Chemical constituents of some mushrooms

The free amino acids, fatty acids and sterol contents of five Basidiomycetes were determined. The most abundant free amino acids were alanine, proline, serine and valine. The mushrooms examined also contained high levels of linoleic and palmitic acid. The most abundant sterol was ergosterol accompanied by its closely related sterols.     

Fatty acid and free amino acid content of some mushrooms

Free amino acids and fatty acids of seven Basidiomycetes belonging to the families Hygrophoraceae and Russulaceae were determined. Pro, Glu, Ser and Val are the main free amino acids. Linoleic, oleic and palmitic acids are essentially the only fatty acids.     

Chemical Profiles of Hydrolyzed Milk Samples after Treatment with Commercial Enzymes

ABSTRACT: Commercial enzymes (protease and lipase) were used to produce highly flavored cheese-like hydrolysates from fluid milk. Free fatty acids, free amino acids, degree of proteolysis, and volatile profiles were assessed to suggest the importance of proteolytic and lipolytic activity on cheese flavor development. Free fatty acid liberation was maximized with the combined Flavourzyme™ (protease) and Palatase ® (lipase) treatment incubated at 30°C, most likely due to synergism conferred by the protease. The Flavourzyme/Palatase samples incubated at 45°C generated the highest total concentration of volatile compounds. The addition of Flavourzyme generated free amino acids and low molecular weight peptides (< 1400 MW).     

Chemical composition of tobacco seeds (Nicotiana tabacum L) from Argentina

The lipid constituents, free fatty acids, triglycerides, sterol esters and free sterols of 11 cultivars of tobacco from Argentina were investigated by gas-liquid chromatography. Palmitic, oleic and linoleic acids were the major components in all fractions studied. Sitosterol was the main component of the free sterol and sterol ester fractions. Oil and protein contents, as well as some physicochemical characteristics of the oils, are also reported.     

卤猪肉加工过程中游离脂肪酸、游离氨基酸及核苷酸变化分析

利用气相色谱质谱联用和高效液相色谱法检测分析了卤猪肉加工过程中游离脂肪酸、游离氨基酸及核苷酸的变化。结果表明,在加工过程中,总游离脂肪酸有效峰面积呈下降趋势,饱和脂肪酸也呈现下降的变化趋势,不饱和脂肪酸含量先增加后减少,在高温煮制1 h时达到最大值。总游离氨基酸的含量在卤猪肉加工过程中变化明显,在原料肉中总游离氨基酸含量为244.39 mg/100 g,其它样品中含量都显著(p0.05)高于原料肉,在二次煮制完成后达到最大值,为349.32 mg/100 g。谷氨酸在成品中的含量达到119.02mg/100 g,占总游离氨基酸的34.12%。呈味核苷酸检测结果显示,在加工过程中5'-IMP和5'-GMP的含量呈现下降趋势。由于加热导致核苷酸热降解,其降解产物肌苷的含量呈现上升趋势,在成品中检测到其含量显著(p0.05)高于原料肉中的含量。本研究结果为改进卤猪肉的生产工艺、提高产品品质提供了理论参考。     

新疆特色酸凝奶酪成熟过程中产生的非挥发性风味物质研究

非挥发性风味物质对奶酪的口味有重要影响,文中对酸凝奶酪成熟过程中非挥发性风味物质含量的变化进行了研究,结果表明:随着奶酪成熟时间的延长有机酸总量和各种有机酸含量变化差异极显著(P<0.01),主要有机酸乳酸含量最高达到10.75 mg/g;各种游离氨基酸含量处于动态变化过程,总游离氨基酸含量变化显著(P<0.05),缬氨酸和亮氨酸是优势氨基酸,最大含量为35.19 mg/100 g和27.06 mg/100 g;游离脂肪酸总量变化差异极显著(P<0.01)。随着成熟时间的延长,奶酪的营养价值更高,口味更浓郁。     

Chemical composition and nutritional quality of sea cucumbers

BACKGROUND: The dried form of sea cucumbers has been a seafood and medicinal cure for Asians over many centuries. In this study the chemical composition and nutritional quality of eight common sea cucumbers (Stichopus herrmanni, Thelenota ananas, Thelenota anax, Holothuria fuscogilva, Holothuria fuscopunctata, Actinopyga mauritiana, Actinopyga caerulea and Bohadschia argus) were determined. RESULTS: All species except T. anax and A. caerulea had higher protein and lower fat levels. A. mauritiana and B. argus had less ash content. Glycine was the dominant amino acid found in all species, and content ranged from 126 to 216 mg g^?1 of crude protein. All species exhibited low lysine:arginine ratio and higher essential amino acid scores were obtained by threonine and phenylalanine + tyrosine. A. mauritiana had proportionally less saturated fatty acids (31.23%), and more monounsaturated fatty acids (45.64%) and polyunsaturated fatty acids (PUFA, 23.13%) than other species. Arachidonic acid (C20:4n‐6) was the major PUFA in all species. T. ananas, A. mauritiana and A. caerulea contained more n‐3 PUFA. The n‐3/n‐6 ratios of eight sea cucumbers species ranged from 0.25 to 0.61. CONCLUSION: Sea cucumbers are a seafood with high protein and low fat levels. The amino acid contents were similar but fatty acid profiles were different among species. The comparison showed that T. ananas, A. mauritiana and B. argus possessed higher nutritional values than other sea cucumber species. Copyright © 2010 Society of Chemical Industry     

Seed compositional studies of some species of Papilionoideae (Leguminosae) native to Argentina

Seeds of 17 wild leguminous species belonging to the Papilionoideae subfamily were analysed for their proximate, fatty acid and sterol compositions. Centrosema virginianum, Tipuana tipu, Adesmia volckmanni and some species of Desmodium contained high amounts (>300 g kg^?1) of protein. Geoffroea decorticans and Clitoria cordobensis were noteworthy for their high oil content (>350 g kg^?1). The seed lipids had a high proportion of unsaturated (oleic and linoleic mainly) fatty acids. Linolenic acid had the highest value in Adesmia volckmanni (25.4% of total fatty acids). β‐Sitosterol was the major component of the sterol fraction. Chemical analyses indicated that all species studied are suitable sources of animal feed. © 2002 Society of Chemical Industry     

羊胎水解液类脂物化学组成的研究

羊胎水解液乙醚萃取物经ＫＯＨ－乙醇皂化,乙醚萃取,过醚萃取,过硅胶色谱柱,淋洗物经Ｎ,Ｎ－二（三甲基硅）三氟乙酰胺（ＢＳＴＦＡ）衍生化后进行ＧＣ－ＭＳ分析。结果表明,羊胎水解液乙醚萃取物中主要含有三类物质：饱和脂肪酸,不饱和脂肪酸,甾醇及微量雌性激素。     

桑椹多酚对广式腊肠风味的影响

植物多酚因能有效抑制肉制品的过氧化近年来备受关注,然而由此造成肉制品风味的变化还鲜有报道。鉴于此,将不同剂量的桑椹多酚提取物（0.5 g/kg和1.0 g/kg）加入到肉糜中,制成广式腊肠,分析多酚添加前后广式腊肠的挥发性风味、游离脂肪酸、游离氨基酸的组成和含量变化,以及桑椹多酚对广式腊肠感官评价的影响。研究发现,添加桑椹多酚后,腊肠中挥发性风味物质由空白组的49种减少到32种,腊肠游离脂肪酸的含量明显下降。值得注意的是,由于蛋白质水解增强,添加桑椹多酚后,腊肠中呈味氨基酸（Glu和Arg）的释放得到促进。储藏末期（10 d）,添加1.0 g/kg桑椹多酚的腊肠游离氨基酸的含量达到5904.91 mg/100 g,较对照组提高了10.82%。总体而言,桑椹多酚的添加会抑制腊肠中某些挥发性风味物质的形成,抑制腊肠中的肉腥味,促进呈味氨基酸的释放,但对腊肠游离脂肪酸组成的影响并不显著。     

即食油炸泥鳅的主要化学组成以及质地分析

以黑龙江省人工养殖泥鳅为原料,经一系列加工后得到即食休闲油炸泥鳅。分析结果表明,成品泥鳅中含蛋白质34.94%、脂肪20.06%、水分37.60%和食盐4.45%,并且,必需氨基酸占氨基酸总量的39.19%,不饱和脂肪酸占总脂肪酸的71.05%。加工处理导致泥鳅的硬度、弹性和咀嚼性指标提高,泥鳅腌制过程中所加入的抗氧化剂茶多酚和没食子酸丙酯,可以抑制脂肪的自动氧化反应,使得20℃贮藏90d后成品泥鳅的脂肪过氧化值、硫代巴比妥酸值分别降低30%~50%。      

欧姆加热与水浴加热对羊肉糜滋味物质及游离脂肪酸的影响

分别以不同电压欧姆加热(5 V/cm、8 V/cm、11 V/cm)以及水浴加热的方法将羊肉肉糜加热至中心温度95℃,用高效液相色谱法(HPLC)测定其中重要滋味物质(游离氨基酸、5’-核苷酸及其降解产物和丁二酸)含量,同时测定水分、粗脂肪、粗蛋白与盐含量等基本指标,并用气相色谱法(GC)测定其在20 d贮藏期内游离脂肪酸的变化情况。结果发现:欧姆加热低中电压(5 V/cm、8 V/cm)组所得样品具有比水浴加热组样品更浓的鲜味,而高电压组(11 V/cm)滋味较淡。欧姆加热对游离脂肪酸产生具有促进作用,且电压越高,促进作用越强。但高电压组贮藏过程中多不饱和脂肪酸氧化作用较强,可能更易产生不愉快气味。综合来看,欧姆加热低中电压组羊肉糜具有较好的滋味与香味,且略优于传统水浴加热。     

Chemical composition of two muscles of the common duiker (Sylvicapra grimmia)

Ten mature male common duikers (Sylvicapra grimmia) were cropped and their M longissimus dorsi (LD) and M biceps femoris (BF) dissected in order to determine the chemical composition of the meat of this species. There was no significant difference in proximate chemical composition between the LD and the BF. The duiker muscle had a moisture content of 713.1 g kg^?1, a high protein content (257.7 g kg^?1) and a low fat content (20.6 g kg^?1). Potassium and phosphorus were the minerals and lysine and leucine the amino acids present in highest concentrations in the meat. The LD contained higher levels of sodium and zinc than the BF but lower levels of alanine, leucine and lysine. Stearic acid, palmitoleic acid, oleic acid and linoleic acid constituted the greatest proportion of fatty acids in the meat. The common duiker's meat also had a high polyunsaturated fatty acid content (414.2 g kg^?1 total fatty acids), allowing it to be considered a healthy food commodity. Copyright © 2004 Society of Chemical Industry     

乳肉兼用型西门塔尔牛乳化学组成及营养评价

对西门塔尔牛乳的常规乳成分、氨基酸、脂肪酸组成以及主要矿物质质量分数进行测定,并对其进行营养评价与分析。结果表明,西门塔尔牛的脂肪质量分数,蛋白质质量分数均显著高于荷斯坦牛乳,多不饱和脂肪酸质量分数也高于荷斯坦牛乳,乳糖质量分数略低于后者。西门塔尔牛乳蛋白质中的必需氨基酸构成和联合国粮农组织/世界卫生组织(FAO/WHO)的推荐值十分相近。本研究为乳肉兼用型中国西门塔尔牛的推广提供了一定理论依据和参考价值。     

Chemical Characterization of Liver Lipid and Protein from Cold-Water Fish Species

ABSTRACT:  The largest US harvests of marine fish for human consumption are from Alaska waters. Livers from these fish are combined with other fish offal and made into fish meal and oil or discarded. The purpose of this study was to characterize liver lipids and proteins from important commercial species including walleye pollock (WP), pink salmon (PS), Pacific halibut (PH), flat head sole (FS), and spiny head rock fish (RF), and underutilized species including arrow tooth flounder (AF) and big mouth sculpin (BS). Liver lipid content ranged from 50.3% in WP to 3.3% in PS. Protein content ranged from 7.7% in WP to 18.4% in BS. PS livers had the highest content of ω-3 fatty acids at 336 mg/g of oil and AF had the lowest content at 110 mg/g of oil. There were significant differences in the content of 9 amino acids with methionine and lysine values ranging from 2.66% to 3.43% and 7.19% to 9.45% of the total amino acids, respectively. Protein from the cold water marine fish livers was of high quality and the oils contained substantial quantities of ω-3 fatty acids. Fish livers had distinct chemical properties and can be used for the development of unique food ingredients.     

云南产6种蜂蜜中35种游离氨基酸的测定

目的采用全自动氨基酸分析仪测定蜂蜜中35种游离氨基酸的含量。方法蜂蜜样品经水溶解,采用全自动氨基酸分析仪进行定量检测。检测器为荧光检测器,脯氨酸在波长440 nm处测定,其余34种氨基酸在570 nm波长下测定。结果蜂蜜中含有丰富的游离氨基酸成分,且氨基酸组成及含量存在较大区别。脯氨酸是蜂蜜中的主要氨基酸,其平均含量为0.042978 g/100g,占氨基酸组分总含量的71.21%。35种游离氨基酸的线性相关系数均达到0.99以上,回收率在92.4%~109.4%范围内。结论该方法快速、准确,可用于蜂蜜中游离氨基酸含量的测定。     

The Use of Fatty Acid and Sterol Analyses as Quality Control Methods in the Brewing Industry

Fatty acid and sterol analyses were evaluated as alternative quality control methods to conventional differentiation and characterisation systems in the brewing industry. The presence of lino‐leic acid (18:2) in brewing yeast could be used to distinguish these from closely related yeast species. Furthermore, the absence of lanosterol and stigmasterol enabled differentiation of the brewing yeast from the rest of the closely related species tested. However, both fatty acid and sterol methods were not sensitive enough to detect mutants (variants) of brewing yeast. Conventional brewing identification tests proved sensitive enough to detect variants at low concentrations.