the factor to estimate the net present value (NPV), break-even points, and payback time; which are benchmarks for profitability evaluation. The positive NPV and reasonable payback time represent a profitable process, and provide an acceptable projection for real operating. Additionally, the capacity of the process is another critical factor. The extruding-expelling process and hexane extraction are the two typical approaches used in industry. When the capacities of annual oil production are larger than 12 and 173 million kg respectively, these two processes are profitable. The solvent free approach, known as enzyme assisted aqueous extraction process (EAEP), is profitable when the capacity is larger than 17 million kg of annual oil production.

Characterization and demusification of cream emulsion from aqueous extraction of peanut

In this study, the effect of aqueous extraction processing (AEP) and enzyme-assisted aqueous extraction processing (EAEP) on peanut oil yield was investigated. Only 34.53 ± 4.07% of free oil was recovered when using AEP without demulsification. In the case of EAEP, 89.31 ± 0.90% of free oil was obtained (1.5% w/w Alcalase 2.4L) without demulsification. Meanwhile, the protein yields of AEP and EAEP were similar, 84.10 ± 0.22% and 80.62 ± 0.92%, respectively. The efficiencies of enzymes (Protex 6L, Protex 7L, Protex 50FP, Alcalase 2.4L, Papain and Lecitase® Ultra) and pH of the released oil from peanut pastes were evaluated. Papain and Protex 50FP were effective in destabilizing the cream emulsion (93.10 ± 0.79% and 94.89 ± 0.19%, respectively). Adjusting the pH of the cream emulsion to the isoelectric point of peanut proteins also destabilized the cream with 85.71% of free oil recovery. Furthermore, the changes in the microstructure of cream emulsion during enzymatic demusification were observed by confocal laser scan microscope (CLSM). The interface tension decreased with the increase in enzymatic treatment time. For surface hydrophobicity (H0), cream emulsions treated by Protex 50FP and Papain had a remarkable decrease. Papain treated cream emulsion had a smaller H0 than that of Protex 50FP due to the protein aggregations formed during adjusting pH value to 4.5. This might have hindered the efficiency of protein hydrolysis and left more basic arachin (MW 18–24 kDa) which have more hydrophobic groups.

Effect of co-products of enzyme-assisted aqueous extraction of soybeans on ethanol production in dry-grind corn fermentation

Enzyme-assisted aqueous extraction processing (EAEP) is an environmentally-friendly alternative to solvent and mechanical oil extraction methods, and can achieve ∼97% oil recovery from soybeans. The present study utilized soy skim (protein rich) and insoluble fiber (IF; carbohydrate rich), both co-products of EAEP, in dry-grind corn fermentation. The effects of adding soy skim and untreated IF (UIF), either separately or together, and adding pretreated IF (TIF), on ethanol production were investigated. Maximum ethanol production was achieved when UIF and skim were slurried together (corn-to-UIF ratio 1:0.16; skim-to-UIF ratio 6.5:1) and when fiber-hydrolyzing enzymes were added to corn fermentation. This modification to corn fermentation increased ethanol yield by 20%, ethanol production rate by 3%, and decreased fermentation time by 38h compared to corn-only fermentation. An attempt was also made to utilize pentoses (from soy skim and IF) in integrated corn-soy fermentation slurry by an additional Escherichia coli KO11 fermentation step.

Enzyme-assisted aqueous extraction of oil from Forsythia suspense seed and its physicochemical property and antioxidant activity

In order to exploit the byproduct of Forsythia suspense, its seed oil was first studied for the extraction, physicochemical property and antioxidant activity. The green and effective enzyme-assisted aqueous extraction processing under microwave irradiation was applied to obtain the oil. The optimal oil yield of 21.62±0.51% (dry weight of F. suspense seed basis) was achieved by the treatment of 1.5% (w/w) enzyme cocktail (cellulase/pectinase/proteinase=1/1/1, w/w/w) under 90min. The fatty acid composition of FSSO exhibited the predominance of linoleic acid (72.96%) along with oleic acid (18.66%) and palmitic acid (5.59%), which was quite similar to that of sunflower oil. Moreover, FSSO showed the notable concentration-dependent antioxidant activity with IC50 values of 22.35 and 29.51mg/mL, according to the DPPH radical scavenging assay and β-carotene/linoleic acid bleaching test, respectively. Thus, FSSO may serve as a potential source of valuable product for the food, pharmaceutical, or cosmetics industries.