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Whole Leaf Marker and Maltodextrin in Aloe Vera Raw Materials – Dry Weight Quantity – Extended 1H NMR Analysis Method

by Herbal Supplement, NMR, PAT Tagged: , , , , , , , , , , , ,

Process NMR Associates has developed an extension of its 1H NMR analysis of Aloe Vera raw materials and products analysis. Powder aloe vera raw materials (100x/200x) can be analyzed directly and juice samples (1x, 5x, 10x, commercial products) must be freeze dried for this analysis. The whole leaf markers utilized in this test to indicate the presence of whole leaf material are iso-citrate and iso-citrate lactone which are formed in the green leaf part of the aloe plant as part of the citric acid cycle. It is possible to assign and quantify the following components of an aloe vera juice or powder:

* aloe vera components: acemannan, glucose, malic acid
* whole leaf markers: isocitrate, iso-citrate lactone, citric acid
* degradation products: lactic acid, acetic acid, fumaric acid, pyruvic acid, formic acid, succinic acid, and ethanol
* adulterants: maltodextrin
* preservatives: sorbate, benzoate
* additives: sucrose, fructose, glycine, flavorants (contain ethanol and propylene glycol)

For the components above it is possible to obtain a wt% of that component in a juice sample – the freeze drying process is then used to determine the wt% solids in the juice and the dry weight concentrations of the organic components in the solids.

Currently testing of aloe vera raw materials revolve around acemannan and whole leaf marker content and the presence of glucose. Process NMR Associates method can perform this analysis but also tell you the “quality” of the aloe vera raw material – the absolute concentrations of degradation products can tell you a lot about the exposure of the raw material to:

* excessive heat (hydrolyzation of acemannan acetyl groups to acetic acid (vinegar) or formic acid)
* lactobacillus bacteria (found on the skin of the aloe vera plant – these bacteria “eat” malic acid and produce lactic acid)
* enzymatic processes (enzymes found in the aloe vera plant itself can cause degradation to succinic acid or fumaric acid

The figure below shows the NMR assignment of a whole leaf juice that has been freeze dried. From the molar ratios of the various 1H NMR peaks it is possible to obtain a wt% value for all components by comparison with a nicotinamide internal standard (spectral range not shown) and the molecular weight of the component molecule or monomer unit.

Whole Leaf Marker and Adulteration Analysis of Aloe Vera Raw Materials

1H NMR spectroscopy observes signals from all protons in the sample simultaneously. Aloe vera components, preservatives, and degradation products yield peaks at specific chemical shifts which can be integrated and quantified. Observations are made on the following peaks:

Nicotinamide – Internal NMR Standard: 1) 8.85 ppm, 2) 8.2 ppm (often coincides with formic acid), 3) 7.55 ppm, 4) 8.65 ppm
Glucose – C1 proton for alpha conformation at 5.2 ppm (doublet) and C1 proton for beta conformation at 4.6 ppm (doublet)
Malic Acid – CH at 4.35 ppm (multiplet), CH2 at 2.4-2.8 ppm (multiplet)
Acemannan – CH3 resonances of acemannan acetylation – fingerprint distribution of methyl resonances from 2.0-2.2 ppm
Lactic Acid – CH3 Peak at 1.33 ppm (doublet)
Acetic Acid – CH3 peak at 1.92 ppm (singlet)
Succinic Acid – 2 x CH2 peak at 2.5 ppm (singlet)
Formic Acid – Aldehyde Resonance at 8.2 ppm (singlet)
Ethanol – CH3 peak at 1.18 ppm (triplet)
Pyruvic Acid – CH3 peak at 2.35 ppm (singlet)
Citric Acid – 2 x CH2 resonances at 2.4 to 3.0 ppm (multiplet)
Iso-Citrate (Whole Leaf Marker) – CH at 4.25 ppm (doublet)
Iso-Citrate Lactone (Whole Leaf Marker) – CH at 5.05 ppm (doublet)
Benzoate – ortho-protons (2H) give peaks at 7.8 ppm.
Sorbate – CH3 peak is observed at 1.77 ppm (doublet) olefin protons observed at 5.7, 6.15, &7 ppm.
Fumaric Acid – CH peak at 6.55 ppm (singlet)
Sucrose – C1 proton observed at 5.4 ppm (doublet)
Maltodextrin – qNMR protons observed at 5.4 ppm

Maltodextrin is readily observed and quantified by 1H NMR – in the figure below is an example of a 100x and a 200x aloe vera gel powder – the 100x sample contains 50 wt% maltodextrin – the peaks at 5.4 and in the 3.5-4.0 ppm region are used to quantify the presence of maltodextrin.

Maltodextrin Adulteration - 1H NMR Test - Aloe Vera Raw Material Testing

Process NMR Associates is currently the only company providing a detailed breakdown of the components of aloe vera including quantitation of the whole leaf markers. Dry weight limits of acemannan, whole leaf markers, and maltodextrin are required for aloe vera raw material certification and quality control.

In the food industry it is found that most fruits, beverages, and dairy products contain a complex mixture of these same organic acid chemistry components. 1H NMR has a unique advantage in the analysis of these types of materials as NMR requires very little sample preparation and the data can be used to unequivocally identify the presence of single component chemistries and to quantify their presence in a single 15-30 minute analysis. Process NMR Associates are available to develop NMR based methodologies on any of these types of food systems and would welcome discussion of this with potential customers. Customers are not charged for initial consultation and project scoping. These NMR methods are universally applicable on NMR systems from 200-900 MHz. If you are interested please contact John Edwards (Tel: +1 (203) 744-5905)

ASTM F2259-03 (2008) – Determining the Chemical Composition of Alginates by 1H NMR Spectroscopy

by Chemistry, Herbal Supplement, NMR

Alginate is a linear polysaccharide composed of mannuronate (M) and a-L-guluronate (G). The polysaccharide is characterized by the relative ratio of M/G, G-Content, and average length of blocks of G in the polymer. M and G are:

ASTM F2259 recounts the standard sample preparation and 1H NMR analysis that allows the following parameters to be calculated:

The 1H Spectra obtained on a typical alginate sample are show below:


Finally the peaks representing the individual M and G components and sequences are deconvoluted from the spectrum.
The intensities obtained from the deconvolution are input into the excel spreadsheet shown above and the various ratios, M and G content and a series of diads and triads are calculated along with some G block lkength information. It is the block length information that often reveals telling differences between samples.

Process NMR Associates performs this analysis at a cost of $225 per sample. The samples, however, must be prepared by the customer using the methodology set forth in the test method.

The Role of NMR in FDA Mandated Identity Testing of Nutritional Supplements

by Chemistry, Herbal Supplement, NMR

Process NMR Associates Offers Testing, Consultation, and Support in Meeting Your Identity Testing, Laboratory Methodology, and Process Analytical Requirements for FDA DS CGMP Rule Compliance.

In conjunction with 21 CFR 111, the FDA’s Office of Nutrition, Labeling and Dietary Supplements has instituted the Dietary Supplement Current Good Manufacturing Practice Rule (DS GCMP Rule) and the Interim Final Rule effective December 2010. Laboratory compliance, including identity testing and analytical method protocols are now required for any manufacturer, packager, labeler or holder of dietary supplements without the previous exemption based on number of full time employees within the company. Smaller companies, typically without in-house laboratory and testing facilities, now need to obtain such services to meet the new compliance rules.

Process NMR Associates (PNA), the process analytical consulting company and analytical testing company with over 45 years of experience in the field of nuclear magnetic resonance spectroscopy (“NMR”) and organic spectroscopy (FTIR, NIR, ESR) is now offering expanded services for DS GCMP Rule compliance. As an example, The International Aloe Science Council (IASC), a trade association representing the global aloe vera industry, has selected Process NMR Associates, LLC (PNA) as its primary provider for Nuclear Magnetic Resonance (NMR) spectroscopic measurement of aloe vera. PNA’s services include measurement of aloe vera concentration, sacharride distributions, formulation ingredients, and, contaminant/degradation products, in aloe vera powders, whole leaf extracts, whole leaf and inner leaf gel concentrates, drink concentrates, and, ready to drink formulations. PNA’s NMR services are an integral part of the IASC certification and compliance program. “We are pleased to partner with Process-NMR Associates for providing analytical services related to the certification program,” said Devon Powell, Executive Director of the IASC. “PNA has demonstrated its capability to provide excellent analytical services in a timely manner to the organization and aloe vera industry at-large.”

Expanding analyses and methodologies beyond aloe vera include essential oil analyses, fish oils and omega-3 fatty acid analyses, herbal supplement characterization, adulteration monitoring, and, ingredient integrity analyses. It is PNA’s commitment to quality analytical services, sample analysis, reporting turnaround, and competitive pricing that enable us to provide value-added services to the dietary supplement market place.

Press Release: IASC Chooses Process NMR Associates to Provide Analytical Services for Certification Program

by Herbal Supplement, NMR Tagged: , ,

The International Aloe Science Council (IASC), a trade association representing the global aloe vera industry, has selected Process NMR Associates, LLC (PNA) as its primary provider for Nuclear Magnetic Resonance (NMR) spectroscopic measurement of aloe vera in regards to the organizations seal-based certification program. PNA’s services include measurement of aloe vera concentration, sacharride distributions, formulation ingredients, and, contaminant/degradation products, in aloe vera powders, whole leaf extracts, whole leaf and inner leaf gel concentrates, drink concentrates, and, ready to drink
formulations.

The IASC certification program, which offers manufacturers the ability to place a seal on products demonstrating that it meets the established standards for quality and purity of aloe vera products available in the marketplace, has elected to use quantitative 1H NMR analysis as a means to determine compliance. “We are pleased to partner with Process-NMR Associates for providing analytical services related to the certification program,” said Devon Powell, Executive Director of the IASC. “PNA has demonstrated its capability to provide excellent analytical services in a timely manner to the organization and aloe vera
industry at-large.”

PNA performs the NMR methodology prescribed by IASC, quantifying constituents such as acemannan, and glucose, identifying breakdown products such as acetic acid, lactic acid, pyruvic and succinic acid, and verifying formulation/preservative additives such as citric and benzoic acids. Adulterants such as maltodextrin can be readily quantified and the presence of non-aloe vera products can also be determined.“Process NMR Associates is proud to have been chosen as a partner for IASC’s certification program needs,” said John Edwards, PNA Manager. “Our commitment to quality analytical services, sample analysis, reporting turnaround, and competitive pricing enable us to provide value-added services to IASC
and others in the aloe vera marketplace.”

The International Aloe Science Council (IASC) is the global trade association dedicated to serving the needs of the aloe vera industry, with a mission to advance, promote and represent the aloe vera industry by providing educational, scientific and self-regulatory leadership and guidance. Membership information can be found at www.iasc.org. Contact: Devon Powell, Executive Director 301.588.2420 x102 (dpowell@iasc.org)

Established in 1997 PNA is a process analytical consulting company and analytical testing laboratory with over 45 years of experience in the field of nuclear magnetic resonance spectroscopy (“NMR”) and organic spectroscopy (FTIR, NIR, ESR). PNA operates high field analytical NMR laboratory for liquid and solid state multinuclear and multi-dimensional NMR analyses. PNA also has several permanent magnet NMR systems that are utilized for laboratory, at-line, and, process FT-NMR and TD-NMR applications. The lab also includes an ATR-FTIR spectrometer, a micro-ESR spectrometer and a Simulated Distillation Gas Chromatograph. Consultation services for analytical technology and application development, development of new instrument platforms and integrate NMR technology with other analytical techniques are also provided. (www.process-nmr.com) Contact: John C. Edwards, Manager, Analytical and Process NMR (john@process-nmr.com)