Food fingerprinting: Mass spectrometric determination of the cocoa shell content (Theobroma cacao L.) in cocoa products by HPLC-QTOF-MS

Detection of carob flour in cocoa powder by direct analysis in real time-mass spectrometry (DART-MS)

Cocoa is a high value product and therefore a potential target for economic adulteration with less expensive ingredients. Carob flour is less expensive than cocoa powder and is frequently cited as a potential cocoa substitute. While carob has legitimate uses as a cocoa replacement, these characteristics also make it a potential adulterant of cocoa powder. Direct analysis in real time mass spectrometry (DART-MS) is an ambient ionization MS technique that can be used to rapidly interrogate samples. Samples of cocoa powders, carob flours, and mixtures of the two were extracted with buffer and interrogated by DART-MS. The mass spectra were used to develop models to distinguish between cocoa powder and cocoa powder adulterated with carob. A principal component-linear discriminant analysis (PCA-LDA) model was used to discriminate between cocoa powder and cocoa powder amended with 15% carob flour. The accuracy using internal validation was 100%. Using an external validation dataset, the accuracy, precision, and recall were 96.0%, 94.8%, and 97.3%, respectively. These results demonstrate that DART-MS can be used to discriminate between cocoa powder and cocoa powder adulterated with 15% carob.

Chromatographic and spectroscopic methods for the detection of cocoa butter in cocoa and its derivatives: A review

Currently, there is fierce competition in the cocoa industry to develop products that possess distinctive sensory characteristics and flavours. This is because cocoa and its derivatives provide numerous health and functional advantages, which is essential to their economics. The fatty acid and triglyceride composition of cocoa determines its quality. This review emphasises the necessity of developing precise, adaptable analytical techniques to identify and quantify cocoa butter in cocoa and its derived products, from cocoa beans to chocolate bars. Key chromatographic and spectroscopic techniques play crucial roles in understanding the fundamental principles underlying the production of cocoa with desirable flavours. This significantly impacts the sustainability, traceability, and authenticity of cocoa products while also supporting the battle against adulteration.

Authentication of Cocoa Products Based on Profiling and Fingerprinting Approaches: Assessment of Geographical, Varietal, Agricultural and Processing Features

Cocoa and its derivative products, especially chocolate, are highly appreciated by consumers for their exceptional organoleptic qualities, thus being often considered delicacies. They are also regarded as superfoods due to their nutritional and health properties. Cocoa is susceptible to adulteration to obtain illicit economic benefits, so strategies capable of authenticating its attributes are needed. Features such as cocoa variety, origin, fair trade, and organic production are increasingly important in our society, so they need to be guaranteed. Most of the methods dealing with food authentication rely on profiling and fingerprinting approaches. The compositional profiles of natural components -such as polyphenols, biogenic amines, amino acids, volatile organic compounds, and fatty acids- are the source of information to address these issues. As for fingerprinting, analytical techniques, such as chromatography, infrared, Raman, and mass spectrometry, generate rich fingerprints containing dozens of features to be used for discrimination purposes. In the two cases, the data generated are complex, so chemometric methods are usually applied to extract the underlying information. In this review, we present the state of the art of cocoa and chocolate authentication, highlighting the pros and cons of the different approaches. Besides, the relevance of the proposed methods in quality control and the novel trends for sample analysis are also discussed.

Rapid determination of the shell content in cocoa products using FT-NIR spectroscopy and chemometrics

The determination of the cocoa shell content is of interest because a high shell content causes a reduction in the quality of cocoa products. Consequently, the aim of the present study was the development of a routinely applicable method for the quantitation of shell material in cocoa nibs. For this, 51 fermented cocoa samples of different varieties from 14 cocoa growing countries covering the crop years 2012-2017 were acquired. Admixtures of cocoa nibs with shell material were prepared in a range of 0-20% cocoa shell and subsequently analysed by Fourier transform near-infrared spectroscopy (FT-NIRS). Support vector machine regression models were created, which enabled the prediction of the cocoa shell content in a mixing ratio range of 0-20% with an RMSE of 2.05% and a R² of 0.88 and in a range of 0-10% with an RMSE of 1.70% and a R² of 0.72. This predictive capability suggests that the presented method is suitable for rapid determination of cocoa shell content in cocoa nibs. In addition, it was demonstrated that the method is applicable to other relevant cocoa matrices, as the prediction of the shell content of several industrial cocoa masses by the FT-NIRS-based model showed good consistency with the prediction by liquid chromatography-mass spectrometry. This emphasizes that FT-NIRS combined with chemometrics has great potential for the determination of cocoa shell content in cocoa nibs and cocoa masses in routine analysis, such as incoming inspection.

Metabolomics during the spontaneous fermentation in cocoa (Theobroma cacao L.): An exploraty review

Spontaneous fermentation is a process that depends on substrates' physical characteristics, crop variety, and postharvest practices; it induces variations in the metabolites that are responsible for the taste, aroma, and quality. Metabolomics makes it possible to detect key metabolites using chemometrics and makes it possible to establish patterns or identify biomarker behaviors under certain conditions at a given time. Therefore, sensitive and highly efficient analytical techniques allow for studying the metabolomic fingerprint changes during fermentation; which identify and quantify metabolites related to taste and aroma formation of an adequate processing time. This review shows that studying metabolomics in spontaneous fermentation permits the characterization of spontaneous fermentation in different stages. Also, it demonstrates the possibility of modulating the quality of cocoa by improving the spontaneous fermentation time (because of volatile aromatic compounds formation), thus standardizing the process to obtain attributes and quality that will later impact the chocolate quality.

Tocochromanol Profiles in Chlorella sorokiniana, Nannochloropsis limnetica and Tetraselmis suecica Confirm the Presence of 11'-α-Tocomonoenol in Cultured Microalgae Independently of Species and Origin

11'-α-Tocomonoenol (11'-αT1) is structurally related to vitamin E and has been quantified in the microalgae Tetraselmis sp. and Nannochloropsis oceanica. However, it is not known whether 11'-αT1 is present in other microalgae independent of species and origin. The aim of this study was to analyze the tocochromanol profiles of Chlorella sorokiniana, Nannochloropsis limnetica, and Tetraselmis suecica and to determine if 11'-αT1 is present in these microalgae. Cultured microalgae were freeze-dried and the presence and identity of α-tocomonoenols were confirmed by LC-MSn (liquid chromatography coupled to mass spectroscopy) and GC-MS (gas chromatography coupled to mass spectroscopy). Tocochromanol profiles were determined by HPLC-FLD (liquid chromatography with fluorescence detection) and fatty acid profiles (as fatty acid methyl esters; FAME) by GC-MS. As confirmed by LC-MSn and GC-MS, 11'-αT1 was the dominant αT1 isomer in cultured microalgae instead of 12'-αT1, the isomer also known as marine-derived tocopherol. αT1 represented less than 1% of total tocochromanols in all analyzed samples and tended to be more abundant in microalgae with higher proportions of polyunsaturated fatty acids. In conclusion, our findings confirm that αT1 is not restricted to terrestrial photosynthetic organisms, but can also accumulate in microalgae of different species, with 11'-αT1-and not the marine-derived tocopherol (12'-αT1)-as the predominant αT1 isomer.

Food Authentication: Truffle Species Classification by non-targeted Lipidomics Analyzes using Mass Spectrometry assisted by Ion Mobility Separation

Truffles are appreciated as food all over the world because of their extraordinary aroma. However, quantities are limited and successful cultivation in plantations is very labor-intensive and expensive, or even...

Cytotoxicity, cellular uptake, and metabolism to short-chain metabolites of 11'-α-tocomonoenol is similar to RRR-α-tocopherol in HepG2 cells

Contrary to the major vitamin E congener α-tocopherol, which carries a saturated sidechain, and α-tocotrienol, with a threefold unsaturated sidechain, little is known about the intracellular fate of α-tocomonoenol, a minor vitamin E derivative with a single double bond in C11'-position of the sidechain. We hypothesized that, due to structural similarities, the uptake and metabolism of α-tocomonoenol will resemble that of α-tocopherol. Cytotoxicity, cellular uptake of α-tocomonoenol, α-tocopherol and α-tocotrienol and conversion into the short-chain metabolites αCEHC and αCMBHC were studied in HepG2 cells. α-Tocomonoenol did not show significant effects on cell viability and its uptake was similar to that observed for α-tocopherol and significantly lower than for α-tocotrienol. α-Tocomonoenol was mainly metabolized to αCMBHC in liver cells, but to a lower extent than α-tocotrienol, while α-tocopherol was not metabolized in quantifiable amounts at all. In summary, the similarities in the cytotoxicity, uptake and metabolism of α-tocomonoenol and α-tocopherol suggest that this minor vitamin E congener deserves more attention in future research with regard to its potential vitamin E activity.

Rapid and comprehensive profiling of α-glucosidase inhibitors in Buddleja Flos by ultrafiltration HPLC-QTOF-MS/MS with diagnostic ions filtering strategy

Buddleja Flos is used as yellow rice colorant and a well-known traditional Chinese medicine. But its biochemical profiling is still lack due to complex matrix. Here, ultrafiltration high-performance liquid chromatograph-quadrupole time-of-flight tandem mass spectrometry (HPLC-QTOF-MS/MS) with diagnostic ions filtering strategy was proposed for rapid and comprehensive investigation of its α-glucosidase inhibitors. As a result, 33 bioactive compounds (13 phenylethanoid glycosides and 20 flavonoids) were successfully screened and identified. In addition, α-glucosidase inhibitory activities of twenty-two references were verified. Six flavonoid aglycones (4, 28, and 30-33) showed excellent α-glucosidase inhibitory activities (IC₅₀, from 5.11 ± 0.85 to 32.49 ± 9.76 μg/mL), much higher than that of acarbose (IC₅₀, 195.49 ± 10.05 μg/mL). Five flavonoid-monoglycosides (7, 12, 13, 20, and 22) presented moderate inhibitory activities with IC₅₀ from 160.98 ± 23.19 to 249.37 ± 35.83 μg/mL. Results showcased the high efficiency of proposed strategy in profiling of bioactive compounds from natural products.

Food Phenotyping: Recording and Processing of Non-Targeted Liquid Chromatography Mass Spectrometry Data for Verifying Food Authenticity

Experiments based on metabolomics represent powerful approaches to the experimental verification of the integrity of food. In particular, high-resolution non-targeted analyses, which are carried out by means of liquid chromatography-mass spectrometry systems (LC-MS), offer a variety of options. However, an enormous amount of data is recorded, which must be processed in a correspondingly complex manner. The evaluation of LC-MS based non-targeted data is not entirely trivial and a wide variety of strategies have been developed that can be used in this regard. In this paper, an overview of the mandatory steps regarding data acquisition is given first, followed by a presentation of the required preprocessing steps for data evaluation. Then some multivariate analysis methods are discussed, which have proven to be particularly suitable in this context in recent years. The publication closes with information on the identification of marker compounds.

HPLC fingerprint analysis of Phyllanthus emblica ethanol extract and their antioxidant and anti-inflammatory properties

ETHNOPHARMACOLOGICAL RELEVANCE

Phyllanthus emblica L. (P. emblica) as a medical plant has been used to treat diseases in Asia. It is famous for a wide range of biological activities, especially for its antioxidant and anti-inflammatory activity. However, quality control underlying the bioactivity of P. emblica fruits remains to be studied.

MATERIALS AND METHODS

In this study, we evaluated the HPLC fingerprint and bioactivity of polyphenols extracted from P. emblica fruits grown in different habitats.

RESULTS

P. emblica fruits collected from 10 different habitats in Guangdong, Fujian, Yunnan, and Guangxi provinces in China were used to establish a simple and reliable HPLC fingerprint assay. Simultaneous quantification of three monophenols was also performed to determine assay quality and consistency. Additionally, chemical assessment of the different ethanolic extract (PEEE) from 10 P. emblica fruits demonstrated that they exhibited antioxidant activity by enhancing reducing power and total antioxidant capacity, scavenging hydroxyl radical and superoxide anion. PEEE protected RAW264.7 cells from oxidative damage by increasing glutathione content and total superoxide dismutase activity, suppressing MDA content. PEPE also alleviated lipopolysaccharide-induced inflammation in RAW 264.7 cells by decreasing release of pro-inflammatory mediators. Notably, the PEEE samples from Yunnan province showed the optimal antioxidant and anti-inflammatory effects among all the PEEE samples.

CONCLUSION

In conclusion, The PEEE HPLC fingerprint may help improve P. emblica quality control, and P. emblica with antioxidant and anti-inflammatory activities may be potentially applied in functional foods or in adjuvant therapy for medicinal development.

Profiling of tyrosinase inhibitors in mango leaves for a sustainable agro-industry

Although mango leaves are the main ingredients in some traditional Chinese medicine preparations and folk tea, they with considerable quantities are usually discarded as agricultural waste. Thus, to extend their potential, reverse ultrafiltration-HPLC-DAD-QTOF-MS/MS combining with key ion filtering strategy was proposed to efficiently fish and systematically identify tyrosinase inhibitors in ethyl acetate fraction of mango leaves, which has the highest total phenolic content (40.00 ± 0.84 mg GAE/g DW) and tyrosinase inhibition activity (IC50, 17.62 ± 1.26 μg/mL). Finally, 36 polyphenolic tyrosinase inhibitors were unambiguously characterized or tentatively identified, and three of them were found in mango leaves for the first time. Results suggested that the proposed strategy was powerful for effective identification of bioactive compounds in complex mixtures (e.g. food, agricultural and sideline products), and the findings would lay a foundation for potential applications of mango leaves in pharmaceutical, cosmetic, and food industrial fields.

Food Targeting: Determination of the Cocoa Shell Content (Theobroma cacao L.) in Cocoa Products by LC-QqQ-MS/MS

A targeted metabolomics LC-ESI-QqQ-MS/MS application for the determination of cocoa shell based on 15 non-polar key metabolites was developed, validated according to recognized guidelines, and used to predict the cocoa shell content in various cocoa products. For the cocoa shell prediction, different PLSR models based on different cocoa shell calibration series were developed and their suitability and prediction quality were compared. By analysing samples from different origins and harvest years with known shell content, the prediction model could be confirmed. The predicted shell content could be verified with a deviation of about 1% cocoa shell. The presented method demonstrates the suitability of the targeted application of metabolomic profiling for the determination of cocoa shell and its applicability in routine analysis is discussed.