美拉德反应制备蛋糕香精及成分分析

研究了蛋黄酶解液的氨基酸组成,其含有可通过美拉德反应产生蛋糕香气的脯氨酸、蛋氨酸、赖氨酸等氨基酸。优化以蛋黄酶解液为前体原料,添加氨基酸、还原糖等通过美拉德反应制备蛋糕香精的条件,并分析产物的组成成分。结果表明,在反应温度110℃、反应时间60min、反应体系pH为6,物料配比为蛋黄液酶解物8.00%、葡萄糖0.40%、木糖0.20%、蛋氨酸0.02%、赖氨酸0.14%、脯氨酸0.04%、精氨酸0.04%、组氨酸0.02%、天冬氨酸0.02%、缬氨酸0.02%、水分14.50%、丙二醇76.60%,所得产物含有29种呈味物质,具有浓郁的蛋糕香味。      

美拉德反应改良四角蛤蜊酶解液的风味

以四角蛤蜊酶解液为原料,通过美拉德反应对其进行风味改良。通过研究还原糖的种类、复合比例与添加量、反应温度、反应时间和反应体系初始pH值对感官评分、反应程度及色差的影响,确定酶解液美拉德反应风味改良工艺,并分析反应前后酶解液中氨基酸和挥发性风味成分的变化。结果表明,还原糖的种类、复合比例与添加量、反应温度、反应时间和反应体系初始pH值均对四角蛤蜊酶解液风味具有显著影响（P＜0.05）。较优的反应条件为：选用木糖与葡萄糖复合添加,质量比1∶2,还原糖添加量（质量分数）4.0%,反应体系初始pH?6.5,100?℃反应90?min。美拉德反应后,酶解液中18?种氨基酸均有不同程度的损失,其中丙氨酸、甘氨酸、牛磺酸和谷氨酸的损失率较大,其次是组氨酸、精氨酸、蛋氨酸、苯丙氨酸、亮氨酸、赖氨酸,说明这些氨基酸可能是参与美拉德反应并对反应产物风味起主要作用的氨基酸。反应前后挥发性化合物的种类和相对含量有所差异,其中醛类、酮类、酯类物质相对含量增加,烯烃类物质相对含量降低。     

河蚌酶解液美拉德反应前后风味成分的分析

重点研究了河蚌酶解液美拉德反应前后风味成分的变化。利用GC-MS联用法分析、鉴定河蚌肉酶解液和酶解液美拉德反应产物的挥发性风味成分,探讨美拉德反应对河蚌酶解液风味的影响。经NIST2005和Willey7数据库检索和文献对照,两个样品都检出50种成分,主要有醇类、醛类、酮类、酯类和含硫化合物等,他们的协同作用构成了河蚌酶解液及其美拉德反应产物的特征香气;其中河蚌酶解液中含有较多的醛类化合物,而美拉德反应之后则含有较多的醛类和酮类化合物,两样品中均检测出较少的烃类物质,归一化含量分别为2.21%和0.58%。结果表明,美拉德反应能够明显的改善河蚌肉酶解液的风味,所制备的美拉德反应产物具有较好的应用前景。     

鱿鱼内脏水解液美拉德反应条件优化及反应前后氨基酸组成的变化

对影响鱿鱼内脏酶解液与葡萄糖美拉德反应的因素进行了优化,以综合感官评分为评价指标,通过单因素和正交实验确定了优化的美拉德反应工艺参数;采用氨基酸自动分析仪对美拉德反应前后氨基酸组分含量进行分析。实验表明,鱿鱼内脏酶解液与还原糖美拉德反应的最适条件是:pH为7.5、时间为45min、温度为95℃、葡萄糖添加量为1.5%。美拉德反应前后氨基酸分析结果显示,含量变化明显的主要是组氨酸(减少86.71%)、脯氨酸(减少39.11%)、精氨酸(减少16.18%)、苯丙氨酸(减少15.96%),说明这4种氨基酸可能是参与该美拉德反应的主要氨基酸。      

温度对鸡骨酶解液-木糖美拉德反应产物中非挥发性物质的影响

以鸡骨酶解液和木糖进行美拉德反应,研究不同温度下鸡骨酶解液-木糖美拉德反应产物中游离氨基酸和肽段等非挥发性物质的变化规律。结果表明,随着温度的增加,鸡骨酶解液-木糖美拉德反应产物中多数游离氨基酸含量显著降低,其损失率总体上与温度呈现正相关,其中丙氨酸、色氨酸、苏氨酸和亮氨酸等损失率高达50%以上;温度越高,鸡骨酶解液中各肽段更易发生美拉德反应,其中1 000~2 000 Da和500~1 000 Da组分具有较高的美拉德反应活性。     

美拉德反应用于牡蛎酶解液脱腥的研究

研究了美拉德反应脱除牡蛎酶解液腥味的最佳工艺参数,并分析了美拉德反应产物的游离氨基酸组成。结果表明,美拉德反应的最佳条件为:温度100℃,时间30min,pH7.5,原料配比1:1。最佳工艺条件下的美拉德反应产物中必需氨基酸含量和风味氨基酸含量分别占49.88%和32.62%。经过美拉德反应后,酶解液达到了很好的脱腥效果。      

低值鱼蛋白酶解产物对酱香型美拉德反应产物风味的影响

本文研究了低值鱼蛋白的不同酶解产物对酱香型美拉德反应产物风味的影响.结果表明:低值鱼蛋白水解液与适当的葡萄糖、木糖和生姜汁等通过美拉德反应不仅可以制备理想的酱香型产物,而且还可完全去除水解液中的鱼腥味;酶解24h的酶解产物获得的美拉德反应产物酱香较浓、风味纯正;美拉德反应后游离氨基酸的损失为9.93%,其中含硫氨基酸半胱氨酸的损失率达75.03%,碱性氨基酸损失率较大,如组氨酸为12.19%,赖氨酸为11.85%,而呈鲜味的天冬氨酸和谷氨酸损失相对比较小;气-质联用色谱仪分析鉴定结果表明,产物中含20种与酱香风味相关的化合物,其中主要由脂肪酸类(特别是乙酸)和少量含氮杂环物质构成的.     

美拉德反应对南极磷虾酶解液中非挥发性物质的影响

以南极磷虾酶解液和木糖进行美拉德反应,研究美拉德反应后,酶解液和美拉德产物中游离氨基酸、肽分子量分布、无机离子含量等非挥发性物质的变化规律。结果表明,美拉德反应后,酶解液中多数游离氨基酸含量显著降低,其中亮氨酸、精氨酸、组氨酸、异亮氨酸、半胱氨酸损失率分别为34.18%、16.75%、16.67%、16.10%、12.37%;酶解液肽段中451 Da～1 450 Da组分具有较高的美拉德反应活性;无机离子含量以Na+含量最高;脂肪酸组成呈现减少趋势,减少组分以多不饱和脂肪酸为主。     

复合酶处理废弃烟末制备烟用美拉德香精

利用α-淀粉酶和β-淀粉酶的复合酶酶解烟草废弃物、浓缩酶解液与特定的氨基酸进行美拉德反应来制备烟用香精。通过单因素实验确定最适酶解条件:质量分数0.2%α-淀粉酶和质量分数3%β-淀粉酶,酶解时间7 h,pH 5.4,温度50℃;在酶解制备的美拉德反应基液中加入氨基酸后,通过正交实验优化美拉德反应条件:反应系含水率15%,反应时间5 h,pH 8,反应温度115℃。经验证实验可知,酶解液中还原糖的质量浓度提高了28.07%,通过GC-MS分析表明,从美拉德反应产物中共检测100种物质,其中与烟草香味有关的化合物有57种,相对质量分数为71.277%。     

美拉德反应制备鸡肉风味基料工艺优化及呈味特性分析

为提高鸡骨架利用率以及制备鸡肉风味基料,以鸡骨架酶解液为原料,通过单因素试验结合Friedman排序检验法和响应曲面优化结合模糊数学感官评价法,探究鸡骨架酶解液美拉德反应的最佳条件,用电子鼻和电子舌测定反应前后的气味和滋味,用高效液相色谱测定氨基酸含量,气相-离子迁移谱测定挥发性物质的含量并进行分析。结果表明,鸡骨架酶解液美拉德反应的最佳条件是pH 6、温度100℃,时间60 min。由电子鼻和电子舌测定结果可知,经过美拉德反应,削弱了酶解液的苦味,降低了胺类等不愉快的气味,丰富了整体风味。对氨基酸含量分析显示,酪氨酸、赖氨酸和异亮氨酸含量明显降低,说明这几种氨基酸是参与美拉德反应的主要氨基酸。对酶解液和美拉德反应产物进行挥发性风味物质检测,发现醇类、醛类和酮类物质是产生风味的主要物质。该研究可以为工业上研发高品质的肉味调味基料提供一定参考。     

Amino acid pattern in eggs as influenced by supplementation of dopamine agonists and antagonists in laying hens

A total of thirty laying hens divided into 3 equal groups was used. The 1st group served as control and was fed a basal ration. The 2nd and 3rd groups received L-Dopa and reserpine, respectively. The goal of the study was devoted to determine the effects of these additives on the rate of egg production, weights of eggs and yolks as well as yolk proteins and their amino acid pattern. In the reserpine-treated hens the rate of egg production was increased whereas in the L-Dopa-treated group, the weights of eggs and yolks, food intake as well as the amino acids aspartate, glutamate, glycine, alanine and methionine were significantly increased. The levels of tyrosine and histidine were decreased in both treatments while methionine was decreased by reserpine only. The addition of dopamine antagonist to a ration containing lysine and leucine in concentrations of 0.55% and 0.9% did not influence their levels in eggs. The increment of methionine, aspartate, glutamate and glycine by the dopamine agonist and their decrease by antagonist revealed that these amino acids are excitatory neurotransmitters in brain.     

Influence of rapeseed cake, linseed cake and hemp seed cake on laying performance of hens and fatty acid composition of egg yolk

In hens the effects of expeller/cakes from rapeseed, linseed, and hemp seed were investigated on feed intake, laying performance and fatty acid composition of egg yolk. A total of 216 individually caged laying hens were allocated to nine dietary treatments (5, 10, 15 % cake) and fed for six laying months. For feed intake, egg mass production and feed-to-egg mass ratio at 15 % dietary cake level a significant lower performance was shown compared with the 5 and 10 % cake level groups. Also interaction was significant for all these parameters, indicating that the cake level acted differently for the three cakes. The egg mass production was lower in the linseed cake than in the hempseed groups and the hens fed the linseed cake needed significantly more feed per kg egg mass compared with both the other cakes tested. Increasing dietary level of all oil seed cakes lowered the yolk percentage and increased the egg white percentage. Increased dietary levels of all three oil seed cakes lowered the percentages of most saturated fatty acids and also the percentages of the monounsaturated fatty acids. The linoleic acid and the linolenic acid as polyunsaturated fatty acids were heightened by increasing the cake levels from 5 to 10 and 15 % in the diet. The results allow the conclusion that compound feeds with up to 10 % of cakes does not negatively influence the laying performance of hens and provides the possibility of the enrichment of yolk fat with polyunsaturated fatty acids.     

黄喉拟水龟蛋营养成分分析及评价

对黄喉拟水龟蛋的蛋白质、氨基酸、矿物质、蛋黄中磷脂及脂肪酸组成等营养成分及价值进行评价。结果表明:与鸡蛋的营养组成相比,黄喉拟水龟蛋蛋清蛋白质种类多于鸡蛋蛋清,氨基酸组成符合理想模式,铁、镁、锌、磷含量高。龟蛋黄脂肪含量低于鸡蛋蛋黄,脂肪酸种类多,不饱和脂肪酸占总脂肪酸的80.72%,多不饱和脂肪酸二十二碳六稀酸(docosahexaenoic acid,DHA)6.39%,花生四稀酸3.72%,二十碳五稀酸(eicosapentaenoic acid,EPA)3.69%。龟蛋蛋白质种类丰富,矿物质和不饱和脂肪酸含量高,是一种高价值优质健康食品。     

DIETARY FATTY ACIDS AND AMINO ACIDS OF CAMELINA SATIVA SEED

Abstract Camelina sativa ( L. ) Crantz is an ancient oilseed crop. Camelina seed can be used as a food ingredient and raw material for the production of oil. The by-product from the production of oil by pressing (oil cakes) was traditionally used as fodder ingredient.
Camelina seed samples for analyses were collected from geographically remote localities in Europe and in Scandinavia (6° W - 25° E, 48 - 61° N). The seed was analyzed for the content of oil, fatty acids, total nitrogen and amino acids.
The mean content of oil in the seed was 43.3 ± 0.22%/DM. The predominating acid, α-linolenic (18:3 n-3), was 37.8 ± 0.17%; and others were oleic acid (18:1 n-6) 13.4 ± 0.13%; linoleic acid (18:2 n-6) 14.8 ± 0.12%; gondoic acid (20: 1 n-9) 15.4 ± 0.16% and erucic acid (22: 1 n-9) was 2.76 ± 0.07%/total FA.
Crude protein was 42.5 ± 0.46%/fat free DM. Considerable amounts of essential amino acids were present, such as arginine 8.15 ± 0.06%; glycine 5.44 ± 0.04%; isoleucine 3.96 ± 0.02%; leucine 6.63 ± 0.04%; lysine 4.95 ± 0.04%; phenylalanine 4.19 ± 0.04%; proline 5.09 ± 0.03%; threonine 4.25 ± 0.03% and valine 5.42 ± 0.04%. The methionine content was 1.72 ± 0.04% and cystine, 2.12 ± 0.05% (A.A. g/16 g N).     

海南茶叶与茶树花氨基酸含量对比分析

主要对比分析了海南五指山、白沙、保亭、琼中、定安5个主要茶产区的茶叶与茶树花中氨基酸总量及氨基酸组成。结果表明:各茶产区茶叶中氨基酸总量均明显高于茶树花,各产区茶叶与茶树花在氨基酸总量上差值接近;不同产区茶叶中的16种氨基酸的组成比例非常接近,不同产区茶树花中的16种氨基酸组成比例也非常接近,组成比例中占比最高的氨基酸是谷氨酸,占比最低的氨基酸是蛋氨酸;茶叶中谷氨酸、酪氨酸、赖氨酸、精氨酸4种氨基酸占比高于茶树花;茶叶中丝氨酸、脯氨酸、丙氨酸、缬氨酸4种氨基酸占比低于茶树花,其余氨基酸在茶叶和茶树花中的占比较为接近。     

Effects of nitrogen,phosphorus and potassium on amino acid composition and on relationships between nitrogen and amino acids in wheat and oat grain

During two seasons, pot experiments in which increasing applications of nitrogen, phosphorus and potassium were given to wheat and oats produced grain with widely varying N contents. The total amino acid composition of the grain was mainly dependent on N content of grain. Phosphorus and potassium affected the amino acid composition of wheat and oat grain only indirectly through their effects on nitrogen concentration. In wheat increasing grain N% was accompanied by a decrease in the amount (as g per 16 g N) of lysine, threonine, methionine, cystine and an increase in glutamic acid, proline, phenylalanine, and serine contents. Lysine, methionine, and cystine in oats decreased with increasing grain N content, but arginine, aspartic acid, glutamic acid and phenylalanine increased. Changes were less pronounced with oats than with wheat, and concentrations of most essential amino acids were higher in oats. When expressed as % dry matter all amino acids increased with increasing N concentration. Linear regression equations were calculated and significant correlations were found in both crops between concentrations of most amino acids and N content in grain. Some correlations between amino acids in the grain are also given. Correlations between amino acids and nitrogen within a variety were similar despite widely differing yields.     

牛油氧化对牛肉风味形成的影响

通过添加不同POV值(40、60、80 meq/kg脂肪)氧化牛油对牛肉酶解液进行Maillard热反应,检测不同牛肉Maillard反应产物的氨基酸组成、肽分子量分布、香气组分以及感官测评的变化情况,研究不同POV值氧化牛油对于牛肉风味味感的影响。结果表明:不同POV值氧化牛油参加反应,主要影响牛肉酶解液Maillard热反应体系中含硫氨基酸和鲜味氨基酸的反应活性,以及Maillard反应产物的肽分子量的分布,从而影响了牛肉香气和味感的形成。      

The nutritive value of triticale in diets for laying hens

The nutritive value of triticale was assessed over a ten-week period with Warren Studler hens. Test diets contained over 85% cereal plus 12% of a mineral/vitamin mixture with and without supplements of the amino acids, lysine and methionine, or a small inclusion of fishmeal. Egg production on such diets was compared with that on control diets based on oats and fishmeal and on diets containing barley grown adjacent to the triticale. Full egg production was achieved on the triticale diet without amino acid or protein supplementation. Corresponding barley diets supported production which was lower by about 10%. Individual egg weights tended to be lower on the triticale diet unsupplemented with amino acids than on the control or fully supplemented diets. Food conversion efficiency was better on the triticale than on the control or barley diets. Hens on triticale diets without amino acid or protein supplements lost more weight during the experiment than did control birds.     

风干武昌鱼的营养及挥发性成分

为研究风干武昌鱼的营养价值和特征风味,分析其灰分、脂肪、蛋白质、多肽含量、游离氨基酸和游离脂肪酸组成及挥发性成分。结果显示,风干武昌鱼中蛋白质和多肽含量高达32.72%、4.26%,脂肪和灰分含量分别为9.40%、9.38%。游离氨基酸含量为0.12%,包括人体必需的8 种氨基酸,且赖氨酸、蛋氨酸含量分别为总游离氨基酸的3.31%和1.26%;呈味氨基酸（天冬氨酸、谷氨酸、甘氨酸、丙氨酸、丝氨酸、脯氨酸）含量为总游离氨基酸的85.64%,鲜味氨基酸（天冬氨酸、谷氨酸、甘氨酸、丙氨酸）含量高达51.07%。游离脂肪酸中不饱和脂肪酸含量为68.80%,以C18∶1含量最高;多不饱和脂肪酸含量为21.98%,其中C20∶5和C22∶6含量分别为0.40%、0.89%。此外,从风干武昌鱼中检测到奇数碳脂肪酸,例如十五碳脂肪酸和十七碳脂肪酸。挥发性成分中醇类、醛类物质相对含量分别达16.65%、10.91%。说明风干武昌鱼营养丰富,呈味氨基酸和不饱和脂肪酸及挥发性成分含量较高,有利于风干武昌鱼特征风味的形成。     

The contents of the neuro-excitatory amino acid β-ODAP (β-N-oxalyl-l-α,β-diaminopropionic acid), and other free and protein amino acids in the seeds of different genotypes of grass pea (Lathyrus sativus L.)

The free and protein amino acids of nine different genotypes of grass pea (Lathyrus sativus L.) seeds were analysed by HPLC with pre-column PITC (phenyl isothiocyanate) derivatisation. Among the free amino acids, homoarginine was quantitatively the most important (up to 0.8% seed weight) and stable while the neuro-excitatory amino acid β-ODAP (β-N-oxalyl-l-α,β-diaminopropionic acid) showed highest variation (0.02–0.54%) in the nine genotypes examined. Among protein amino acids, glutamic acid was quantitatively most significant, followed by aspartic acid, arginine, leucine, lysine and proline. The sulphur amino acid, methionine, showed the lowest concentration in all the L. sativus genotypes, and also in lentil (Lens culinaris) and in soybean (Glycine max) seeds analysed at the same time.