DHA藻油调和油用于炒土豆丝的品质评价

通过对DHA藻油(DHA≥40%)添加量分别为2%、3%、5%、10%、15%的大豆油-DHA藻油调和油、花生油-DHA藻油调和油、菜籽油-DHA藻油调和油进行氧化稳定性实验和家庭实际烹饪炒土豆丝实验的研究,考察了富含DHA的藻油调和油的氧化稳定性以及用于炒土豆丝的感官评价和炒菜后调和油的品质变化。结果表明:适量DHA藻油的添加可以提高调和油的氧化稳定性,炒土豆丝后的感官风味接受度也比较高,同时炒菜前后调和油的过氧化值符合国家标准,而DHA的保留率至少达95%,说明富含DHA的藻油调和油可以作为家庭烹饪用油。     

富含n-3多不饱和脂肪酸调和油模拟家庭食用的存储稳定性研究

研究了两种富含n-3多不饱和脂肪酸的调和油模拟家庭食用过程中,在室温不避光条件下的存储稳定性,每周测定油样的色泽、酸值、过氧化值、茴香胺值、羰基价、聚合物含量及EPA、DHA和α-亚麻酸含量.试验结果表明:除过氧化值小幅上升外,其他指标均未发生明显变化,在家庭持续7周使用的存储过程中,两种调和油稳定性均非常优越,说明在家庭常规储存条件下,开封后一定时间内食用完,不会对n-3调和油品质造成影响.     

菜籽油-DHA藻油调和油在不同鸡肉烹饪方式下的品质变化

为了对DHA藻油调和油的开发和合理烹饪提供相关指导,将DHA藻油分别按菜籽油质量的2%、3%、5%、10%、15%与菜籽油复配制成菜籽油-DHA藻油调和油,并以蒸、炒、烧三种不同方式烹饪鸡肉,测定烹饪前后油样的脂肪酸组成、酸值和过氧化值的变化,分析探讨DHA藻油比例及烹饪方式对调和油脂肪酸组成及理化指标的影响。结果表明：烹饪后,调和油的单不饱和脂肪酸含量减少,饱和脂肪酸和多不饱和脂肪酸含量增加;三种主要脂肪酸油酸、亚油酸、亚麻酸含量随DHA藻油比例增加呈不规律波动变化;除DHA藻油比例为2%的调和油外,其余调和油的酸值均在烹饪后增加,其中,DHA比例为3%、5%和10%的调和油炒鸡肉后酸值增加最大,蒸和烧这两种烹饪方式对酸值的影响相对较小;纯菜籽油、DHA藻油比例为15%的调和油的过氧化值增加量明显大于其他的调和油,总体上炒较另外两种烹饪方式更易导致过氧化值增加。综上,建议蒸鸡肉或烧鸡肉宜采用DHA藻油比例为2%、3%、5%的调和油,炒鸡肉则不宜采用DHA藻油调和油。     

海藻油、鱼油和DHA调和油在烹调过程中DHA损失研究

为确定海藻油、鱼油及DHA调和油在烹调过程中DHA的损失情况,模拟烹调环境,对海藻油、鱼油和DHA调和油进行了比较研究.结果表明:海藻油、鱼油在加热条件下DHA损失较大;而将海藻油、鱼油添加到植物油中作为含量相对较低的DHA植物调和油时,在加热及烹调环境中DHA损失会大大降低,在一般家庭烹调炒菜条件下,DHA损失率在5％以内,保留率超过95％.     

鳡鱼调和油的配制及烹饪应用效果

根据不同油脂的脂肪酸含量特点,通过数学建模的方法将鳡鱼油、花生油和大豆油进行调和,并用于土豆丝的烹饪,以扩大鳡鱼油的应用范围。结果表明,调和油中各油质量分数为鳡鱼油19.2%～28.5%、花生油55.5%～66.6%、大豆油14.2%～16.0%时,脂肪酸配比较合理,能同时满足单不饱和脂肪酸∶多不饱和脂肪
酸=1∶1和ω-6多不饱和脂肪酸∶ω-3多不饱和脂肪酸=（4～6）∶1。烹饪后,调和油的酸值增幅比鳡鱼油降低了83.7%～123.6%,过氧化值没有显著变化,丙二醛含量低于0.3 mg/kg,二十二碳六烯酸（DHA）＋二十碳五烯酸（EPA）保留率高达90.3%～92.7%。调和油添加0.2‰复合抗氧化剂时,保质期可达到12 个月。     

酶法制备n-3多不饱和脂肪酸型磷脂的工艺

研究了无溶剂体系中固定化磷脂酶A1催化大豆磷脂与乙酯型鱼油进行酯交换反应,制备n-3多不饱和脂肪酸型磷脂的工艺。考察了反应温度、反应时间、底物比(乙酯型鱼油与磷脂的质量比)以及加水量的影响,得到了较优的反应条件。实验结果表明,加酶量(按大豆磷脂的质量计算)20%,底物比8∶1,底物总质量5.0g,加水量55μL,55℃反应12h时,所得产物中EPA和DHA的含量分别为8.0%和17.8%。     

ω-3脂肪酸强化鸡蛋在不同烹饪方法中的营养损失

目的:以ω-3脂肪酸强化鸡蛋为原料,分析比较不同烹饪方法对鸡蛋黄中EPA、DHA及胆固醇含量的影响。方法:采用不同烹饪方法 (水煮蛋、荷包蛋、煎鸡蛋、鸡蛋糕)加工新鲜鸡蛋,利用气相色谱法与高效液相色谱法对鸡蛋黄中DHA、EPA与胆固醇的含量进行检测分析。结果:不同烹饪方法处理后鸡蛋黄中EPA、DHA均有不同程度的损失,其中煮鸡蛋中二者的损失率最低;水煮蛋和荷包蛋胆固醇含量略微上升、煎鸡蛋和鸡蛋糕胆固醇含量下降。结论:在4种不同的烹饪方法中,水煮蛋的营养损失最小,为鸡蛋最适合的烹饪方法。     

HPLC法测定海鲈鱼鱼油中EPA和DHA的含量

设计建立测定海洋鲈鱼鱼油中EPA (二十碳五烯酸)和DHA (二十二碳六烯酸)含量的方法,并测定尿素包合前后鱼油中EPA和DHA含量变化。采用Agilent色谱柱型号XDB (C_(18)),设置柱温38℃、检测波长220 nm、恒定流速1 mL/min,流动相乙腈-水梯度洗脱。结果表明, EPA甲酯和DHA甲酯的检测线性范围分别为0.059～5.9和0.094～9.4μg (R~2_(EPA)=0.999 6, R~2_(DHA)=0.999 9),检出限分别为0.5和0.9μg/mL。在精密度试验中, EPA甲酯和DHA甲酯的RSD分别为0.29%和0.34%。在加样回收率试验中,分别设计了6个加标浓度做检测, EPA甲酯和DHA甲酯的平均回收率分别为99.29%～99.87%(平均99.52%)和99.59%～101.48%(平均100.22%),平均RSD分别为0.24%和0.83%。尿素包合前,原料鱼油中EPA和DHA的含量分别为1.23%和2.52%;尿素包合后,含量分别为5.66%和12.34%。建立的HPLC法稳定、快捷、重复性好,适用于海鲈鱼下脚料鱼油中EPA和DHA含量测定。尿素包合后EPA和DHA的含量显著增长,达到包合前的4.8倍。     

主成分分析法用于调和油配方设计的研究

利用主成分分析,对市售38种调和油的27个因素进行分析,得到影响调和油产品得分排名的主要因素。根据分析结果,在调和油配方设计中,将油茶籽油等油酸含量较高的植物油作为优选原料油进行添加,并依据膳食脂肪酸均衡的需求,强化添加二十碳五烯酸(DHA)、二十六碳六烯酸(EPA)长链多不饱和脂肪酸成分,生产调和油。研究结果为调和油配方设计中基油的选取提供了依据。     

一种营养均衡型配方油脂家庭烹饪稳定性的研究

通过模拟家庭烹饪实验,考察了一种富含亚油酸和亚麻酸且具有适宜的ω-6/ω-3脂肪酸比例的营养均衡型配方油脂的烹饪稳定性,研究结果表明:配方油应用于炒青菜、炒青椒肉片、火锅水煮烹饪时,以市售常用食用油为对照,油样的指标酸价、过氧化值与丙二醛含量有所变化,但最终的指标值都能满足GB2716-2005与GB/T 8937-2006的规定,达到一般烹饪用油的要求;对烹调后的油样进行脂肪酸组成的分析,结果表明:在所研究的烹调过程中,配方油未发生明显的氧化、异构化等劣变反应。多不饱和脂肪酸含量≥60%、ω-6/ω-3脂肪酸比例≤4:1的配方油应用于家庭烹饪是可行的,是人们一种日常补充ω-3脂肪酸的有效途径。     

Oxidative stability,shelf-life and stir-frying application of Torreya grandis seed oil

Torreya grandis seed oil, with a feature of Δ5-sciadonic acid (SA, 20:3 Δ5, 11, 14 ω-6), is an attractive woody oil as its potential health benefits in lowering blood and hepatic lipids and anti-inflammatory properties. In the present study, its oxidative stabilities at both room temperature and heating conditions were investigated by analysing oxidation stability index (OSI), shelf-life, changes of fatty acids, acid value and peroxide value during stir-frying tests. Also, its effects on the sensory qualities of stir-fried shredded potatoes were evaluated. The OSI of T. grandis seed oil was 2.97 h at 120 °C, which was 11.24% higher than that of the control soybean oil, contributing to a longer predicted shelf-life of 135–195 d for T. grandis seed oil than 127–180 d for soybean oil. T. grandis seed oil also exhibited superior thermal stability compared to soybean oil. The feature fatty acid, SA, only lost 2.48–5.73% (decreasing from 14.14 to 13.33–13.79%) under the optimised stir-frying conditions at 140–180 °C for 3–5 min. For the stir-frying shredded potatoes, T. grandis seed oil made it more pleasing in colour, odour and palatability. Due to its desirable oxidative stability at room temperature and stir-frying performance at high temperature, T. grandis seed oil is suitable for use as a domestic cooking oil.     

Mechanisms of Docosahexaenoic and Eicosapentaenoic Acid Loss from Pacific Saury and Comparison of Their Retention Rates after Various Cooking Methods

The docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) contents of Pacific saury (Cololabis saira), a fatty fish and staple of the Japanese diet, have been reported to decrease after cooking. This study compared the DHA and EPA contents remaining in saury after grilling, pan‐frying or deep‐frying to center temperatures of 75, 85, or 95 °C, and examined physical loss, lipid oxidation, and thermal degradation as mechanisms of DHA and EPA loss. Temperature changes inside the saury were monitored using thermocouples, while DHA and EPA contents, oxygen radical absorbance capacity, and measurements of lipid oxidation (that is, carbonyl value and thiobarbituric acid value) were determined chemically. Visualization of temperature distribution inside fish samples during cooking revealed large differences in heat transfer among cooking methods. True retention rates in grilled (DHA: 84 ± 15%; EPA: 87 ± 14%) and pan‐fried samples (DHA: 85 ± 16%; EPA: 77 ± 17%) were significantly higher than deep‐fried samples (DHA: 58 ± 17%; EPA: 51 ± 18%), but were not affected by final center temperatures despite differences in cooking times. Physical loss via cooking losses (grilling and pan‐frying) or migration into frying oil (deep‐frying) accounted for large quantities of DHA and EPA loss, while lipid oxidation and thermal degradation did not appear to be major mechanisms of loss. The antioxidant capacity of saury was not significantly affected by cooking treatments. The results of this study suggest that minimization of physical losses during cooking may increase DHA and EPA contents retained in cooked Pacific saury.     

水酶法提取北太平洋鱿鱼肝脏油脂及其脂肪酸组成分析

研究了水酶法提取北太平洋鱿鱼肝脏油脂的工艺,考察了蛋白酶种类、料液比、反应温度、提取时间和加酶量对油脂提取率的影响,并采用气相色谱-质谱法（GC-MS）对所提油脂的脂肪酸组成进行分析。通过单因素和正交优化实验得到水酶法提取北太平洋鱿鱼肝脏油脂的最佳条件:中性蛋白酶为水解酶、料液比1∶0（g/m L）、反应温度55℃、提取时间6 h、加酶量1800 U/g;在该优化条件下,油脂提取率为79.21%。北太平洋鱿鱼肝脏油脂脂肪酸主要为C16∶0（16.27%）、C18∶1n-9（11.68%）、C20∶1n-11（12.94%）、EPA（9.81%）和DHA（23.61%）,其中n-3型多不饱和脂肪酸高达35.97%,且∑n-3 PUFA/∑n-6 PUFA为7.99,表明北太平洋鱿鱼肝脏油脂具有很高的营养价值和保健功能,可作为EPA和DHA等功能性脂肪酸的重要食药来源。      

气相色谱法测定海豹油中EPA、DPA、DHA含量的方法学研究

目的：建立气相色谱检测海豹油中EPA、DPA和DHA的方法。方法：采用氢氧化钾-甲醇酯化法将海豹油中的脂肪酸快速、有效的转化成脂肪酸甲酯,并通过方法学实验验证其可行性。结果：EPA、DPA和DHA甲酯含量在10～2000μg/mL范围内,峰面积与EPA、DPA和DHA甲酯含量呈良好线性关系;加样回收率在96.93%～103.38%之间,相对标准偏差小于2%;结论：该方法可以快速、准确地同时测定EPA、DPA和DHA含量。     

n-3多不饱和脂肪酸对疾病的预防与治疗作用

n-3多不饱和脂肪酸主要源于亚麻籽、胡桃仁、大豆以及海洋生物。增加n-3多不饱和脂肪酸摄取量可以促进视网膜、大脑和神经系统发育。n-3多不饱和脂肪酸通过各种途径降低人体心血管疾病和炎症的发生,降低糖尿病患者血清低密度脂蛋白胆固醇(LDL-C)和甘油三酯(TG)水平。膳食中增加n-3多不饱和脂肪酸的含量可以对心血管疾病、糖尿病、炎症等患者有辅助治疗效果;n-3多不饱和脂肪酸可以作用于神经细胞,对注意力不集中、抑郁症、精神分裂症有一定的疗效。n-3多不饱和脂肪酸可抑制体外培养的乳腺、前列腺和结肠癌细胞增生,促进细胞凋亡。     

Evaluating nutritional quality of pacific fish species from fatty acid signatures

Eight fish species common to the Pacific Northwest coastal waters were categorised according to total lipids in a ranking from lean fish (e.g. walleye pollock) to oily fish (e.g. herring) species. Comprehensive fatty acid signatures were compared on both the relative proportion of total fatty acids and the proportion of total carcass lipid content. Generally, fish species from the Pacific coast had a relatively high proportion of n-3 highly polyunsaturated fatty acids (n-3 HUFAs), of which more than 80% was accounted for by C20:5n-3 (EPA) and C22:6n-3 (DHA), with species-specific and lower proportions of oleic acid (C18:1n-9) and palmitic acid (C16:0) also dominating. The MUFA contents of fish were lower (P < 0.05) in the lipids of lean and low-fat fish compared to those of fattier species. In contrast, higher (P < 0.05) proportions of polyunsaturated fatty acids (PUFAs) existed in the low-fat species with DHA contents ranging from 18% to 29% in the low-fat fish and from 8% to 10% in the fattier fish, such as herring and capelin. Expressing the same fatty acid content data in terms of absolute amount of fatty acids (e.g. gFA/100 g wet tissue) showed that both EPA and DHA contents in the flesh of pollock and hake were indeed many fold lower than those found in fatty fish, such as herring. The findings confirm that it is important that both the total lipid content and the fatty acid composition of these Pacific fish food sources be considered when making evaluations on the nutritional quality.     

Retention of health-related beneficial components during household preparation of selenium-enriched African catfish (Clarias gariepinus) fillets

Industrial processing and heat treatment of fish muscle generally lead to losses of water-soluble components, some of which may have beneficial health effects. The aim of this work was to determine the retention of taurine, selenium and n-3 polyunsaturated fatty acids when preparing African catfish by three traditional household techniques: boiling in pouches, deep-frying and baking. Cooking did not significantly reduce the content of selenium, having retention between 91and 104%. Deep-frying resulted in a taurine loss of 40%, which was significantly higher than in baking where losses were 25% The fatty acid profiles were similar for baked and boiled fillets, but were significantly different from deep-fried fillets, due to absorption of vegetable frying oil. Baking was the best preparation technique with regard to retention of 20:5n-3 (eicosapentaenoic acid; EPA) and 22:6n-3 (docosahexaenoic acid, DHA), retaining above 80% for both fatty acids, whereas boiling and deep-frying were able to retain only approximately 54 and 65% of each, respectively.     

Effect of cooking on the chemical composition of low-salt, low-fat Wakame/olive oil added beef patties with special reference to fatty acid content

Changes in chemical composition, with special reference to fatty acids, as affected by cooking, were studied in low-salt (0.5%)/low-fat patties (10%) with added Wakame (3%) and partial or total replacement of pork backfat with olive oil-in-water emulsion. The addition of Wakame and olive oil-in-water emulsion improved (P < 0.05) the binding properties and the cooking retention values of moisture, fat, fatty acids and ash, which were close to 100%. Partial and total replacement of animal fat with olive oil-in-water emulsion reduced (P < 0.05) saturated fatty acids (SFAs), while total replacement also reduced (P < 0.05) polyunsaturated fatty acid (PUFAs) contents. The fatty acid concentration in cooked patties was affected by product formulation. Unlike the case of all animal fat patties, when olive oil was added the cooking process increased (P < 0.05) SFAs, monounsaturated fatty acids (MUFAs) and PUFA n-3 (linolenic acid) and n-6 (linoleic acid) contents. Cooked formulated patties with seaweed and partial or total replacement of pork backfat by oil-in-water emulsion and with seaweed added were less calorie-dense and had lower SFAs levels, while samples with olive oil had higher MUFAs levels.     

Stability of potassium iodide and omega-3 fatty acids in fortified freshwater fish emulsion sausage

Oxidative stability of emulsion sausages prepared from African walking catfish (AF: Clarias gariepinus) and rohu (RH: Labeo rohita) fortified with three levels of the refined tuna oil (2%, 6%, and 10%) with 150 μg KI/100 g sample and without KI was investigated. The control was prepared using 20% soybean oil and without KI. Samples were vacuum-packed and stored at 4 °C. Iodine content decreased approximately 14% after cooking and remained constant throughout storage. Sausages fortified with tuna oil showed higher level of n-3 (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), but lower level of n-6 fatty acids (P<0.05) than the control. The ratio of n-6 to n-3 fatty acids of all samples decreased with an increase of tuna oil addition and was stable throughout 4 weeks of storage. Degradation of linoleic (LA) and linolenic acid (LNA) mainly occurred in the samples added 2% tuna oil whereas samples fortified with higher tuna oil (6-10%) exhibited higher loss of EPA and DHA. Hydroperoxide (HPV) and thiobarbituric reactive substances (TBARS) values were increased as addition level of tuna oil increased. Textural properties were not affected during storage at 4 °C for up to 4 weeks (P<0.05). Based on lipid stability results, 2% fortification of the refined tuna oil was recommended for emulsion sausage prepared from both species. Addition of 150 μg KI/100 g had no effect on lipid oxidation of fish sausages (P<0.05).