Mineral Contents of Jerusalem Artichoke (Helianthus tuberosus L.) Growing Wild in Turkey

Macro- and micro-elements of Jerusalem artichoke (Helianthus tuberosus L.) tubers growing in Konya (Karap?nar and Çumra locations) provinces in Turkey were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Potassium, phosphorus, magnesium, and calcium contents of Jerusalem artichoke were found at high levels, whereas K content was found as 21615 mg/kg and 26251 mg/kg for Jerusalem artichoke; P contents of Jerusalem artichoke were found between 2585 and 4791 mg/kg; and Ca was determined between 1573 and 2073 mg/kg for Jerusalem artichoke. In addition, Zn content was found in a range from 11.0 mg/kg for Yaylap?nar to 15.6 mg/kg for Saraco?lu artichoke. While Fe content of Jerusalem artichoke was found between 23.32 mg/kg to 54.46 mg/kg, Cu content of Jerusalem artichoke was determined between 4.50 mg/kg to 8.98 mg/kg. The Cr contents of Jerusalem artichoke were found between 0.396 mg/kg to 0.642 mg/kg. Ash contents of Jerusalem artichoke tubers were found between 5.70% to 7.63%. Protein contents of Jerusalem artichoke samples were found between 6.23% to 10.71%.     

Hypoglycemic constituents of Gynura divaricata subsp. formosana

Gynura divaricata Kitam. subsp. formosana is a folk medicine used as a hypoglycemic agent for diabetes patients in Taiwan. Guided by the hexose transport assay, the hypoglycemic constituents of the aerial part of this plant were disclosed through chromatographic methods. They are fructooligosaccharides, including beta-D-fructofuranose, sucrose, 1-kestose, nystose, and 1(F)-beta-fructofuranosylnystose. The hexose transport assay indicated that nystose was the most potent among these compounds, showing a 46.7% difference from pinitol in the stimulation index at a concentration of 0.5 mg/mL.     

A new acetonitrile-free mobile phase method for LC-ELSD quantification of fructooligosaccharides in onion (Allium cepa L.)

Onion soluble non-structural carbohydrates consist of fructose, glucose and sucrose plus fructooligosaccharides (FOS) with degrees of polymerisation (DP) in the range of 3-19. In onion, sugars and FOS are typically separated using liquid chromatography (LC) with acetonitrile (ACN) as a mobile phase. In recent times, however, the production of ACN has diminished due, in part, to the current worldwide economic recession. A study was therefore undertaken, to find an alternative LC method to quantify sugars and FOS from onion without the need for ACN. Two mobile phases were compared; the first taken from a paper by Vågen and Slimestad (2008) [3] using ACN mobile phase, the second, a newly reported method using ethanol (EtOH). The EtOH mobile phase eluted similar concentrations of all FOS compared to the ACN mobile phase. In addition, limit of detection, limit of quantification and relative standard deviation values were sufficiently and consistently lower for all FOS using the EtOH mobile phase. The drawback of the EtOH mobile phase was mainly the inability to separate all individual sugar peaks, yet FOS could be successfully separated. However, using the same onion extract, a previously established LC method based on an isocratic water mobile phase could be used in a second run to separate sugars. Although the ACN mobile phase method is more convenient, in the current economic climate a method based on inexpensive and plentiful ethanol is a valid alternative and could potentially be applied to other fresh produce types.In addition to the mobile phase solvent, the effect of extraction solvents on sugar and FOS concentration was also investigated. EtOH is still widely used to extract sugars from onion although previous literature has concluded that MeOH is a superior solvent. For this reason, an EtOH-based extraction method was compared with a MeOH-based method to extract both sugars and FOS. The MeOH-based extraction method was more efficacious at extracting sugars and FOS from onion flesh, eluting significantly higher concentrations of glucose, kestose, nystose and DP5-DP8.     

NMR study of a novel pentasaccharide isolated from Penicillium citrium

Penicillium citrium produces several fructose oligomers, namely kestose, neokestose, nystose, 1‐furanosylnystose and a novel pentasaccharide. The pentasaccharide consists of four fructoses and one glucose but its structure is different from that of 1‐furanosylnystose. Its complete structure was determined based on various two‐dimensional NMR experiments. Copyright © 2003 John Wiley & Sons, Ltd.     

Properties of a thermostable nonspecific fructofuranosidase produced by cladosporium cladosporioides cells for hydrolysis of Jerusalem artichoke extract

Thermostable invertase (E.C. 3.2.1.26) and inulinase 2,1-beta-D-fructan fructanohydrolase (E.C. 3.2.1.7) activities were produced by Cladosporium cladosporioides grown on sucrose, inulin, yam extract, or Jerusalem artichoke. The ratio I (inulinase)/S(invertase) activity was between 0.31 and 0.36. Both activities had high temperature optima (60 degrees C) and were stable during pretreatment for 4.5 h at this temperature. Whole cells of C. cladosporioides were used for batch fructose production from Jerusalem artichoke extract at several concentrations. With the highest extract concentration used (260 g total sugars/L), total hydrolysis was achieved in 150 min at 60 degrees C. Thin-layer chromatography of the enzymatic hydrolysis of inulin and Jerusalem artichoke extract showed that from the beginning of the reaction, fructose was the only product released. This suggests an exoaction mechanism, beta-D-fructofuranoside fructohydrolase [E.C. 3.2.1.2.6].     

Importance of enzyme purity and activity in the measurement of total dietary fiber and dietary fiber components

A study was made of the effect of the activity and purity of enzymes in the assay of total dietary fiber (AOAC Method 985.29) and specific dietary fiber components: resistant starch, fructan, and beta-glucan. In the measurement of total dietary fiber content of resistant starch samples, the concentration of alpha-amylase is critical; however, variations in the level of amyloglucosidase have little effect. Contamination of amyloglucosidase preparations with cellulase can result in significant underestimation of dietary fiber values for samples containing beta-glucan. Pure beta-glucan and cellulase purified from Aspergillus niger amyloglucosidase preparations were used to determine acceptable critical levels of contamination. Sucrose, which interferes with the measurement of inulin and fructooligosaccharides in plant materials and food products, must be removed by hydrolysis of the sucrose to glucose and fructose with a specific enzyme (sucrase) followed by borohydride reduction of the free sugars. Unlike invertase, sucrase has no action on low degree of polymerization (DP) fructooligosaccharides, such as kestose or kestotetraose. Fructan is hydrolyzed to fructose and glucose by the combined action of highly purified exo- and endo-inulinases, and these sugars are measured by the p-hydroxybenzoic acid hydrazide reducing sugar method. Specific measurement of beta-glucan in cereal flour and food extracts requires the use of highly purified endo-1,3:1,4 beta-glucanase and A. niger beta-glucosidase. Beta-glucosidase from almonds does not completely hydrolyze mixed linkage beta-glucooligosaccharides from barley or oat beta-glucan. Contamination of these enzymes with starch, maltosaccharide, or sucrose-hydrolyzing enzymes results in production of free glucose from a source other than beta-glucan, and thus an overestimation of beta-glucan content. The glucose oxidase and peroxidase used in the glucose determination reagent must be essentially devoid of catalase and alpha- and beta-glucosidase.     

Rapid simultaneous quantification of fructooligosaccharides in Morinda officianalis by ultra‐high performance liquid chromatography

Many Chinese herbal medicines with tonifying effects contain high levels of inulin fructooligosaccharides. These herbal medicines have high development and utilization value because of their effects against dementia, depression, and oxidative stress; on improving learning and memory ability; and on enhancing immunity. In this study, a method was developed for the separation and simultaneous quantitation of fructose, glucose, sucrose, and ten inulin fructooligosaccharides by ultra‐high‐performance liquid chromatography with evaporative light scattering detection within 10 min. Separation was performed on an Amide column with gradient elution. The calibration curves for the 13 constituents showed good linearity (R² > 0.9991). The limits of detection and quantification were 10.78–33.44 and 35.94–124.81 μg/mL, respectively, and the recoveries ranged from 98.90 to 103.67%. This method was successfully used to quantify the 13 constituents in the Chinese herbal medicine Morinda officinalis. The contents of the ten inulin fructooligosaccharides ranged from 56.28 to 60.71%. This method is accurate, rapid and simple and can be used for quantitative analysis in the quality control of herbal medicines and functional foods.     

Cloning and functional characterization of a fructan 1-exohydrolase (1-FEH) in edible burdock (<Emphasis Type="Italic">Arctium lappa</Emphasis>L.)

Background  

We have previously reported on the variation of total fructooligosaccharides (FOS), total inulooligosaccharides (IOS) and inulin in the roots of burdock stored at different temperatures. During storage at 0°C, an increase of FOS as a result of the hydrolysis of inulin was observed. Moreover, we suggested that an increase of IOS would likely be due to the synthesis of the IOS by fructosyltransfer from 1-kestose to accumulated fructose and elongated fructose oligomers which can act as acceptors for fructan:fructan 1-fructosyltransferase (1-FFT). However, enzymes such as inulinase or fructan 1-exohydorolase (1-FEH) involved in inulin degradation in burdock roots are still not known. Here, we report the isolation and functional analysis of a gene encoding burdock 1-FEH.     

高效液相色谱-蒸发光散射法测定食品中的单糖、双糖、低聚果糖和糖醇

建立了食品中常用的木糖、果糖、葡萄糖、蔗糖、麦芽糖、乳糖、蔗果三糖、蔗果四糖、蔗果五糖、赤藓糖醇、木糖醇、甘露糖醇、麦芽糖醇等13种单糖、双糖、低聚果糖和糖醇的高效液相色谱同时分离检测的方法。该法采用NH₂色谱柱,以乙腈-水为流动相梯度洗脱,蒸发光散射检测器检测;13种糖在0.1~5 g/L内均具有良好的线性关系,检出限均在0.1 g/L以下,精密度(RSD)为2.69%~7.21%,回收率为96.1%~105.2%,结果较为理想。将该法用于实际样品检测,结果显示食品标签明示和实际成分相差较大。     

Chemical Fingerprint Analysis and Quantitative Analysis of Saccharides in Morindae Officinalis Radix by HPLC-ELSD

A method based on high performance liquid chromatography with evaporative light scattering detection (HPLC-ELSD) was developed for the quantitative analysis of three active compounds and chemical fingerprint analyses of saccharides in Morindae officinalis radix. Ten batches of Morindae officinalis radix were collected from different plantations in the Guangdong region of China and used to establish the fingerprint. The samples were separated with a COSMOIL Sugar-D column (4.6 mm × 250 mm, 5 μm) by using gradient elution with water (A) and acetonitrile (B). In addition, Trapped-Ion-Mobility (tims) Time-Of-Flight (tims TOF) was used to identify saccharides of Morindae officinalis radix. Fingerprint chromatogram presented 26 common characteristic peaks in the roots of Morinda officinalis How, and the similarities were more than 0.926. In quantitative analysis, the three compounds showed good regression (r = 0.9995–0.9998) within the test ranges, and the recoveries of the method were in the range of 96.7–101.7%. The contents of sucrose, kestose and nystose in all samples were determined as 1.21–7.92%, 1.02–3.37%, and 2.38–6.55%, respectively. The developed HPLC fingerprint method is reliable and was validated for the quality control and identification of Morindae officinalis radix and can be successfully used to assess the quality of Morindae officinalis radix.     

Purification and determination of stachyose in Chinese artichoke (Stachys Sieboldii Miq.) by high-performance liquid chromatography with evaporative light scattering detection

A high-performance liquid chromatography (HPLC) method with evaporative light scattering detection (ELSD) was applied for simultaneous determination of stachyose, sucrose and raffinose in Chinese artichoke (Stachys Sieboldii Miq.). Carbohydrates were separated on a Bondapak NH₂ column using a ternary solvent mixture of methanol-acetonitrile-water (55:25:20, v/v/v) as mobile phase. Two different crafts (method 1 and method 2) for extraction and purification of stachyose in Chinese artichoke tubers were detailed and evaluated. Method 1 can meet the purpose of quantification and method 2 is appropriate for the purpose of purification. The content of stachyose in dry tubers was determined to be 236.0 mg/g (from method 1) and the purity of the extracted stachyose flour was calculated to be 87.34% (from method 2), respectively. The analytical method fulfills all the standard requirements of linearity, accuracy and precision. Therefore, it is suitable for purification and routine quantification of stachyose in Chinese artichoke.     

<Emphasis Type="Italic">Rhizopus stolonifer</Emphasis> LAU 07: a novel source of fructosyltransferase

Increasing awareness of the importance of fructooligosaccharides (FOS) as ingredients of functional foods has led to intensive search of new sources of fructosyltransferases (FTase), enzymes responsible for the conversion of sucrose to fructooligosaccharides. A local strain of Rhizopus stolonifer isolated from spoilt orange fruit with high fructosyltransferase activity (U _t) of 12.31–45.70 U mL⁻¹ during a fermentation period of 24–120 h is herein reported. It showed low hydrolytic activity (U _h) in the range of 0.86–1.78 U mL⁻¹ during the same period. FOS yield of 34 % (1-kestose, GF₂, nystose, GF₃) was produced by FTase obtained from a 72 h-old culture using 60 g of sucrose per 100 mL of the substrate. When the isolate was grown in a defined submerged medium, its pH dropped sharply from the intial value of 5.5 to 1.0 within 24 h, and this value was maintained throughout the fermentation. The biomass content ranged from 8.8 g L⁻¹ at 24 h of fermentation to reach the maximum of 10 g L⁻¹ at 72 h. It was reduced to 5.6 g L⁻¹ at the end of 120 h of fermentation. This report represents the first reference to a strain of Rhizopus as a source of FTase for the production of FOS. The high U _t/U _h ratio shown by this isolate indicates that it may be a good strain for the industrial and commercial production of FOS. However, there is a need of further optimization of the bioprocess to increase the conversion efficiency of sucrose to FOS by the enzyme.     

Glucofructans from <Emphasis Type="Italic">Saussurea lappa</Emphasis> roots

Glucofructans from Saussurea lappa (Asteraceae) roots were studied. It was found that free fructose and oligomeric glucofructans (saccharose, 1-kestose, nystose, 1^F-β-fructofuranosylnystose, and 1^F-β-fructofuranosyl-1^F-β-fructofuranosylnystose) were present. The dominant polymer Sl-GF (MW 51.4 kDa), which was a linear inulin-type glucofructan consisting of β-(2 → 1)-bonded fructofuranose units, was isolated and characterized. The total content of glucofructans in Saussurea lappa roots was 476.97–578.27 mg/g.     

Measurement of total fructan in foods by enzymatic/spectrophotometric method: collaborative study

An AOAC collaborative study was conducted to evaluate the accuracy and reliability of an enzyme assay kit procedure for measuring oligofructans and fructan polysaccharide (inulins) in mixed materials and food products. The sample is extracted with hot water, and an aliquot is treated with a mixture of sucrase (a specific sucrose-degrading enzyme), alpha-amylase, pullulanase, and maltase to hydrolyze sucrose to glucose and fructose, and starch to glucose. These reducing sugars are then reduced to sugar alcohols by treatment with alkaline borohydride solution. The solution is neutralized, and excess borohydride is removed with dilute acetic acid. The fructan is hydrolyzed to fructose and glucose using a mixture of purified exo- and endo-inulinanases (fructanase mixture). The reducing sugars produced (fructose and glucose) are measured with a spectrophotometer after reaction with para-hydroxybenzoic acid hydrazide. The samples analyzed included pure fructan, chocolate, low-fat spread, milk powder, vitamin tablets, onion powder, Jerusalem artichoke flour, wheat stalks, and a sucrose/cellulose control flour. Repeatability relative standard deviations ranged from 2.3 to 7.3%; reproducibility relative standard deviations ranged from 5.0 to 10.8%.     

Effect of the Addition of Dried Dandelion Roots (Taraxacum officinale F. H. Wigg.) on Wheat Dough and Bread Properties

Dried and crushed dandelion roots (Taraxacum officinale F. H. Wigg.) (TO) were used as a formulation additive (at the amount of 0, 1, 3, 4, 5, and 6 g 100 g⁻¹ flour) to wheat bread. The farinographic properties of the dough and the physical and chemical properties of the bread were evaluated. It was found that the addition of dried flour caused a significant decrease in water absorption by the flour (1% and higher TO level), an increase in the development time (from 2% to 5% TO addition) and dough stability (3% and 4% TO level), and an increase in dough softening (4% and higher TO level). As the substitution of TO for wheat flour increased, there was a gradual decrease in loaf volume, an increase in specific weight and crumb hardness, and a darkening of the crumb color. The total polyphenol content increased linearly with the percentage increase of dried root additions TO from 0.290 to 0.394 mg GAE g⁻¹ d.m_., which translated into an increase in the antioxidant activity of the bread. It was found that dried crushed roots of Taraxacum officinale can be a recipe additive for wheat bread; however, due to their specific smell and bitter aftertaste, the level of this additive should not exceed 3 g 100 g⁻¹ flour.     

Glucofructans from <Emphasis Type="Italic">Taraxacum officinale</Emphasis> roots

The structure of glucofructans from Taraxacum officinale roots growing in Buryatia was studied by chemical, chromatographic, and spectral methods. It was found that fructose,glucose, saccharose, 1-kestose, and nystose were present in the free state. The structures of the two dominant polymeric compounds, TGf-1 (5.7 kDa) and TGf-2 (2.6 kDa), which were linear inulin-type macromolecules consisting of fructofuranose units bonded through β-(2→1)-bonds, were studied. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 125–127, March–April, 2009.     

Hydrolytic Methods for the Quantification of Fructose Equivalents in Herbaceous Biomass

A low, but significant, fraction of the carbohydrate portion of herbaceous biomass may be composed of fructose/fructosyl-containing components (“fructose equivalents”); such carbohydrates include sucrose, fructooligosaccharides, and fructans. Standard methods used for the quantification of structural-carbohydrate-derived neutral monosaccharide equivalents in biomass are not particularly well suited for the quantification of fructose equivalents due to the inherent instability of fructose in conditions commonly used for hemicellulose/cellulose hydrolysis (>80% degradation of fructose standards treated at 4% sulfuric acid, 121°C, 1 h). Alternative time, temperature, and acid concentration combinations for fructan hydrolysis were considered using model fructans (inulin, β-2,1, and levan, β-2,6) and a grass seed straw (tall fescue, Festuca arundinacea) as representative feedstocks. The instability of fructose, relative to glucose and xylose, at higher acid/temperature combinations is demonstrated, all rates of fructose degradation being acid and temperature dependent. Fructans are shown to be completely hydrolyzed at acid concentrations well below that used for the structural carbohydrates, as low as 0.2%, at 121°C for 1 h. Lower temperatures are also shown to be effective, with corresponding adjustments in acid concentration and time. Thus, fructans can be effectively hydrolyzed under conditions where fructose degradation is maintained below 10%. Hydrolysis of the β-2,1 fructans at temperatures ≥50°C, at all conditions consistent with complete hydrolysis, appears to generate difructose dianhydrides. These same compounds were not detected upon hydrolysis of levan, sucrose, or straw components. It is suggested that fructan hydrolysis conditions be chosen such that hydrolysis goes to completion; fructose degradation is minimized, and difructose dianhydride production is accounted for.     

Optimum conditions for transformed Panax ginseng hairy roots in flask culture

Panax ginseng hairy roots were transformed by Agrobacterium rhizogenes KTCT 2744. They showed an active branching pattern and fast growth in hormone-free medium, and good growth at 23°C, pH 5.8, 1/2 MS medium, and 3% sucrose. Sucrose provided the highest growth among seven carbon sources tested. Six complex media were also tested. In the combined sugar study, hairy roots grew better on sucrose without glucose or fructose than with glucose or fructose. In the 1/2 MS basal medium, 30 mM in nitrogen and 0.62 mM phosphate salt concentration was the optimum. The growth ratio was maximal at an inoculum size of 0.4% (w/v). Crude saponin and polysaccharide levels were also measured.     

Design and economics of industrial production of fructooligosaccharides

A process for industrial production of fructooligosaccharides (FOS’s) based on the conversion of sucrose by immobilized fructosyltransferase (FTase) from the cells of Aureobasidium pullulans CCY 27-1-94 was developed. Particular process operations and conditions were designed employing results of laboratory and semi-pilot scale experiments. The process flowsheet comprised three sections: FTase production, which included fermentation, isolation and purification of the enzyme, FTase immobilization and FOS’s production where a product with a high content of FOS’s was prepared by the removal of glucose, fructose and unreacted sucrose from the reaction mixture using simulated moving-bed chromatography. Two alternative process flowsheets were proposed for the annual production of 10 000 t of FOS’s: one for a powdery product and the second one for syrup. The economic analysis provided the costs for the production of immobilized FTase and FOS’s using two different price estimates for sucrose.     

Extraction,purification procedures and HPLC-RI analysis of carbohydrates in olive (Olea europaea L.) plants

Summary Qualitative and quantitative analyses of carbohydrates in olive (Olea europaea L.) tissues have been carried out by HPLC-RI. Sample purification was by two successive solid-liquid extractions to remove completely plant phenolics and pigments. Five carbohydrate peaks; sucrose (stachyose + raffinose + sucrose), glucose, galactose, fructose (fructose + myo-inositol) and mannitol were detected when plant extracts were run on a Sugar SC 1011 column operating at 75°C, using water as eluent 0.5 ml min⁻¹. The use of two serial Sugar SC 1011 columns operating at 90°C and eluting the plant extracts with H₂O−CH₃CN (95/5 v/v) enables identification and quantification of nine carbohydrates, including tetra and tri-saccharides.