RP-HPLC法测定新疆6种红枣中齐墩果酸和熊果酸的含量

采用反相高效液相色谱法测定新疆不同品种红枣中齐墩果酸和熊果酸的含量。采用Kromasil C18柱(4.6 mm×250 mm,5μm),流动相为甲醇-0.03 mol/L的磷酸二氢钠(磷酸调pH至3.0)(90:10),流速为0.8 mL/min,检测波长为210 nm,柱温25℃。上述色谱条件下红枣中齐墩果酸、熊果酸可完全分离,线性范围分别为齐墩果酸0.4～ 2.0μg(r=0.9998),熊果酸0.448～ 2.24μg(r=0.9999);平均回收率分别为齐墩果酸99.4%,RSD=1.33%,熊果酸99.6%,RSD=1.43%(n=6)。该方法快速、准确、可靠,可用于红枣中齐墩果酸和熊果酸含量的同时测定。     

高效液相色谱法测定芍药中齐墩果酸和熊果酸含量

目的：建立高效液相色谱法测定芍药不同器官中齐墩果酸和熊果酸含量的检测方法。方法：超声波乙醇提取样品中的齐墩果酸和熊果酸,色谱柱为Lichrospher C18柱(250mm×4.6mm,5μm),流动相为甲醇-0.1%磷酸溶液(85:15,V/V),柱温30℃,流速1mL/min,检测波长210nm。结果：齐墩果酸和熊果酸在25～100μg/mL范围内均呈良好的线性关系,相关系数均在0.998(n＝5)以上;日内差异系数和日间差异系数分别为1.27%～2.96%和1.33%～3.64%,OA和UA精确性分别为1.28%～3.52%和0.96%～2.88%,平均回收率分别为98.87%和98.70%。结论：该方法简单快速、结果准确,可为测定芍药不同组织中齐墩果酸和熊果酸含量提供一种高效快速的测定方法。     

反相高效液相色谱测定不同品种皱皮木瓜中齐墩果酸和熊果酸含量

采用反相高效液相色谱法测定鲜皱皮木瓜中齐墩果酸和熊果酸含量,并进行方法学考察.采用Agilent C18 柱(4.6mm×250mm,5μm);流动相:甲醇-1%HAc水溶液(85:15);流速:0.6ml/min;柱温:35℃;检测波长:210nm.齐墩果酸在0.162～6.48 μg范围内线性良好,回归方程为y=512802x 19211(R2=0.9997),平均回收率分别为100.2%,RSD为0.9%(n=6);熊果酸在0.391～15.62μg范围内线性良好,回归方程为y=50865x-5090.4(R2=0.9998),平均回收率为100.0%,RSD为1.1%.该方法简便准确,重现性好,适用于鲜皱皮木瓜中齐墩果酸和熊果酸的定量分析.     

HPLC法同时测定野木瓜中齐墩果酸与熊果酸的研究

采用HPLC法,同时测定贵州特产野木瓜中差向异构体--齐墩果酸、熊果酸含量.实验表明在色谱柱为Shim-pack VP-ODS柱(250nm×4.6mm,5μm);流动相为乙腈-1.1%乙酸水(94:6);流速为0.5mL/min;检测波长205nm;柱温为室温;进样量20μl时,两物质特征峰分离良好,检测结果准确,测得野木瓜中齐墩果酸平均含量为0.1138%,熊果酸平均含量为0.4400%.     

高效液相色谱法(HPLC)测定山楂片中的熊果酸和齐墩果酸

建立了高效液相色谱同时测定山楂片中熊果酸和齐墩果酸含量的方法。色谱条件：色谱柱Hypersil BDS C18（4.6mm×200mm,5μm）,柱温为25℃,UV检测波长2l0nm,流动相为甲醇-磷酸水溶液（pH=3.0）（85∶15）,流速为0.5mL/min。结果表明：熊果酸和齐墩果酸的线性范围38.0μg/mL～600μg/mL（r=0.9991）和12.5μg/mL～200μg/mL（r=0.9994）,平均回收率分别为99.06%和99.17%,RSD分别为1.43%（n=5）和2.49%（n=5）;该方法简便、准确,适合于山楂片中熊果酸和齐墩果酸含量的测定。     

RP-HPLC法测定石榴不同部位中熊果酸和齐墩果酸的含量

采用超声技术提取石榴不同部位中熊果酸和齐墩果酸,建立RP-HPLC法测定其含量。色谱柱为KromasilC18柱(250mm×4.6mm,5μm),流动相为甲醇-0.2%磷酸水溶液(87∶13),光电二极管阵列检测器,检测波长210nm,流速0.8mL/min,柱温28℃。熊果酸进样量在0.443~7.088μg,齐墩果酸进样量在0.247~3.952μg时呈现良好的线性关系,相关系数均为0.9999,平均加样回收率分别为98.53%和98.36%,RSD分别为1.3%和1.5%。本方法灵敏、准确,重现性好,可用于石榴不同部位中熊果酸和齐墩果酸含量的测定。     

RP-HPLC法测定核桃外果皮中齐墩果酸的含量

建立核桃外果皮中齐墩果酸含量测定的反相高效液相色谱法(RP-HPLC),采用色谱柱为Intersil ODS(150 mm×4.6 mm,5μm);流动相为甲醇:水:冰乙酸(265:35:0.1,V/V);流速0.8 mL/min;进样量20 μL;检测波长为210 nm;柱温30℃.结果表明,齐墩果酸进样量在0.728～7.28 μg(r=0.999 7)范围内呈现良好的线性关系,齐墩果酸平均回收率(n=9)为101.1%,相对标准偏差(RSD)为2.44%.测得核桃外果皮中齐墩果酸含量为2.1 mg/100 g.该方法简便快速,结果可靠准确,重现性和稳定性好.     

HPLC法测定山茱萸及其浸泡酒中熊果酸和齐墩果酸总量

建立了测定山茱萸及其浸泡酒中熊果酸和齐墩果酸总量的方法.样品使用无水乙醇超声提取,0.45 μm微孔滤膜过滤,滤液用高效液相法分析.色谱柱为Phenomsil C18 BDS柱(250 m×4.6 m,5μm),色谱柱温35℃,检测波长为215 nm,流动相为甲醇-水-冰乙酸(85:15:0.3);流速为0.6 mL/min.该法测得熊果酸的线性范围为0.52～5.20 μg,回归方程为A=381.63C-3.0644(R=0.9995),平均回收率为99.13%,RSD=1.98%(n=5);山茱萸及其浸泡酒中熊果酸和齐墩果酸总量分别为0.324%、0.147%.此法准确、快捷、重复性好,适合于山茱萸及其浸泡酒中熊果酸和齐墩果酸总量的测定.     

高效液相色谱法检测果蔬饮料中齐墩果酸和熊果酸

建立一种快速、有效的固相萃取-高效液相色谱法测定果蔬饮料中齐墩果酸、熊果酸的方法。样品经乙醇提取后,采用氨基固相萃取小柱进行净化和富集。采用Waters RP C18色谱(4.6mm×250mm,5μm)分离,以甲醇︰0.1%磷酸溶液(85︰15)作为流动相,用PDA检测器检测,外标法峰面积定量。结果表明,齐墩果酸、熊果酸标准在10.0μg/m L~100.0μg/m L浓度范围内线性良好,相关系数均r~2均为0.999,齐墩果酸组分的LOD为0.05 mg/kg,LOQ为0.15 mg/kg,熊果酸组分的LOD为0.08 mg/kg,LOQ为0.24 mg/kg,加标回收率达到87.9%~94.1%。该方法具有前处理简单、净化效果好、灵敏度高和检测速度快的优点,适用于果蔬饮料中齐墩果酸、熊果酸的富集和定量检测。     

建立反相高效液相色谱法测定宣木瓜中齐墩果酸的含量

建立反向高效液相色谱法测定宣木瓜中齐墩果酸的含量。采用PhenomenexC18色谱柱(250mm×4.6mmi.d.,5μm),流动相为V(甲醇)∶V(磷酸水溶液,pH=2.0)=85∶15,柱温27℃,流速0.8mL/min,进样量5μL,检测波长210nm。结果:齐墩果酸进样量在(0.5～3)μg范围内,线性关系良好,回归方程为:Y=4103095.714X-49564.000(R2=0.999)。齐墩果酸的平均回收率为93.59%,RSD为2.81%。方法操作简便,精密度高,重复性好,为宣木瓜中齐墩果酸的含量测定提供可靠的科学研究依据。     

ANTIFUNGAL EFFECTS OF SORBIC ACID AND PROPIONIC ACID AT DIFFERENT pH AND NaCl CONDITIONS

The effect of pH (7, 5.6, 3.5), NaCl concentration (3 to 20% w/v) and EDTA on the antifungal activity of sorbic acid and propionic acid (Ca salt) against Candida spp. , Sporothrix sp. , Fusarium sp. , Penicillium spp. , Paecilomyces sp. and Aspergillus spp. was investigated by the Spiral Gradient End Point Test. Sorbic acid was active against most yeasts and molds, and in the presence of EDTA, which enhanced the effect of sorbic acid, all the organisms tested were inhibited. Sorbic acid was most effective at low pH. The inhibitory effect of sorbic acid increased with increasing NaCl concentration for all test organisms. Propionic acid was not as active as sorbic acid, but when combined with EDTA the inhibition was improved for some of the molds tested. Increasing or decreasing the pH did not change the antifungal activity of propionic acid. Synergistic effects of NaCl occurred at concentrations higher than 10%, but when EDTA was added, the inhibition was seen even at the lower NaCl concentrations.     

异Vc和Vc水溶液稳定性的比较研究

将Vc和异Vc配成水溶液，利用碘量法测定在不同时间、不同条件下它们的浓度，通过比较保存率，考察了水溶液pH值、金属离子和金属络合剂、光、水质、食盐和温度等因素对它们稳定性的影响。试验所表现出的总体规律是：相同条件下，Vc比异Vc更稳定。     

SYNERGISM BETWEEN HOP RESINS AND PHOSPHORIC ACID AND ITS RELEVANCE TO THE ACID WASHING OF YEAST

Hop resins present in brewery yeast slurries have a bactericidal action on lactic acid bacteria during the acid washing process.     

SYNERGISM OF CRANBERRY PHENOLICS WITH ELLAGIC ACID AND ROSMARINIC ACID FOR ANTIMUTAGENIC AND DNA PROTECTION FUNCTIONS

Several studies have shown the antimutagenic DNA protective functions of some naturally occurring phenolic phytochemicals. Emerging research also indicates that synergistic functionality of these phytochemicals in whole foods benefits the management of many diseases. Here we have investigated the potential antimutagenic properties of cranberry phenolics, ellagic acid (EA), rosmarinic acid (RA) and their synergistic interactions on enhancing antimutagenic properties in Salmonella typhimurium tester system against mutagens sodium azide and N‐methyl‐N′‐nitro‐N‐nitrosoguanidine. Ability of these phytochemical treatments to protect oxidative damage to DNA was also investigated using the supercoiled DNA strand scission assay. Results showed that EA was most effective in inhibiting the mutations in S. typhimurium system, whereas RA and EA were equally effective in protecting the DNA from oxidative damage. Results also showed that the antimutagenic functionality of cranberry powder (CP) made from juice extracts was significantly enhanced when 30% (w/w) of phenolics in CP was substituted with RA and EA possibly because of synergistic redox modulation that can influence mutagen function. It is also suggested that the synergistic mixture of cranberry phenolics with RA could also be protecting the cell from mutations by modulating DNA repair systems.     

FATTY ACID COMPOSITION AND CONJUGATED LINOLEIC ACID CONTENT OF COW AND GOAT CHEESES FROM NORTHWEST ARGENTINA

ABSTRACT

In this study, we evaluated chemical characteristics, fatty acid composition and conjugated linoleic acid (CLA) content of cow and goat cheeses from Northwest Argentina. Similar chemical and fatty acid composition were determined in milk and cheese of both species. Palmitic, oleic and myristic acids were the most abundant fatty acids in dairy products. CLA level averaged 0.85 and 0.96 in milk and 0.76 and 1.04 g/100 g of fatty acids in cheese of cow and goat, respectively. Cis‐9,trans‐11 was the major isomer present in both species. Significant differences in CLA desaturase activity were observed, showing a value of 0.068 and 0.064 in milk, and 0.077 and 0.071 in cheese of cow and goats, respectively. Good nutritional properties were determined for cheeses of both species, which are fed on natural pasture during spring and summer seasons. Goat's cheese represents a higher source of CLA for human consumers than cow's cheese, offering from 156.6 to 222.6 mg/ 100 g of sample.

PRACTICAL APPLICATIONS

The present work shows the fatty acid composition and chemical characteristics of two fresh cheeses manufactured with cow and goat milk. Animals were fed on natural pasture during summer and spring seasons. It is known that pasture increases conjugated linoleic acid (CLA) concentration in milk fat, and the content in cheese is directly related to it. The CLA content of dairy products for the human consumers was analyzed, showing goat cheese with high polyunsaturated fatty acid content, including CLA. Cow and goat fresh cheese offer CLA as many ripening products of different countries, as cheddar or hard cheeses. Lipid composition of food is related to many illnesses, but some compounds are beneficial to human health. The main sources of CLA are milk and cheeses, and in Northwest of Argentina, no data are reported about it, where artisanal cheeses are consumed by the population. Therefore, the atherogenicity index was determined as well.     

FATTY ACID COMPOSITION IN TISSUES OF MICE FED DIETS CONTAINING CONJUGATED LINOLENIC ACID AND CONJUGATED LINOLEIC ACID

The influence of 1% alpha-eleostearic acid (α-ESA, cis9,trans11,trans 13-18:3) and 1% punicic acid (PA, cis9,trans11,cis13-18:3) on fatty acid composition in mouse tissues was compared with conjugated linoleic acid (CLA, mixture of primarily cis9,trans11- and trans10,cis12-18:2) in the present study. The content (% total fatty acids) of 18:2n-6 was significantly reduced in the heart and adipose tissues, and total polyunsaturated fatty acids (PUFAs) and n-6 PUFA were significantly reduced in adipose tissue by α-ESA, PA and CLA feeding. The content of 22:6n-3 and total n-3 PUFA were significantly increased in the liver, kidney and heart by PA feeding, but not by α-ESA. In contrast to PA, supplementation with CLA significantly decreased 22:6n-3 in the liver, kidney and heart. The content of 20:4n-6 was significantly decreased in the liver and kidney by CLA feeding, but not by α-ESA and PA. The present results indicate that α-ESA, PA and CLA have differential effects on 22:6n-3 and 20:4n-6 content in mouse tissues.

PRACTICAL APPLICATIONS

Conjugated linolenic acid (CLnA), a group of octadecatrienoic acid isomers with a conjugated triene system, has been reported to exhibit favorable physiological effects, including anticancer properties and regulation of lipid metabolism. Punicic acid and alpha-eleostearic acid, two isomers of CLnA, have been shown to convert into cis 9, trans 11-18:2 in vivo . The effect of CLnA on fatty acid composition in mouse tissues was investigated in comparison with CLA mixtures in the present study. The data obtained here could provide information for the potential application of CLnA-containing seeds as functional food ingredients, a natural source of endogenously formed cis 9, trans 11-18:2 and a dietary feeding strategy to beneficially modify the fatty acid composition of animal tissues.     

SOYBEAN WHEY PROTEINS-RECOVERY AND AMINO ACID ANALYSIS

SUMMARY– About 14 million Ib of soybean whey protein of high biological value is disposed of as waste based on estimated production figures for soybean concentrates and isolates. An estimated 5–7% annual increase in consumption poses serious waste disposal problems and alternates should be sought. By simulated commercial procedures, yield and protein content of soybean whey were determined. Whey solids account for 2–28% of original nitrogen in dehulled, defatted flakes. Whole whey protein was prepared by dialysis, and whey was also fractionated by heating into heat-coagulable and supernatant proteins. Whole whey protein has a good balance of essential amino acids when compared with a system followed by the Food and Agricultural Organization of United Nations based on hen's egg protein. Heat-coagulable and supernatant proteins varied greatly: heat-coagulable fractions had 42% of the sulfur amino acid content but 181% of the tryptophan content of hen's egg protein; supernatant protein had 142% of the sulfur amino acid content but only about 60% of the isolevcine, valine, leucine and tryptophan content of hen's egg protein. All three whey protein fractions would be suitable for addition to feeds.     

CARBOISIYL AND FATTY ACID ANALYSIS OF ANTELOPE AND BEEF FAT

Characterization of kidney fat from twelve antelope and four beef was accomplished by monocarbonyl, ketoglyceride and fatty acid analysis. Antelope lipids are highly saturated, possessing strong odor and flavor characteristics which many people find objectionable. The antelope fat had a stearic acid content of 42% and an oleic acid content of only 20% while beef fat contained 28% stearic and 34% oleic acid. The lipid was further analyzed by reacting on a 2, 4-DNPH Celite impregnated column. The derivatives were separated from unreacted lip-id, and monocarbonyls and ketoglycerides fractionated using column chromatography. The ratio of monocarbonyls to ketoglycerides was about 1:3 in beef and 1:1 in antelope. Amounts of monocarbonyls average 0.70 μM/g of fat for beef and 1.47 μM/g of fat for antelope. Further analysis of the monocarbonyls indicated 7% methyl ketones, 70% saturated aldehydes, 18% enals and 6% 2,4 dienals in beef while antelope had 15%, 70%, 11% and 4%, respectively. Major constituents of the saturated aldehydes were C₂ through C₈ for both species and C₁₀ for beef while the major methyl ketones were C₃ through C₇ for both species. Methyl ketone, saturated aldehyde and enal fractions showed similar trends in composition with short-chain components higher in antelope and long-chain components higher in beef. Considerable variation occurred among animals of the same species.