Turmeric (Curcuma longa L.) products: What quality differences exist?

Abstract

Background: Curcuma longa L. (root and rhizome), commonly known as turmeric, is a plant of high medicinal and economic value globally, including within the EU where it is mainly used as a food and food supplement. Its key active ingredients have been studied extensively, but concerns remain about the composition and thus the quality of extracts and products on the market. Recently, problems of adulteration with other Curcuma species and general poor quality have been detected within crude turmeric powders and final products. This study aimed to investigate the chemical variation of turmeric finished products available in the UK and identify the quality of turmeric products obtained from specific stages of the supply chain, with a focus on quality differences in the UK. 1 H-NMR spectroscopy metabolomics coupled to Principle Component Analysis (PCA) and HPTLC methods were used for the phytochemical and metabolomics investigation of 72 turmeric samples, including crude powders, intermediate products from different manufacturing stages and commercial products obtained from health food stores and the Internet. A significant variation in the chemical composition of turmeric finished products, especially in the ones containing turmeric extracts, was found. Several products were found to contain only curcumin or curcuminoids, while the other active ingredients and marker compounds of C. longa were lacking. Products obtained from different stages of the Pukka value chain presented similar chemical composition, with the intermediate products (S57-59) showing the highest amount of active ingredients. Consequently, the manufacturing practices involved in the production of turmeric food supplements are critical stages to obtain high-quality final products. Often the focus has been only on the primary material, its natural variation and forms of production. This study highlights the importance of developing well-controlled integrated systems for the quality assurance of dietary supplements throughout the supply chain from seed to final product.

The Untargeted Capability of NMR Recognizes Adulterated Natural Products

“…First, each batch was extracted twice, accompanied by ultrasonic treatment for 20 min, with 160 mL of CH2Cl2, yielding 1.15 g (14.4%, w/w) for batch A and 1.29 g (16.0%) for batch B. This was followed by MeOH extraction under the same conditions to yield 2.63 g (33.0%) and 3.22 g (39.9%), respectively ( Figure S1 Analysis by 1 H NMR can produce metabolomic fingerprints for chemometric evaluation and detection of adulteration of C. longa powders, 21,31 and MS has been utilized to confirm the presence of compounds following structure elucidation by NMR. 32 NMR offers a meaningful advantage due to its simple sample preparation, high reproducibility, and ability to detect diverse plant metabolites simultaneously.…”

Effect of Turmeric Concentrations on the Rate of Growth of Oral Bacteria—An In-Vitro Study

“…However, our study was designed to incorporate the Do it yourself (DIY) and home remedy methods that CAM users can readily prepare at home. Store-bought turmeric that is readily available to consumers consists of approximately 60% carbohydrates, 6% water, 6% protein, 5% fat, 3% dietary minerals, 3% essential oils, 2% dietary fiber, and only 1% curcumin [ 17 ]. This is in stark contrast to the studies which use 3–5% curcumin from 100 g of turmeric to achieve a minimum inhibitory concentration of the bacteria [ 3 , 12 , 17 ].…”

“…Store-bought turmeric that is readily available to consumers consists of approximately 60% carbohydrates, 6% water, 6% protein, 5% fat, 3% dietary minerals, 3% essential oils, 2% dietary fiber, and only 1% curcumin [ 17 ]. This is in stark contrast to the studies which use 3–5% curcumin from 100 g of turmeric to achieve a minimum inhibitory concentration of the bacteria [ 3 , 12 , 17 ]. Therefore, to achieve a concentration of active ingredient that is bacteriostatic or bactericidal, we would require a significantly higher amount of store-bought turmeric in solution than what is normally consumed in conventional holistic mouthwashes.…”

The Application of NMR Spectroscopy and Chemometrics in Authentication of Spices

“…Both root and rhizome are mainly used as a spice and food supplement. The main active component of Curcuma longa L. is curcumin, which is responsible for many pharmacological activities such as antioxidant, anti-inflammatory, and antibacterial activity [ 69 ]. Unfortunately, the lower price, strong yellow color and a wide availability of other Curcuma species lead to adulteration of Curcuma longa L. Thus, it is important to check the authenticity of Curcuma longa L. in order to ensure the good quality and safety of the products.…”