Chemical Properties and Oxidative Stability of Perilla Oils Obtained From Roasted Perilla Seeds As Affected by Extraction Methods

Abstract: The chemical properties and oxidative stability of perilla oils obtained from roasted perilla seeds as affected by extraction methods (supercritical carbon dioxide [SC‐CO₂], mechanical press, and solvent extraction) were studied. The SC‐CO₂ extraction at 420 bar and 50 °C and hexane extraction showed significantly higher oil yield than mechanical press extraction (P < 0.05). The fatty acid compositions in the oils were virtually identical regardless of the extraction methods. The contents of tocopherol, sterol, policosanol, and phosphorus in the perilla oils greatly varied with the extraction methods. The SC‐CO₂‐extracted perilla oils contained significantly higher contents of tocopherols, sterols, and policosanols than the mechanical press‐extracted and hexane‐extracted oils (P < 0.05). The SC‐CO₂‐extracted oil showed the greatly lower oxidative stability than press‐extracted and hexane‐extracted oils during the storage in the oven under dark at 60 °C. However, the photooxidative stabilities of the oils were not considerably different with extraction methods.     

提取方法对大豆油脂体组成及氧化稳定性的影响

以大豆为原料,比较缓冲溶液法、水相法和酶法3种提取方法对大豆油脂体提取率、组成、脂肪酸组成、磷脂、生育酚、ζ-电势和粒径的影响,以及对大豆油脂体氧化稳定性的影响.试验结果表明,酶法提取大豆油脂体的提取率(19.74±0.14)％显著高于缓冲溶液法(12.76±0.14)％和水相法(6.67±0.32)％的提取率(P<0...     

Extraction Technology Can Impose Influences on Peanut Oil Functional Quality: A Study to Investigate the Lipid Metabolism by Sprague–Dawley Rat Model

In this study, peanut oil was prepared by cold pressing (temperature under 60 °C), hot pressing (temperature above 105 °C), and enzyme‐assisted aqueous extraction technology. Influences of an extraction technology on the oil fatty acid composition and the content of minor bioactive compounds, including tocopherols, polyphenols, and squalene, were investigated in detail. High‐fat‐diet Sprague–Dawley (SD) rat model was then established to probe the impact of cold‐pressed peanut oil (CPO), hot‐pressed peanut oil (HPO), and enzyme‐assisted aqueous‐extracted peanut oil (EAO) on lipid metabolism outcomes, to explore influences of different extraction technologies on lipid functional quality. Results showed that oleic acid was the predominate fatty acid in the EAO (52.57 ± 0.11%), which was also significantly higher (P < 0.05) than CPO and HPO. The HPO showed higher total tocopherol and polyphenol contents (206.84 ± 6.93 mg/kg and 47.87 ± 6.50 mg GA/kg, respectively) than CPO and EAO (P < 0.05). However, the squalene content in CPO was 475.47 ± 12.75 mg/kg, which was the highest among the three oils (P < 0.05). The animal experiment results revealed that EAO could be more prone to induce lipid accumulation in the liver, which may likely to cause nonalcoholic fatty liver disease. However, the serum lipid profiles indicated that the CPO was more beneficial than the EAO and HPO in lowering the serum low‐density lipoprotein cholesterol, alanine aminotransferase, and aspartate aminotransferase contents, and increasing the high‐density lipoprotein cholesterol content. All of our efforts indicated that an extraction technology can affect the peanut oil lipid fatty acid composition, the bioactive compounds content, and, correspondingly, the lipid metabolism in SD rats.     

Effects of frying on polar material and free fatty acids in soybean oils

The purpose of this study was to investigate the quality deterioration of pressed soybean oil (PSBO), first grade solvent extracted soybean oil (FG‐SESBO) and third grade solvent extracted soybean oil (TG‐SESBO) with respect to time at 180 °C. It was found that there was a significant increase in total polar material (PM; P < 0.01) and free fatty acids (FFA; P < 0.05) in PSBO, FG‐SESBO and TG‐SESBO with increased time of frying. After forty‐five frying cycles, the final concentration of total PM was significantly higher in TG‐PSBO (30.39%) than in PSBO (21.10%) and FG‐SESBO (25.93%; P < 0.05). During frying cycles, the final acid value (AV) was significantly higher in PSBO (0.84 ± 0.02 mg KOH/g fat) than in TG‐SESBO (0.59 ± 0.01 mg KOH/g fat) and FG‐SESBO (0.56 ± 0.03 (mgKOH/g oil; P < 0.05). The content of saturated fatty acids in the three types of frying oils was significantly increased after forty‐five cycles of frying. However, even larger changes were observed in the content of unsaturated fatty acids, with decreases in C18:2, 9 c 12 c and C18:3, 9c 12c 15c and increase in C18:1, 9 c. The highest increasing slopes of PM and AV were observed in the TG‐SESBO.     

不同方法提取火麻籽油的品质分析

采用热榨法、冷榨法、不同酶制剂辅助压榨(热榨、冷榨)法、水酶法提取火麻籽油,并对不同方法提取的火麻籽油进行提取率、感官特性、理化特性、营养成分的比较分析。结果表明:水酶法提取火麻籽油的提取率最高,为83.2%;冷榨法提取火麻籽油和水酶法提取火麻籽油的酸值和过氧化值都相对较低;不同方法提取的火麻籽油的脂肪酸含量无明显差异;碱性蛋白酶Alcalase2.4L辅助冷榨法提取的火麻籽油VE含量最高,达到42.10 mg/100 g。对不同方法提取火麻籽油的品质进行分析,可为提取高品质火麻籽油奠定理论基础,同时也为水酶法提油技术工业化提供了参考依据。     

4种提取工艺橡胶籽油的品质比较研究

以橡胶籽仁为原料,采用压榨法、浸出法、超声波辅助溶剂法和水酶法制备橡胶籽油。比较不同提取工艺的油脂提取率、理化性质及脂肪酸组成。结果表明:超声波辅助溶剂法油脂提取率最高,水酶法的最低;水酶法得到的橡胶籽油的水分及挥发物含量较高;浸出法所得橡胶籽油的酸价最高,压榨法的最低;压榨法橡胶籽油过氧化值最高,水酶法的最低; 4种提取工艺所得橡胶籽油的脂肪酸组成基本相同。     

Aqueous enzymatic sesame oil and protein extraction

In the present work we evaluated five enzyme-mixtures (Protex 7L, Alcalase 2.4L, Viscozyme L, Natuzyme, and Kemzyme) for their effectiveness in extracting the oil and protein recovery from sesame seeds during an enzyme-assisted aqueous extraction (EAAE) process. Alcalase 2.4L was found to be the best for attaining a high oil yield (57.4% of the total oil content in the seed), whereas, the maximum amount of protein (87.1% of the total seed protein), was recovered in the aqueous phase with Protex 7L. The quality attributes such as fatty acids profile, density, refractive index, free fatty acid contents, iodine value, colour, saponification number and unsaponifiable matter of the sesame oil, extracted by aqueous enzymatic process, were comparable with that of the control (oil extracted without enzyme treatment) and hexane-extracted oil (HEO), revealing no significant (p > 0.05) variations among oils, produced by either of the methods. The oxidative stability state of the enzyme-extracted oil (EEO) was noted to be considerably improved relative to the control and HEO. The amount of tocopherols for the oils, produced by the enzyme–adjuvant was found to be higher than the control and HEO. An appreciable increase in the antioxidant activity as assessed by determinations of total phenolic contents, DPPH radical scavenging capacity, and inhibition of linoleic acid oxidation of EEO was also established. Overall, the present results revealed improvement in the quality of the EEO while a major portion of the food grade protein was also extracted in the aqueous phase.     

水酶法芝麻油与其他工艺芝麻油品质差异研究

通过对芝麻油外观品质、理化特性、抗氧化成分及脂肪酸组成进行对比,研究了水酶法芝麻油与其他工艺芝麻油(热榨法芝麻油、冷榨法芝麻油、水代法芝麻油)的品质差异。结果表明:水酶法芝麻油的外观品质好,色泽浅,符合一级成品芝麻油标准;水酶法芝麻油的水分及挥发物的含量介于冷榨法芝麻油和水代法芝麻油之间,酸价、过氧化值、不皂化物含量最低;水酶法芝麻油的抗氧化成分(生育酚、芝麻素和芝麻林素)含量最高,但未检出芝麻酚;与热榨法芝麻油、冷榨法芝麻油、水代法芝麻油相比,水酶法芝麻油的饱和脂肪酸含量最高,不饱和脂肪酸含量最低。     

Effects of Different Pretreatments to Fresh Fruit on Chemical and Thermal Characteristics of Crude Palm Oil

This study selected 5 methods, including boiling, hot air drying, high‐pressurized steam, freezing, and microwave radiation to pretreat fresh oil palm fruit before solvent extraction of the oil. Using fresh fruit as a control, the pretreatment methods were compared for the effects on the activity of the 2 main enzymes in the fruit and some physicochemical properties of the crude palm oil. The results indicated, although all the 5 pretreatments could inactivate lipase and peroxidase in the treated flesh significantly (P < 0.05), the high‐pressurized steam was the most effective. There were also differences in the unsaturated fatty acid contents of the 6 oils. The crude oil from frozen fruit contained significantly more vitamin E (37829.33 ppm) than previously reported. Microwave radiation was shown to significantly decrease the free fatty acid content and the peroxide value, while increasing the oxidative stability index. Thermal behaviors of the oils were significantly different to each other with the exception a few parameters (P < 0.05).     

Optimisation of red pepper seed oil extraction using supercritical CO2 and analysis of the composition by reversed‐phase HPLC‐FLD‐MS/MS

Oil extractions from red pepper seed were performed by supercritical CO₂. Three‐level Box–Behnken factorial design (BBD) from response surface methodology (RSM) was applied to optimise the main extraction conditions including pressure, temperature and concentration of modifier (ethanol). The optimum conditions were as follows: extraction pressure, 27.17 MPa; extraction temperature, 47.67 °C; and the added concentration of modifier, 8.11 vol.%. Under the optimum conditions, the oil yield of 18.4% was obtained, which was well matched with the predicted yield. A simple, stable and sensitive method for the simultaneous determination of saturated and unsaturated free fatty acids in extracted oils using 2‐(11H‐benzo[a]carbazol‐11‐yl)‐ethyl‐4‐methylbenzenesulfonate (BCETS) as labelling reagent with fluorescence detection has been developed. All of free fatty acids (FFA) were found to give a linear response with correlation coefficients of >0.9991. The detection limits at a signal‐to‐noise ratio (S/N) of three are in the range of 19.06–41.19 fmol. This method should have powerful potential for the trace analysis of short‐ and long‐chain FFA from edible oils, foodstuff and other complex samples.     

不同提油方法对光皮树果实油品质的影响

比较了不同提油方法所得光皮树果实油的理化性质及脂肪酸组成。结果表明:不同提油方法对光皮树果实油的折光指数、相对密度及脂肪酸组成和含量影响不显著;对皂化值、酸值、过氧化值、磷脂含量有显著影响。生物酶法所提光皮树果实油经精炼后色泽浅、透明澄清,折光指数、相对密度、不饱和脂肪酸含量较高,皂化值、过氧化值、磷脂含量较低,品质优于索氏抽提法、化学溶剂浸提法、压榨法和水剂法所得油。     

Efficiency of dietary vegetable oils in preserving the quality of shell eggs under ambient tropical conditions

The study evaluates the efficacy of three common market-grade culinary vegetable oils—groundnut oil, cottonseed oil and coconut oil—in preserving the internal quality of freshly laid eggs coated with them and stored under tropical room conditions of 25–32°C and 40–85% r.h. for 36 days. All three vegetable oils significantly (P<0.01) limited diurnal weight losses of the eggs to 0.013–0.016 g as against 0.186 ± 0.013 g for the untreated eggs over 36 days storage. Liquefaction of the yolk and albumen was also significantly reduced (P<0.05) such that the albumen pH of the oiled eggs increased from 7.65 to only 8.35–8.65 after 36 days when the untreated eggs had an albumen pH of 9.80. Subsequently, the yolk index of oiled eggs dropped by only 0.10–0.13 after 36 days and remained significantly superior (P<0.001) to that of the untreated eggs which had dropped from an initial value of 0.47 to 0.11. These preservative effects of the vegetable oils may be attributable to their fatty acid component, rather than their glycerol which showed no significant (P>0.05) improvement over untreated eggs.     

Extraction and characterisation of lipids from Antarctic krill (Euphausia superba)

There is significant commercial interest in oil extraction from krill because it is rich in omega-3 polyunsaturated fatty acids (n-3 PUFA) such as eicosapentaenoic (EPA, 20:5n3) and docosahexaenoic (DHA, 22:6n3) acids. The objectives were to determine oil extraction efficiency using different solvent systems and the composition of extracted oil and spent krill following extraction. Extraction efficiency was the highest (P < 0.05) for one-step extraction using freeze-dried krill with 1:12 or 1:30 krill:solvent ratio (w:v) compared to Folch, Soxhlet, and conventional two-step extraction. Extracted oils contained predominantly phospholipids (20–33%), polar non-phospholipids (64–77%), and minor triglycerides (1–3%). Triglycerides contained much less (P < 0.05) total n-3 (4.0%), DHA (1.1%), and EPA (2.3%), but more (P < 0.05) saturated FA (38.7%) than phospholipids (total n-3-47.4%, DHA-18.0%, EPA-28.2%, saturated FA-23.5%). Antioxidant capacity of krill oil extracted by one-step extraction (9.4–14.2 μmol Trolox Equivalents/ml oil) was generally similar to antioxidant capacity of krill oil extracted by ethanol (22.9), but greater (P < 0.05) than antioxidant capacity of krill oil extracted by acetone (1.2) and Folch method (1.5). The spent krill following oil extraction contained protein (72.9–75.8%, dry basis). Based on the extraction efficiency and composition of the extracted oil, the one-step extraction using 1:12 krill:solvent ratio is recommended.     

水酶法和溶剂法提取核桃油理化性质比较

本实验进行了水酶法和溶剂法提取核桃油的理化性质比较研究。结果表明:不同提取方法(水酶法、溶剂法)对核桃油的理化特性有一定的影响。水酶法提取的核桃油透明度高,色值低,且风味好;水酶法提取所得核桃油的酸值、未皂化值及磷脂含量均低于溶剂法,有利于油脂的后续精炼;水酶法与溶剂法对核桃油的脂肪酸组成影响不显著;水酶法提取核桃油的氧化稳定性低于溶剂法。     

Physico‐enzymatic production of monoacylglycerols enriched with very‐long‐chain polyunsaturated fatty acids

BACKGROUND: Monoacylglycerols (MAG) containing polyunsaturated fatty acids (PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have interesting applications. The enzymatic processing of such MAG directly from fish oils is highly interesting, integrating the processing of MAG and concentration of EPA and DHA. The aim of this study was to develop an efficient enzymatic glycerolysis system together with physical fractionation for the production of PUFA‐MAG from tuna oil. RESULTS: Novozym 435 was eventually selected after evaluation together with immobilized lipase AK in a tertiary alcohol‐based system. A further evaluation of solvent mixtures involving tertiary alcohols was made, taking ease of operation into consideration. It turned out that a number of mixtures gave a similar performance to that of tert‐butanol (TB). Basic reaction parameters were thoroughly evaluated. In the batch reaction system with TB as solvent, the recommended conditions were: glycerol/tuna oil 4:1 (mol/mol), TB/tuna oil 2:1 (wt/wt), 15 wt% Novozym 435, and temperature 40 °C. Under these conditions, the yield of MAG was up to 90% after 3 h incubation. Crude MAG from the production was fractionated to produce MAG with higher EPA and DHA content. Using acetone as solvent at 0 °C led to ca 50% yield of MAG but contained EPA and DHA up to 71% in comparison with ca 30% in tuna oil. CONCLUSION: Potentially practical process steps have been developed for the production of MAG containing a high content of EPA and DHA from natural fish oils with high efficiency and simplicity. Copyright © 2007 Society of Chemical Industry     

不同提取方法所得茶油的品质比较

通过茶油的感官指标、理化指标及部分功能性成分含量,比较水酶法、水代法、压榨法、超临界CO2萃取法以及有机溶剂浸出法所得茶油的品质。结果表明,水代法和水酶法茶油的感官指标和理化指标相近,并优于其他方法所提茶油。茶油中的维生素E(VE)几乎全部是α-VE。压榨茶油中角鲨烯含量最高,VE含量最低;超临界提取的茶油中VE含量最高,水代法、水酶法与浸出法所得茶油角鲨烯和VE含量相近。各方法提取的茶油中脂肪酸组成没有显著差异。     

Fatty acid profile of olive oil extracted from irradiated and non-irradiated olive fruits

Syrian Kaissy cv olive fruit (SKOF) was irradiated (0, 1, 2, and 3 kGy). Oils were extracted from irradiated and un-irradiated olive fruits. Fatty acid profiles of Syrian Kaissy cv olive oil (SKOO) were measured by gas chromatography immediately after irradiation and after 6, 12, 24, and 36 months of storage. Results of the study showed that composition of fatty acids of SKOO were determined as palmitic (C16:0) (14.69%), palmitoleic acid (C16:1) (1.18%), stearic (C18:0) (2.19), oleic (C18:1) (68.94%), linoleic (C18:2) (12.22%), and linolenic acid (C18:3) (0.79%). The fatty acid composition of SKOO contains a healthy mixture of all the types of saturated mono-unsaturated and poly-unsaturated fatty acids. The data showed an increase (p < 0.05) in the percentage of the total saturated fatty acids and decrease (p < 0.05) in the percentage of the total unsaturated fatty acids of SKOO during storage. In general, there were no significant (p > 0.05) differences in fatty acids compositions of both oils extracted from irradiated and un-irradiated SKOF.     

Effect of processing and storage on the fatty acid composition of n‐3 or n‐6 fatty acid‐enriched eggs

Fresh eggs from hens fed diets supplemented with 4% linseed oil (LO) or sunflower oil (SO) were either directly submitted to pasteurisation, hard‐boiling or scrambling processing, or first submitted to refrigerated storage at 4 °C for 60 day and then to processing. Fresh LO eggs showed higher (P ≤ 0.05) proportions of monounsaturated fatty acids (MUFAs) and n‐3 polyunsaturated fatty acids (PUFAs), but lower (P ≤ 0.05) proportions of saturated fatty acids (SFAs), PUFAs and n‐6 PUFAs than the SO eggs. Storage decreased (P ≤ 0.05) the proportion of PUFAs and increased (P ≤ 0.05) that of MUFAs in egg yolks from both treatments. The pasteurisation process had no effect on the fatty acid composition of fresh eggs from both treatments, but increased (P ≤ 0.05) n‐6 PUFAs and decreased (P ≤ 0.05) n‐3 PUFAs in stored LO eggs. Hard‐boiling and scrambling modified the fatty acid composition of fresh and stored eggs from both treatments by decreasing (P ≤ 0.05) the proportion of PUFAs, particularly of the very long‐chain n‐3 eicosapentaenoic, docosapentaenoic and docosahexaenoic PUFAs. LO eggs showed a higher susceptibility to fatty acid modification upon processing as compared to the SO eggs.     

破乳方式对水酶法提取大豆油过程中的乳状液回收油品质影响和水解蛋白风味研究

为研究破乳方式对粗酶水相提取大豆油过程形成的乳状液回收油品质影响和所得水解蛋白风味,分别对等电点法、添加CaCl₂法、Alcalase酶法、加热破乳方式回收油的理化性质和脂肪酸组成进行分析,并以溶剂浸提油为对照样。结果表明,各破乳方式所得油的色泽、酸价、过氧化值、皂化值、碘值均低于溶剂浸提油,破乳油中,等电点法破乳油酸价最高,达0.83 mg/g,其次是加热破乳油,CaCl₂和Alcalase酶法破乳油的酸价最低,仅为0.52 mg/g;加热破乳油过氧化值高于其他破乳油,达0.85 μg/g,CaCl₂和Alcalase酶法破乳油的过氧化值最低,仅为0.62 μg/g。各破乳油色泽、皂化值和碘值之间均无显著性差异(P>0.05),破乳油脂肪酸组成与溶剂浸提油相同,不饱和脂肪酸总含量均在84%以上,符合国际法典委员会推荐的食用油标准。因此,破乳油的品质均优于溶剂浸提油,而CaCl₂和Alcalase酶法破乳油的品质最好。粗酶水解蛋白必需氨基酸含量与原料大豆相近,尽管仍具有苦味,但苦味值低于Alcalase酶解蛋白,因此粗酶水解蛋白仍然保持大豆蛋白的营养品质。     

提取方法对核桃油脂理化性质的影响

研究了水酶法和溶剂法两种提油方法对核桃油的理化性质的影响,结果表明:不同提取方法(水酶法、溶剂法)对核桃油的理化特性有一定的影响。水酶法提取的核桃油透明度高、色值低、且风味好;水酶法提取所得核桃油的酸值、未皂化值及磷脂含量均低于溶剂法,有利于油脂的后续精炼。水酶法与溶剂法对核桃油的脂肪酸组成影响不显著,水酶法提取核桃油的氧化稳定性低于溶剂法。