Enzymatic pretreatment on rose-hip oil extraction: Hydrolysis and pressing conditions

In a previous report [Zúñiga, M.E., J. Concha, C. Soto, and R. Chamy, Effect of the Rose Hip (Rosa aff. rubiginosa) Oil Extraction Cold-Pressed Process, in Proceedings of the World Conference and Exhibition on Oilseed Processing, and Utilization, edited by R.F. Wilson, AOCS Press, Champaign, 2001, pp. 210–213], the authors showed that an enzymatic pretreatment of rose-hip seeds, prior to oil extraction by cold pressing, improves the oil yield. In this work, we studied the effects of temperature and moisture during the enzymatic hydrolysis stage using two previously selected mixtures of commercial enzymes: (i) Olivex (mainly pectinase) plus Cellubrix (mainly cellulase), and (ii) Finizym (mainly β-glucanase) plus Cellubrix (mainly cellulase) (all from Novozymes A/S, Madrid, Spain). In addition, we evaluated the effect of enzymatic hydrolysis on the oil extraction pressing rate at different operational pressures. Samples hydrolyzed enzymatically by either of the two commercial enzyme mixtures at 45°C and 30–40% moisture showed oil extraction yields up to 60%, an increase of greater than 50%, as compared with control samples in which the enzyme solutions were replaced by water. Both the oil extraction rate and yield by pressing increased when enzymatic pretreatment was applied. The oil extraction yield increased slightly when the operation pressure was elevated; however, when the sample was preheated, the oil extraction yield was greatly increased, especially for enzyme-treated samples. Results confirmed the importance of temperature and moisture as enzymatic hydrolysis parameters that improve rose-hip oil extraction yields in the cold-pressing process. When pressing was carried out after preheating enzymatically treated samples, it was possible to increase the oil extraction yield to 72% compared with the control without preheating, which resulted in a 46% oil yield.     

Rapid Salt‐Assisted Microwave Demulsification of Oil‐Rich Emulsion Obtained by Aqueous Enzymatic Extraction of Peanut Seeds

Aqueous enzymatic extraction (AEE) is an environmentally friendly edible‐oil‐extraction process that can also provide edible protein. However, the AEE process may form a stable emulsion in most cases, which seriously limits the large‐scale industry applications for producing vegetable oils. In this study, the salt‐assisted microwave radiation demulsification of the oil‐rich emulsion prepared with AEE from peanuts is investigated. The microwave demulsification method is compared with other conventional demulsification methods, including heating, and freezing–thawing. The salt‐assisted microwave demulsification of the emulsions shows a greater free oil yield than conventional heating demulsification. Moreover, the microwave demulsification shows a similar free oil yield in less time than freezing–thawing method. Under the optimal operating conditions of demulsification, the free oil yield can reach 92.3% with CaCl₂‐assisted microwave demulsification for only 2 min. In addition, the oxidative properties and the fatty acid compositions of the demulsified peanut oil are investigated. No significant difference in the fatty acid composition is observed among salt‐assisted microwave, freezing–thawing, and heating demulsified oil. The oxidative properties of the salt‐assisted microwave demulsified peanut oil is better than the conventional heating demulsified oil. Thus, salt‐assisted microwave demulsification provides a quick and effective demulsification method to obtain vegetable oils with high quality. Practical Applications: Aqueous enzymatic extraction (AEE) is an environmentally friendly edible‐oil‐extraction process. To solve the problem of stable emulsion formed during AEE process, the salt‐assisted microwave demulsification of the oil‐rich emulsion prepared with AEE is developed with high efficiency (demulsification for 2 min). In addition, the oxidative properties of the microwave demulsified oil is better than the conventional heating demulsified oil.     

水酶法提取大豆油

The procedure of enzymatic aqueous extraction of soybean oil was assessed when two-step controlled enzymatic hydrolysis was applied. With aqueous extraction of soybean oil-containing protein, the highest yield of oil was 96.1% at the optimized conditions studied. Soybean oil-containing protein was hydrolyzed and resulted in releasing part of oil. The separated protein that contained 40% oil was enriched due to its adsorption capacity of released oil, the average oil extraction yeild reached 93.5%. Then the high oil content protein was hydrolyzed again to release oil by enzyme, the oil extraction yeild was 80.4%. As a result, high quality of soybean oil was obtained and the content of total oil vield was 74.4%.     

Ethanol-Assisted Aqueous Enzymatic Extraction of Peony Seed Oil

An ethanol-assisted aqueous enzymatic extraction was performed for peony seed oil (content of 30%). This method included cooking pretreatment, pectinase hydrolysis, and aqueous ethanol extraction, and the corresponding variables in each step were investigated. The changes in viscosity and dextrose equivalent values of the reaction medium as a function of changing enzymatic hydrolysis time were compared to the oil yield. The microstructures of peony seeds were analyzed using confocal laser scanning microscopy to understand the process of oil release as a result of cooking and grinding. The highest oil yield of 92.06% was obtained when peony seeds were cooked in deionized water with a solid–liquid ratio of 1:5 (w/v) at 110°C for 1 hour, ground to 31.29 μm particle size, treated with 0.15% (w/w) pectinase (temperature 50°C, pH 4.5, time 1 hour), and then extracted with 30% (v/v) aqueous ethanol (temperature 60°C, pH 9.0, time 1 hour). After processing with pectinase followed by ethanol extraction, the residual oil content in water and sediment phase decreased to 5% and 3%, respectively. The quality of the oil obtained by ethanol-assisted aqueous enzymatic extraction was good, complying with the Chinese standard.     

Effect of rosehip extraction process on oil and defatted meal physicochemical properties

The physicochemical properties of oil from Rosa affinis rubiginosa seeds were analyzed after extraction by (i) organic solvent, (ii) cold pressing, and (iii) cold pressing assisted by enzymatic pretreatment using a mixture of the Novo-Nordisk A/S products Cellubrix (cellulase and hemicellulase activities) and Olivex (pectinase, cellulase, and hemicellulase activities). There were no significant differences in oil quality parameters, such as iodine value, refractive index, saponification value, unsaponifiable matter, and FA profile, when applying any of the three extraction processes. Although significant variations were observed in FFA content (acid value) and PV of the oil obtained by both of the cold-pressing oil extraction processes, these results were lower than the maximum value established from the Codex Alimentarius Commission. All-trans-retinoic acid content improved by 700% in rosehip oil obtained through cold pressing, with and without enzymatic pretreatment, in comparison with organic solvent extraction. This result is quite important for cosmetic oil because all-trans-retinoic acid is the main bioactive component responsible for the regenerative properties of this oil.     

Optimization of Aqueous Enzymatic Microwave Assisted Extraction of Macadamia Oil And Evaluation of Its Chemical Composition,Physicochemical Properties,and Antioxidant Activities

This study presents the green and effective aqueous enzymatic process assisted microwave extraction (AEME) to preparate macadamia nut oil (MNO). The conditions of the extraction process are optimized (extraction temperature 50 °C, extraction time 64 min, enzyme concentration 1.60% (w/w), and irradiation power 450 W). An oil yield of 58.09 ± 0.63% is achieved under these optimal conditions. The scanning electron micrograph (SEM) analysis of nuts before and after extraction illustrates that AEME promotes the emancipation of oil stored within the organelles. Gas chromatography-flame ionization detector (GC-FID) analysis reveals the fatty acid compositions of MNOs obtained by AEME and the Soxhlet extraction (SE) are similar and mainly dominated by monounsaturated fatty acids beneficial to human health which is higher in MNO than in any other known food. Moreover, gas chromatography-mass spectrometry (GC-MS) analysis reveals higher amounts of more odoriferous oxygenated terpenes is present in the MNO extracted by AEME in comparison with SE. The physicochemical properties of AEME oil are more excellent than those of SE oil. Moreover, AEME oil exhibits superior antioxidant capacities. In conclusion, green AEME gives relatively satisfactory yield and better retains the fragrance and functionality of MNO. Practical Applications: The present study provides a green extraction method and valuable data for the process design as well as industrial scale-up applications. In addition, compared to the nonsustainable and environmentally nonfriendly traditional method, AEME preserves the initial composition of the flavor substances and enhances the extraction of healthy beneficial compounds in MNO. Therefore, AEME oil can be used to develop functional edible oils or even in medicinal, cosmetic, and pharmaceutical preparations.     

Aqueous enzymatic oil extraction from Irvingia gabonensis seed kernels

The objective of this study was to extract the fat from Irvingia gabonensis kernels without using organic solvent but by using the enzyme aqueous oil extraction process. The aqueous dispersion of kernel flour of bush mango was treated with a protease (Alcalase®), a pectinase (Pectinex®) and a mixture of cell wall‐degrading enzymes (Viscozyme®) before centrifugation. The yield of oil extracted was calculated in comparison with the chemical extraction method using hexane as solvent. A central composite experimental design was used for the determination of optimized conditions. The results showed that aqueous extraction without enzyme allows recovering 27.4% of the kernel oil. When Alcalase, Pectinex and Viscozyme were added separately, the oil yields were 35.0, 42.2 and 68.0%, respectively. Optimized conditions for Viscozyme resulted in a model of oil yield with a high coefficient of determination (r² = 0.94). These conditions were the following: kernel‐to‐water ratio 0.11–0.19, concentration of enzyme 1.4–2.0%, and time of incubation 14–18 h. Confirmation of the model led to 83.0% oil yield after treatment of the kernel flour at a kernel‐to‐water ratio of 0.16, using 2% Viscozyme for 18 h. Under the same conditions, followed by addition of 1% Alcalase for 2 h, the yield was 90.0%.     

Enzyme-assisted aqueous extraction of peanut oil

Enzyme-assisted aqueous extraction of oil from oilseeds is a relatively recent technique. In the present study, peanut oil was extracted under optimized aqueous extraction conditions using Protizyme^™, which is predominantly a mixture of acid, neutral, and alkaline proteases. The optimal conditions were: enzyme concentration of 2.5% (w/w) in 10 g of peanut seeds, pH 4.0, 40°C, and 18 h incubation with constant shaking at 80 rpm. Centrifuging the mixture at 18,000 × g for 20 min separated the oil with a recovery of 86–92%. The merits of this process over existing solvent extraction and/or mechanical pressing methods are discussed.     

Enzymatic Demulsification of the Oil-Rich Emulsion Obtained by Aqueous Extraction of Peanut Seeds

This study details the enzymatic destabilization of the emulsion formed during aqueous extraction of peanut seeds and the quality of the resulting oil. The emulsion was exposed to enzymatic treatment and pH adjustment. The experimental results suggest that the alkaline endopeptidase Mifong^®2709 was the most effective demulsifier, while Phospholipase A2 and pH adjustment had little effect on emulsion stability. The demulsifying conditions of Mifong^®2709 were optimized by response surface methodology (RSM). The optimal conditions which produced a free oil yield of ~94 % were: 1:1 water-to-emulsion ratio, enzyme concentration of 1,600 IU/g of emulsion and 70 min hydrolysis time at 50 °C. We found that these conditions resulted in a positive relationship (R ² = 0.9671) between free oil yield and the degree of protein hydrolysis. Increased protease treatment produced a smaller number of oil droplets, but the size of these droplets increased significantly. When compared to demulsified oil products obtained by using thermal treatment, the oil obtained by Mifong^®2709 exhibited lower acid and peroxide values, contained more tocopherols and had a longer induction time as determined in the Rancimat test. The high yield and quality of peanut oil obtained by enzymatic treatment makes enzyme demulsification a promising approach to recovering free oil in aqueous extractions of peanuts.     

The combined application of extrusion and enzymatic technology for extraction of soybean oil

This paper describes a new technological process for soybean oil extraction. The process deals with the combined effect of thermoplastic extrusion of beans and the subsequent action of hydrolytic and proteolytic enzymes in aqueous medium to recover the oil, thus, avoiding solvent application. The thermoplastic extrusion is fundamental for the process, because it facilitates the action of enzymes in oil containing cells, reduces the non-hydratable phosphatides and promotes protein denaturation by reducing the emulsion stability and thus enhancing the oil extraction. The main parameters affecting the oil yield are: the temperature and diameter of the die in the extrusion process, the dilution, the concentration of enzymes and the incubation time of the enzymatic treatment. The highest yield was obtained under the following conditions: extrusion of beans at 90°C and exit die of 6 mm, enzymatic incubation time of 6 h, extruded soy/water dilution ratio 1:10 and concentration of enzyme 6%. With these conditions 88% of the oil were obtained after centrifugation. Moreover, the aqueous enzymatic extraction is easier than solvent extraction, and leads to high value products: a solvent-free meal more suitable for human consumption, a protein hydrolysate that can be used as ingredient for liquid foods and an oil of better quality. The non-hydrolyzed meal contains ca 25% of original soybean protein and the residual oil. The protein hydrolysate in the liquid phase contains ca 75% of the total protein in the original grain with a molecular weight below 20 kDa.     

Enzymatic treatment of rice bran to improve processing

A modification of the process of oil extraction from rice bran is proposed, introducing one or two enzymatic reactions previous to solvent extraction. Although a total aqueous enzymatic extraction process did not result in reasonable oil extraction yields, an interesting alternative results from enzymatic reactions previous to solvent extraction or pressing. A thermal treatment of rice bran is first applied to deactivate lipase, but also to gelatinize starch previous to reaction with α-amylase. This is followed by a saccharifying step with glucoamylase to produce glucose (28 g/100 g of rice bran treated), while the residual paste, 66.7% of the original bran, may be subjected to a proteolytic process for protein extraction or directly treated with the solvent to obtain bran oil. Finally, under the defined extraction conditions using hexane, yields of oil are 5% higher when rice bran has been previously treated with α-amylase.     

Solvent and enzymatic extraction of Safou and Kolo oils

Safou (Dacryodes edulis) pulp oil became a new hope for fragile economics of central Africa countries. Raphia sese palm tree (Kolo) produces also an edible vegetable oil of well nutritious value. Various extraction methods were checked for the best yields. By soxhlet extractor using petroleum ether best yields were attained (47% for Safou and 52% for Kolo; dry weight) followed by the Bligh and Dyer method (43.2% for Safou and 50.8% for Kolo). No further improvement was obtained by the enzymatic treatment with Viscozym L (42% for Safou, 51.3% for Kolo). The application of enzyme added to the preservation of oil from oxidation during extraction process.     

Extraction and characterization ofDimorphotheca pluvialis seed oil

Dimorphotheca pluvialis is increasingly recognized as an interesting industrial new oilseed crop because it contains up to 60% of the unusual fatty acid dimorphecolic acid (9-hydroxy,10t,12t-18∶2) (DA) for which new applications are being developed. In this paper, the yield, composition and quality are evaluated for dimorphotheca oils (DMO) which were recovered by pressing, conventional solvent extraction and supercritical carbon dioxide extraction (SCE). Mechanical pressing of the seeds required high temperatures and resulted in an oil recovery of only 40%, whereas the extraction protocols yielded more than 95%. Oil recovery by pressing of winged seed was even more difficult than that of unwinged seeds; hence, solvent extraction of winged seeds was preferred. The dark-colored DMO, recovered by expelling or by extraction with organic solvents, needed further refining to remove pigments and gums, whereas the light yellow-colored SCE DMO did not require further refining. SCE oil had a low phospholipid content (11 mg P/kg). Pressed oil (95 mg P/kg) and hexaneor pentane-extracted DMO (200 mgP/kg) had much higher phospholipid contents. Peroxide andp-anisidine values were low for freshly recovered oils, but increased after storage, especially in the SCE oil, due to the low concentration of natural antioxidants in SCE DMO, such as tocopherols. The DA content of the oils recovered by the various techniques showed only minor differences, except that supercritical carbon dioxide had slightly decreased solubilizing power for tri- and di-dimorphecolin as compared to hexane and pentane.     

Enzyme‐assisted aqueous extraction of oil and protein from canola (Brassica napus L.) seeds

The emphasis of this study was to investigate the effect of enzymes on aqueous extraction of canola (Brassica napus L.) seed oil and protein. Four enzymes, Protex 7L, Multifect Pectinase FE, Multifect CX 13L, and Natuzyme, were tested for their effectiveness in releasing oil and protein during aqueous extraction. The enzyme‐extracted oil content of canola seeds (22.2–26.0%) was found to be significantly (p <0.05) higher than that of the control (without enzyme) (16.48%). An appreciable amount of protein (3.5–5.9%) originally present in the seed was extracted into the aqueous and creamy phases during aqueous extraction of oil. The physicochemical properties of oils extracted from canola seed by conventional solvent extraction, and aqueous extraction, with or without enzyme addition were compared. Significant (p <0.05) differences were observed in free fatty acid content, specific extinctions at 232 and 270 nm, peroxide value, color (1‐inch cell) and concentration of tocopherols (α, γ, and δ). However, no significant variation (p <0.05) was observed in iodine value, refractive index (40 °C), density (24 °C), saponification value, unsaponifiable matter and fatty acid composition. A better oil quality was obtained with aqueous extraction (with and without enzyme) than with solvent extraction. While the enzymes enhanced the oil extraction, the oil yield was still significantly (p <0.05) lower than that obtained by solvent (hexane) extraction.     

Enzymatic Extraction of Wheat Germ Oil

In this study enzymatic extraction of oil from wheat germ (WG) was investigated. Four enzymes (Viscozyme L, Multifect CX 13L, Multifect CX GC and Alcalase 2.4L FG) were screened for their efficacy to release oil from WG. Alcalase 2.4L FG treatment of WG improved oil extraction yield as compared to a control (aqueous extraction without enzyme). Alcalase 2.4L FG, which resulted in significantly higher oil yield than the other three enzymes, was chosen for optimization of the enzymatic oil extraction process by using Response Surface Methodology (RSM). Three processing parameters, liquid/solid ratio, extraction time and enzyme concentration, were investigated as the independent variables. Based on the experimental results, the highest oil yield, 66.5% (w/w), was obtained under the following conditions; liquid/solid ratio 16.5, enzyme concentration 1.1% and extraction time 19.25 h. A cubic model with R ² of 0.91 was developed to describe the enzymatic extraction process. Although the cubic model predicted WG oil extraction yields well within the processing conditions studied in this study it was not effective beyond the experimental range. Further research focusing on high liquid/solid ratio, 16–20, and extraction time in 18–24 h and 0.5–5 h ranges is necessary to improve the model developed in this study.     

A novel process for extraction of tea oil from Camellia oleifera seed kernels by combination of microwave puffing and aqueous enzymatic oil extraction

The objective of this study was to extract the oil from Camellia oleifera seed kernels by aqueous enzymatic oil extraction (AEOE). We describe a novel process for extraction of tea oil preceded by tea saponin extraction from C. oleifera seed kernels. The extraction efficiency obtained with microwave‐assisted extraction (MAE) is very high, which the recovery yield is up to 83% in 30 s and the saponins in camellia seed kernels can be completely removed by the second MAE. Moreover, an important step in the process development has been the pretreatment by microwave puffing of camellia seed kernel residues followed by AEOE increased oil extraction yield from 53% to 95%, which will is comparable to hexane oil extraction yields from plant materials.     

Effect of Enzyme Pre-treatments on Bioactive Compounds in Extracted Tiger Nut Oil and Sugars in Residual Meals

Tiger nut oil is a novel oil that requires more research data on its characteristics. In this study, the oil was extracted using both enzyme‐aided pressing (EAP) and aqueous enzymatic extraction (AEE) methods. Using enzymes as a pre‐treatment prior to mechanical pressing increased the concentration of some phenolic acids and tocopherols present in extracted oils compared to controls. High pressure processing as a pre‐treatment before aqueous enzymatic extraction also enhanced tocopherols and total polyphenolic content in oils. The percentage free fatty acid and peroxide values indicated that under the initial extraction parameters, the oils were stable and they all met the standards for virgin olive oil set by the International Olive Oil Council. Residual meals from both extraction processes contained low protein contents ranging from 2.4 to 4.6 %. Additionally, EAP and AEE meals contained low DP (degree of polymerisation) sugars that appeared as 1‐kestose (DP3) and nystose (DP4). EAP had the highest total DP3 and DP4 sugar content of 82.5 mg/g. These sugars would need further assessment to verify their identity and determine their suitability as a potential food.     

水酶法提取肉桂油的工艺研究

探索了肉桂油的水酶法提油工艺.研究了不同酶系以及酶解条件对肉桂油得率的影响.结果表明,果胶酶的作用效果好;酶解条件中,加酶量、酶解时间都对肉桂油得率有显著的影响,通过单因素分析及正交试验的结果,得出在固液比1∶6、酶解pH=3.5、酶解温度40℃、加酶量1.5％、酶解时间2h条件下,肉桂油得率能达到1.72％.经检测得到处理得到的肉桂油中桂皮醛含量达到83.6％.     

Aqueous enzymatic extraction and quality evaluation of Acer truncatum Bunge seed oil

Aqueous enzymatic extraction (AEE) of oil from Acer truncatum Bunge seed kernel was investigated. The effects of enzyme type on the extraction yield of oil were studied, and the results showed that the oil yield obtained with pentosanase was higher than that obtained with the other enzymes. The combination of pentosanase and cellulase showed better extraction performance than a single enzyme, and the operation parameters of the AEE method were optimized. A maximum oil yield of 37.94% was obtained. The analysis results of chemical compositions of the extracted oils showed that the content of unsaturated fatty acids in the oil extracted by the AEE method was 90.28%, and the content of nervonic acid was about 5.59%. In addition, the main physical and chemical properties of A. truncatum Bunge seed oil were measured. The oil obtained by the AEE method met the China National Standard of A. truncatum Bunge oil.     

A Comparative Study on Response Surface Optimization of Supercritical Fluid Extraction Parameters to Obtain Portulaca Oleracea Seed Oil with Higher Bioactive Content and Antioxidant Activity Than Solvent Extraction

Portulaca oleracea (purslane) seed oil is a rich source of omega-6 and omega-3 fatty acids. Extraction of the purslane seed oil while preserving its high nutritive quality has been a challenge since conventional solvent extraction has many adverse effects on bioactive content. This study aims the optimization of purslane seed oil supercritical fluid extraction (SFE) conditions and to compare purslane seed oils obtained with SFE and conventional solvent extraction in terms of oil yield, along with the purslane seed oil quality and bioactive content. For this purpose, the SFE process parameters (pressure, temperature, static time, and dynamic time) are optimized for oil yield, omega-6, omega-3, and antioxidant activity using response surface methodology (RSM). Optimum SFE pressure, temperature, static time, and dynamic time levels are determined as 350 bar, 50 °C, 20 min, and 90 min, respectively. Oil yield and physicochemical quality properties of conventional solvent extract and SFE samples are determined and compared. Consequently, samples obtained via SFE and solvent extraction have similar quality properties. Distinctly, SFE allows an extraction with 5.6% higher total phenolic compound (TPC) and 33% higher antioxidant activity than solvent extraction. Practical Applications: In the study, the extraction of purslane oil using supercritical fluid extraction is optimized with different approaches. At optimum conditions, purslane oil is extracted and all physicochemical properties and the process efficiency (yield) are compared with the solvent-extracted samples. The results of this study make supercritical fluid extraction of purslane seed oil possible since all optimum operating conditions of a pilot-sized extractor are reported in the study. It is believed that the results provide a good starting point for industrial operations. Moreover, researchers also believe that research studies unveiling the new potential oil-bearing seeds are important to overcome the vegetable oil shortage that emerged this year.