Classification of Angelica species found in various foods using an LC-QTOF/MS-based metabolomics approach.

In Korea, Angelica gigas is commonly known as Danggui. However, two other species on the market, Angelica acutiloba and Angelica sinensis, are also commonly called Danggui. Since the three Angelica species have different biologically active components, thus, different pharmacological activities, clear discrimination between them is needed to prevent their misuse. A. gigas is used not only as a cut or powdered product but also in processed foods, where it is mixed with other ingredients. To discriminate between the three Angelica species, reference samples were analysed as non-targeted using liquid chromatography-quadrupole time of flight/mass spectrometry (LC-QTOF/MS) and a metabolomics approach in which a discrimination model was established by partial least squares-discriminant analysis (PLS-DA). Then, the Angelica species in the processed foods were identified. First, 32 peaks were selected as marker compounds and a discrimination model was created using PLS-DA, and its validation was confirmed. Classification of the Angelica species was undertaken using the YPredPS value, and it was confirmed that all 21 foods examined contained the appropriate Angelica species indicated on the product packaging. Likewise, it was confirmed that all three Angelica species were accurately classified in the samples to which they were added.

Discrimination of three Angelica herbs using LC-QTOF/MS combined with multivariate analysis.

Angelica gigas, a popular medicinal herb in Korea, is locally called Danggui; this name is similarly used for Angelica acutiloba and Angelica sinensis, which are also sold in the retail market. These three herbs have differing therapeutic effects and should be used according to their prescribed purposes. In some retail markets, though, all three herbs are known by the same common name rather than a scientific name and can therefore be confused with each other. In particular, in the case of powdered products, intentional or unintentional wrong sales activity by the seller may occur. In this study, non-targeted analysis was performed using liquid chromatography quadrupole time-of-flight mass spectrometry to discriminate between the three Angelica herbs, and marker compounds were identified by principal component analysis. Principal component analysis was applied to the whole dataset with the variables being sample name, peak name (m/z with retention time), and ion intensity extracted in advance by peak finding, alignment, and filtering. All three herbs were visually and clearly differentiated in the score plot, and the marker compounds that contributed to their discrimination were found in the loading plot through principal component variable grouping (PCVG). Among the marker compounds, coumarins contributed to the classification of A. gigas, and phthalides contributed to the classification of A. sinensis. The three Angelica herbs were well discriminated from each other. Within the three Angelica species investigated, marker compounds can determine the species of even powdered or extracted samples that cannot be visually identified.

Analysis of Korean Peninsula Earthquake Network Based on Event Shuffling and Network Shuffling.

In this work, a Korean peninsula earthquake network, constructed via event-sequential linking known as the Abe-Suzuki method, was investigated in terms of network properties. A significance test for these network properties was performed via comparisons with those of two random networks, constructed from two approaches, that is, EVENT (SEQUENCE) SHUFFLING and NETWORK (MATRIX) SHUFFLING. The Abe-Suzuki earthquake network has a clear difference from the two random networks. However, the two shuffled networks exhibited completely different functions, and even some network properties for one shuffled datum are significantly high and those of the other shuffled data are low compared to actual data. For most cases, the event-shuffled network showed a functional similarity to the real network, but with different exponents/parameters. This result strongly claims that the Korean peninsula earthquake network has a spatiotemporal causal relation. Additionally, the Korean peninsula network properties are mostly similar to those found in previous studies on the US and Japan. Further, the Korean earthquake network showed strong linearity in a specific range of spatial resolution, that is, 0.20°~0.80°, implying that macroscopic properties of the Korean earthquake network are highly regular in this range of resolution.

Analysis of Solidarity Effect for Entropy, Pareto, and Gini Indices on Two-Class Society Using Kinetic Wealth Exchange Model.

It is well known that two different underlying dynamics lead to different patterns of income/wealth distribution such as the Boltzmann-Gibbs form for the lower end and the Pareto-like power-law form for the higher-end. The Boltzmann-Gibbs distribution is naturally derived from maximizing the entropy of random interactions among agents, whereas the Pareto distribution requires a rational approach of economics dependent on the wealth level. More interestingly, the Pareto regime is very dynamic, whereas the Boltzmann-Gibbs regime is stable over time. Also, there are some cases in which the distributions of income/wealth are bimodal or polymodal. In order to incorporate the dynamic aspects of the Pareto regime and the polymodal forms of income/wealth distribution into one stochastic model, we present a modified agent-based model based on classical kinetic wealth exchange models. First, we adopt a simple two-class society consisting of the rich and the poor where the agents in the same class engage in random exchanges while the agents in the different classes perform a wealth-dependent winner-takes-all trading. This modification leads the system to an extreme polarized society with preserving the Pareto exponent. Second, we incorporate a solidarity formation among agents belonging to the lower class in our model, in order to confront a super-rich agent. This modification leads the system to a drastic bimodal distribution of wealth with a varying Pareto exponent over varying the solidarity parameter, that is, the Pareto-regime becomes narrower and the Pareto exponent gets larger as the solidarity parameter increases. We argue that the solidarity formation is the key ingredient in the varying Pareto exponent and the polymodal distribution. Lastly, we take two approaches to evaluate the level of inequality of wealth such as Gini coefficients and the entropy measure. According to the numerical results, the increasing solidarity parameter leads to a decreasing Gini coefficient not linearly but nonlinearly, whereas the entropy measure is robust over varying solidarity parameters, implying that there is a trade-off between the intermediate party and the high end.

Determination of 12 herbal compounds for estimating the presence of Angelica Gigas Root, Cornus Fruit, Licorice Root, Pueraria Root, and Schisandra Fruit in foods by LC-MS/MS.

A wide variety of plant raw materials thought to promote health are used as herbal medicines as well as foods. However, there is no legal maximum or minimum concentration limit on any herbal compound when these plant raw materials are used in processed foods. Legally, these processed foods are regulated only for harmful substances, and there is no other guarantee of their contents. Therefore, the objective of this study was to determine the concentrations of 12 herbal compounds (nodakenin, decursin, decursinol angelate, morroniside, loganin, glycyrrhizic acid, liquiritigenin, puerarin, daidzin, schisandrin, gomisin A, gomisin N) in commonly used plant raw materials, such as "Angelica Gigas root", "Cornus Fruit", "Liquorice Root", "Pueraria Root", and "Schisandra Fruit"; and also in 45 processed foods, using high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). Method validation was performed successfully using the parameters of specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, precision, matrix effect, extraction recovery, and stability. The 12 herbal compounds were determined to be present in all the foods advertised as containing each ingredient, although in very low concentrations in some cases. Three solid samples labelled as 100% pure material from one herbal species also contained herbal compounds found in others, so that intentional or unintentional adulteration was suspected.

Comprehensive analysis to determine the differences of solar salt produced in South Korea and China.

Food fraud, including adulteration, addition, tampering, and misrepresentation of food ingredients and packaging for improper economic profit, has been global concerns affecting public health and safety. In South Korea, counterfeit expression of solar salt has been a problem causing improper economic profit, especially for those products produced from China, but labeled as 'domestics'. In this study, we were tried to discriminate geographical origins of solar salt between South Korea and China through various analytical techniques, the determination of moisture and sodium chloride contents, multi-elemental analysis, and isotope analysis. With the application of a statistical analysis, more than 93.3% of discrimination capability of positive classification was achieved in this study.

Comparison of Physicochemical Characteristics of Garlic Produced from South Korea and China.

Garlic is widely cultivated and frequently used as a spice in South Korea, due to its characteristic flavor. It is rich in sulfur-containing compounds (for example, allicin) and nonsulfur elements (for example, phosphorus and potassium). During the last few years, the cultivation area of garlic in South Korea has gradually decreased, one of the reasons being the increase in low-priced imported garlic from China. Several studies have reported the discrimination of foods originating from different geographical areas by analyzing their physicochemical properties using various statistical methods. In this study, the differentiation of geographical origin of garlic between South Korea (60 samples) and China (41 samples) was performed by analyzing their physicochemical properties (for example, pH, soluble solid, moisture, free sugars, mineral elements, total flavonoid, and total phenolic contents) combined with statistical methods. The significant difference between domestic garlic from South Korea and imported garlic from China was investigated in terms of pH, moisture content, total flavonoid content, and all trace minerals except for manganese and magnesium. Logistic regression analysis was performed to determine the geographical origin (South Korea or China) of garlic after selecting the appropriate independent variables. As a result, the calculated logistic regression equation from the analysis of copper, iron, phosphorus, zinc, and sucrose contents could be used to determine whether the geographical origin of garlic was South Korea or China. PRACTICAL APPLICATION: Despite being widely used in South Korea, the cultivation area of garlic in South Korea has gradually decreased over the last few years. One of the reasons is the increase in low-priced imported garlic from China. To discriminate the geographical origin of garlic between South Korea and China, analyzed physicochemical properties (that is, Cu, Fe, P, Zn, and sucrose contents) of garlic in combination with logistic regression analysis can be helpful for scientists working on food forensics. This discrimination technique can help to maintain the quality of garlic and prevent economic fraud by confirming the authenticity of garlic from South Korea.