Chemical composition,amino acid and fatty acid contents,and mineral concentrations of European beaver (<Emphasis Type="Italic">Castor fiber</Emphasis> L.) meat

The present investigation was designed to determine the meat nutritional profile of European beaver (Castor fiber L.). The proximate composition, energy value, amino acids composition, chemical scores for indispensable amino acids, fatty acids composition and mineral concentrations were determined. In 100 g of meat the content for moisture ranged from 75.42 to 77.32 g, for protein from 20.21 to 22.33 g, for fat from 0.66 to 2.44 and for ash from 1.12 to 1.24 g. The Nutritional Quality Index for muscle protein was 9. The indispensable amino acids (IAA) at the highest content were lysine and leucine (1.85 and 1.65 g 100 g^?1). The average percentage of IAA was 45% and their chemical scores amounted to more than 100. The total percentages of trans-, saturated (SFA), mono, and polyunsaturated (PUFA) fatty acids were 2.25, 32.25, 18.83 and 49.08%. The ratio of PUFA/SFA and n-6/n-3 PUFA were 1.56 and 5.58. The cholesterol content averaged 55.10 mg 100 g^?1. The muscle tissue of beavers contained favourable amount of minerals, particularly Fe and heme Fe (64.49 and 45.60 mg kg^?1), Zn and Cu (45.07 and 0.98 mg kg^?1), as well a low level of Na (461.9 mg kg^?1). Summing up, beavers are a valuable nutritional meat source with a desirable chemical composition and a low calorific value and can constitute a healthy alternative food as advantageous for human health and coherent with diet recommendations.     

Determination of Free Amino Acids in Coated Foods by GC–MS: Optimization of the Extraction Procedure by Using Statistical Design

The development and validation of an extraction procedure for quantification of free amino acids in coated products by MTBSTFA derivatization and GC–MS detection is described. The extraction method entailed the sample homogenization with hydrochloric acid (HCl) by stirring at 40 °C followed by two centrifugation steps. The optimum combination of the extraction variables was achieved by response surface methodology. HCl concentration and volume and stirring time influenced free amino acid extraction yield. The selected optimal extraction conditions were 5 g of sample mixed to 7.5 ml of 0.1 N HCl and stirred during 90 min. Consistency between predicted and experimental values as well as in the quality parameters was observed. The calibration curves were linear within the range 5–100 μg ml^?1 with correlation coefficient values (R ² ) higher than 0.99. Detection and quantification limits of the analytical procedure ranged from 2.10^?5 to 18.10^?2 μg μl^?1 and from 8.10^?5 to 60.10^?2 μg μl^?1, respectively. Precision was 0.20–12.59 % for run-to-run and 3.38–17.60 % for day-to-day. The accuracy is between 82.99 and 115.77 %. Nineteen amino acids were analyzed in frozen-thawed and deep-fried coated products from different origin, with cysteine being the most relevant.     

氨基酸自动分析仪法测定云南新鲜羊肚菌中16种氨基酸的含量

目的 建立氨基酸自动分析仪法测定和分析云南新鲜羊肚菌中16种氨基酸含量的方法。方法 样品匀浆后采用酸水解处理, 使用氨基酸自动分析仪法测定样品中的氨基酸含量。通过计算氨基酸总含量, 必需氨基酸比值, 呈鲜味氨基酸比值等对云南羊肚菌中的氨基酸进行分析。结果 16种氨基酸在10~150 nmol/mL的浓度范围内线性关系良好, 相关系数为0.9988~0.9999, 检出限为1.0~2.5 mg/100 g, 定量限为3.0~7.5 mg/100 g, 16种氨基酸的加标回收率为88.2%~105.2%, 相对标准偏差为3.95%~11.67%。云南新鲜羊肚菌中均含所测16种氨基酸, 平均含量为3.298 g/100 g, 必需氨基酸占总氨基酸总量的35.8%~38.0%。其中谷氨酸和天冬氨酸是含量最高, 占到氨基酸总量的21.8%~24.4%。结论 氨基酸自动分析仪法测定羊肚菌中氨基酸具有重现性好、结果可靠的优点; 云南羊肚菌中氨基酸含量丰富, 各州市间样品间氨基酸含量相对稳定。     

Multiresidue method for the determination of 77 pesticides in wine using QuEChERS sample preparation and gas chromatography with mass spectrometry

A method based on a QuEChERS (quick, easy, cheap, effective, rugged, safe) sample preparation method and gas chromatography with mass spectrometric detection by selected ion monitoring (GC/MS-SIM) was developed for simultaneous determination of 77 pesticide residues in wine. An extraction of 10 ml of sample with acetonitrile followed by liquid–liquid partition formed by the addition of 4 g MgSO₄ and 3 g NaCl was applied in the sample preparation. The clean-up was carried out by applying dispersive solid-phase with 150 mg MgSO₄ as well as 50 mg primary secondary amine (PSA). One quantitation ion and at least two identification ions were selected in the analytical method for each pesticide compound by GC/MS. The recovery data were obtained by spiking blank samples at two concentration levels (0.05 and 0.2 mg l^?1). The recoveries of all pesticides were in the range 70–110%, with intra-day precision of less than 15%, and the inter-day precision of less than 22% and 15% for 0.05 and 0.2 mg l^?1 fortification levels, respectively. Linearity was between 0.02 and 2 mg l^?1 with determination coefficients (R ²) greater than 0.98 for all compounds. The limits of quantification (LOQs) for the 77 pesticides ranged from 0.003 to 0.05 mg l^?1. This method was applied for routine analysis in market products.     

蜂蜜中17种水解氨基酸的测定

目的采用酸水解法和全自动氨基酸分析仪同时测定蜂蜜中17种氨基酸的含量。方法 8种不同蜜源的蜂蜜经酸水解后,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16种氨基酸在570 nm波长下测定。结果 17种氨基酸的线性回归系数均达到0.99以上;方法检出限为5~10 nmoL/L,样品平均回收率为92.1%~99.3%,相对标准偏差RSD小于8.5%。经检测实际样品发现,蜂蜜中不含胱氨酸,氨基酸总量在32.214~78.439 mg/100 g范围。结论该方法快速、准确,可适用于蜂蜜中水解氨基酸含量的测定。     

Protein,amino acid,ash and mineral contents in Brassica spp. grown in Northwest Spain

The protein, amino acid, ash, and mineral composition of different Brassica spp. grown in several areas of Galicia (Northwest Spain) were studied. The highest protein values were observed in Galega kales (crude protein: 29.66 g per 100 g) and turnip greens and turnip tops (27.74–31.46 g per 100 g), whereas the leaves showed higher protein contents than the stems. Glutamic acid was the most abundant amino acid present (14.53% in turnip greens to 18.45% in white cabbage). Other amino acids such as arginine, aspartic acid, lysine, alanine and glycine were also observed in higher quantities. The stems contained the same amino acid as the leaves but at a lower level. Furthermore, differences in amino acid contents were observed among varieties. The proportion of essential amino acids was high (41% in leaves of turnip top to 47% in external leaves of oxheart cabbage). The studied varieties are also a good source of some minerals, which include as main element potassium (27.24–37.57 mg g^?1 in whole plants), followed by calcium (4.27–17.48 mg g^?1 in whole plants) and magnesium (1.62–2.92 mg g^?1 in whole plants). Significant differences among varieties and edible portions were found concerning ash and mineral contents.     

Changes in nitrogen content and amino acid composition of navel oranges during ripening

Nitrogen content and composition of amino acids in juice and rind of navel oranges were studied. The compared varieties were ‘Navelina’ ‘Washington Navel’ and ‘Navelate’, early, mid-season and late types, respectively. Total N content in juice increased during the season with values from about 60 to near 100 mg 100 ml^?1 in Navelina and ‘Washington Navel’ and from 60 to about 80 mg 100 ml^?l in ‘Navelate’; amino N increased from 30 to 60 mg 100 ml^?lapproximately in the three varieties. The total N content in rind was quite similar in all cases, with values that decreased with time from 1 to around 0·6 g 100 g^?l dry weight (DW), 50–60% corresponding to the protein N. The main free amino acids in juice and rind at different maturity stages are tabulated. Proline represents at maturity around 50% of the total free amino acids in rind, with values near to 1·5 mmol 100 ml^?l in juice and over 5·0 mmol 100 g^?1 DW in rind. Total protein amino acids in rind decreased during maturation, reaching final values of about 20 mmol 100 g^?1 DW. Differences in composition among the three studied varieties are discussed.     

烟用香料浸膏中的氨基酸分析研究

目的检测烟用香料浸膏中的氨基酸,为烟用香料浸膏的安全使用和烟用香料浸膏标准的制定提供参考数据。方法采用酸水解法和氨基酸自动分析仪测定了11种烟用香料浸膏中16种氨基酸的含量,如天冬氨酸(Asp)、谷氨酸(Glu)、苯丙氨酸(Phe)等。通过单因素方差分析和聚类分析对实验数据进行统计分析。结果 11种烟用香料浸膏中氨基酸的总量均偏低,在4.52~3699.35 mg/100 g之间;罗汉果浸膏中总氨基酸的平均值最高,其平均值为2168.83 mg/100 g,爱普罗汉果浸膏的氨基酸总量最高,为3699.35 mg/100 g,且其中天冬氨酸、谷氨酸的含量较高,平均值分别为346.76、409.55 mg/100 g;西湖芸香浸膏的氨基酸总量最低,为4.52mg/100 g;通过单因素方差分析,显示不同浸膏中氨基酸的含量具有显著性差异;通过聚类分析,表明所测浸膏主要分为两类,第一大类包括西湖,烟草罗汉果浸膏、西湖啤酒花浸膏、山楂浸膏、吉水枸杞浸膏、西湖芸香浸膏,第二类包括拓普,爱普罗汉果浸膏、西湖枸杞。结论 11种烟用香料浸膏中氨基酸的总量偏低,且不同浸膏中的氨基酸含量具有显著性差异。     

A comparative study of the different analytical methods for analysis of S-allyl cysteine in black garlic by HPLC

A sensitive and reproducible analytical method to measure S-allyl cysteine (SAC) in black garlic was developed using the HPLC-FLD (fluorescence detection) with prior derivatization with AccQ-Fluor Reagent. The results were then compared with those from obtained using the HPLD-UVD (ultraviolet detection) that has been conventionally used for measuring SAC in raw garlic. The SAC content in raw garlic measured by the HPLC-FLD and the HPLD-UVD were 21.52 and 22.73 μg/g, respectively. And these results were satisfactory with %CV (coefficient of variation) less than 2%. However, the application of the HPLC-UVD for the determination of SAC in black garlic was limited due to the high %CV that arose from the unstable baseline. However, the HPLC-FLD could be applied to the measurement of SAC in black garlic with satisfactory %CV. The HPLC-FLD method was validated by determining the linearity, limit of detection, limit of quantification, accuracy and precision. This method showed excellent linearity with a coefficient of determination (R²) greater than 0.998. The limits of detection (LOD) and the limit of quantification (LOQ) were 6.28 and 19.02 μg/mL, respectively. The accuracy ranged from 98.51 to 102.08%, and the precision of the method was found to be less than 2%.     

大麦苗粉中氨基酸组成及含量

对大麦苗粉中的氨基酸进行了定性、定量分析研究。结果表明:大麦苗粉中共分析检测出26种氨基酸,其中,水解氨基酸17种,游离氨基酸26种。大麦苗粉中17种水解氨基酸总含量为9 163.422mg/100g,其中人体必需氨基酸含量占总含量的40%以上,大麦苗粉中含有9种药用氨基酸,其中Glu含量最高,达1 390.873mg/100g;大麦苗粉中26种游离氨基酸总含量为983.852 mg/100g;其中Asp、Glu、Arg、Pro、His、Val 6种游离氨基酸,是形成大麦苗粉风味的主要氨基酸。     

贵州喀斯特地区果梅果实游离氨基酸含量分析

以贵州喀斯特地区野生果梅为试材,利用氨基酸自动分析仪测定了果梅果实的氨基酸组分和含量。结果表明,野生果梅果实中共含有23种氨基酸,其中有6种是人体必需氨基酸,2种是儿童必需氨基酸。果梅果实中氨基酸总量最高的是荔波-14,可达10925.31 mg/100 g,显著高于其余单株和栽培品种,其人体必需氨基酸和儿童必需氨基酸含量也较丰富,含量分别为1226.24、1957.33 mg/100 g。而果梅果实中氨基酸种类最多的是荔波-11和荔波-16,均含有21种氨基酸。果梅果实中以Arg为主的药效氨基酸含量丰富;大部分果梅果实中支链氨基酸含量亦很丰富,荔波-10中可达212.05 mg/100 g。此外,还发现多数果梅果实中呈味氨基酸含量较高,占总氨基酸含量的50%左右,其中以荔波-19果实中鲜味氨基酸含量(866.63 mg/100 g)和甜味氨基酸含量(828.14 mg/100 g)最高。     

鱼腐乳发酵过程中游离氨基酸含量及抗氧化活性的变化

利用总状毛霉（Mucor racemosus）和红曲霉（Monascus）F1对鱼豆腐进行发酵研制鱼腐乳,对鱼腐乳发酵过程中的游离氨基酸及抗氧化活性的变化规律进行分析。结果表明：在发酵过程中,鲜味氨基酸、必需氨基酸、疏水氨基酸、总氨基酸的含量都呈逐渐升高的趋势,在后熟第28天时分别达到了138.57 mg/100 g、491.68 mg/100 g、340.06 mg/100 g、915.77 mg/100 g。在发酵过程中DPPH自由基清除率和羟自由基清除率也呈逐渐升高的趋势,在后熟第28天时分别达到70.30%和63.11%,分别比发酵开始时提高了53.09%和24.14%。     

Nutrient and antinutrient distribution of edible mushroom, Pleurotus tuber-regium (fries) singer

Edible mushroom Pleurotus tuber-regium, separated into cap, stalk, and tuber, was analysed. The macronutrient profile (g/100 g) showed crude protein ranging from 4.1 to 13.8, with the highest concentration in the cap (13.8) than any of the other parts and total carbohydrates from 34.0 to 56.2, while the crude fat and ash contents were generally low. Potassium, the most abundant nutritive element was found to be the highest concentration (mg/g) in the stalk (3.3) while copper was found in trace amounts in all the parts. The total cyanide (mg/100 g), phytate (mg/100 g) and tannin (%TA) concentrations were all below levels considered harmful. Amino acids analysis show that the protein contained all essential amino acids while the calculated amino acids scores showed the sulphur containing amino acids to be most limiting. The foregoing highlights the high nutritive values of the major parts of the edible mushroom, Pleurotus tuber-regium.     

HPLC-fluorimetric method for analysis of amino acids in products of the hive (honey and bee-pollen)

An optimization of the OPA method has made feasible separation and quantification of 23 amino acids, which include 5 infrequently searched for. Detection limits ranged from 0.24 to 10.1 pmol in honey and from 29.1 to 0.42 pmol in bee-pollen; reproducibility (C.V.) ranged from 5.3% to 20.4%; recoveries were above 78.8%. Forty monovarietal honey samples from ilex, oak, heather and chestnut-tree were analyzed for their free amino acid profiles. α-Aminoadipic acid and homoserine are reported for the first time in honeys. Thirty-two samples of Spanish bee-pollen, made of a majority of pellets from Cistus Ladanifer (67.1%) and Echium plantagineum (8.9%), were analyzed for their free and total amino acid profiles. Free γ-aminobutyric acid was extensively found with an average of 0.53 mg/g, while Hser and Orn were infrequent. Manually separated monofloral pellets from Cistus ladanifer and Echium plantagineum were analyzed for their free amino acid contents (including proline): 32.46 and 21.87 mg/g for the former and 22.18 and 12.23 mg/g for the latter. In contrast, the total amino acid percentage (on a dry weight basis) was 13.95% for Cistus ladanifer and 32.22% for Echium plantagineum.     

Effect of local processing methods (boiling,frying and roasting) on the amino acid composition of four marine fishes commonly consumed in Nigeria

The effects of different processing methods on the amino acid contents of four marine fishes commonly consumed in Nigeria: Clupea harengus, Scomber scombrus, Trachurus trachurus and Urophycis tenuis were investigated. The samples were boiled, roasted over hot charcoal, or fried in any of four different oil types (palm oil, soybean oil, vegetable oil and groundnut oil). The total amino acids for all the fish samples ranged from 76.72 to 98.01 g/100 g protein and the total essential amino acids from 28.95 to 44.73 g/100 g protein. Frying reduced the total amino acid contents, with the lowest values obtained in samples fried in palm oil. Boiling and roasting increased the total amino acid contents, with the values higher in roasted than boiled samples. The percentage of essential amino acids reduced with processing in almost all samples, but the reduction was more pronounced in the fried samples. The raw, boiled and roasted samples had amino acid scores greater than 100%, while for the fried samples, the limiting amino acids were either leucine or threonine. The results showed that roasting and boiling had more desirable effects on the amino acid content of the fish samples.     

Validation of a headspace solid-phase microextraction procedure with gas chromatography-electron capture detection of pesticide residues in fruits and vegetables

Headspace solid-phase microextraction (HS-SPME) was evaluated for the determination of pesticide residues in fruits and vegetables by gas chromatography with an electron capture detector (GC-ECD). The fibre used was coated with polydimethylsiloxane (100 μm thickness) and the analytical conditions employed have been developed and optimised in a previous work [Chai, M. K., Tan, G. H., & Asha, L. (2008). Optimisation of headspace solid-phase microextraction for the determination of pesticide residues in vegetables and fruits. Analytical Sciences, 24 (2), 273–276]. The results show that the HS-SPME procedure gave a better linear range, accuracy, precision, detection and quantification limits and is adequate for analysing pesticide residues in fruits and vegetables. The average recoveries obtained for each pesticide ranged between 71% and 98% at three fortification levels with the relative standard deviation of less than 5%. Repeatability (0.3–3.7%) and intermediate precision (0.8–2.5%) were shown to be satisfactory. The limits of detection (0.01–1 μg L⁻¹) and the limits of quantification (0.05–5 μg L⁻¹) of these pesticides were much lower than the maximum residue levels (MRL), allowed for fruits and vegetables in Malaysia.     

Rumen microbial growth rates and yields: effect of amino acids and protein.

Effects of amino acids upon microbial growth, optimum ratio of nonprotein to amino acid nitrogen for microbial growth, and incorporation of amino acids into microbial cells were determined with washed cell suspension in vitro as were rumen microbial cells. Rumen microbial dry matter, nitrogen, ribonucleic acid, deoxyribonucleic acid, and substrate disappearance was greatest when a mixture of 18 amino acids was substituted for urea. Substitutions of mixtures of 10 essential amino acids, 8 nonessential amino acids, and sulfur containing amino acids and glutamate also stimulated microbial growth. Acid hydrolyzed casein markedly improved microbial growth. Branched amino acid addition did not affect growth. The optimum ratio of nonprotein to amino acid nitrogen for microbial growth was 75% urea nitrogen and 25% amino acid nitrogen. With this amount of amino acids, an average of 53% of added amino acid was incorporated into microbial cells, 14% was fermented to carbon dioxide and volatile fatty acids, and 33% remained in the supernatant. Both 100% urea and 100% amino acid in growth media were unfavorable for maximal microbial growth. With all carbohydrate substrates, 100% urea nitrogen supported the growth of 9 mg bacterial dry matter per 100 mg of substrate. Substitutions of amino acids for urea increased yields to over 20 mg/100 mg. Microbial growth yields in incubations under carbon dioxide were less than when flasks were flushed with nitrogen. However, yield of bacterial dry matter per unit of substrate was less under nitrogen than under carbon dioxide.     

Estimation of Protein in Anhydrous Milk Fat

A method for the estimation of protein in anhydrous milk fat is described. The protein concentration is estimated by quantifying the arginine and aspartic acid (ASX) released upon acid hydrolysis of the anhydrous milk fat. Arginine and aspartic acid are derivatized with the fluorescent tag 9-fluorenylmethoxycarbonyl (FMOC), the derivatives are quantified by reversed phase HPLC, and the protein concentration in the anhydrous milk fat is estimated as 8.77?×?(Arg?+?ASX). Method suitability was defined by experimental assessments of FMOC-arginine and FMOC-aspartic acid linearity (R ² averages?>?0.999), protein estimate precision [day-to-day RSD values (n?=?8 days) ranged from 7.3 to 14 % for protein concentrations of 9.42 to 40.0 mg/kg of anhydrous milk fat], protein estimate accuracy [spike recovery average?=?95.6 % (9.3 %), n?=?8, spiking level?=?20 mg/kg and agreement of the experimental protein estimate for butter, 0.611 (0.044)?g/100 g, n?=?3 lots, with a published value 0.6/100 g], and analyte selectivity (baseline resolution of FMOC-arginine and FMOC-aspartic acid from the FMOC derivatives of other common amino acids). The method provides for a reliable estimation of the protein content of anhydrous milk fat, when present at concentrations >2 mg/kg.     

Quality evaluation of Korean soy sauce fermented in Korean earthenware (Onggi) with different glazes

The aim of this study was to investigate the effect of porosity‐controlled earthenware as fermentation vessels for Korean soy sauce. Porosity of fermentation vessels was controlled by glazing the surfaces of Korean earthenware. Three kinds of onggis– the outside glazed, inside and outside glazed, and unglazed onggi – were made and used to investigate the effect of glazing on the fermentation of soy sauce. During fermentation of soy sauce in porosity‐controlled earthenwares at 30 °C for 4 months, physical, chemical, microbiological and sensory quality attributes were monitored. Compared to other vessels, soy sauce fermented in onggi with both inside and outside surfaces glazed showed less water loss (10.7%), salt content (17.6%) and pH (pH4.4) after the fourth month. It also produced higher total acidity (1.43%), protease activity (810 μg mL^?1 min^?1) and microbiological changes that included total aerobic bacteria [4.3 log(cfu mL^?1)], lactic acid bacteria [3.8 log(cfu mL^?1)] and yeast [4.2 log(cfu mL^?1)]. The contents of total nucleotide (200–255 mg per 100 g sample) and free amino acids (4634–4848 mg per 100 g sample) in soy sauce were not consistent with glazing, which may be more affected by other factors, such as water loss, than the porosity of vessels. However, the percentage of glutamic acid among total free amino acids was 23.6% in onggi with both surfaces glazed, which was a little higher than the 21.9% in the outside glazed and 21.5% in the unglazed. These positive physicochemical and microbiological changes during fermentation in onggi with both sides glazed also resulted in higher sensory quality.     

液相色谱-电喷雾飞行时间质谱法同时测定虫生真菌菌丝中16种游离氨基酸

采用液相色谱-电喷雾飞行时间质谱(LC-ESI-TOF-MS)法,选择阴离子电离模式,建立了一种同时检测虫生真菌菌丝中16种游离氨基酸的定性定量分析方法。研究结果表明:16种氨基酸的色谱特征和质谱离子特征明显,可用来对氨基酸进行准确定性分析。定量实验结果表明,16种氨基酸的线性范围广准确性高,在氨基酸浓度线性范围4.0～125μmol/L,16种氨基酸的峰面积与浓度相关系数都大于0.998。在氨基酸浓度为50μmol/L时,16种氨基酸的相对标准偏差在0.84%～2.75%之间。用液质联用法对7种虫生真菌菌丝样品中16种游离氨基酸含量的测定结果显示,同一菌株中各种氨基酸的含量相差较大,但所有供菌株中含量最高的均为苯丙氨酸,它在不同供试菌株中的含量范围为0.718～2.173 mg/g,其中中国被毛孢的苯丙氨酸含量最高。供试菌株中含量较高的氨基酸还有脯氨酸、缬氨酸、亮氨酸、异亮氨酸、赖氨酸和谷氨酸,它们含量大部分都在0.3mg/g以上,较其他氨基酸含量明显较高,这些含量较高的氨基酸可作为判定虫生真菌菌丝中游离氨基酸的特征指标。不同菌株的游离氨基酸总量也存在较大差异,中国被毛孢中游离氨基酸总含量为7.537 mg/g,较蝉棒束孢(3.196 mg/g)的总含量高出1.36倍。