Influence of species and processing techniques on phlorin in Citrus juices as quantified by 1H-NMR spectroscopy

Jungen, Markus; Schütz, Birk; Schweiggert, Ralf M.

doi:10.1016/j.lwt.2020.109949

Cited by 7 publications

(2 citation statements)

References 15 publications

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“…The method was successfully applied to a wide range of food and beverages including black tea, fruit juices, vinegar, wine, sake, soy milk and soy sauce, chocolate, honey, cookie, sauce paste, etc. The targeted NMR approach has been mainly used in food authentication, e.g., to distinguish between the two marketable oregano species with apigenin and p-cymene as biomarkers of Origanum onites and salvianolic acid B of Origanum vulgare [65]; to identify fraudulent processing techniques (with phlorin as marker) [66] or adulteration (with coumarins and psoralens as markers) [67] of Citrus juices; to evaluate saccharide adulteration in honey [68]; to detect illegal adulterants in herbal medicines [69]; and to quantify compound markers of quality in spirit drinks [70]. The targeted approach has been also used for the quantification of chosen metabolites in food matrices, e.g., in the quantification of polyols in sugar-free foodstuffs by the Chemical Shift Selective Filter-Total Correlation Spectroscopy (CSSF-TOCSY) NMR experiment [71]; the analysis of fatty acids in walnut oil [72]; the quantification of methylglyoxal in manuka honey [73]; and the quantification of cannabinoids in hempseeds [74] and hempseed oils [75].…”

Section: Third Starting Point: Nmr Methodologymentioning

confidence: 99%

NMR-Based Approaches in the Study of Foods

Sobolev¹,

Ingallina

Spano

et al. 2022

Molecules

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In this review, the three different NMR-based approaches usually used to study foodstuffs are described, reporting specific examples. The first approach starts with the food of interest that can be investigated using different complementary NMR methodologies to obtain a comprehensive picture of food composition and structure; another approach starts with the specific problem related to a given food (frauds, safety, traceability, geographical and botanical origin, farming methods, food processing, maturation and ageing, etc.) that can be addressed by choosing the most suitable NMR methodology; finally, it is possible to start from a single NMR methodology, developing a broad range of applications to tackle common food-related challenges and different aspects related to foods.

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Section: Third Starting Point: Nmr Methodologymentioning

confidence: 99%

NMR-Based Approaches in the Study of Foods

Sobolev¹,

Ingallina

Spano

et al. 2022

Molecules

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“…V případě citronových šťáv by bylo vhodné doplnit výše uvedené markery např. o phlorin 34 , jakožto marker přídavku pulpwash, dále o profil a stanovení karotenoidů a aminokyselin 35 . LITERATURA…”

Section: Výsledky a Diskuseunclassified

Possibilities for Detection of Adulteration of Lemon Juices and Lemon-Based Beverages

et al. 2023

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Lemon juice and other lemon-based beverages are subject to economically motivated fraud, primarily including a reduced fruit content closely related to excessive dilution with water, undeclared addition of sugars or synthetic citric acid, and substitution of lemons with cheaper fruit. Eight tested samples of 100% juices showed good agreement between the measured concentrations and the reference values for the following markers: formol number (range from 16.9 to 26.5 mL of 0.1M NaOH 100 mL–1), ash (2.5 to 3.9 g L–1), phosphorus (84 to 145 mg L–1), potassium (931 to 1720 mg L–1), magnesium (81 to 114 mg L–1), malic acid (1.8 to 6.0 g L–1), and ᴅ‑isocitric acid (277 to 560 mg L–1). The following markers were suggested as an evidence of adulteration, processing method, and recipe alteration after the subsequent analysis of the beverage concentrates: 1) Citric acid is a substance whose content can be increased by adding synthetic citric acid. 2) Calcium content was impacted by clarification or reconstitution in some beverage concentrate samples tested. 3) Increased content of glucose and fructose confirmed exogenous sugar addition. 4) Ascorbic acid levels below 150 mg L–1 indicated severe processing or long-term storage. The flavonoid profile, characterized mainly by the ratio of eriocitrin and hesperidin (average value 0.7), serves as an indicator of the addition of another citrus species. However, the finding for the Interdonato variety suggests that this ratio is quite variable and not entirely specific because lime juice exhibits a similar value. Citronová šťáva a další nápoje na bázi citronů podléhají ekonomicky motivovaným podvodům, mezi které primárně patří snížený obsah ovoce úzce spojený s nadměrným naředěním vodou, nedeklarovaným přídavkem cukrů nebo syntetické citronové kyseliny a záměnou citronů levnějším druhem ovoce. U 8 testovaných vzorků 100% šťáv byla potvrzena dobrá shoda naměřených koncentrací s referenčními hodnotami u těchto znaků: formolové číslo (rozsah 16,9 až 26,5 ml 0,1M NaOH 100 ml–1), popel (2,5 až 3,9 g l–1), fosfor (84 až 145 mg l–1), draslík (931 až 1720 mg l–1), hořčík (81 až 114 mg l–1), jablečná kyselina (1,8 až 6,0 g l–1) a ᴅ-isocitronová kyselina (277 až 560 mg l–1). Po následném proměření nápojových koncentrátů byly jako indikátory falšování, způsobu zpracování a úpravy receptury doporučeny tyto markery: 1) obsah citronové kyseliny, jejíž nálezy mohou být zvýšeny přídavkem citronové kyseliny syntetického původu, 2) obsah vápníku, který byl u řady testovaných vzorků ovlivněn čiřením nebo rekonstitucí koncentrátu, 3) zvýšená hodnota glukosy a fruktosy potvrzovala exogenní přídavek cukrů, 4) pokles askorbové kyseliny pod 150 mg l–1 vypovídal o nešetrném zpracování nebo dlouhodobém skladování. Profil flavonoidů charakterizovaný především poměrem eriocitrinu a hesperidinu (průměrná hodnota 0,7) slouží jako indikátor přídavku jiného citrusového druhu. Je však třeba brát v potaz, že je poměrně variabilní, což ukázal nález zjištěný pro odrůdu Interdonato a ne zcela specifický, protože obdobný poměr vykazuje i šťáva z limet.

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