Human placental amino acid transporter genes: expression and function

Recent findings on amino acid transporter genes are reviewed with particular focus on matching previously described transport systems to individual genes. Functional studies using cloned and expressed transporters are considered as the critical tool allowing identification of the functional properties of individual genes. Specifically, these experiments allow identification of the transported substrate amino acids and of the transport mechanism. We focus on the very recent discovery and properties of the heterodimeric family of amino acid transport proteins where two subunits encoded in different genes are required. For these transporters, co-expression of both subunits is mandatory for functional studies. The field of placental amino acid transport is further complicated by complexities arising from both gestational age-specific and species-specific gene expression. The function of the transporter also depends on its cellular localization in the trophoblast. In addition, for transporters that are coupled to ion gradients, both membrane potential and ion pumping will contribute to the rate of amino acid delivery to the fetus. Regulation of function is important not only for fetal nutrition but also for specific additional aspects of placental biology.     

Development,amino acid utilization and cell allocation in bovine embryos after in vitro production in contrasting culture systems

The effects of protein-supplemented and protein-free media on amino acid uptake, protein synthesis and cell differentiation in bovine blastocysts were investigated. Four formulations of synthetic oviduct fluid were used. Each formulation was identified by the principal supplement: bovine serum albumin (0.4%, w/v); polyvinyl alcohol (0.3%, w/v); or either of two steer sera (10%, v/v). After zygote culture, blastocyst yields (day 7.5) were lowest in protein-free medium and highest in albumin-supplemented medium. Subsequent 12 h incubation in the presence of both essential and non-essential amino acids was used for the measurement of amino acid flux. All blastocysts released alanine but consumed aspartate (P < 0.001) and the extent was influenced by prior culture conditions. Aspartate uptake was lower in blastocysts produced in protein-free conditions (P < 0.05) than in blastocysts produced in albumin-supplemented conditions. Consumption indices for 16 other amino acids were not influenced by blastocyst source. Cell counts and hatching incidences were highest for albumin-supplemented blastocysts, but were similar among blastocysts from the protein-free and serum-dependent treatments. Crucially, the use of protein-free medium for zygote culture did not compromise resultant blastocysts in terms of either de novo protein synthesis ([3H]phenylalanine incorporation) or trophectoderm function (phenotype based on interferon-tau detection). Thus, although blastocyst yields were compromised after zygote culture in a protein-free (vis-à-vis albumin-supplemented) medium, amino acid flux was qualitatively conserved, and only quantitatively modified in the case of alanine and aspartate. Moreover, vital properties of blastocysts that were produced, including de novo protein synthesis and trophectodermal cell function, apparently were not adversely affected by protein deprivation.     

坛子肉中氨基酸和脂肪酸营养品质评价

目的评价坛子肉中氨基酸和脂肪酸的营养品质。方法运用多种方法对坛子肉中氨基酸和脂肪酸的组成及含量进行测定,并用必需氨基酸指数法(essential amino acid index method,EAAI)、氨基酸评分法(amino acid score, AAS)、化学评分法(chemical score, CS)评价坛子肉中蛋白质的营养价值。结果坛子肉中氨基酸总量为20.76%±0.21%, 8种必需氨基酸占氨基酸总量的42.60%, 4种鲜味氨基酸占氨基酸总量的36.90%,AAS和CS均表明第一限制性氨基酸为色氨酸。坛子肉中粗脂肪含量为28.15%±0.31%,不饱和脂肪酸占脂肪酸总量的70.79%±0.31%。必需氨基酸占氨基酸总量的38.15%,必需氨基酸与非必需氨基酸的比值为61.68%。结论坛子肉是一种具有独特风味的优质蛋白源以及具有均衡脂肪酸的高营养价值的肉制品。     

Chemical,amino acid and fatty acid composition of Sterculia urens L. seed

The chemical, amino acid and fatty acid compositions of Sterculia urens seeds are reported. The cotyledons were found to be rich in protein (30.88%) and lipids (39.2%). The major amino acids in defatted Sterculia urens cotyledon flour (DSCF) were determined as glutamic acid, arginine and aspartic acid. Cysteine, methionine, tyrosine and histidine were observed in minor quantities. The ratio of essential to non-essential amino acids was observed to be 0.45. Among the essential amino acids, isoleucine was found to be higher than the reported FAO/WHO requirements. The GC-FID and GC–MS analysis revealed that the major fatty acids of the total lipid were stearic acid (31.72%), linoleic acid (28.83%) and palmitic acid (26.79%). Eicosadienoic acid (4.98%) and eicosatrienoic acid (2.96%) were also found in the total lipid.     

广西海鸭蛋中氨基酸的含量及组成分析

目的 研究广西区内海鸭蛋氨基酸含量及其组成分析广西海鸭蛋的品质。方法 采用盐酸水解法处理18组海鸭蛋样品,通过日立氨基酸自动分析仪测定16种氨基酸总含量,分析海鸭蛋各氨基酸的含量及其组成。结果 18份海鸭蛋样品中氨基酸的测定结果表明,广西海鸭蛋中氨基酸总量在11.99 g/100 g~13.79 g/100 g范围,各氨基酸占氨基酸总量的比值相近,其中谷氨酸的含量最高, 约占氨基酸总量的13%, 组氨酸含量最低,约占氨基酸总量的2%,其他氨基酸的含量均在3%~9%的范围内。结论 广西海鸭蛋氨基酸总含量有差异,但氨基酸组成较稳定,各氨基酸占氨基酸总量的比值相近,谷氨酸的含量最高,组氨酸含量最低。人体必需氨基酸占氨基酸总量的百分比（E/T）为47.25%,人体必需氨基酸含量与9种非必须氨基酸含量的比值（E/N ）为0.89,符合1973年FAO/WHO提出的理想模式,说明海鸭蛋中氨基酸都属于优质蛋白质,具有很好的营养价值。     

Response to labeled precursor amino acids, varying cell density, and graded amino acid complement for protein synthesis in mammary cell culture.

Effect of labeled precursor amino acids, varying cell densities, graded quantities of amino acid complement, and incubation environment on milk protein synthesis were studied with cultures of mammary cells isolated from Sprague Dawley rats. The essential amino acid complement of Eagle's minimal essential medium was used as base. Protein synthesis, measured by incorporation of labeled lysine, leucine, and phenylalanine, was affected by source of label for the "beta-lactoglobulin fraction" and beta-casein but not alpha-lactalbumin. Cell numbers between 6 X 106 and 6 X 107 per 5 ml of culture medium did not significantly alter rates of synthesis. Increasing amounts of amino acid concentration from one to three-fold increased synthesis of "beta-lactoglobulin fraction" and alpha-lactalbumin regardless of cell population. Response to addition of essential amino acid for "beta-lactoglobulin fraction" synthesis was linear over one to five-fold with 30.9 mug/flask per fold addition (linear regression coefficient; squared correlation = .91). Results were similar for beta-casein synthesis; 25.9 mug/flask and squared correlation = .91. No culturing effects between carbon dioxide and conventional incubators were significant.     

Competitive amino acid transport between L-tryptophan and other amino acids in Schizophyllum commune

In our study on nutritional requirement for the hyphal growth of Schizophyllum commune, we found that a Trp- mutant could not grow in the L-Trp-supplied medium in the presence of L-Ser. Further growth studies showed that not only L-Ser but also as many as 11 kinds of amino acid including L-Ala, L-Arg, L-Asn, L-His, L-Leu, L-Met, L-Phe, L-Ser, L-Thr, L-Tyr and L-Val inhibited the growth of the Trp- mutant in the L-Trp-supplied medium. However, these amino acids did not inhibit the growth of a Trp+ strain. The inhibition of growth of Trp+ strain induced by a Trp analogue of 5-fluoro-DL-tryptophan (5FT), which was usually recovered by L-Trp, was rescued by the same amino acids mentioned above. The exceptions were Gly and L-Ile, which also recovered the growth inhibition induced by 5FT. These results indicate that the permease responsible for the Trp transport in S. commune might also be active to other amino acids. However, it is considered that the permease shows high affinity to L-Trp and low affinity to other amino acids. As a result, the transport of L-Trp and 5FT may be counteracted by other amino acids.     

Cationic amino acid transport by bovine mammary tissue

Cationic amino acid transport (arginine and lysine) into bovine mammary tissue occurs by a sodium independent and saturable mediated system. Concentrative uptake ratios (cell concentration/media concentration) for both arginine and lysine varied between 6 and 22. High concentrations of specific inhibitors of the neutral amino acid transport systems had no effect upon arginine or lysine uptake. Both arginine and lysine were strong inhibitors of each others uptake, whereas ornithine showed less specificity for inhibition of arginine and lysine uptake. In the presence of all amino acids, cationic amino acid uptake occurred at a rate equivalent to that with cationic substrates alone. The presence of the independent cationic amino acid transport system in bovine mammary tissue accounts for the high cationic amino acid uptake by measuring arteriovenous differences of plasma across the bovine mammary gland. This transport system is responsible for excess uptake (beyond milk protein synthesis requirements) of cationic amino acids for catabolism to other amino acids or potential oxidation.     

盐酸水解方法对鸡肉中氨基酸含量的影响

摘 要: 目的 研究盐酸水解过程中, 水解时间和添加巯基乙醇和苯酚保护剂对鸡肉中18种氨基酸含量的影响, 确定获得鸡肉氨基酸最高含量的盐酸水解方法。方法 以30个鸡胸肌(3种鸡、每种10个)为实验对象, 设计6个水解时间, 研究盐酸水解时间对鸡肉样品中18种氨基酸含量的影响, 确定获得氨基酸最高含量的盐酸水解时间。在上述研究的基础上, 随机选择6个鸡胸肌(3种鸡、每种2个)为实验对象, 设置3个水解时间, 研究巯基乙醇和苯酚对鸡肉样品中18种氨基酸含量的影响, 最终确定获得鸡肉中18种氨基酸最高含量的盐酸水解方法。结果 缬氨酸(valine, Val)和异亮氨酸(isoleucine, Ile)的最佳水解时间为24或26 h, 两水解时间无显著性差异(P>0.05); 其余16种氨基酸的最高含量均在22 h; Ile的含量在盐酸水解法水解24 h显著高于20 和22 h(P<0.05), 但在苯酚+盐酸水解法水解22h含量最高; 天冬氨酸(aspartate, Asp) 的含量在巯基乙醇+盐酸水解法水解22 h显著高于20 和24 h(P<0.05), 但在盐酸水解法水解22h含量最高; 甘氨酸(glycine, Gly)、丙氨酸 (alanine Ala)、酪氨酸(tyrosine, Tyr) 和苯丙氨酸 (phenylalanine, Phe)的含量在苯酚+盐酸水解法水解22 h显著高于20 h(P<0.05), 但水解22与24 h之间无显著性差异(P>0.05), 其中, Gly在苯酚+盐酸水解法水解22 h含量最高, Ala在盐酸水解法水解22 h含量最高, Tyr和Phe在巯基乙醇+盐酸水解法水解22 h含量最高; Val在盐酸水解法水解24 h含量最高, 脯氨酸(proline, Pro)和赖氨酸 (lysine, Lys)在苯酚+盐酸水解法水解22 h含量最高, 亮氨酸 (leucine, Leu) 在巯基乙醇+盐酸水解法水解22 h含量最高; 其余氨基酸在不同水解方法及水解时间中均无显著性差异(P>0.05), 但都在盐酸水解法水解22 h时含量最高。结论 巯基乙醇和苯酚对鸡肉中的含硫氨基酸无保护作用, 获得鸡肉中18种氨基酸最高含量的盐酸水解方法是盐酸水解法水解22 h。     

Limiting amino acid for protein synthesis with mammary cells in tissue culture.

To identify the limiting amino acid in the minimal essential medium as published by Eagle (Science 130:432, 1959) for milk protein synthesis in rat mammary cells in tissue culture, two different experimental approaches were used. The first study involved the reduction of amino acids singly from the total amino acid complement of the medium for milk protein synthesis. The second study was to investigate the effect on milk protein synthesis of single amino acid addition to the basic complement of amino acids. Order of limiting amino acids was lysine (first) and possible methionine, valine, or arginine (second).     

Heterogeneity of cationic amino acid transport systems in mouse mammary gland and their regulation by lactogenic hormones

The mechanism of cationic amino acid transport in lactating mouse mammary gland was investigated. Two Na(+)-independent systems of arginine transport were discriminated on the basis of their sensitivity to leucine. The leucine-sensitive uptake of arginine (Km 0.4 mM) was through a broad specificity system that interacted with both cationic and neutral amino acids, and was inhibited by preloading mammary tissue with neutral amino acids. The leucine-insensitive uptake was identified as the y+ system (Km 0.76 mM). Preloading mammary tissue with cationic amino acids increased the uptake of arginine by the y+ system. Decreasing the pH of the external medium to 6.0 suppressed the y+ system-mediated uptake by approximately 25%, whereas the broad specificity system remained unaffected. Lactogenic hormones upregulated the y+ system-mediated uptake of arginine in pregnant mouse mammary tissue cultured in vitro, although the broad specificity system remained unaffected. The y+ system-mediated uptake increased 2-fold with insulin alone and 4-fold with the combination of insulin, cortisol and prolactin.     

Effects of atropine on plasma amino acid profiles and on the synthesis of individual milk proteins in dairy cows fed with pasture

Effects of atropine on blood plasma amino acid profile and on the yields and concentration of milk components were investigated in 12 Friesian cows in early lactation. Cows were housed indoors and fed with cut pasture ad libitum. Each cow received four treatments over 12 d during a replicated 4 x 4 Latin square experiment. Treatments were: control (saline); low dose (L; 30 microg atropine/kg body weight (BW)); medium dose (M; 40 microg atropine/kg BW); and 2 x L dose, 2 h apart (2 x L). On each of four treatment days, cows were milked at about 7.00, after which treatments were administered by subcutaneous injection. Cows were milked again at 2 h, 6 h and 10 h after injection. Milk samples were collected at each milking. Immediately after the 2 h milking, blood samples were drawn from each cow and the second injection was given for the 2 x L treatment. Atropine reduced hourly milk yield, and concentrations and hourly yields of total protein, casein, whey protein, alpha-casein, beta-casein, kappa-casein, beta-lactoglobulin and alpha-lactalbumin, but by differing amounts. Milk concentrations of bovine serum albumin and immunoglobulin G were increased by atropine, and overall yields of these proteins were mostly unchanged. Atropine lowered concentrations of most, but not all, amino acids in blood plasma, with essential amino acids reduced more than non-essential amino acids. Concentrations of alpha-amino N in whole blood, and glucose and insulin in blood plasma, fell after atropine injection. There was no difference between the L and M doses of atropine, but the 2 x L dose had greater effects on milk composition than the single doses. For yields of milk and milk components, the effect of the 2 x L dose was also more persistent. The results highlight the differential synthesis of individual milk proteins, and suggest that atropine might be useful for evaluating the mechanisms regulating milk protein composition.     

Short communication: Dietary conjugated linoleic acid down-regulates fatty acid transporters in the mammary glands of lactating rats

Recent studies indicated that reduction of milk triacylglycerol concentrations by dietary conjugated linoleic acid (CLA) involves an impairment of both de novo fatty acid synthesis and uptake of fatty acids from circulating triacylglycerol-rich lipoproteins into the mammary gland. However, nonesterified fatty acids (NEFA) in the plasma released from adipose tissue and taken up into the mammary gland by fatty acid transporters are a further important source of fatty acids available for milk triacylglycerol synthesis. Therefore, the aim of the present study was to investigate the effect of dietary CLA on plasma concentrations of NEFA and the expression of fatty acid transporters in the mammary glands of lactating rats fed either a CLA diet or a control diet. Dams fed diets with CLA had a greater concentration of NEFA in plasma than those fed the control diet. In addition, relative mRNA concentrations of fatty acid transporters (fatty acid translocase/CD36, fatty acid transport protein, and plasma membrane fatty acid binding protein) were about 45, 75, and 70% lower, respectively, in the mammary gland of dams fed diets with CLA compared with those fed the control diet. In conclusion, the present findings indicate that reduced uptake of circulating NEFA released from white adipose tissue into the mammary gland could also contribute to the reduction of milk triacylglycerol concentrations by dietary CLA in rats. The mechanism through which CLA inhibits expression of fatty acid transporters deserves further study.     

闽产食用菌的氨基酸组成特征及其营养评价

目的 探究闽产食用菌的氨基酸组成特征及其营养价值。方法 采用氨基酸自动分析仪分析食用菌氨基酸含量, 利用鸡蛋蛋白模式和联合国粮食及农业组织(Food and Agriculture Organization, FAO)/世界卫生组织(World Health Organization, WHO)推荐的理想蛋白模式系统评价各食用菌的氨基酸营养价值。结果 食用菌至少包含18种氨基酸, 包括8种成人必需氨基酸、2种儿童必需氨基酸。成人必需氨基酸、非必需氨基酸、酸味类氨基酸、甜味类氨基酸、苦味类氨基酸、儿童必需氨基酸、药用氨基酸、支链氨基酸、增香与着色氨基酸、伯胺基氨基酸含量等特殊功效氨基酸含量分别为3.19%~10.90%、4.51%~16.24%、1.73%~7.77%、2.09%~7.39%、3.03%~9.73%、0.55%~2.30%、4.84%~17.16%、1.30%~4.86%、2.90%~12.06%、3.94%~14.89%, 品种间含量差异明显。必需氨基酸与氨基酸总量的百分比、必需氨基酸与非必需氨基酸含量的百分比、氨基酸比值系数分、必需氨基酸指数和营养指数依次为40.86%~48.72%、69.10%~95.00%、46.19~88.18、58.37~83.43、7.12~24.53, 品种间营养价值差异明显。蛋氨酸+胱氨酸均相对过剩, 缬草氨酸、异亮氨酸、亮氨酸、赖氨酸表现严重不足, 而苯丙氨酸+酪氨酸、苏氨酸、色氨酸各品种表现不一。通过聚类分析, 样品可分为3大类: 高、中、低品质蛋白组。结论 18种食用菌氨基酸组成及营养价值存在一定的差异, 具有不同的开发应用前景。     

Amino acid requirements for maturation of rhesus monkey (Macacca mulatta) oocytes in culture

This study evaluated the effects of different amino acid formulations on supporting meiotic and cytoplasmic maturation of rhesus monkey (Macacca mulatta) oocytes in vitro. Five hundred and forty-six cumulus-oocyte complexes (COCs) aspirated from unstimulated adult monkey follicles (> or = 1000 microm in diameter) were cultured in either modified Connaught Medical Research Laboratories 1066 medium (mCMRL-1066) or in one of eight chemically defined media (modified basic medium 5 supplemented with 5.5 mmol glucose l(-1), 0.003 mmol pantothenic acid l(-1) and different amino acid formulations) as below: (1) modified basic medium 5 (mBM5) containing no amino acid; (2) mBM5 + 0.2 mmol glutamine l(-1); (3) mBM5 + 11 amino acids from hamster embryo culture medium 6 (HECM-6) (11 AA); (4) mBM5 + Eagle's non-essential amino acids (NEA); (5) mBM5 + NEA + 0.2 mmol glutamine l(-1); (6) mBM5 + Eagle's essential amino acids (EA) without glutamine; (7) mBM5 + EA + 0.2 mmol glutamine l(-1); (8) mBM5 + Eagle's 20 amino acids (20 AA) + 0.2 mmol glutamine l(-1); and (9) mCMRL-1066 (control). All media contained FSH, LH, oestradiol and progesterone. After maturation, mature oocytes were subjected to the same fertilization and embryo culture procedures. COCs matured in treatment 5 had greater potential to progress to metaphase II (66%; P < 0.05) than did those in treatments 1 (37.3%), 2 (48.3%), 3 (41%), 6 (41%) and 9 (43%). Oocytes matured in treatment 8 had the best morula (53%) and blastocyst (18%) developmental responses (P < 0.05). The lowest (P < 0.05) morula and blastocyst developmental responses were obtained from COCs matured in treatments 1 (0%) and 6 (8%). The other media supported intermediate embryonic development (range 11-38% of morula and blastocyst). These results indicate that the choice of amino acids affects the competence of oocyte maturation and that Eagle's 20 AA with 0.2 mmol glutamine l(-1) is more efficient than the other amino acid formulations for maturation of rhesus monkey oocytes.     

蟾蜕的氨基酸分析及其对小鼠营养作用观察

对一种新的中华大蟾蜍药用和食用部位-蟾蜕氨基酸组成和含量进行分析并观察其对实验小鼠饲养效果。用日立835-50型氨基酸自动分析仪对蟾蜕水解液中氨基酸组成和含量进行了检测,以大剂量蟾蜕(16g/kg/d)给实验小鼠连续喂养2周,观察其对小鼠的饲养效果。氨基酸检测结果:提示蟾蜕富含多种必需和非必需氨基酸,总含量达到干质量的50%以上。而小鼠短期大剂量服用蟾蜕后,生长状况极佳,无明显毒副作用。以上结果提示,蟾蜕营养价值较高,有一定滋补作用,可能是其具有保健作用的机制之一,因而是一种潜在的很有价值的新药用和食用资源。     

苏尼特羊肉氨基酸组成及与其他羊肉的对比分析

目的 分析苏尼特羊肉氨基酸组成以及与其他羊肉氨基酸组成进行对比分析。方法 以锡林郭勒放牧型苏尼特羊肉、乌珠穆沁羊肉、察哈尔羊肉以及两个区域舍饲型小尾寒羊肉为研究对象,通过氨基酸自动分析仪测定不同样品中氨基酸组成和含量,并进行比较分析。结果 苏尼特羊肉的水解氨基酸和游离氨基酸含量显著高于乌珠穆沁羊肉和察哈尔羊肉(P<0.05);苏尼特羊肉的水解氨基酸含量与舍饲型小尾寒羊肉无显著差异(P>0.05),但是其游离氨基酸含量显著高于舍饲型小尾寒羊肉。5种羊肉必需氨基酸/非必需氨基酸均高于60%,必需氨基酸/总氨基酸在40%左右,符合联合国粮农组织/世界卫生组织(UnitedNationsFood Agriculture Organization/World Health Organization, FAO/WHO)人体理想蛋白质模式。结论 苏尼特羊肉水解氨基酸和游离氨基酸组成丰富,含量较高,具有较高营养价值和食用品质。     

不同方式发酵的哈密瓜幼果泡菜理化特性和氨基酸含量分析

为提高哈密瓜幼果的综合利用价值,拓宽泡菜种类,采用5种不同发酵方式制得哈密瓜幼果泡菜,在测定发酵过程中的pH、质构、总酸、亚硝酸盐、盐度和感官品质的基础上,采用全自动氨基酸分析仪对原料、泡菜发酵中点和终点泡菜的氨基酸含量进行测定,通过氨基酸比值系数法进行营养评价。结果表明:发酵终点时,5种发酵方式发酵的泡菜pH均在3.6以下,总酸质量分数在0.5%左右,盐度最高达到3.3 g/100 g,亚硝酸盐含量均低于5 mg/kg,咀嚼性在23~31 mJ之间,其中卤水发酵泡菜的感官综合得分最高;在各发酵方式制备的哈密瓜幼果泡菜中均检测出了17种氨基酸,发酵过程中氨基酸总含量不断降低,但必需氨基酸/非必需氨基酸的值均在0.24~0.32,发酵终点时,氨基酸比值系数分在54~62,超过大豆。表明哈密瓜幼果泡菜营养均衡性较好,营养价值较高。     

不同产地雪菊氨基酸组成分析及综合评价

目的:深入研究和开发利用雪菊资源。方法:采用盐酸水解法处理样品(和田、乌鲁木齐、阿坝、泸定、西宁5个产地雪菊),使用全自动氨基酸分析仪测定其17种氨基酸含量,在此基础上,分析雪菊氨基酸的呈味特征,与联合国粮农组织/世界卫生组织 FAO/WHO颁布氨基酸模式谱相比较,计算雪菊的氨基酸比值(RAA)、氨基酸比值系数(RC)、氨基酸比值系数分(SRC),并对雪菊的17种氨基酸进行相关性分析和聚类分析,综合评价雪菊蛋白质的营养价值。结果:5种产地雪菊均含有17种氨基酸,氨基酸总含量差距不大。泸定、阿坝雪菊呈味特征以苦味为主,其余3种雪菊呈味强度从大到小依次为鲜味、苦味、甜味。与氨基酸模式谱相比较,5个产地雪菊中Met+Cys均低于模式谱标准,泸定、和田与乌鲁木齐的其他必需氨基酸占总氨基酸的比例均接近并高于模式谱标准。根据RC值大小,可确定Met与Cys为雪菊的第一限制氨基酸。各产地雪菊SRC值为75~80,必需氨基酸占氨基酸总量的比值(E/T值)为31%~36%,必需氨基酸与非必需氨基酸的比值(E/N值)为46%~55%。5个产地雪菊E/N值均略低于FAO/WHO理想蛋白质标准。结论:雪菊有丰富的氨基酸,具有一定的药用价值且冲泡口感好,可深入开发。