Authentication of the geographical origin of Maca (Lepidium meyenii Walp.) at different regional scales using the stable isotope ratio and mineral elemental fingerprints

Variation and fractionation of δ2H, δ18O, and δ17O stable isotopes from irrigation water to soil, grapes, and wine for the traceability of geographical origins

To investigate the variation and fractionation of stable isotopes from irrigation water to soil, grapes, and wine, δ2H, δ18O, and δ17O in different samples from 10 regions in China were determined using a water isotope analyser. The values were significantly different among regions according to the chemometric analysis. All isotopes were significantly and positively correlated with irrigation water-soil and grape-wine. A significant water isotopic fractionation effect was observed from the irrigation water to the soil, grapes, and wine. Stable isotope distribution characteristics correlated with longitude, latitude, altitude, temperature, precipitation, station pressure and wind speed. The linear discriminant analysis (LDA), random forest (RF), support vector machine (SVM), and feed-forward neural network (FNN) models 58.33-100 %, 80-100 %, 53.33-100 %, and 73.33-100 % accurate for distinguishing the geographical origins of all samples from training and test data, respectively. These findings provide a theoretical basis for authenticating the geographic origin of Chinese wines using stable isotope analysis.

Lepidium meyenii (Maca) polysaccharides mitigate liver toxicity of aflatoxin B1 through activation of NRF-2/GPX and AhR/STAT3 signaling pathways

Aflatoxin B1 (AFB1) can induce serious liver toxicity in human. While completely avoiding AFB1 exposure is difficult, dietary intake of natural products may be leveraged to mitigate its adverse health effects. The roots of Lepidium meyenii (Maca) is rich in beneficial polysaccharides. Here we first evaluated dietary safety of MPs and then investigated MPs mitigating effects on the liver toxicity of AFB1. A 28-day sub-acute administration of Maca polysaccharides (MPs) demonstrated to be safe in mice at dose 0.2-1.2 g/kg.bw/day that significantly elevated mice stamina. Also, no toxicity was observed in human PC12 cells treated with MPs 25-100 μg/mL which successfully alleviated cobalt-caused cell apoptosis by ∼20%. In terms of anti-AFB1 hepatoxicity function, MPs 0.4-1.6 g/kg.bw/day significantly alleviated liver tissue damage, lipid accumulation, ROS damage, NF-κB p65, secretion of cytokines such as IL-6 and TNF-α in AFB1-treated mice. Flow cytometry found that MPs treatment recovered the elevation of F4/80 in the primary macrophages of AFB1-treated mice. At molecular level, MPs treatment activated liver NRF-2/GPX/SOD anti-oxidant system. In human macrophage model, MPs restored the inflammatory AhR/STAT3 pathway and mRNA expressions of Tnf-a, Inos, Arg-1 disrupted by AFB1. Our findings not only add to the current understanding on the toxicity mechanism of AFB1, but also provide references to the development of dietary intervention strategy using MPs.

The Impact of Sample Quantity, Traceability Scale, and Shelf Life on the Determination of the Near-Infrared Origin Traceability of Mung Beans

This study aims to address the gap in understanding of the impact of the sample quantity, traceability range, and shelf life on the accuracy of mung bean origin traceability models based on near-infrared spectroscopy. Mung beans from Baicheng City, Jilin Province, Dorbod Mongol Autonomous, Tailai County, Heilongjiang Province, and Sishui County, Shandong Province, China, were used. Through near-infrared spectral acquisition (12,000-4000 cm-1) and preprocessing (Standardization, Savitzky-Golay, Standard Normal Variate, and Multiplicative Scatter Correction) of the mung bean samples, the total cumulative variance contribution rate of the first three principal components was determined to be 98.16% by using principal component analysis, and the overall discriminatory correctness of its four origins combined with the K-nearest neighbor method was 98.67%. We further investigated how varying sample quantities, traceability ranges, and shelf lives influenced the discrimination accuracy. Our results indicated a 4% increase in the overall correct discrimination rate. Specifically, larger traceability ranges (Tailai-Sishui) improved the accuracy by over 2%, and multiple shelf lives (90-180-270-360 d) enhanced the accuracy by 7.85%. These findings underscore the critical role of sample quantity and diversity in traceability studies, suggesting that broader traceability ranges and comprehensive sample collections across different shelf lives can significantly improve the accuracy of origin discrimination models.

Non-invasive prediction of maca powder adulteration using a pocket-sized spectrophotometer and machine learning techniques

Discriminating different cultivars of maca powder (MP) and detecting their authenticity after adulteration with potent adulterants such as maize and soy flour is a challenge that has not been studied with non-invasive techniques such as near infrared spectroscopy (NIRS). This study developed models to rapidly classify and predict 0, 10, 20, 30, 40, and 50% w/w of soybean and maize flour in red, black and yellow maca cultivars using a handheld spectrophotometer and chemometrics. Soy and maize adulteration of yellow MP was classified with better accuracy than in red MP, suggesting that red MP may be a more susceptible target for adulteration. Soy flour was discovered to be a more potent adulterant compared to maize flour. Using 18 different pretreatments, MP could be authenticated with R2CV in the range 0.91-0.95, RMSECV 6.81-9.16 g/,100 g and RPD 3.45-4.60. The results show the potential of NIRS for monitoring Maca quality.

Not All Maca Is Created Equal: A Review of Colors, Nutrition, Phytochemicals, and Clinical Uses

Maca (Lepidium meyenii, Lepidium peruvianum) is part of the Brassicaceae family and grows at high altitudes in the Peruvian Andes mountain range (3500-5000 m). Historically, it has been used as a nutrient-dense food and for its medicinal properties, primarily in enhancing energy and fertility. Scientific research has validated these traditional uses and other clinical applications by elucidating maca's mechanisms of action, nutrition, and phytochemical content. However, research over the last twenty years has identified up to seventeen different colors (phenotypes) of maca. The color, hypocotyl size, growing location, cultivation, and post-harvest processing methods can have a significant effect on the nutrition content, phytochemical profile, and clinical application. Yet, research differentiating the colors of maca and clinical applications remains limited. In this review, research on the nutrition, phytochemicals, and various colors of maca, including black, red, yellow (predominant colors), purple, gray (lesser-known colors), and any combination of colors, including proprietary formulations, will be discussed based on available preclinical and clinical trials. The gaps, deficiencies, and conflicts in the studies will be detailed, along with quality, safety, and efficacy criteria, highlighting the need for future research to specify all these factors of the maca used in publications.

Effect of maca (Lepidium meyenii) extract on non-obstructive azoospermia in male mice

ETHNOPHARMACOLOGICAL RELEVANCE

Maca (Lepidium meyenii) is a medicinal and edible plant that has a long history attention because of its potential to improve fertility and sexual function.

AIM OF STUDY

In this study, effects of maca on azoospermia were investigated. The effective components of maca were screened.

MATERIALS AND METHODS

The therapeutic action of maca were evaluated in a busulfan-induced azoospermic model.

RESULTS

It was found that maca could alleviate the vacuolation of spermatogenic tubules and testicular lesions, promote the recovery of spermatogenic epithelium, inhibit the proliferation of stromal cells, significantly increase the serum testosterone content, and improve the number and quality of sperm. Maca extract was then divided into polysaccharides, oligosaccharides and small molecules fractions for preliminary screening of efficacy. These results showed that there was no significant difference between the maca polysaccharide fraction and maca extract.

CONCLUSIONS

The results were shown that maca can improve non-obstructive azoospermia, the polysaccharide fraction was the active components.

Exploration of microbial profile of traditional starters and its influence on aroma profile and quality of Chinese steamed bread

BACKGROUND

Chinese steamed bread (CSB) is a popular staple food in China with traditional ethnic characteristics. CSB with traditional starters has good flavor and texture but is unstable and requires a long preparation time. Therefore, it is necessary to analyze the traditional starters (ST) and their influence on the flavor and quality of steamed bread to meet people's requirements as a staple food.

RESULTS

The count of yeast, lactic acid bacteria and total microbial population significantly varied in different traditional starters; Saccharomyces and Lactobacillus were the predominant genera. Among the tested samples, fungi were found in ST from Shijiazhuang (SJ), Handan (HD) and Langfang (LF), while bacteria were found in ST from Tangshan (TS) and SJ at sub-predominant levels. In terms of the bread quality, the highest specific volume and porosity were in XT-CSB (Xingtai); the highest height/diameter ratio was in SJ-CSB; and the highest sensory score was in TS-CSB. A total of 26 aroma compounds (VIP > 1; variable importance for predictive components) were identified to discriminate CSB fermented with different starters, which were separated by stepwise canonical discriminant analysis using two functions. The correlation analysis among microbiota, aroma compounds and bread quality showed a higher contribution of bacteria than of fungi.

CONCLUSION

Differences in microbial profiles caused different aroma profiles and quality of CSB; and the CSB fermented with traditional starters were sufficiently separated by stepwise canonical discriminant analysis based on aroma compounds. © 2023 Society of Chemical Industry.

Efficacy and Safety of Maca (Lepidium meyenii) in Patients with Symptoms of Late-Onset Hypogonadism: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

PURPOSE

To evaluated the efficacy and safety of gelatinized Maca (Lepidium meyenii) for eugonadal patients with late onset hypogonadism symptoms (LOH).

MATERIALS AND METHODS

Participants were instructed to receive 1,000 mg of Maca or placebo, two pills at a time, three times per day for 12 weeks before food intake. To evaluate the efficacy of the drug, Aging Males' Symptoms scale (AMS), Androgen Deficiency in the Aging Males (ADAM), International Prostate Symptom Score (IPSS), and International Index of Erectile Function (IIEF) questionnaires, serologic tests (total testosterone and free testosterone, total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, triglyceride), body weight, and waist circumference were assessed at 4 and 12 weeks after treatment.

RESULTS

A total of 80 participants were enrolled and randomly assigned to Maca treated group (n=41) or the placebo group (n=39). AMS, IIEF, and IPSS were significantly (p<0.05) improved in Maca treated group than in the placebo group. ADAM positive rate was also significantly (p<0.0001) decreased in Maca treated group.

CONCLUSIONS

Maca may be considered an effective and safe treatment for eugonadal patients with late onset hypogonadism symptoms.

Rapid discrimination of the authenticity and geographical origin of bear bile powder using stable isotope ratio and elemental analysis

Bear bile powder (BBP) is one of the most famous traditional Chinese medicines derived from animals. It has a long history of medicinal use and is widely used in the treatment of hepatobiliary and ophthalmic diseases. Due to its similar morphological characterizations and chemical composition compared with other bile powders, it is difficult to accurately identify its authenticity. In addition, there are very few methods that could analyze the geographical origins of BBP. In this study, elemental analysis isotope ratio mass spectrometry (EA-IRMS) and inductively coupled plasma mass spectrometry (ICP-MS) were used to determine stable isotope ratios and elemental contents, respectively. Combined these variables with chemometrics, the discrimination models were established successfully for identifying the authenticity and geographical origins of BBP. Meanwhile, the discrimination markers were identified by calculating the variable importance for the projection (VIP) value of each variable. A total of 13 discrimination markers (δ¹³C, δ¹⁵N, C, Li, Mg, K, Ca, Cr, Ni, Zn, As, Se, and Sr) were used to further establish the fingerprint of BBP. According to similarity analysis, the authenticity and geographical origins of BBP could be identified without chemometrics. In conclusion, the present study established a reliable method for authenticity identification and origin traceability of BBP, which will provide references for the quality control of bile medicines.

Discrimination of Curculigo orchioides Rhizoma and Curculigo glabrescens Rhizoma using stable isotope and mineral element analyses coupled with chemometrics

Correct species identification is crucial for ensuring the quality, safety, and efficacy of herbal medicine. Market research indicates that Curculigo glabrescens Rhizoma (CGR) was the major counterfeit of the medicine Curculigo orchioides Rhizoma (COR). To accurately discriminate COR and CGR remains a challenge, and it becomes even more difficult when the herbs have been heavily processed into a powder. In this work, combined with high performance liquid chromatography analysis, a novel component in CGR was discovered, and two stable isotopes (N%, C%, δ15N, δ13C) and nineteen mineral elements were determined along with multivariate statistical analysis to distinguish the authentic COR samples and counterfeit CGR samples. The results showed that there were significant differences between the mean value of N%, δ15N and δ13C according to the botanical origins. In addition, these two species can be differentiated by principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) analysis. A linear discriminant analysis (LDA) model with a good classification rate (100%) and cross-validation rate (100%) was established. Hence, stable isotope and mineral element contents combined with chemometrics analysis could be considered as an effective and reliable method for discriminating the source species of COR and CGR.

Geographical Origin Determination of Cigar at Different Spatial Scales Based on C and N Metabolites and Mineral Elements Combined with Chemometric Analysis

In this paper, five C and N metabolites and eighteen mineral elements were used to identify the cigar's geographical origin on a country scale (Dominica, Indonesia, and China) and on a prefecture scale (Yuxi, Puer, and Lincang in China). The results show that the best origin traceability method is the combination of C and N metabolites and mineral elements method. Its. Its accuracy of cross-validation can achieve 95% on a country scale and 94% on a prefecture scale. Determination accuracy is ranked as identification by combination > mineral elements > C and N metabolites. For geo-origin determination of cigars, mineral element identification is better than that metabolite identification. The algorithm and factors for origin determination are selected. The results can be used to guide cigar agricultural practices and monitor and regulate the cigar in production and circulation.

An overview on multi-elemental profile integrated with chemometrics for food quality assessment: toward new challenges

Food products, especially those with high value-added, are commonly subjected to strict quality controls, which are of paramount importance, especially for attesting to some peculiar features related, for instance, to their geographical origin and/or the know-how of their producers. However, the sophistication of fraudulent practices requires a continuous update of analytical platforms. Different analytical techniques have become extremely appealing since the instrumental analysis tools evolution has substantially improved the capability to reveal and understand the complexity of food. In light of this, multi-elemental composition has been successful implemented solving a plethora of food authentication and traceability issues. In the last decades, it has existed an ever-increasing trend in analysis based on spectrometry analytical platforms in order to obtain a multi-elemental profile that combined with chemometrics have been noteworthy analytical methodologies able to solve these problems. This review provides an overview of published reports in the last decade (from 2011 to 2021) on food authentication and quality control from their multi-element composition in order to evaluate the state-of-the-art of this field and to identify the main characteristics of applied analytical techniques and chemometric data treatments that have permit achieve accurate discrimination/classification models, highlighting the strengths and the weaknesses of these methodologies.

Multivariate Statistical Analysis of Metabolites in Anisodus tanguticus (Maxim.) Pascher to Determine Geographical Origins and Network Pharmacology

Anisodus tanguticus (Maxim.) Pascher, has been used for the treatment of septic shock, analgesia, motion sickness, and anesthesia in traditional Tibetan medicine for 2,000 years. However, the chemical metabolites and geographical traceability and their network pharmacology are still unknown. A total of 71 samples of A. tanguticus were analyzed by Ultra-Performance Liquid Chromatography Q-Exactive Mass Spectrometer in combination with chemometrics developed for the discrimination of A. tanguticus from different geographical origins. Then, network pharmacology analysis was used to integrate the information of the differential metabolite network to explore the mechanism of pharmacological activity. In this study, 29 metabolites were identified, including tropane alkaloids, hydroxycinnamic acid amides and coumarins. Principal component analysis (PCA) explained 49.5% of the total variance, and orthogonal partial least-squares discriminant analysis (OPLS-DA) showed good discrimination (R2Y = 0.921 and Q2 = 0.839) for A. tanguticus samples. Nine differential metabolites accountable for such variations were identified through variable importance in the projection (VIP). Through network pharmacology, 19 components and 20 pathways were constructed and predicted for the pharmacological activity of A. tanguticus. These results confirmed that this method is accurate and effective for the geographic classification of A. tanguticus, and the integrated strategy of metabolomics and network pharmacology can explain well the "multicomponent--multitarget" mechanism of A. tanguticus.

Comprehensive Profiling of Macamides and Fatty Acid Derivatives in Maca with Different Postharvest Drying Processes Using UPLC-QTOF-MS

Macamides are characteristically found in maca (Lepidium meyenii Walper). Fatty acid derivatives are also an important type of constituent in maca, since they not only relate to the biosynthesis of macamides in the postharvest process but also possess some bioactivities. To study their comprehensive profiles in maca tubers processed via the air-drying method, ultraperformance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) analyses were performed to identify macamide and fatty acid molecules. Their contents in maca tubers that were processed via air drying and freeze drying, respectively, were further quantified using high-performance liquid chromatography (HPLC) analyses comparing with eight macamide and three fatty acid reference standards. A total of 19 macamides (including four novel ones) and 16 fatty acid derivatives (two found in maca for the first time) were identified. Quantification analyses results showed the eight macamides with contents ranging from 31.39 to 1163.19 μg/g (on dry tuber), and fatty acids from 18.71 to 181.99 μg/g in the air-dried maca, but there were only three macamides and one fatty acid detected with very low contents (3.97-34.36 μg/g) in the freeze-dried maca. The results demonstrated that the air-drying method can increase the accumulations of macamides and fatty acids in the metabolism of maca in the postharvest process. The biosynthesis of two types of macamides, i.e., N-benzyl-oxo-octadecadienamides and N-benzyl-oxo-octadecatrienamides, was further elucidated in detail. These results provide more valuable insights into the phytochemicals of maca, which is helpful to explain its health benefits.

Authentication of Geographical Origin in Hainan Partridge Tea (Mallotus obongifolius) by Stable Isotope and Targeted Metabolomics Combined with Chemometrics

Partridge tea (Mallotus oblongifolius (Miq.) Müll.Arg.) is a local characteristic tea in Hainan, the southernmost province of China, and the quality of partridge tea may be affected by the producing areas. In this study, stable isotope and targeted metabolomics combined chemometrics were used as potential tools for analyzing and identifying partridge tea from different origins. Elemental analysis-stable isotope ratio mass spectrometer and liquid chromatography-tandem mass spectrometrywas used to analyze the characteristics of C/N/O/H stable isotopes and 54 chemical components, including polyphenols and alkaloids in partridge tea samples from four regions in Hainan (Wanning, Wenchang, Sanya and Baoting). The results showed that there were significant differences in the stable isotope ratios and polyphenol and alkaloid contents of partridge tea from different origins, and both could accurately classify partridge tea from different origins. The correct separation and clustering of the samples were observed by principal component analysis and the cross-validated Q² values by orthogonal partial least squares discriminant analysis (OPLS-DA) were 0.949 (based on stable isotope) and 0.974 (based on polyphenol and alkaloid), respectively. Potential significance indicators for origin identification were screened out by OPLS-DA and random forest algorithm, including three stable isotopes (δ¹³C, δ D, and δ¹⁸O) and four polyphenols (luteolin, protocatechuic acid, astragalin, and naringenin). This study can provide a preliminary guide for the origin identification of Hainan partridge tea.

Classification of organic and ordinary kiwifruit by chemometrics analysis of elemental fingerprint and stable isotopic ratios

Elemental fingerprint, stable isotopic analysis, and chemometrics were combined to identify organic kiwifruit from ordinarily cultivated kiwifruit. Samples of organic (n1 = 78) and ordinary kiwifruit (n2 = 85) were collected from neighboring areas. For elemental fingerprint, the contents of 15 elements in fresh fruits, including Al, Cr, Mg, Pb, Zn, Ca, Cu, Mn, Se, Cd, Fe, Na, Sr, Co, and K, were determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Three stable isotopes, including δ¹³ C, δ¹⁵ N, and δ¹⁸ O, were analyzed using an isotope-ratio mass spectrometer (IRMS). Different classification methods including soft independent modeling of class analogy (SIMCA), partial least squares discriminant analysis (PLSDA), and least squares support vector machines (LS-SVM), were used to discriminate the organic and ordinary kiwifruits by fusion of elemental and stable isotopic. As a result, the sensitivity, specificity, and overall accuracy of SIMCA model were 0.885, 0.857, and 0.864, respectively. PLSDA and LS-SVM obtained 0.950 and 0.983 classification accuracy of organic and ordinary kiwifruits, respectively. It was demonstrated that elemental fingerprint and stable isotopic analysis would provide useful chemical information for the identification of organic fruits, and the capacity of these methods could be enhanced by chemometrics. PRACTICAL APPLICATION: The classification of kiwifruit usually relies on the label assigned by the merchant, which is prone to deceive consumers. This research has developed an accurate and effective classification method based on stable isotopes and mineral elements for the identification of ordinary kiwifruit and organic kiwifruit, providing a tool for the quality monitoring of organic food.

Combination of a multiplatform metabolite profiling approach and chemometrics as a powerful strategy to identify bioactive metabolites in Lepidium meyenii (Peruvian maca)

Lepidium meyenii is an edible plant that has been used as a nutritional supplement worldwide due to its medicinal properties. However, most of the studies have focused on the pharmacological activities of the extracts rather than their chemical composition. Herein, we used a combination of a multiplatform metabolite profiling approach and chemometrics to identify bioactive metabolites in L. meyenii. Extracts obtained with ethyl acetate and ethanol showed the promising antioxidant, anti-glioma and antibacterial activities. Sixty metabolites were identified by HPLC-MS, whereas fifteen were identified by GC-MS. Partial least squares discriminant analysis (PLS-DA), hierarchical cluster analysis (HCA), and Variable Importance in Projection (VIP) successfully discriminated extracts obtained in different organic solvents from in natura dry roots and commercial product samples of L. meyenii. Additionally, correlation analysis allowed us to pinpoint potential candidates responsible for each biological activity tested for the extracts, which could be extrapolate for other food-related species.

Preliminary Study on Tracing the Origin and Exploring the Relations between Growing Conditions and Isotopic and Elemental Fingerprints of Organic and Conventional Cavendish Bananas (Musa spp.)

The stable isotopic ratios and elemental compositions of 120 banana samples, Musa spp. (AAA Group, Cavendish Subgroup) cultivar Williams, collected from six countries (Colombia, Costa Rica, Dominica Republic, Ecuador, Panama, Peru), were determined by isotope ratio mass spectrometry and inductively coupled plasma mass spectrometry. Growing conditions like altitude, temperature, rainfall and production system (organic or conventional cultivation) were obtained from the sampling farms. Principal component analysis (PCA) revealed separation of the farms based on geographical origin and production system. The results showed a significant difference in the stable isotopic ratios (δ¹³C, δ¹⁵N, δ¹⁸O) and elemental compositions (Al, Ba, Cu, Fe, Mn, Mo, Ni, Rb) of the pulp and peel samples. Furthermore, δ¹⁵N was found to be a good marker for organically produced bananas. A correlation analysis was conducted to show the linkage of growing conditions and compositional attributes. The δ¹³C of pulp and peel were mainly negatively correlated with the rainfall, while δ¹⁸O was moderately positively (R values ~0.5) correlated with altitude and temperature. A moderate correlation was also found between temperature and elements such as Ba, Fe, Mn, Ni and Sr in the pulp and peel samples. The PCA results and correlation analysis suggested that the differences of banana compositions were combined effects of geographical factors and production systems. Ultimately, the findings contribute towards understanding the compositional differences of bananas due to different growing conditions and production systems linked to a defined origin; thereby offering a tool to support the traceability of commercial fruits.

Stable isotope ratio analysis combined with inductively coupled plasma-mass spectrometry for geographical discrimination between Italian and foreign saffron

Seventy-six samples of saffron were analysed through inductively coupled plasma-mass spectrometry (ICP-MS) and stable isotope ratio analysis. The dataset was formed by 67 samples harvested in different areas of Italy, Morocco and Iran, and nine samples purchased in the Italian market. For the first time, 42 elements and five stable isotopes (δ¹³ C, δ¹⁵ N, δ³⁴ S, δ² H and δ¹⁸ O) were considered to carry out the discrimination of the samples on the basis of their geographical origin. Combined ICP-MS and isotopic composition data turned out to be a useful tool for the geographical discrimination of saffron among predefined cultivation sites. K, Cr, Mn, Ni, Zn, Rb, Sr, Mo, Cs, Nd, Eu, Pb, δ¹³ C, δ¹⁵ N, δ³⁴ S and δ² H were identified as the significant variables in geographical discrimination. Moreover, the class models generated for saffron cultivated in two specific areas of Central Italy exhibited 100% specificity for Moroccan, Iranian and commercial samples and a high specificity (83% and 84%) for the saffron samples cultivated in other, although close, Italian sites.