兰州鲇肌肉生化成分分析及营养学评价

测定了黄河中上游特有鱼类兰州鲇的肌肉生化成分并对其进行了营养学评价。结果表明,兰州鲇肌肉（鲜样）中粗蛋白质量分数(17.4±0.7)%,粗脂肪(2.22±1.09)%,粗灰分(1.12±0.09)%,水分(80.4±0.8)%。肌肉中含有18种氨基酸,总量为(71.29±3.71)%（质量分数,干样）,其中含量最高的为谷氨酸(10.43±0.47)%,含量最低的为胱氨酸(0.663±0.040)%,8种人体必需氨基酸总量为(30.24±2.18)%,占氨基酸总量的42.38%,其构成比例符合FAO/WHO标准。兰州鲇肌肉中限制性氨基酸为缬氨酸、亮氨酸和异亮氨酸,必需氨基酸指数（EAAI）为69.3,4种呈味氨基酸总质量分数为24.62%（干样）。不饱和脂肪酸占脂肪酸总量的65.21%,并以油酸（C18:1）和亚油酸（C18:2）为主。磷含量显著高于其余12种矿物元素 (p＜0.05),锌在8种微量元素中含量（10.18 mg/kg,鲜样）最高,铁（8.31 mg/kg,鲜样）次之,硒含量（0.31 mg/kg,鲜样）丰富。从营养学角度,兰州鲇是一种营养价值较高的优质鱼类。     

双斑蟋营养成分分析及评价

由于具有较好的营养价值以及较高的食物转化效率,食用昆虫特别是蟋蟀受到普遍关注。在双斑蟋（Gryllus bimaculatus,GB）营养成分测定的基础上,对比家蟋（Acheta domesticus,AD）和黑蟋（Gryllus testaceus,GT）的营养及含量,分析评价了双斑蟋的使用价值。结果显示：双斑蟋水分含量71.0%、粗蛋白含量58.60%（干重）、粗脂肪含量28.90%（干重）、粗纤维含量7.23%（干重）、灰分4.93%（干重）;蛋白含量与黑蟋相当而高于家蟋,粗脂肪和灰分含量要高于家蟋和黑蟋;双斑蟋含有17种氨基酸,总氨基酸含量51.03%（干重）,必需氨基酸含量24.76%（干重）、占总氨基酸的48.3%,氨基酸含量低于其他两种蟋蟀;双斑蟋中常量元素含量最高的为钾（6 416 mg/kg,干重）、含量最低的是钙（92 mg/kg,干重）,微量元素中锌含量较高（241 mg/kg,干重）;双斑蟋油脂中不饱和脂肪酸的相对含量为65.33%,以亚油酸（37.05%）和油酸（25.86%）为主、饱和脂肪酸以棕榈酸（25.44%）和硬脂酸（8.74%）为主。双斑蟋的脂肪酸组成、含量与家蟋相近,而与黑蟋的脂肪酸组成差别较大,三种蟋蟀中含量最高的饱和脂肪酸为棕榈酸,而含量最高的不饱和酸为亚油酸。结果表明,双斑蟋的必需氨基酸组成符合FAO/WHO推荐的氨基酸构成比例的蛋白条件,具有较高的营养价值和食用价值。     

斑嘴野鸭肉质及肌肉营养成分分析

斑嘴野鸭是我国家鸭的祖先之一,已被世界自然保护联盟列为保护鸟种。为研究和分析其肉质及肌肉营养成分,通过对散养并适量补饲17周龄的斑嘴野鸭进行常规肉质、肌肉营养成分及氨基酸、脂肪酸含量进行测定。结果表明,斑嘴野鸭公鸭肌肉嫩度明显高于母鸭,且差异显著;公鸭和母鸭粗脂肪含量差异显著,其余三个指标之间差异不显著;其胸肌中氨基酸总量占总氨基酸的60.95%,必需氨基酸之和占44.75%,必需氨基酸总和与非必需氨基酸总和的比值为80.89%。肌肉含饱和脂肪酸3种,占总脂肪酸的36.99%;含6种不饱和脂肪酸,占总脂肪酸的60.58%,必需脂肪酸与总脂肪酸含量的比值为9.77%。综上所述,斑嘴野鸭肌肉中氨基酸的含量较多,种类齐全,人体必需氨基酸含量较高,富含高脂肪,具有较高营养价值和较好的风味与口感,为今后利用斑嘴野鸭开展驯化和培育提供了理论依据和物质基础,同时为家禽肌肉中脂肪酸成分分析及营养价值的评定提供了基础依据。     

樟芝液体发酵粉化学成分分析

对樟芝发酵粉的化学成分进行较全面的分析.包括水分、灰分、脂肪、蛋白、纤维、还原糖、氨基酸、矿物元素、多糖、三萜、总酚.结果表明,樟芝发酵粉粗蛋白含量为47.78%,氨基酸含量为36.71%.不饱和脂肪酸是优势脂肪酸,以亚油酸,油酸为主.还含有丰富的多糖、三萜类化合物、酚类物质和多种矿物元素.樟芝发酵粉的营养价值较高.     

刺猬肌肉营养成份分析

对刺猬肌肉营养成分测定及其氨基酸分析,评价其营养价值。结果表明,刺猬肌肉(鲜样)中粗蛋白含量丰富(20.92±0.14)%,肌肉中含18种氨基酸,占肌肉总量的80.13%(干样百分比),其中人体必需氨基酸8种,占氨基酸总量的46.88%,必需氨基酸指数(EAAI)为64.58,氨基酸构成比例符合FAO/WHO标准;鲜味氨基酸总量为30.82%;钙和铁的含量分别为33.8mg/100g和11.0mg/100g。说明其具有较高的营养和食用价值。     

花鱼骨 和唇鱼骨 的含肉率及肌肉营养成分分析

利用国内外通用的营养测试方法测定了花[鱼骨]（Hemibarbus maculates）和唇[鱼骨]（Hemibarbu labeo）的含肉率和肌肉营养成分。结果表明：花[鱼骨]和唇[鱼骨]含肉率分别是70.61%7、1.52%;花[鱼骨]肌肉（鲜样）中蛋白质（18.41%）和脂肪含量（2.46%）显著高于唇[鱼骨]的,而花[鱼骨]的灰分含量要显著低于唇[鱼骨];水分含量分别是78.35%、78.51%,两者无显著差异。花[鱼骨]和唇[鱼骨]肌肉中脂肪酸种类丰富,饱和脂肪酸（SFA）4种,不饱和脂肪酸（UFA）7种;其中单不饱和脂肪酸（MUFA）4种,多不饱和脂肪酸（PUFA）3种;其中DHA含量高达5.00%和14.32%。花和唇肌肉中的氨基酸总量分别是63.07%和67.63%,呈味氨基酸分别为25.96%和26.30%。缬氨酸、蛋氨酸和胱氨酸为限制性氨基酸。     

五种鳗鲡的含肉率及肌肉营养成分分析

研究利用营养测试方法对日本鳗鲡、欧洲鳗鲡、美洲鳗鲡、花鳗鲡和太平洋双色鳗鲡共5种养殖鳗鲡的含肉率及肌肉营养成分进行了分析比较。结果表明:5种鳗鲡含肉率61.77%—69.22%,日本鳗鲡和太平洋双色鳗鲡显著高于欧洲鳗鲡和花鳗鲡(P0.05);水分含量为62.34%—71.80%,粗蛋白含量为11.31%—18.47%,脂肪含量为8.62%—24.48%,灰分含量为0.92%—1.06%;均含有18种氨基酸,其中包括8种人体必须氨基酸,总氨基酸含量存在差异,鲜味氨基酸含量占37.43%—38.77%,必需氨基酸指数(EAAI)为65.25—74.77,其构成比例符合FAO/WHO的标准,色氨酸、异亮氨基酸和缬氨酸等氨基酸为限制性氨基酸;富含磷、钾、铁和锌等多种矿物元素,日本鳗鲡和花鳗鲡含量最高;均含有16种脂肪酸,其中饱和脂肪酸(SFA)7种,不饱和脂肪酸(UFA)9种;脂肪酸中多不饱和脂肪酸(PUFA)和二十二碳六烯酸(DHA)含量较高,分别占总量的41.92%—48.27%和6.63%—16.87%。研究结果表明:5种鳗鲡的肌肉为高蛋白、鲜味氨基酸与必需氨基酸含量高的优质蛋白源;富含磷、钾、铁、锌等矿物元素,可作为补充人体矿物质营养的膳食来源;脂肪酸以不饱和脂肪酸为主,多不饱和脂肪酸和DHA比值高。因此,5种鳗鲡具有较高的营养价值且有益人体健康,均是优良的水产养殖种类。     

秦巴山区野生多鳞白甲鱼的营养成分分析与评价

选取不同体质量的秦巴山区野生多鳞白甲鱼(Onychostoma macrolepis)20尾,对其肌肉中的常规营养成分、氨基酸和脂肪酸以及微量元素硒的含量进行检测和分析,以期对多鳞白甲鱼的营养价值进行评估。研究结果显示:秦巴山区野生多鳞白甲鱼的粗蛋白和粗脂肪含量分别为17. 37%和1. 76%。谷氨酸含量最高,天冬氨酸和赖氨酸次之,蛋氨酸含量最低,鲜味氨基酸和必需氨基酸分别占氨基酸总量的38. 46%和37. 10%,氨基酸评价指数(EAAI)为77. 00%。野生多鳞白甲鱼二十二碳六烯酸(DHA)和二十碳五烯酸(EPA)的总量为6. 32%,饱和脂肪酸(SFA)和不饱和脂肪酸的比值约为1∶1。肌肉中硒的含量为(0. 058±0. 017)mg/kg。研究结果表明,秦巴山区野生多鳞白甲鱼的营养价值较高,硒含量适中,可以在当地进行进一步产业化开发和推广。     

三种乌贼内骨骼生化成分研究

曼氏无针乌贼（Sepiella maindroni）和金乌贼（Sepia esculenta）的内骨骼称为海螵蛸,可用于制酸、止血等。通过对曼氏无针乌贼、金乌贼和虎斑乌贼（Sepia pharaonis）内骨骼生化成分的比较,有望实现传统中药海螵蛸原料质量的提升和替代。分别使用烘干干燥法、高温灼烧法、凯氏定氮法、索氏提取法、酸碱浸泡法、茚三酮柱后衍生离子交换色谱法、离子发光色谱法检测水分、灰分、粗蛋白、粗脂肪、粗甲壳素、氨基酸及矿物质。结果显示：三种内骨骼营养成分中,虎斑乌贼水分和粗蛋白含量最高,分别为（2.52±0.16）%和（3.43±0.10）%;金乌贼灰分和粗脂肪含量最高,分别为（94.7±0.26）%和（0.24±0.04）%;甲壳素含量最高的为曼氏无针乌贼内骨骼,为（9.48±0.36）%,约为其他两种的1.50倍。三种乌贼内骨骼共检出15种氨基酸,其中必需氨基酸（EAA）7种,半必需氨基酸（HEAA）1种,非必需氨基酸（NEAA）7种,三种乌贼骨的EAA/TAA为44.64%~47.09%,符合FAO/WHO中对于蛋白质EAA/TAA的理想评定标准。金乌贼内骨骼的钙含量最高（3.93×10⁵ mg/kg）、曼氏无针乌贼的钠含量最高（1.02×10⁴ mg/kg）、虎斑乌贼的钾含量最高（589.5 mg/kg）。可见三种乌贼内骨骼均是低脂肪、高甲壳素、高矿物质的中药。虎斑乌贼内骨骼蛋白和灰分营养成分含量较为丰富,是否可以作为传统海螵蛸的替代品,值得进一步探讨。     

池养南美蓝对虾与南美白对虾肌肉营养品质的比较

对南美蓝对虾和南美白对虾的肌肉营养成分与营养品质进行了分析比较。结果表明:南美蓝对虾的粗蛋白含量显著高于南美白对虾(P>0.05),南美白对虾的水分、粗脂肪和粗灰分含量均显著高于南美蓝对虾(P>0.05)。两种对虾的氨基酸组成基本一致,均含有18种氨基酸,四种鲜味氨基酸总量分别为31.30%、30.73%(干样百分比),必需氨基酸指数(EAAI)分别为69.88、62.42,其构成比例符合FAO/WHO的标准。脂肪酸中EPA与DHA含量均较高,分别为20.91%、18.60%,矿物元素含量丰富。上述分析表明,南美蓝对虾和南美白对虾肌肉均为优质的动物蛋白食品,从营养学的角度,南美蓝对虾的蛋白质营养价值要高于南美白对虾,南美白对虾的脂肪酸营养价值高于南美蓝对虾。     

Nutritional composition of frog (Rana esculanta) waste meal

In the present study, the waste obtained from the frozen frog leg industry was used for the production of frog waste meal, and its proximate, amino acids, fatty acids, mineral and vitamin compositions were evaluated to determine the nutritional quality. In addition, the total bacterial count, Salmonella, total volatile basic nitrogen (TVB-N, mgN/100g) and thiobarbituric acid (TBA, mg malonaldehyde/kg) were also measured to determine the microbiological and chemical quality of frog waste meal (FWM). The crude protein, fat and ash content of FWM on a dry weight basis were 68.6%, 17.0% and 13.2%, respectively. The amino acid profiles were found to be fairly close to those of fish meal in terms of protein sources and rich in the glutamic acid, glycine, proline, arginine, and methionine. The proportions of fatty acid composition in FWM were analysed and findings were 26.7% for total saturated fatty acid (SFA), 42.5% for total monounsaturated fatty acid (MUFA), 17.0% for total n - 6 and 3.3% for n - 3 ratio. The major SFA, MUFA and PUFA in FWM were palmitic acid (19.1%), oleic acid (26.0%) and linoleic acid (16.7%), respectively. FWM was found to be high in mineral content, especially Zn, K, Cu, Mn, and Mg and high level of some vitamins such as folic acids and thiamin. The total bacterial count was found to be 2.9x10(4) CFU/g, and Salmonella was not observed. TVB-N and TBA in FWM was determined to be 157.4+/-5.8 mg N/100g and 1.2+/-0.1 mg malonaldehyde/kg, respectively.     

Studies on the Utilization of Hydrocarbons by Microorganisms

It is well known that a good many microorganisms can utilize hydrocarbons as a sole carbon source. We have as yt little information, however, as to what kinds of intermediate or end products are produced by the microbial dissimilation of hydrocarbons. Above all, the formation of amino acids from hydrocarbons has not been reported. We have isolated many strains of microorganisms from soil samples by selective culture techniques in a medium containing kerosene and mineral salts, in order to examine if the products of economical value such as amino acids, organic acids, fatty acids, steroids, nucleic acids and their related compounds, can be produced by those microorganisms. Shaking cultures of those microorganisms were carried out in the medium containing 3.5% kerosene, 3.5% liquid paraffin and mineral salts (K₂HPO₄ 0.25%; MgSO₄·7H₂O 0.1%; NH₄MO₈ 0.5% or urea 0.3%); we found that 55 strains out of 127 strains tested produced amino acids in their broths, after 4 days cultivation at 26.5°C. The kinds and maximum yields of amino acids were as follows: alanine 50mg/l, aspartic acid 23mg/l, glutamic acid 485 mg/1, glycine 8.5mg/l, isoleucine 15 mg/1, lysine 23.9 mg/1, and valine 38 mg/1.     

Circulating nutrient concentrations in free-ranging Humboldt penguins (Spheniscus humboldti) in Punta San Juan,Peru

Free-ranging Humboldt penguin (HP, Spheniscus humboldti) populations are under pressure from resource competition with industrial fisheries, habitat loss, and El Niño Southern Oscillation events. Foraging patterns for this top marine predator change during periods of aberrant oceanographic conditions and scarce fish stock numbers. These radical dietary fluctuations can lead to poor fertility, early embryonic death, poor hatchability, suppressed immune function, high chick mortality, and illness. To understand the variability of nutrient status in reproductive seasons, we measured select circulating nutrient concentrations (fat-soluble vitamins A, D, E, and carotenoids, fatty acids, amino acids, minerals, and electrolytes) of 105 HP at Punta San Juan, Peru during the first reproductive seasons of 2007 and 2008. We determined significant differences in nutrient status between sexes, years of sampling, and reproductive stages. Males (4.5 ± 0.38 kg) weighed more than females (4.0 ± 0.29 kg) and exhibited higher concentrations of vitamin A (0.71 ± 0.11 vs. 0.61 ± 0.12 µg/ml) and docosahexaenoic acid (6.70 ± 1.61 vs. 5.65 ± 1.59%). Males also displayed lower concentrations of β-carotene (0.01 ± 0.01 vs. 0.012 ± 0.001 µg/ml) and phosphorus (3.43 ± 0.83 vs. 4.40 ± 1.66 mg/dl). Comparison between the 2 years showed most circulating amino acid concentrations were higher in 2007. Significant differences in circulating amino acids and vitamins were also noted between different reproductive stages. These results demonstrate concentrations of nutrients can vary due to the physiological state of the animal, as well as the overall dynamics of their marine ecosystem habitat.     

Evaluation of nutritional status of an edible grasshopper,Oxya Chinensis Formosana

This study was conducted to examine the nutritional status of the grasshopper (Oxya chinensis formosana, OCF) as human food, exploring it as an alternative edible resource. Analysis of free amino acid shows that there are various essential amino acids in addition to saturated and unsaturated fatty acids in OCF dried powder. Analysis of the mineral contents and vitamins of dried OCF indicates that it is rich in calcium, vitamin B₆, and niacin. The heavy metal content of OCF recorded was low, making it safe for human consumption: OCF had plumbum at 0.01–0.03 mg/100 g, cadmium at 0.002–0.005 mg/100 g, arsenic at 0.07–0.17 mg/100 g, and mercury at 0.0003–0.0007 mg/100 g. In conclusion, given its high nutritive quality in terms of proteins and fats, coupled with lower heavy metal content, it would be recommended to use the grasshopper (OCF) as substitute to the traditional sources of protein.     

金银花尺蠖幼虫、蛹和成虫的营养成分分析

【目的】了解金银花尺蠖Heterolocha jinyinhuaphaga Chu幼虫、蛹和成虫的主要营养成分,评价其营养价值,为金银花尺蠖的食用开发提供理论依据。【方法】采用国家标准检测方法,测定金银花尺蠖幼虫、蛹和成虫的水分、蛋白质、脂肪、总糖、氨基酸、脂肪酸、微量元素和维生素的含量,分析金银花尺蠖幼虫、蛹和成虫的氨基酸分、必需氨基酸指数、必需氨基酸与非必需氨基酸的比值、不饱和脂肪酸与饱和脂肪酸的比值,并与常见食物进行比较分析。【结果】结果表明,金银花尺蠖幼虫、蛹和成虫的水分含量分别为72.93%、64.92%和56.16%;蛋白质含量分别为50.64%、60.12%和48.38%;脂肪含量分别为21.98%、23.84%和20.60%;总糖含量分别为3.32%、5.35%和2.79%;总氨基酸含量分别为394.31、413.54和356.09 mg/g;必需氨基酸总含量分别为158.80、166.83、132.67 mg/g;必需氨基酸占总氨基酸的比例分别为40.27%、40.34%和37.26%;必需氨基酸与非必需氨基酸的比值分别为67.43%、67.62%和59.38%;必需氨基酸指数分别为1.02、1.07和0.87;不饱和脂肪酸的含量分别为68.45%、69.09%和66.29%,其P/S值分别为2.17、2.24和1.95;必需脂肪酸含量分别为34.35%、34.77%和32.71%;微量元素Zen的含量分别为11.29、98.42、66.98 mg/100 g,Fe的含量分别为32.31、19.84、13.04 mg/100 g,幼虫中Cu的含量为18.54 mg/100 g,蛹和成虫中均不含Cu;维生素以B6的含量最高,分别为7.93、25.82、26.21 mg/100 g。【结论】金银花尺蠖具有较高的营养价值和食用价值,具有极大的开发潜力。     

Effects of Obesity on Substrate Utilization during Exercise

Objective: The capacity for lipid and carbohydrate (CHO) oxidation during exercise is important for energy partitioning and storage. This study examined the effects of obesity on lipid and CHO oxidation during exercise. Research Methods and Procedures: Seven obese and seven lean [body mass index (BMI), 33 ± 0.8 and 23.7 ± 1.2 kg/m², respectively] sedentary, middle‐aged men matched for aerobic capacity performed 60 minutes of cycle exercise at similar relative (50% Vo _2max) and absolute exercise intensities. Results: Obese men derived a greater proportion of their energy from fatty‐acid oxidation than lean men (43 ± 5% 31 ± 2%; p = 0.02). Plasma fatty‐acid oxidation determined from recovery of infused [0.15 μmol/kg fat‐free mass (FFM) per minute] [1‐¹³C]‐palmitate in breath CO₂ was similar for obese and lean men (8.4 ± 1.1 and 29 ± 15 μmol/kg FFM per minute). Nonplasma fatty‐acid oxidation, presumably, from intramuscular sources, was 50% higher in obese men than in lean men (10.0 ± 0.6 versus 6.6 ± 0.8 μmol/kg FFM per minute; p < 0.05). Systemic glucose disposal was similar in lean and obese groups (33 ± 8 and 29 ± 15 μmol/kg FFM per minute). However, the estimated rate of glycogen‐oxidation was 50% lower in obese than in lean men (61 ± 12 versus 90 ± 6 μmol/kg FFM per minute; p < 0.05). Discussion: During moderate exercise, obese sedentary men have increased rates of fatty‐acid oxidation from nonplasma sources and reduced rates of CHO oxidation, particularly muscle glycogen, compared with lean sedentary men.     

“太湖鲂鲌”及其亲本肌肉营养成分的分析与评价

为评价新型杂交鱼“太湖鲂鲌”(翘嘴鲌Culter alburnus♀×三角鲂Megalobrama terminalis♂)的肌肉营养价值, 采用生化测定法比较分析了“太湖鲂鲌”、翘嘴鲌和三角鲂的肌肉营养成分, 结果表明: (1)“太湖鲂鲌”肌肉水分含量显著低于翘嘴鲌和三角鲂(P<0.05), 而肌肉粗蛋白质含量较高(P<0.05)。(2)“太湖鲂鲌”的必需氨基酸(EAA)含量显著高于三角鲂(P<0.05); 3种鱼的第一限制性氨基酸均为含硫氨基酸(蛋氨酸+胱氨酸)。(3)“太湖鲂鲌”肌肉脂肪酸中的不饱和脂肪酸(UFA)含量显著高于翘嘴鲌和三角鲂(P<0.05)。(4)3种鱼肌肉矿物质元素铁、铜、锰、锌含量均无显著差异(P>0.05)。综上所述, “太湖鲂鲌”肌肉营养继承并综合了双亲的优良性状, 是一种富含蛋白质、EAA和UFA的优良养殖品种, 具有推广价值。     

A role for membrane transport in modulation of intramuscular free glutamine turnover in streptozotocin diabetic rats

We wished to examine the effects of diabetes on muscle glutamine kinetics. Accordingly, female Wistar rats (200 g) were made diabetic by a single injection of streptozotocin (85 mg/kg) and studied 4 days later; control rats received saline. In diabetic rats, glutamine concentration of gastrocnemius muscle was 33% less than in control rats: 2.60 ± 0.06 μmol/g vs. 3.84 ± 0.13 μmol/g (P < 0.001). In gastrocnemius muscle, glutamine synthetase activity (V_max) was unaltered by diabetes (approx. 235 nmol/min per g) but glutaminase V_max increased from 146 ± 29 to 401 ± 94 nmol/min per g; substrate K_m values of neither enzyme were affected by diabetes. Net glutamine efflux (AZ concentration difference × blood flow) from hindlimbs of diabetic rats in vivo was greater than control values (?30.0 ± 3.2 vs. ?1.9 ± 2.6 nmol/min per g (P < 0.001) and hindlimb NH₃ uptake was concomitantly greater (about 27 nmol/min per g). The glutamine transport capacity (V_max) of the Na-dependent System N^m in perfused hindlimb muscle was 29% lower in diabetic rats than in controls (820 ± 50 vs. 1160 ± 80 nmol/min per g (P < 0.01)), but transporter K_m was the same in both groups (9.2 ± 0.5 nM). The difference between inward and net glutamine fluxes indicated that glutamine efflux in perfused hindlimbs was stimulated in diabetes at physiological perfusate glutamine (0.5 mM); ammonia (1 mM in perfusate) had little effect on net glutamine flux in control and diabetic muscles. In Intramuscular Na⁺ was 26% greater in diabetic (13.2 μmol/g) than control muscle, but muscle K⁺ (100 μmol/g) was similar. The accelerated rate of glutamine release from skeletal muscle and the lower muscle free glutamine concentration observed in diabetes may result from a combination of; (i), a diminished Na⁺ electrochemical gradient (i.e., the net driving force for glutamine accrual in muscle falls); (ii), a faster turnover of glutamine in muscle and (iii), an increased V_max/K_m for sarcolemmal glutamine efflux.     

刺参的营养成分分析

对刺参的营养成分进行了分析,结果表明,刺参中含有多种营养成分,19种氨基酸和多种维生素以及丰富的矿物元素,旨在为刺参的开发利用提供科学依据。     

Omega-3 fatty acids concentrate production by enzyme-catalyzed ethanolysis of supercritical CO<Subscript>2</Subscript> extracted oyster oil

The separation of oil by a suitable technique from the Pacific oyster muscle is important for the utilization of the oil as a ω-3 polyunsaturated fatty acids (ω-3 PUFAs) source and production of bio-functional peptides/ oligosaccharides from oil-free residue. This study was conducted to prepare ω-3 PUFAs concentrate from supercritical carbon dioxide (SC-CO₂) extracted Pacific oyster oil by enzyme-catalyzed ethanolysis reactions. SC-CO₂ extractions were done at different temperatures and pressures to optimize suitable extraction conditions and extracted oils were compared with Soxhlet (n-hexane) extracted oil to evaluate the yield and quality. Oil extracted by SC-CO₂ at optimized conditions was used for ethanolysis reaction catalyzed by immobilized sn-1,3 specific lipases, namely Novozymes-435, Lipozyme TLIM, and Lipozyme RMIM to produce 2-monoacylglycerols (2-MAG) rich in ω-3 PUFAs. The optimum temperature and pressure for SC-CO₂ extractions of oyster oil was 50°C and 30 MPa. In this condition, the yield of oil was 5.96% and the acid, peroxide, free fatty acid, and p-anisidine values were 4.49 mg KOH/g, 4.72 meq/kg, 3.42%, and 10.03, respectively. The ω-3 PUFAs content significantly increased in 2-MAG obtained from Novozymes 435, Lipozyme TLIM, and Lipozyme RMIM to 43.03 ± 0.36, 45.95 ± 0.29, and 40.50 ± 0.77%, respectively (p < 0.05). A thin layer chromatography (TLC) analysis confirmed the production and separation of 2-MAG in the ethanolysis process. The ratio of total ω-3 to ω-6 fatty acids was almost twice in 2-MAG of SC-CO₂ extracted oyster oil. SC-CO₂ extracted Pacific oyster oil can be used for sn-1,3 specific lipases catalyzed ethanolysis to produce ω-3 PUFAs rich in 2-MAG.