Evaporative Light Scattering Detection Method Research Articles

Beeswax Fractions Used as Potential Oil Gelling Agents

AbstractThe objective of this work was the fractionation of beeswax to investigate the phase behavior of binary blends of the fractions and their potential use as gelling agents in edible oleogels. We have extracted seven distinctive fractions, using preparative flash chromatography with eluents permitted to be used in the processing of food raw materials. The odor profile of the fractions was characterized. The high purity of collected fractions was shown through thin‐layer chromatography, Fourier‐transform infrared spectroscopy, and high‐performance liquid chromatography with an evaporative light scattering detector methods for hydrocarbons (94.8%), monoesters (97.6%), and mixed mono‐, di‐, and triesters fraction (98.7%). Free fatty acids and fatty alcohol fractions had lower purity which equals 82.6% and 39%, respectively. The analysis of the binary pseudo phase diagram revealed that all fractions combined with hydrocarbons express eutectic behavior. Combinations of all other fractions resulted in the formation of solid solutions. This study shows that the texture of oleogels can be improved by using a combination of various fractions of beeswax instead of native wax.

Quality control of Dioscoreae Nipponicae Rhizoma based on fingerprint and quantitative analysis

Dioscoreae Nipponicae Rhizoma, the dried rhizoma of Dioscorea nipponica, has been widely used in traditional Chinese medicines. According to the different of the growth and cultivation patterns, Dioscoreae Nipponicae Rhizoma can be divided into two species, the wild Dioscoreae Nipponicae Rhizoma and the cultivated Dioscoreae Nipponicae Rhizoma. In this paper, an accurate and reliable fingerprint of Dioscoreae Nipponicae Rhizoma was established based on HPLC coupled with evaporative light scattering detector(ELSD). A total of 6 common peaks were marked, and the similarity of the Dioscoreae Nipponicae Rhizoma samples was above 0.950. The results indicated that the established fingerprint could be used for quality evaluation of Dioscoreae Nipponicae Rhizoma. Moreover, an HPLC coupled with ELSD method was developed for simultaneous quantitative analysis of six steroidal saponins, including protodioscin, protogracillin, methyl protodioscin, pseudoprotodioscin, dioscin and gracillin in wild Dioscoreae Nipponicae Rhizoma and cultivated Dioscoreae Nipponicae Rhizoma samples. Furthermore, chemometrics analysis such as principal component analysis and partial least squares discriminant analysis were performed to compare and discriminate wild Dioscoreae Nipponicae Rhizoma and cultivated Dioscoreae Nipponicae Rhizoma samples based on the quantitative data. The results indicated that the contents of steroidal saponins were notably different between the wild and cultivated Dioscoreae Nipponicae Rhizoma, and protodioscin and protogracillin were significant to effectively discriminate the wild and cultivated Dioscoreae Nipponicae Rhizoma samples, and these two compounds could be recognized as chemical markers. In conclusion, this present study might provide useful data and acceptable analysis method for identification and quality evaluation of Dioscoreae Nipponicae Rhizoma.

Erythrocyte Membrane and Plasma Fatty Acids Composition in Patients with Coronary Heart Disease Requiring Percutaneous Angioplasty

Aims: Atherosclerosis is associated with oxidative stress and fatty acid composition plays a critical role in vascular endothelial dysfunction and injury leading to the coronary atherosclerotic progression. However, the correlation between the fatty acid profile and coronary atherosclerosis is debatable. The goal of this study is to assess the erythrocyte membrane and plasma fatty acid composition in patients with coronary heart disease.
 Methods: The erythrocyte membrane and plasma distributions of fatty acids were quantified in patients with coronary heart disease (n = 30, group A) which needs both intensive medication and elective percutaneous coronary intervention and age-matched controls (n = 38, group B) using high-performance liquid chromatography combined with evaporative light scattering detection method. Baseline data were extracted from medical records.
 Results: Logistic regression analysis demonstrated that hypoalbuminemia (p = 0.010) and HbA1c (p = 0.005) are associated with required percutaneous coronary intervention. Although appropriate logistic regression model for percutaneous coronary intervention could not be obtained by incorporating fatty acid components, percutaneous coronary intervention was correlated mostly to the increased oleic acid and decreased stearic acid in both erythrocyte membrane and plasma in receiver-operating characteristic analysis.
 Conclusion: This single-center, cross-sectional study indicated that erythrocyte membrane and plasma fatty acids have a potential impact on the coronary atherosclerotic progression which requires coronary intervention. Longitudinal studies are necessary to clarify the clinical role of fatty acids distribution as a novel atherogenic marker.

Dynamic Analysis of Nucleosides and Carbohydrates during Developmental Stages of Cordyceps militaris in Silkworm (Bombyxmori).

Background: Cultured Cordyceps militaris is very popular. Objective: To gain dynamic insight into activity markers in fruiting body of Cordyceps militaris (C. militaris) in Bombyxmori (B. mori), also named silkworm. Methods: The development stages of samples at 3, 9, 12, 19, 27, and 33 days after inoculation (DAI) were collected. HPLC coupled with diode array detection and evaporative light-scattering detection method (HPLC-DAD-ELSD) was used to determine eight makers, including six nucleosides and two carbohydrates from the samples. Results: C. militaris cultured 33 DAI with fifth star silkworm larva could accumulate higher levels of cordycepin (13.43 mg/g) than the highest reported cordycepin (8.57 g/L). The contents of cordycepin, adenosine, and trehalose were gradually increased with the formation of C. militaris fruiting bodies on silkworm larva, while mannitol was decreased. The change of guanosine was similar to uracil. Conclusions: Results suggested that mannitol could be accumulated in a short period during mycelium growth and could metabolize and transform into energy store and trehalose during fruit body formation. The inosine in the insect was completely utilized and transformed. The synergistic formation of cordycepin and adenosine or differences in metabolized pathways are a great possibility according to the same trend. Highlights: This research offered some reference to further find a certain regularity or metabolic mechanism.

Comparative Analysis of Carbohydrates, Nucleosides and Amino Acids in Different Parts of Trichosanthes kirilowii Maxim. by (Ultra) High-Performance Liquid Chromatography Coupled with Tandem Mass Spectrometry and Evaporative Light Scattering Detector Methods.

Trichosanthes kirilowii Maxim. is one of the original plants for traditional Chinese medicines Trichosanthis Fructus, Trichosanthis Semen, Trichosanthis Pericarpium and Trichosanthis Radix. Amino acids, nucleosides and carbohydrates are usually considered to have nutritional value and health-care efficacy. In this study, methods involving high-performance liquid chromatography coupled with evaporative light scattering detector (HPLC-ELSD), UV-visible spectrophotometry and ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) were established for quantifying carbohydrates (fructose, glucose, stachyose, raffinose and polysaccharide), fourteen nucleosides and twenty one amino acids. Moreover, sixty-three samples from nine different parts, including pericarp, seed, fruit pulp, stem, leaf, main root, main root bark, lateral root and lateral root bark of T. kirilowii from different cultivated varieties were examined. The established methods were validated with good linearity, precision, repeatability, stability, and recovery. The results showed that the average content of total amino acids in roots (15.39 mg/g) and root barks (16.38 mg/g) were relatively higher than for others. Contents of nucleosides in all parts of T. kirilowii were below 1.5 mg/g. For carbohydrates, fruit pulp has a higher content than others for glucose (22.91%), fructose (20.63%) and polysaccharides (27.29%). By using partial least-squared discriminate analysis (PLS-DA), Variable importance in the projection (VIP) plots and analysis of variance (ANOVA) analysis, the characteristic components of the different organs (fruit, stems and leaves, roots) were found. This analysis suggested there were potential medicinal and nutritive health care values in various parts of the T. kirilowii, which provided valuable information for the development and utilization of T. kirilowii.

Dipalmitoylphosphatidylcholine (DPPC): Annealing Strategy to Mitigate Variability in Thermotropic and Moisture Sorption Behavior

Dipalmitoylphosphatidylcholine (DPPC) demonstrated complex differential scanning calorimetry (DSC) thermal behavior. Transitions below 100°C showed variability in their thermotropic reversibility. An experimental design employing a DSC heat-cool-heat-cool-heat cycle and modulated DSC were used to gain insight into the DPPC's complex thermal nature. An annealing strategy was developed to reduce DPPC's thermotropic variability, moisture uptake rate, and rate variability. Samples annealed at 110°C for 5 min provided a reproducible, thermally reversible material. The annealed material also exhibited an 8-fold decrease in moisture sorption rate and a statistically significant (p = 0.0233) 100-fold decrease in water sorption rate variability compared to DPPC “as is.” An optimized validated stability-indicating high performance liquid chromatography with evaporative light scattering detection method was developed and showed no change in DPPC chemical stability under the annealing treatment conditions.

Stability-Indicating Liquid Chromatographic Methods with Photodiode Array Detection and Light Scattering Detection for Simultaneous Determination of Candesartan and Hydrochlorothiazide.

Development, validation and comparison of two stability-indicating LC methods, one with photodiode array detector (DAD) and the other with evaporative light scattering detector (ELSD), were performed for simultaneous determination of candesartan cilexetil (CANC) and hydrochlorothiazide (HCTZ), in pharmaceutical samples. A RP-18 column (125 mm × 4 mm, 5 μm) was used for separation of CANC, HCTZ and its major degradation products, using acetonitrile and phosphate buffer (pH 6.0) for DAD method and acetonitrile and water with acetic acid and triethylamine (pH 4.1) for ELSD method, as mobile phase in a gradient mode. The response with ELSD was fitted to a power function and the DAD response by a linear model over a range of 32-160 μg/mL for CANC and 25-125 μg/mL for HCTZ. The precision and accuracy of the methods were similar, with RSD below 3.0% and recovery between 98.1% and 103.9%. The drugs were subjected to stress conditions of hydrolysis, oxidation, photolysis, humidity and temperature. The degradation products were satisfactory separated from the main peaks and from each other. Both drugs mainly degrade by hydrolysis, showing the formation of one degradation product for HCTZ and two for CANC; its identification was conducted by LC/MS/MS. The methods were successfully applied to the analysis of CANC and HCTZ in combined commercial tablets. The performance of DAD and ELSD methods are comparable, therefore both methods are suitable for stability study and determination of CANC and HCTZ in pharmaceutical samples.

Short-Chain Polysaccharide Analysis in Ethanol-Water Solutions.

This study demonstrates that short-chain polysaccharides, or oligosaccharides, could be sufficiently separated with hydrophilic interaction LC (HILIC) conditions and quantified by evaporative light-scattering detection (ELSD). The multianalyte calibration approach improved the efficiency of calibrating the nonlinear detector response. The method allowed easy quantification of short-chain carbohydrates. Using the HILIC method, the oligosaccharide solubility and its profile in water/alcohol solutions at room temperature were able to be quantified. The results showed that the polysaccharide solubility in ethanol-water solutions decreased as ethanol content increased. The results also showed oligosaccharides to have minimal solubility in pure ethanol. In a saturated maltodextrin ethanol (80%) solution, oligosaccharide components with a degree of polymerization >12 were practically insoluble and contributed less than 0.2% to the total solute dry weight. The HILIC-ELSD method allows for the identification and quantification of low-MW carbohydrates individually and served as an alternative method to current gel permeation chromatography procedures.

Statistical Optimization of Evaporative Light Scattering Detection for Molten Sucrose Octaacetate and Comparison With Ultraviolet Diode Array Detection Validation Parameters Using Tandem HPLC Ultraviolet Diode Array Detection/Evaporative Light Scattering Detection–Specific Stability-Indicating Method

A sucrose octaacetate (SOA) gradient HPLC evaporative light scattering detection (ELSD) and low-wavelength UV-diode array detection (UV-DAD)-specific stability-indicating method development and validation comparison is reported. A central composite response surface design and multicriteria optimization was used to maximize molten SOA area-under-the-curve response and signal-to-noise ratio. The ELSD data were also analyzed using multivariate principal component analysis, analysis of variance, and standard least squares effects modeling. The method suitability and validation parameters of both methods were compared. To the authors’ knowledge, this is the first report that validates an ELSD method using a molten analyte. SOA exhibited a low molar absorptivity of 439 absorption units/cm/M in water at 210 nm requiring low-wavelength UV-DAD detection. The low-wavelength UV-DAD method provided substantially better intraday and interday precision, intraday and interday goodness-of-fit, detection limit, and quantitation limit than ELSD. ELSD exhibited a 60-fold greater area-under-the-curve response, better resolution, and 58% more theoretical plates. On balance, the UV-DAD method was chosen for SOA chemical kinetic studies. This study illustrates that ELSD may not always be the best alternative to gradient HPLC low-wavelength UV detection.

Comparison of Stability-Indicating LC Methods Using Light Scattering and Photodiode Array Detection with Monolithic Column for Determination of Quinapril and Hydrochlorothiazide.

Rapid stability-indicating LC methods for simultaneous analysis of quinapril and hydrochlorothiazide were developed, validated and compared using evaporative light scattering detection (ELSD) and diode array detection (DAD). For the separation of quinapril, hydrochlorothiazide and its major degradation products, a monolithic column was used and the analytes were eluted within 7 min, applying gradient mobile phase in both methods. Quinapril was subjected to hydrolytic, oxidative, thermal, humidity and photolytic stress conditions. Degradation products were well resolved from main peaks and from each other, proving the stability-indicating power of the methods. The response with DAD was linear and the response with ELSD was fitted to a power function, for quinapril and hydrochlorothiazide concentrations of 20-160 and 12.5-100 µg mL(-1), respectively. DAD method achieved better precision than ELSD method, the LOQ of DAD was lower and the accuracy of the methods was similar. Quinapril degrade by hydrolysis and thermal stress, showing the formation of quinaprilat and quinapril diketopiperazine as degradants, which were identified by MS-MS. The methods were successfully applied to quantify quinapril and hydrochlorothiazide in commercial tablets. LC-DAD and LC-ELSD methods are suitable to assess the stability and routine analysis of quinapril and hydrochlorothiazide in pharmaceutical industry.

Application of LC with Evaporative Light Scattering Detector for Biogenic Amines Determination in Fair Trade Cocoa-Based Products

In this study, the separation of eight biogenic amines (cadaverine, serotonin, histamine, spermidine, spermine, tyramine, putrescine and β-phenylethylamine) by a liquid chromatography (LC) method with evaporative light scattering detection (ELSD) was performed. The LC–ELSD method was validated by comparison of the results with those obtained through LC–ultraviolet (UV) determination, based on a pre-column dansyl chloride derivatisation step, and the recorded data showed as both analytical methods can be interchangeably used for biogenic amines determination. LC–ELSD methodology showed good precision and permitted to achieve, for standard solutions, limits of detection (LOD) ranging from 0.01 to 0.02 μg ml−1 and limits of quantitation (LOQ) ranging from 0.03 to 0.05 μg ml−1. The whole methodology, comprehensive of the homogenization–extraction process and LC–ELSD analysis, has been applied in the analysis of several samples of fair trade cocoa derivatives. The most abundant amine found was histamine for a total amount of biogenic amines in the range 5.81–38.82 μg g−1. The highest amounts of biogenic amines (BAs) were found in the most processed products but never representing a possible risk for consumer health, according to the toxicity levels reported in literature and regarded as acceptable.

Simultaneous Determination of Four Active Ingredients in Sargentodoxa cuneata by HPLC Coupled with Evaporative Light Scattering Detection.

A HPLC coupled with evaporative light scattering detection method had been developed for the simultaneous determination of 3,4-dihydroxyphenylethyl alcohol glycoside, salidroside, chlorogenic acid, and liriodendrin in the stem of Sargentodoxa cuneata. With a C18 column, the analysis was performed using acetonitrile and 0.2% formic acid aqueous solution as mobile phase in gradient program at a flow rate of 0.9 mL/min. The optimum drift tube temperature of evaporative light scattering detection was at 105°C with the air flow rate of 2.5 L/min. The calibration curves showed good linearity during the test ranges. This method was validated for limits of detection and quantification, precision, and reproducibility. The recoveries were within the range of 96.39%–104.64%. The relative standard deviations of intraday and interday precision were less than 2.90% and 3.30%, respectively. The developed method can be successfully used to quantify the four analytes in the stem of Sargentodoxa cuneata from various regions in China.

Contents Changes of Triterpenic Acids, Nucleosides, Nucleobases, and Saccharides in Jujube (Ziziphus jujuba) Fruit During the Drying and Steaming Process.

Chinese jujube (Ziziphus jujuba), a medicinal and edible plant, is widely consumed in Asian countries owing to the remarkable health activities of its fruits. To facilitate selection of the suitable processing method for jujube fruits, in this study their contents of triterpenic acids, nucleosides, nucleobases and saccharides after drying and steaming treatment were determined using ultra-high performance liquid chromatography and high performance liquid chromatography coupled with evaporative light scattering detector methods. The results showed that except for sucrose, the content levels of most analytes were increasing in the jujube fruits during drying treatment at 45 °C. The levels of cyclic nucleotides such as adenosine 3′,5′-cyclic monophosphate and guanosine 3′,5′-cyclic monophosphate, were significantly decreased after the fruits were steamed. Therefore, owing to the bioactivities of these components for human health, the dried fruits would be the better choice as medicinal material or functional food, and dried jujube fruit should not be further steamed.

Simultaneous determination of multiple platycosides with a single reference standard in Platycodi Radix by high-performance liquid chromatography coupled with evaporative light scattering detection.

A traditional external standard method using HPLC coupled with evaporative light scattering detection has been developed for fast and accurate determination of seven platycosides in Platycodi Radix. However, inevitable difficulties in reference standards preparation process, which are quite costly and time consuming, have made its application limited. To avoid this inconvenience, a simultaneous determination of multiple components with a single reference standard strategy, which could be realized by calibrating the standard curve with internal standard and response factors, was introduced to the HPLC coupled with evaporative light scattering detection method. This is the first time that an incorporation of these two methods has been realized. Among seven ingredients, platycodin D was selected as the internal standard for its relatively easy preparation and low cost. Moreover, according to the investigation on concentration-dependent effects over response factors and robustness test, platycoside E, deapioplatycodin D, platycodin D, and polygalacin D2 were chosen to be the indicators for this novel method. The present method has not shown statistically significant differences with a traditional external standard method as verified sample analysis by the F-test (p = 95%, n = 6).

Development and validation of a simple high performance liquid chromatography – evaporative light scattering detector method for direct quantification of native cyclodextrins in a cyclization medium

A simple HPLC–ELSD method was developed for the separation and quantification of native cyclodextrins. The technique was validated in the presence of two interfering matrices composed of byproducts from the cyclization medium. A fast separation of the compounds was achieved (in <20min) using a NUCLEODUR® C18 Pyramid column (150mm×4.6mm; particle size 5μm) at 30°C. The analytes were eluted using a linear gradient of acetonitrile and water containing 1% (v/v) of acetic acid at a flow rate of 0.3mL/min. Validation results showed that the method was accurate (93–110%) and selective. The precision was ≤5.7% for a hydrolyzed starch blank matrix spiked with cyclodextrins, and ≤6.2% for a blank matrix composed of a mixture of dextrin and glucose spiked with cyclodextrins. The limit of quantification was 0.05g/L for alpha- and 0.06g/L for beta- and gamma-cyclodextrins. The new HPLC–ELSD method could accurately quantify the three cyclodextrins directly in a cyclization medium, without pretreatment of the samples.

Analysis of L-Quebrachitol from the Waste Water of Rubber Latex Serum Using Hydrophilic Interaction Chromatography and Evaporative Light Scattering Detector Method

L-Quebrachitol (QCT) is a valuable active ingredient found in rubber latex serum. Due to its high polarity, quantitative analysis of QCT is difficult on traditional reverse phase liquid chromatography (RPLC). Hydrophilic interaction chromatography (HILIC) using a Shiseido PC HILIC column (250 × 4.6 mm) and an evaporative light-scattering detector (ELSD) was found to be convenient for the analysis of QCT. The mobile phase was acetonitrile–water (60:40, v/v), retention factor is 0.92. Outstanding detection linearity (5 × 10−5–4 g/L) and limit of detection (LOD, 8 × 10−6 g/L) was achieved. Using this method, 2.2% wt QCT was determined to be present in rubber latex waste water. The retention of QCT on PC HILIC, which was immobilized with phosphorylcholine, was also investigated theoretically, the interaction energy between QCT and phosphorylcholine group is −51.498 kJ/mol, and ΔH0 and ΔS0 for the retention of QCT on PC HILIC is −0.699 kJ/mol and 2.72 J/mol · K, respectively.

Carbohydrate analysis: From sample preparation to HPLC on different stationary phases coupled with evaporative light‐scattering detection

After 20 years of development, evaporative light-scattering detection (ELSD) has become the mainstream choice for the detection of various classes of natural products. ELSD continues to grow in popularity as a "quasi-universal" technique because of the specificity of the detection method, which is based on the scattering of laser light from nonvolatile analyte particles. It represents an attractive alternative compared to other types of detection, such as refractive index detection and/or ultraviolet detection. This review presents issues concerned with the separation of carbohydrates in plant materials by HPLC and ELSD, as well as the advantages and limitations relating to the ELSD method. Additionally, an overview of possible ELSD applications in the analysis of carbohydrates in natural products is presented.

Analysis of maltooligosaccharides in honey samples by ultra-performance liquid chromatography coupled with evaporative light scattering detection

We report the use of ultra performance liquid chromatography (UPLC) separation together with evaporative light scattering detection (ELSD) to effectively distinguish honey adulterated with maltooligosaccharides. UPLC separation utilizing a mobile phase with pure water and acetonitrile containing 0.2% triethylamine, resulted in enhanced separation and a running time of less than 6min. Also, only a simple liquid–liquid extraction was required for the sample pretreatment. This UPLC–ELSD method provides limits of quantifications (LOQs) from 0.30 to 0.60mg/g for the six maltooligosaccharides (maltose, maltotriose, maltotetraose, maltopentaose, maltohexaose and maltoheptaose) ranging from 15 to 2000μg/mL with excellent linearity(R2≥0.9914). This optimized method also offers a satisfactory intra-day precision of 2.4%–9.4%, inter-day precision of 5.5%–12.1% and accuracy of −7.7%–+11.4% at each level. We successfully applied this system for detecting maltooligosaccharide contamination in 290 honey samples collected from apiaries, supermarkets and traditional agri-product markets. Concentrations of the six maltooligosaccharides varied from undetectable to 14.1mg/mL. The lowest quantifiable concentration that could be detected by this established method was 0.132mg/mL. This study therefore demonstrates the reliability and potential use of the UPLC–ELSD technique in scrutinizing the authenticity of honey in the food processing industry.

Determination of azithromycin in raw materials and pharmaceutical formulations by HPLC coupled with an evaporative light scattering detector

A simple high-performance liquid chromatography (HPLC) method coupled with an evaporative light scattering detector (ELSD) was developed for the determination of azithromycin in raw materials and pharmaceutical formulations (injections, capsules and tablets) without any pretreatment or derivatization step. Azithromycin, degradation products and formulation ingredients were separated efficiently by using the mobile phase consisted of ammonium acetate (0.05 M, pH 8.0) and acetonitrile (60:40, v/v) in an isocratic mode at 0.8 ml/min flow rate. Parameters of ELSD were 60 °C for evaporation temperature and 50 psi for pressure of carrier gas (air). A logarithmic calibration curve was obtained from 50.93 to 509.30 μg/ml (r = 0.9996) for azithromycin, with the limit of detection (LOD) of 6.75 μg/ml (S/n = 3) and the limit of quantification of 22.50 μg/ml (S/n = 10). The developed method was validated and applied with satisfactory accuracy and precision for the determination of azithromycin in raw materials and pharmaceutical formulations (recovery 99–102%, RSD <1.2%, n = 3). No significant difference (t-test) was found between the results of the developed HPLC–ELSD method and the HPLC–UV or microbiological method.

Simultaneous separation and determination of fructose, sorbitol, glucose and sucrose in fruits by HPLC–ELSD

A high-performance liquid chromatography (HPLC) method with evaporative light scattering detection (ELSD) was optimised for simultaneous determination of fructose, sorbitol, glucose and sucrose in fruits. The analysis was carried out on a Phenomenex Luna 5u NH2 100A column (250mm×4.60mm, 5micron) with isocratic elution of acetonitrile:water (82.5:17.5, v/v). Drift tube temperature of the ELSD system was set to 82°C and nitrogen flow rate was 2.0Lmin−1. The regression equation revealed good linear relationship (R=0.9967–0.9989) within test ranges. The limits of detection (LOD) and quantification (LOQ) for four analytes (peach, apple, watermelon, and cherry fruits) were in the range of 0.07–0.27 and 0.22–0.91mgL−1, respectively. The proposed HPLC–ELSD method was validated for quantification of sugars in peach, apple, watermelon, and cherry fruits, and the results were satisfactory. The results showed that the contents of the four sugars varied among fruits. While fructose (5.79–104.01mgg−1) and glucose (9.25–99.62mgg−1) emerged as common sugars in the four fruits, sorbitol (8.70–19.13mgg−1) were only found in peach, apple and cherry fruits, and sucrose (15.82–106.39mgg−1) were in peach, apple and watermelon. There was not detectable sorbitol in watermelon and sucrose in cherry fruits, respectively.