Inconsistency between declared versus determined trans resveratrol and/or quercetin contents in food supplements

Dicle Çevik; Elif Begüm Yıldırım; Etil Güzelmeriç; Erdem Yeşilada

Article Details

Inconsistency between declared versus determined trans resveratrol and/or quercetin contents in food supplements

Authors:

Dicle Çevik | Elif Begüm Yıldırım | Etil Güzelmeriç | Erdem Yeşilada

Publisher:

Marmara University

Main Topics:

Pharmacognosy

Journal:

Journal of Research in Pharmacy Vol.28 Issue 6, pp.2078-2091

Document Type:

Article

Publication Date:

6/2025

Document Language:

English

Document ID (Org No.):

2001334781

pISSN:

2630-6344

Keywords:

Abstract:

 The utilization of nutraceuticals consisting of trans-resveratrol or quercetin or combination of these two compounds or food supplements contain extracts rich with trans-resveratrol or quercetin have become very popular due to their protective and health-beneficial effects especially after the Coronavirus 2019 COVID-19 pandemic. As the safety and quality control of the food supplements is very important in terms of well-being of consumers, the objective of this study was to qualitatively analyze commercially available trans-resveratrol andor quercetin supplements sold in the Turkish market by using High-Performance Thin-Layer Chromatography HPTLC and to measure trans-resveratrol and quercetin quantitatively by using a newly developed and validated High Performance Liquid Chromatography HPLC method. The HPTLC analysis was performed on silica gel 60 F254 glass HPTLC plates using toluene-chloroform-ethyl acetate-formic acid 3:2:10:0.1, vvvv as a developing solvent system. Standard compounds trans-resveratrol and quercetin were parallelly analyzed with sample test solutions belong to different brands. The chemical fingerprintings of analyzed samples showed that 8 of the 33 of them did not exhibit the expected zones corresponding to reference compounds. According to quantitative analysis via HPLC, the determined contents of trans-resveratrol and quercetin were found to be different from the declared amounts in all of the investigated products. The deviation of determined trans-resveratrol content from the declared content was calculated as  10.0 in only four food supplements R4, R5, R8, QR4; percent of declared trans-resveratrol contents ranged between 90.3 and 101.2 , whereas deviation of quercetin levels was found higher in all quercetin containing products. To conclude, the majority of the marketed products containing trans-resveratrol andor quercetin in Türkiye had lower levels of the active compounds indicating the inconsistency between the declared and the actual content of these substances. It should be highlighted that quality control of food supplements must be done by authorities before marketing.

 The utilization of nutraceuticals consisting of trans-resveratrol or quercetin or combination of these two compounds or food supplements contain extracts rich with trans-resveratrol or quercetin have become very popular due to their protective and health-beneficial effects especially after the Coronavirus 2019 COVID-19 pandemic. As the safety and quality control of the food supplements is very important in terms of well-being of consumers, the objective of this study was to qualitatively analyze commercially available trans-resveratrol andor quercetin supplements sold in the Turkish market by using High-Performance Thin-Layer Chromatography HPTLC and to measure trans-resveratrol and quercetin quantitatively by using a newly developed and validated High Performance Liquid Chromatography HPLC method. The HPTLC analysis was performed on silica gel 60 F254 glass HPTLC plates using toluene-chloroform-ethyl acetate-formic acid 3:2:10:0.1, vvvv as a developing solvent system. Standard compounds trans-resveratrol and quercetin were parallelly analyzed with sample test solutions belong to different brands. The chemical fingerprintings of analyzed samples showed that 8 of the 33 of them did not exhibit the expected zones corresponding to reference compounds. According to quantitative analysis via HPLC, the determined contents of trans-resveratrol and quercetin were found to be different from the declared amounts in all of the investigated products. The deviation of determined trans-resveratrol content from the declared content was calculated as  10.0 in only four food supplements R4, R5, R8, QR4; percent of declared trans-resveratrol contents ranged between 90.3 and 101.2 , whereas deviation of quercetin levels was found higher in all quercetin containing products. To conclude, the majority of the marketed products containing trans-resveratrol andor quercetin in Türkiye had lower levels of the active compounds indicating the inconsistency between the declared and the actual content of these substances. It should be highlighted that quality control of food supplements must be done by authorities before marketing.

 The utilization of nutraceuticals consisting of trans-resveratrol or quercetin or combination of these two compounds or food supplements contain extracts rich with trans-resveratrol or quercetin have become very popular due to their protective and health-beneficial effects especially after the Coronavirus 2019 COVID-19 pandemic. As the safety and quality control of the food supplements is very important in terms of well-being of consumers, the objective of this study was to qualitatively analyze commercially available trans-resveratrol andor quercetin supplements sold in the Turkish market by using High-Performance Thin-Layer Chromatography HPTLC and to measure trans-resveratrol and quercetin quantitatively by using a newly developed and validated High Performance Liquid Chromatography HPLC method. The HPTLC analysis was performed on silica gel 60 F254 glass HPTLC plates using toluene-chloroform-ethyl acetate-formic acid 3:2:10:0.1, vvvv as a developing solvent system. Standard compounds trans-resveratrol and quercetin were parallelly analyzed with sample test solutions belong to different brands. The chemical fingerprintings of analyzed samples showed that 8 of the 33 of them did not exhibit the expected zones corresponding to reference compounds. According to quantitative analysis via HPLC, the determined contents of trans-resveratrol and quercetin were found to be different from the declared amounts in all of the investigated products. The deviation of determined trans-resveratrol content from the declared content was calculated as  10.0 in only four food supplements R4, R5, R8, QR4; percent of declared trans-resveratrol contents ranged between 90.3 and 101.2 , whereas deviation of quercetin levels was found higher in all quercetin containing products. To conclude, the majority of the marketed products containing trans-resveratrol andor quercetin in Türkiye had lower levels of the active compounds indicating the inconsistency between the declared and the actual content of these substances. It should be highlighted that quality control of food supplements must be done by authorities before marketing.

 The utilization of nutraceuticals consisting of trans-resveratrol or quercetin or combination of these two compounds or food supplements contain extracts rich with trans-resveratrol or quercetin have become very popular due to their protective and health-beneficial effects especially after the Coronavirus 2019 COVID-19 pandemic. As the safety and quality control of the food supplements is very important in terms of well-being of consumers, the objective of this study was to qualitatively analyze commercially available trans-resveratrol andor quercetin supplements sold in the Turkish market by using High-Performance Thin-Layer Chromatography HPTLC and to measure trans-resveratrol and quercetin quantitatively by using a newly developed and validated High Performance Liquid Chromatography HPLC method. The HPTLC analysis was performed on silica gel 60 F254 glass HPTLC plates using toluene-chloroform-ethyl acetate-formic acid 3:2:10:0.1, vvvv as a developing solvent system. Standard compounds trans-resveratrol and quercetin were parallelly analyzed with sample test solutions belong to different brands. The chemical fingerprintings of analyzed samples showed that 8 of the 33 of them did not exhibit the expected zones corresponding to reference compounds. According to quantitative analysis via HPLC, the determined contents of trans-resveratrol and quercetin were found to be different from the declared amounts in all of the investigated products. The deviation of determined trans-resveratrol content from the declared content was calculated as  10.0 in only four food supplements R4, R5, R8, QR4; percent of declared trans-resveratrol contents ranged between 90.3 and 101.2 , whereas deviation of quercetin levels was found higher in all quercetin containing products. To conclude, the majority of the marketed products containing trans-resveratrol andor quercetin in Türkiye had lower levels of the active compounds indicating the inconsistency between the declared and the actual content of these substances. It should be highlighted that quality control of food supplements must be done by authorities before marketing.

Article Details

Inconsistency between declared versus determined trans resveratrol and/or quercetin contents in food supplements

Authors:

Dicle Çevik | Elif Begüm Yıldırım | Etil Güzelmeriç | Erdem Yeşilada

Publisher:

Marmara University

Main Topics:

Pharmacognosy

Journal:

Journal of Research in Pharmacy Vol.28 Issue 6, pp.2078-2091

Document Type:

Article

Publication Date:

6/2025

Document Language:

English

Document ID (Org No.):

2001334781

pISSN:

2630-6344

Trans-resveratrol

Quercetin

Nutraceuticals

Food supplements

High-Performance Thin-Layer Chromatography

High-Performance Liquid Chromatography

Quality control

Issues

Article Details

Authors: Dicle Çevik | Elif Begüm Yıldırım | Etil Güzelmeriç | Erdem Yeşilada

Publisher: Marmara University

Main Topics: Pharmacognosy

Journal: Journal of Research in Pharmacy Vol.28 Issue 6, pp.2078-2091

Document Type: Article

Publication Date: 6/2025

Document Language: English

Document ID (Org No.): 2001334781

pISSN: 2630-6344

Issues

Authors:

Dicle Çevik | Elif Begüm Yıldırım | Etil Güzelmeriç | Erdem Yeşilada

Publisher:

Marmara University

Main Topics:

Pharmacognosy

Journal:

Journal of Research in Pharmacy Vol.28 Issue 6, pp.2078-2091

Document Type:

Article

Publication Date:

6/2025

Document Language:

English

Document ID (Org No.):

2001334781

pISSN:

2630-6344