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Aerosol whipped cream, widely used in various foods, relies on solid fats rich in saturated fatty acids (SFAs) for stable gas entrapment. In this study, the potential of oleogels as a healthy fat substitute for formulating aerosol whipped cream was studied. The analysis focused on the effects of different types (beeswax [BW], rice bran wax [RW], and carnauba wax) and the quantities of wax on the properties of the aerosol whipped creams. The BW‐oleogel‐based aerosol whipped cream exhibited the highest foam ability and foam stability. The superior physical properties of the bees wax‐oleogel were attributed to the higher overrun and height stability of its whipped cream compared to RW and carnauba oleogels. The 6% BW‐whipped cream showed significantly higher overrun and cream stability. The 6% BW oleogel whipped cream contained 4.4 times lower SFAs than the dairy milk fat whipped cream. This study represents the first exploration into the feasibility of formulating oleogel‐based aerosol whipped cream using liquid vegetable oil. [ABSTRACT FROM AUTHOR]

This study was conducted to identify high‐risk factors and mitigation strategies for acrylamide formation in air‐fried lotus root chips by studying the impact of various cooking parameters, including temperature, time, presoaking, and pre‐seasoning treatments. The temperature and time had a surprisingly high impact on acrylamide formation. The chips prepared at high temperatures with longer cooking times contained an extremely high acrylamide content, reaching 12,786 ng/g (e.g., 170°C/19 min). A particularly concerning discovery was that the chips with extremely high acrylamide content (up to 17 times higher than the EU benchmark level for potato chips) did not appear overcooked or taste burnt. Higher cooking temperatures required shorter cooking times to properly cook lotus root chips for consumption. A high temperature with a short cooking time (170°C/13 min) greatly benefited acrylamide reduction compared to low temperature with a long cooking time (150°C/19 min). Presoaking in a 0.1% acetic acid solution and pre‐seasoning with 1% salt reduced acrylamide levels by 61% and 47%, respectively. However, presoaking in water, vinegar solution, and citric acid solution did not significantly decrease the acrylamide content in the chips. Furthermore, some seasonings significantly increased acrylamide levels (up to 7.4 times higher). For the first time, these findings underscore the high risks associated with air‐frying lotus root chips without considering these factors. This study also provides proper air‐frying parameters and pretreatment strategies for minimizing acrylamide formation in air‐fried lotus chips. [ABSTRACT FROM AUTHOR]

Free myo‐inositol is a bioavailable form of a cyclitol having various health‐promoting activities. The impact of cultivar and home‐cooking practice on the content of free myo‐inositol in sweet potatoes (12 cultivars grown in 2 different locations) was studied. A GC–MS/MS method following in situ trimethylsilylation was established and validated to determine free myo‐inositol. The established analytical method was sensitive, precise, and accurate. It was found that free myo‐inositol content in sweet potato varied greatly (sevenfolds) with cultivar, ranging from 377.1 to 2628.3 mg/kg dw. A cultivar Poongwon‐mi was found to be an exceptionally rich source of free myo‐inositol (2628.3 mg/kg dw). Home‐cooking practice markedly increased free myo‐inositol content (maximum 240%). Baking showed the highest impact on the increase in free myo‐inositol, followed by steaming, microwave cooking, and boiling, in decreasing order. This represents the first report of the remarkably high impact of cultivar and home‐cooking practice on the free myo‐inositol content in sweet potato. Practical Application: The free myo‐inositol content in sweet potato varied greatly with the cultivars. Poongwon‐mi contained a surprisingly high content of free myo‐inositol. Home‐cooking dramatically increased the free myo‐inositol content. [ABSTRACT FROM AUTHOR]

Welsh onion (Allium fistulosum L.) is widely used in diverse Asian cuisines, especially in stir-fried and deep-fried foods. This study investigated the effects of different temperatures (140, 165, and 190 °C) and types of the vegetable frying oil (soybean, corn, canola, and palm oils) on the formation of volatile profiles and hazardous compounds [polycyclic aromatic hydrocarbons (PAHs) and acrylamide] in Welsh onion. Specific volatile chemical groups such as aldehydes, sulfur-containing compounds, and furans/furanones were major volatiles in Welsh onion fried (WOF). The composition of aldehydes and sulfur-containing compounds decreased, while those of furans/furanones increased when WOF samples were exposed to higher temperatures. At 190 °C, PAHs were detected at lower than the EU maximum tolerable limit (the sum of 4 PAHs, <10 µg/kg), and acrylamide was detected below 36.46 μg/kg. The integrated study of both the quality and safety properties can provide fundamental data for the industrial processing of WOF. [ABSTRACT FROM AUTHOR]

The classification of six mushroom species (white beech, brown beech, button, oyster, king oyster, and enoki mushrooms) was successfully achieved using canonical discriminant analysis (CDA) on volatile metabolite data sets obtained by headspace‐solid‐phase microextraction gas chromatography (HS‐SPME‐GC). Twenty‐seven major volatile compounds in six edible mushrooms were positively identified by HS‐SPME‐GC mass spectroscopy. The total volatile content was highest in brown beech mushroom (P < 0.05). Significant difference in volatile profile was observed between brown beach and white beech mushrooms. Button mushroom contained significantly higher contents of benzaldehyde and benzyl alcohol than the other mushrooms (P < 0.05). Oyster mushroom contained 1‐octen‐3‐ol as the most prevalent volatile, representing 67% out of total volatiles. Hexanal (35.0%) and 1‐octen‐3‐ol (22.5%) were the most abundant volatiles found in king oyster. Hexanal (29.1%) was the most prevalent volatile in enoki mushroom only. Several volatile pairs with very high positive correlation in their levels were identified, representing the highest correlation coefficient (r = 0.970) for the pair of t‐2‐octenal and 2,4‐octandienal. CDA was much more efficient than principal component analysis for the differentiation of mushroom species. Practical Application: The present study provided the important information on the volatile metabolite profiles of popular six commercial mushroom species. The present data will be useful for the quality control of mushrooms cultivated in farms and mushroom products processed in food industry. The strategy of canonical discriminant analysis in combination with HS‐SPME‐GC could be expanded for the determining the authentication of mushroom species. [ABSTRACT FROM AUTHOR]

Highlights • A simple and cheap MP-AES was developed and validated for the quantitation of Mn in wine. • The analytical features for the MP-AES were greatly different with those of ICP-OES. • Significant matrix effect in wine sample matrices was observed with MP-AES, but not with ICP-OES. • The low matrix tolerance of MP-AES was overcome by a standard addition method. • The contents of Mn in wild grape (Vitis coignetiae) wines are reported for the first time. Abstract The analytical features of MP-AES for the determination of Mn in wine were studied as compared with ICP-OES. The optimum spectral line (403.076 nm) of MP-AES was different from that (259.373 nm) of ICP-OES. Significant matrix effect was observed with MP-AES, but not with ICP-OES. A simple and cost-effective MP-AES for the quantitation of Mn in wild grape (Vitis coignetiae) red wines were developed and validated. A standard addition method was used to compensate the matrix effects. The sensitivity of MP-AES was comparable to that of ICP-OES. MP-AES was sensitive, precise, accurate and reliable. The Mn concentration in the wild grape wines was in the range of 502–3627 μg L−1. MP-AES had a distinct drawback of low matrix tolerance. However, MP-AES had a clear advantage of the low running cost due to the use of nitrogen gas generated from air with a nitrogen generator. [ABSTRACT FROM AUTHOR]

• A highly efficient analytical strategy for 11 hydroxylated stilbenes in wines and grape juices is proposed. • The proposed method is highly simple, fast, reliable, sensitive, precise, and accurate. • The total analytical time required for sample preparation and chromatography was only 18 min. • The method was successfully applied to determine hydroxylated stilbenes in wines and grape juice. Wine and grape juice are known to have hydroxylated stilbenes, a group of phytoalexins, health-promoting compounds. The determination of stilbene species in wine and grape juices remains a challenging task. Here, we propose an efficient strategy for the simultaneous determination of eleven hydroxylated stilbenes in grape wines and grape juice by a SALLE in conjunction with an HPLC-ESI-MS/MS. SALLE and HPLC-MS/MS conditions were optimized. The proposed method was validated and found to be a simple, sensitive, and reliable measure for the determination of the stilbene species in wine and grape juice. The SALLE was fast and efficient, taking only 10 min. The HPLC-MS/MS was able to quickly separate and quantitate the eleven stilbenes (9 min running). This method was successfully applied to determine the contents of stilbene species in commercial wine and grape juice in Korea. This method is advantageous in reduced sample preparation time, low labor, and cost efficiency. [ABSTRACT FROM AUTHOR]

The impact of heat type, sample type, temperature and time on the heat-induced conversion of gingerols to shogaols in ginger were studied by an UHPLC-ESI-MS/MS. Heat treatments greatly induced the conversion of gingerols to shogaols in ginger. As the temperature increased, the faster conversion of gingerols into shogaols were observed. However, the efficiency of the heat-induced conversion differed greatly with the heat types. Moist heat treatment induced significantly higher quantity of shogaols than dry heat treatment. The moist heat treatment at 120 °C for 360 min induced the highest conversion, reaching to 2991 mg 6-shogaol per kg ginger. In addition, dry-heat induced conversion was affected by the sample type. The dry-heat treatment on dried powder induced significantly higher quantity of shogaols than that on sliced fresh ginger. This represents the first systematic comparative study on the heat and sample types on the heat-induced conversion of gingerols into shogaols in ginger. [ABSTRACT FROM AUTHOR]

Toxic inorganic arsenic (iAs) has been reported to be present in high quantity in rice and rice-based products. The inorganic arsenic contents in infant foods (n = 59) of ready-to-cook infant rice powders and infant rice snacks marketed in Korea were determined by a highly sensitive gas chromatography-tandem mass spectrometry (GC-MS/MS). The mean iAs contents in the infant rice powder and infant rice snacks were 65.6 and 54.0 μg/kg, respectively. The percentages of rice powders and rice snack containing iAs over the maximum level (100 μg/kg) set by EU for the infant foods were found to be 21, and 6%, respectively. This result clearly suggested that regulation regarding the maximum limit of iAs levels for the baby rice products is urgently needed to be set in Korea. This represents the first report on the iAs levels in ready-to-cook infant rice powder products and infant snacks marketed in Korea. [ABSTRACT FROM AUTHOR]

Rice and rice products have been reported to contain high contents of toxic inorganic arsenic (iAs). The inorganic arsenic contents in microwavable ready-to-eat rice products (n = 30) and different types of Korean rice (n = 102) were determined by a gas chromatography-tandem mass spectrometry (GC–MS/MS). The method showed low limit of detection (0.015 pg), high intra- and inter-day repeatability (<7.3%, RSD), and recovery rates (90–117%). The mean iAs content in the ready-to-eat rice products was 59 μg kg −1 (dry weight basis). The mean iAs contents in polished white, brown, black, and waxy rice were 65, 109, 91, and 66 μg kg −1 , respectively. The percentages of ready-to-eat rice products, white, brown, black, and waxy rice containing iAs over the maximum level (100 μg kg −1 ) set by EU for the infant foods were 17, 4, 70, 36 and 0%, respectively. [ABSTRACT FROM AUTHOR]

We developed and validated a fast UHPLC-ESI-MS/MS in combination with one step salting-out assisted liquid-liquid extraction (SALLE) for high throughput analysis of 12 isoflavones in soy milks. Conventional sample preparation requires two steps composing time-consuming freeze-drying (72 h) and solvent extraction (2 h). The SALLE required only about 40 min, which was over 100 times faster without compromising the extraction efficiency. The baseline separation of 12 isoflavones was achieved in 2.5 min by the UHPLC-MS/MS which is the fastest chromatographic method ever reported. The new method was fast, simple, selective, sensitive, precise and accurate. The method was successfully applied to 22 commercial soy milks for the high throughput analysis of isoflavones. The new method would be a fast, simple, reliable, and useful measure for the analysis of isoflavones in soy milk especially in the laboratories facing the challenges of saving the analytical time, labor cost and solvent usage. [ABSTRACT FROM AUTHOR]

We have developed a simple and fast sample preparation technique in combination with a gas chromatography-tandem mass spectrometry (GC-MS/MS) for the quantification of 2-methylimidazole (2-MeI) and 4-methylimidazole (4-MeI) in colas and dark beers. Conventional sample preparation technique for GC-MS requires laborious and time-consuming steps consisting of sample concentration, pH adjustment, ion pair extraction, centrifugation, back-extraction, centrifugation, derivatization, and extraction. Our sample preparation technique consists of only 2 steps ( in situ derivation and extraction) which requires less than 3 min. This method provided high linearity, low limit of detection and limit of quantification, high recovery, and high intra- and interday repeatability. It was found that internal standard method with diluted stable isotope (4-MeI-d6) and 2-ethylimidazole (2-EI) could not correctly compensate the matrix effects. Thus, standard addition technique was used for the quantification of 2- and 4-MeI. The established method was successfully applied to colas and dark beers for the determination of 2-MeI and 4-MeI. The 4-MeI contents in colas and dark beers ranged from 8 to 319 μg/L and from trace to 417 μg/L, respectively. Small quantity (0 to 8 μg/L) of 2-MeI was found only in dark beers. The contents of 4-MeI (22 μg/L) in colas obtained from fast food restaurants were significantly lower than those (177 μg/L) in canned or bottled colas. [ABSTRACT FROM AUTHOR]

We developed and validated an improved ultra high performance liquid chromatography (UHPLC)-electrospray ionization (ESI)-tandem mass spectrometry (MS/MS) method for the fast separation and quantification of 8 major gingerols and shogaols (4-, 6-, 8-, 10-, and 12-gingerols, and 6-, 8-, and 10-shogaols) in gingerol products. The ionization polarity and mobile phase modifier greatly affected the mass ion profiles and sensitivity of the analytes. A mobile phase modifier of 0.05 mM ammonium formate dramatically decreased the sodium adduct ions and greatly increased the protonated ions of the gingerols and shogaols. Positive ion UHPLC-MS/MS with the ammonium formate in mobile phase showed greatly higher (4.5- to 15.7-fold) sensitivities than negative ion UHPLC. The positive ion UHPLC-MS/MS method showed excellent linearities ( r2 > 0.999), low limits of detection (LOD = 2.5 to 8.2 pg), high accuracy and precision, and no considerable matrix effect. Baseline separation of the 8 target compounds was achieved in 1 min by the UHPLC with a short C18 core-shell column. The method was successfully applied to analyze the compounds in fresh and dried powdered gingers, and dietary supplements. The total contents of the major compounds in the fresh gingers, dried powdered gingers, and dietary supplements were in the range of 1114 to 1478, 4380 to 11324, and 2915 to 29998 mg/kg, respectively. There was about 10-fold variation of the content in the dietary supplements with the commercial brands. This represents the 1st report on the ionization polarity and mobile phase modifier on the sensitivity of gingerols and shogaols in LC-mass spectrometry. Furthermore, the established method provided great improvement in chromatographic separation of the target gingerols. [ABSTRACT FROM AUTHOR]

The chemical properties and oxidative stability of perilla oils obtained from roasted perilla seeds as affected by extraction methods (supercritical carbon dioxide [SC-CO2], mechanical press, and solvent extraction) were studied. The SC-CO2 extraction at 420 bar and 50 °C and hexane extraction showed significantly higher oil yield than mechanical press extraction ( P < 0.05). The fatty acid compositions in the oils were virtually identical regardless of the extraction methods. The contents of tocopherol, sterol, policosanol, and phosphorus in the perilla oils greatly varied with the extraction methods. The SC-CO2-extracted perilla oils contained significantly higher contents of tocopherols, sterols, and policosanols than the mechanical press-extracted and hexane-extracted oils ( P < 0.05). The SC-CO2-extracted oil showed the greatly lower oxidative stability than press-extracted and hexane-extracted oils during the storage in the oven under dark at 60 °C. However, the photooxidative stabilities of the oils were not considerably different with extraction methods. [ABSTRACT FROM AUTHOR]

Reportedly policosanols (PCs) have various beneficial functionalities on health. A gas chromatography-tandem mass spectrometry (GC-MS/MS) with a low limit of detection (LOD), and high specificity, recovery, and precision was successfully established for the PC analysis in vegetable oils. The LODs for the PCs were in the range of 0.002 to 0.016 μg/mL. The relative standard deviation (RSD) for the repeated analysis of PCs was less than 3.356%. The mean recoveries for spiked heptacosanol and octacosanol in vegetable oil were 102.3% and 106.3%, respectively. The total PC contents in the vegetable oils varied from 3.01 to 427.83 mg/kg oil. Perilla seed, grape seed, and rice bran oils were found to be highly rich sources of PCs, containing 427.83, 245.15, and 171.17 mg PCs/kg oil, respectively. Corn, sesame, and soybean oils contained only a negligible quantity of PCs. The PC composition in vegetable oils was greatly source dependent. In perilla seed oil, octacosanol was the single most predominant component, representing 55.93% of the total PC. In grape seed oil, however, hexacosanol is the most abundant PC, followed by octacosanol, tetracosanol, and triacontanol in a decreasing order. The major PCs in rice bran oil were triacontanol, octacosanol, hexacosanol, and tetracosanol, which constituted over 87.3% of the total PC. This represents the 1st report on the composition and contents of PC in most vegetable oils analyzed here. Practical Application: The information might be used for the development of vegetable oil products with beneficial functionality. [ABSTRACT FROM AUTHOR]

Singlet oxygen quenching by synthetic antioxidants (BHA, BHT, and TBHQ) was directly observed by spectroscopic monitoring of luminescence at 1268 nm. The luminescence data showed unambiguous evidence of singlet oxygen quenching by synthetic phenolic antioxidants with the highest activity for TBHQ, followed by BHA and BHT. The protective activities of these synthetic antioxidants on α-terpinene oxidation with chemically-induced singlet oxygen under dark further confirmed their singlet oxygen quenching abilities. Total singlet oxygen quenching rate constants ( kr + kq) of BHA, BHT, and TBHQ were determined in a system containing α-terpinene (as a singlet oxygen trap) and methylene blue (as a sensitizer) during light irradiation, and the values were 5.14 × 107, 3.41 × 106, and 1.99 × 108 M−1s−1, respectively. After the kr value of α-terpinene was first determined, the kr values of the synthetic antioxidants were calculated by measuring their relative reaction rates with singlet oxygen to that of α-terpinene under the identical conditions. The kr values of the BHA, BHT, and TBHQ were 3.90 × 105, 1.23 × 105, and 2.93 × 106, M−1s−1. The percent partition of chemical quenching over total singlet oxygen quenching ( kr × 100)/( kr + kq) for BHA, BHT, and TBHQ were 0.76%, 3.61%, and 1.47%, respectively. The results showed that the synthetic antioxidants quench singlet oxygen almost exclusively through the mechanism of physical quenching. This represents the first report on the singlet oxygen quenching mechanism of these synthetic antioxidants. Practical Application: The synthetic antioxidants, especially TBHQ, have been found to have a strong singlet oxygen quenching ability. This article also clearly showed that singlet oxygen quenching by synthetic antioxidants was mainly by the physical quenching mechanism. The results suggested that these synthetic antioxidants, especially TBHQ, could be used practically for the protection of the food components such as edible oils and vitamins against singlet oxygen induced oxidations without significant losses of antioxidant activity during storage under light. [ABSTRACT FROM AUTHOR]

The article discusses a study which examined the effects of fruit and vegetable juices on rubrene oxidation induced by a chemical source of oxygen in a microemulsion system. A description of the method for determining the radical scavenging activities of juices is given. Results of the study showed that excessive amount of hydrogen peroxide led to the destruction of juices' antioxidant component. It also found that the highest inhibitory activity on oxidation was shown by the pear juice.

Phenolic acids of dried white and red ginsengs were extracted and fractionated into free, esterified, and insoluble-bound forms. The contents of individual phenolic acids in different forms were quantified by gas–liquid chromatography. Identification of all phenolic acids was confirmed by gas chromatography–mass spectrometry and comparison of gas chromatographic retention times. Twelve different phenolic acids as free, esterified, and insoluble-bound forms were identified in Korean ginsengs. Total phenolic acids in white and red ginsengs were 27.2 and 26.8 mg/100 g, respectively. Seven free phenolic acids were identified and their total contents in white and red ginsengs were 4.70 and 4.14 mg/100 g, respectively. trans-Ferulic acid was the predominant free phenolic acid, representing 47.9 and 57.7% of total free phenolic acids in white and red ginsengs, respectively. Esterified phenolic acids represented 71.9 and 77.1% of total phenolic acids in white and red ginsengs, respectively. The most predominant esterified phenolic acids were cis-ferulic acid and trans-ferulic acid. Total insoluble-bound phenolic acid contents in white and red ginsengs were 2.93 and 1.99 mg/100 g, respectively. Ferulic acid (cis and trans isomers) was also the major insoluble-bound phenolic acids. This paper represents the first report of systematic identification and quantification of phenolic acids in different forms in white and red Korean ginsengs. [Copyright &y& Elsevier]

• A novel sample preparation for the complete control of volatile emission in mushrooms was developed. • An unattended HS-SPME-GC–MS/MS was developed for accurate quantitation of C8 volatiles in mushrooms. • The proposed method was reliable, sensitive, precise, and accurate. • The profiles of C8 volatiles in mushrooms differed with mushroom species. Eight carbon (C8) compounds are the key characteristic flavors of mushrooms. The quantitative analysis of the volatiles in mushrooms is challenging especially with the unattended HS-SPME-GC–MS. An unattended HS-SPME-GC–MS/MS in combination with novel sample preparation of the complete control of volatile emissions was developed for the quantitation of the C8 volatiles in mushrooms. The sample preparation strategy was composed of freeze-drying, rehydration, and the addition of a 15% citric acid solution. With this strategy, the volatile emission from mushroom was fully controlled at a certain time point. This method was found to be highly reliable, sensitive, precise, and accurate. This method was successfully applied to measure the contents of the C8 volatiles in the beech, button, and shiitake mushrooms. 1-Octene-3-ol was the most predominant compound in the mushrooms, representing 62.4, 69.0, and 89.2% of the total C8 volatiles in the beech, button, and shiitake mushrooms, respectively. [ABSTRACT FROM AUTHOR]

Shiitake mushroom (Lentinula edodes) is commonly consumed worldwide and is cultivated in many farms in Korea using Chinese substrates owing to a lack of knowledge on how to prepare sawdust-based substrate blocks (bag cultivation). Consequently, issues related to the origin of the Korean or Chinese substrate used in shiitake mushrooms produced using bag cultivation have been reported. Here, we investigated differences in fatty acids (FAs) and stable isotope ratios (SIRs) in shiitake mushrooms cultivated using Korean and Chinese substrates under similar conditions (strain, temperature, humidity, etc.) and depending on the harvesting cycle. The total FA level decreased significantly by 5.49 mg∙g−1 as the harvesting cycle increased (p < 0.0001); however, no differences were found in FAs between shiitake mushrooms cultivated using Korean and Chinese substrates. Linoleic acid was the most abundant FA, accounting for 77–81% of the total FAs during four harvesting cycles. Moreover, the SIRs differed significantly between the Korean and Chinese substrates, and the harvesting cycles resulted in smaller maximum differences in SIR values compared to those of the cultivation substrate origins. Our findings contribute to the identification of the geographical origin of shiitake mushrooms and may have potential applications in international shiitake-mushroom markets. [ABSTRACT FROM AUTHOR]

This study was aimed to verify the regional traceability of Agaricus bisporus mushroom using unique δ 13 C, δ 15 N, δ 18 O, and δ 34 S features combined with chemometric approaches. Ten cultivars from 15 mushroom farms in six regions of Korea were measured their isotopic signatures by stable isotope ratio mass spectrometer. The δ 13 C, δ 15 N, δ 18 O, and δ 34 S values were significantly different among mushrooms collected from six cultivation regions ( P  < 0.05). Multi-dimensional plots including the δ 15 N and δ 34 S values demonstrated clear regional discrimination of the Saedo and Saehan cultivars produced from Buyeo, Nonsan, Eumseong, Boryeong, or Gyeongju. Partial least-squares discriminate analysis models showed good discrimination for Saedo (R x 2  = 0.798 and Q 2  = 0.563) and Saehan (R x 2  = 0.819 and Q 2  = 0.894). These preliminary results can extend knowledge of regional isotope signatures in A. bisporus mushroom produced in Korea, contributing to accurate geographical authenticity with potential broader applications for the international mushroom market. [ABSTRACT FROM AUTHOR]

Policosanol (PC) is a mixture of health promoting bioactive long-chain aliphatic alcohols. Here, we report that green tea ( Camellia sinensis ) leaves are the exceptionally rich plant-sources of PC. Young and tender leaves and old and turf leaves of C. sinensis were hand-picked in spring and autumn. The total contents of PC in the leaves were in the range of 726.2–1363.6 mg/kg as determined by a GC–MS/MS. The compositions of PC in the leaves were different with harvest season and types. The total contents of PC in commercial green tea leaves were found to be in the range of 856.7–1435.1 mg/kg. Interestingly, the infused green tea leaves contained the higher PC than the non-infused green tea product, reaching to 1629.4 mg/kg. This represents the first report on the contents and compositions of PC in green tea leaves, showing unambiguous evidence of their potential as rich sources of PC. [ABSTRACT FROM AUTHOR]

A high resolution LC–ESI-TOF-MS analytical method was established for the rapid isolation, identification, and quantification of 12 isoflavones in soybean and soybean products. Individual isoflavones were identified on the basis of the accurate mass data of their respective protonated mass ions, Na or K adduct ions, fragment ions, and isotope ion patterns. The protonated mass ions of isoflavones were extracted for their quantification in soybean products. Twelve different isoflavones in the soybean products were fully separated, identified and quantified within 12 min separation time. The established LC–TOF/MS was an effective analytical method for the simultaneous characterization and quantification of isoflavones with exceptionally short analytical time, high selectivity, a high linearity ( r 2 > 0.992) in a wide range, low LOD and LOQ, high precision, inter-and intra-day repeatability, and no significant matrix effect. Furthermore, it requires simple sample preparation procedure (solvent extraction, dilution, and syringe filtration). [ABSTRACT FROM AUTHOR]