Absence of genotoxicity of purified Aloe vera whole leaf dry juice as assessed by an in vitro mouse lymphoma tk assay and an in vivo comet assay in male F344 rats.

Hydroxyanthracene derivatives (HAD) are naturally present in the latex layer of Aloe vera leaf, predominantly as aloins A, B and aloe-emodin. HAD are typically removed from commercial ingestible aloe products through activated charcoal filtration (decolorization). Current research aimed to evaluate genotoxic potential of a purified aloe whole leaf dry juice containing 0.3 ppm of total aloins and non-detectable aloe-emodin (LOD =0.01 ppm) in the L5178Y mouse lymphoma assay (MLA; OECD 490) and in vivo comet assay (OECD 489). No marked increases in mutant frequency at the tk locus were observed in the MLA at concentrations up to 5000 µg/mL for 3 h and 24 h (-S9), and up to a precipitating concentration of 3000 µg/mL for 3 h (+S9) compared to concurrent vehicle control. Relative total growth at the highest analyzable concentrations at 3 h (±S9) and 24 h (-S9) ranged from 64 to 133 %. In the comet assay, no statistically significant increases in DNA strand breaks were detected in the colon or kidney following oral gavage of 500, 1000 or 2000 mg/kg/day in male F344 rats for 2 days compared to concurrent vehicle control. Overall, these findings demonstrated the test article containing minimal HAD is not genotoxic under the described experimental conditions.

Single-Laboratory Validation Study of a Rapid TD-NMR Method for Quantitation of Total Fat in Sunflower Oil Powder.

BACKGROUND: A rapid total fat quantitation method for sunflower oil powder was developed using time-domain nuclear magnetic resonance (TD-NMR). Currently, industry has three major methods for the total fat quantitation: gravimetric analysis after ether extraction (AOAC Methods 933.05 and 989.05), gas chromatography with flame ionization detector (GC-FID; AOAC Method 996.06), and High-resolution NMR. The gravimetric analysis method takes a day using highly flammable solvents, and the GC-FID method takes two days requiring harsh chemicals for hydrolyzation, extraction, and methylation. The High-resolution NMR spectroscopy method requires simpler sample preparation and shorter analysis time compared to the other two methods. Often, the only required sample preparation step is to dissolve a sample in a solvent. The acquisition time depends on types of analyzing nuclei and sample. The vegetable oil analysis by 13C NMR takes about 4 h per sample. 1H NMR usually takes less time to analyze. In contrast, the TD-NMR relaxometry method takes only 1 h to prepare and analyze samples if the test is for total fat only. The acquisition time is 40 s per sample, and samples are analyzed "as is". A rapid analysis method in a quality control laboratory is very crucial for laboratory efficiency in releasing products. In this paper, a single-laboratory validation study is described for a rapid TD-NMR method to quantitate total fat in sunflower oil powder. OBJECTIVE: This validation work is to provide documented evidence for the method validity as well as the method performance. METHOD: The method used a Bruker minispec mq-20 NMR analyzer® with minispec plus® software. A Hahn echo pulse program was used in the method to collect spin echo signal to determine total fat content. RESULTS: The linearity/range result from 10 standards (0, 21, 42, 63, 83, 92, 100, 108, 117, and 125%) has coefficients of determination (R2) of 1.0000. The 100% level is 1.2 g-fat in 2.5 g sample, which is targeted fat content in a sunflower oil powder raw material. The method is specific for the quantitation of total fat in sunflower oil powder with no background interference from the matrix. The precision result of the 6 replicate samples at 100% level is 0.3% RSD. The accuracies measured from triplicate analysis of 80, 100, and 120% sample matrices are 100, 100, and 100% average recoveries, respectively. The ruggedness of the test method is 0.4% RSD of 12 analysis from 2 analysts (6 results from each analyst) on the different days. CONCLUSIONS: The test method is proven to be specific, linear, precise, accurate, rugged, and suitable for the intended use of quantitative analysis for total fat in sunflower oil powder. HIGHLIGHTS: Traditional methods of gravimetric or GC-FID for total fat analysis of raw materials require lengthy sample preparation and experiment time. Laboratory needs to spend a day to perform gravimetric analysis following ether extraction method and 2 days for the GC-FID method. In addition, these test methods use highly flammable and harsh chemicals that generate hazardous chemical wastes. These hazardous wastes are harmful to analysts and environments. In contrast, the TD-NMR method is safe, environmentally friendly, and fast. Therefore, TD-NMR is a preferred method for quality control laboratories.

Differentiation of Milk and Whey Protein Concentrates by Microbiome Profiling Using 16S Metagenomics.

BACKGROUND: Protein powder identification presents a challenge in quality control. There is current deliberation of the specificity of methods for the identification of milk proteins, and the consensus identification method of whey protein from the United States Pharmacopeia Food Chemical Codex relies on a combined analysis of the testing of ash, fat, lactose, loss on drying, and protein. These methods are non-specific. Milk and whey proteins both contain background DNA content. Both milk and whey proteins retain source DNA (cow), but also have bacterial DNA from natural flora, the dairy plant, and in whey protein, the cheesemaking process. The DNA in these materials is retained post-processing, even after the pasteurization process. OBJECTIVE: By utilizing 16S metagenomics, the bacterial DNA in protein powders can be sequenced and cross-referenced to a curated library to ultimately create a microbiome profile of these raw materials. This microbiome can be measured for alpha and beta diversity, specifically how many and which species of bacteria are present. METHOD: Using 16S metagenomics, we measure alpha and beta diversity of the microbiome profile of each protein powder and use principle coordinate analysis to produce differential groupings, providing a novel identification method for raw materials. RESULTS: In this study, we demonstrate that the microbiome of cow proteins can be used for raw material identification, as the microbiome of milk and whey proteins differ significantly. We also demonstrate that the microbiome of whey protein concentrate can differ from supplier to supplier. CONCLUSIONS: Microbiome profiling by 16S metagenomics can be an important forensic tool for quality control. HIGHLIGHTS: Principle Coordinate Analysis can be used as a statistical tool for protein differentiation using the protein microbiome.

Single-Laboratory Validation Study of a Proton NMR Method for the Determination of L-Arginine, L-Citrulline, and Taurine Contents in Dietary Supplements.

BACKGROUND: A quantitative NMR (qNMR) method can provide rapid analysis compared to chromatographic methods. Sample preparation steps are relatively simpler and run time is shorter. Rapid analysis methods for release tests in quality control laboratories are very important for laboratory efficiency. Here, we describe a single-laboratory validation study for a rapid qNMR analysis of L-arginine, L-citrulline, and taurine in powdered and tablet dietary supplement products. OBJECTIVES: This validation work is to provide documented evidence for the qNMR method validity as well as method performance. METHODS: The method used Bruker 400 MHz high-resolution proton NMR spectroscopy for simultaneous determination of L-arginine, L-citrulline, and taurine contents in dietary supplement product 1 (powder) and dietary supplement product 2 (tablet). The absolute NMR quantitation is based on a principle of universal proton response intensity correlation with the number of protons in each target analyte (amino acids) vs. that of a reference standard (maleic acid). RESULTS: The test method performance was validated with dietary supplement-1 (powder) and dietary supplement-2 (tablet). The linearity of the method was studied from about 360 mg/g to about 675 mg/g of L-arginine; from about 15 mg/g to about 30 mg/g of L-citrulline; and from about 20 mg/g to about 40 mg/g of taurine in dietary supplement-1, and from about 15 mg/g to about 30 mg/g of taurine in dietary supplement-2. The coefficients of determination (R2) are 1.0000 for L-arginine, 0.9967 for L-citrulline, and 0.9995 for taurine in dietary supplement-1 and 0.9903 for taurine in dietary supplement-2. The accuracies measured from the sample matrices are 102%, 101%, and 100% average recoveries for 80%, 100%, and 120% concentration levels of L-arginine, 105%, 105%, and 103% average recoveries for 80%, 100%, and 120% concentration level of L-citrulline, and 101%, 102%, and 100% average recoveries of taurine for 80%, 100%, 120% concentration levels in dietary supplement-1; and 95, 98%, and 93% average recoveries of taurine for 80%, 100%, 120% concentration levels in dietary supplement-2, respectively. The precisions (RSD) are 1% for L-arginine, 5% for L-citrulline, and 2% for taurine in dietary supplement -1, respectively; and 4% for taurine in dietary supplement-2. The ruggedness of the test method is within 2%, 4%, and 2% for L-arginine, L-citrulline, and taurine for dietary supplement -1, respectively, and within 4% for dietary supplement-2. The method is specific for the quantitation of each nutrient with no background interference from the matrix for the proton peaks of L-arginine, L-citrulline, taurine, and maleic acid (standard). CONCLUSIONS: The test method is proven to be specific, precise, accurate, rugged, and suitable for intended quantitative analysis of L-arginine, L-citrulline, and taurine in powdered and tablet finished products. HIGHLIGHTS: The simultaneous determination of all three nutrients of L-arginine, L-citrulline, and taurine using proton NMR provides rapid analysis for quality control release tests that is more efficient versus that of two HPLC methods. Previously, our laboratory was using one HPLC method to analyze L-arginine and L-citrulline while using a second HPLC method to analyze taurine. That approach required two HPLC instruments and two analysts for parallel analysis that takes 2 days using volatile and flammable solvents for extraction and chemical derivatization. This rapid NMR method can analyze the sample "as is" with results obtained in less than 4 h, and is efficient, safe, and environmentally friendly. The initial higher NMR instrument investment versus two HPLC instruments is rewarded with high returns for continued quality control tests.

Development of a Differential Multiplex PCR Assay for the Supplemental Identification of Different Sources of Proteins.

BACKGROUND: Differentiation of proteins from multiple sources provides challenges in the accuracy using multiple and often disputed protein identification methods. The U.S. Pharmacopeia Food Chemical Codex does not include monographs for many protein sources, including milk proteins and soy protein isolate. Monographs that are included for proteins do not list a single comprehensive identification method but instead rely on a combined assessment of ash (total), fat, lactose, loss on drying, and protein content. A fast, inexpensive, and accurate protein source assay is tantamount to prevention of economic adulteration in protein powders. OBJECTIVE: This study describes the development of a novel method to identify and differentiate animal proteins (cow protein powders as milk protein and whey protein) and plant proteins (soy protein powders). These proteins powders are of high importance to the food and dietary supplement industries, as they encompass the highest grossing and fastest growing protein sources in the global protein powder market. METHODS: The developed method uses PCR amplification and gel electrophoresis of short chain DNA fragments found in processed protein powders to identify and differentiate the source of each powder. The original development was performed using reference materials of known identity and tested against an inclusivity panel of protein powders from commercial sources. Bands were identified using the Agilent Tapestation 4200 and Tapestation Analysis Software A.02.02 (SR1) using proprietary band analysis. RESULTS: The developed method was found to be specific for the identification of each protein source, passing a computational (National Center for Biotechnology Information Basic Local Alignment Search Tool) exclusivity panel and an experimental inclusivity panel. The method was also able to detect multiple adulterants in concentrations as low as 1% (w/w). CONCLUSIONS: The developed method is fast, inexpensive, and accurate (100%) for the supplemental identification of cow and soy proteins and able to detect adulteration as low as 1% (w/w). HIGHLIGHTS: A new method can identify cow and soy proteins, and detect low levels of adulteration using DM-PCR.

Single-Laboratory Validation of a Two-Tiered DNA Barcoding Method for Raw Botanical Identification.

Background: The applications of deoxyribonucleic acid (DNA) barcoding methods have been extended from authenticating taxonomic provenance of animal products to identifying botanicals used as herbal medicine and in botanical dietary supplements. DNA barcoding methods for botanical identification must be adequately validated to meet regulatory compliance. Objective: The goal of this study is to provide a validation protocol for a two-tiered DNA barcoding method that aims to identify raw botanicals. Methods: A barcode database was computationally validated to define the barcode combinations that can unambiguously identify botanicals in the database. A maximum variation sampling technique was used to capture a wide range of perspectives relating to DNA barcode-based botanical identification, including plant parts and species distance, for the experimental validation. Twenty-two authenticated botanicals were purposively sampled from different plant parts-covering both closely related and distantly related species-to validate the two-tiered DNA barcoding method. The performance of the method was assessed on accuracy, precision, ruggedness, and uncertainty. Results: High accuracy (100%) and precision (1.0) were obtained from the validation samples. The method was also found to be rugged and have acceptable uncertainty. Conclusions: The method was validated and suitable for DNA-based identification of botanical raw materials listed in the current database. Highlights: This work will provide support guidance for manufacturers and regulatory policy makers to implement equivalent validated and compliant DNA-based testing in quality control processes to improve botanical raw material identification and authentication.

Quantitative Analysis of Aloins and Aloin-Emodin in Aloe Vera Raw Materials and Finished Products Using High-Performance Liquid Chromatography: Single-Laboratory Validation, First Action 2016.09.

A single-laboratory validation study is described for a method of quantitative analysis of aloins (aloins A and B) and aloe-emodin in aloe vera raw materials and finished products. This method used HPLC coupled with UV detection at 380 nm for the aloins and 430 nm for aloe-emodin. The advantage of this test method is that the target analytes are concentrated from the sample matrix (either liquid or solid form) using stepwise liquid-liquid extraction (water-ethyl acetate-methanol), followed by solvent evaporation and reconstitution. This sample preparation process is suitable for different forms of products. The concentrating step for aloins and aloe-emodin has enhanced the method quantitation level to 20 parts per billion (ppb). Reversed-phase chromatography using a 250 × 4.6 mm column under gradient elution conditions was used. Mobile phase A is 0.1% acetic acid in water and mobile phase B is 0.1% acetic acid in acetonitrile. The HPLC run starts with a 20% mobile phase B that reaches 35% at 13 min. From 13 to 30 min, mobile phase B is increased from 35 to 100%. From 30 to 40 min, mobile phase B is changed from 100% back to the initial condition of 20% for re-equilibration. The flow rate is 1 mL/min, with a 100 µL injection volume. Baseline separation (Rs > 2.0) for aloins A and B and aloe-emodin was observed under this chromatographic condition. This test method was validated with raw materials of aloe vera 5× (liquid) and aloe vera 200× (powder) and finished products of aloe concentrate (liquid) and aloe (powder). The linearity of the method was studied from 10 to 500 ppb for aloins A and B and aloe-emodin, with correlation coefficients of 0.999964, 0.999957, and 0.999980, respectively. The test method was proven to be specific, precise, accurate, rugged, and suitable for the intended quantitative analysis of aloins and aloe-emodin in raw materials and finished products. The S/N for aloins A and B and aloe-emodin at 10 ppb level were 12, 10, and 8, respectively, indicating our conservative LOD level at 10 ppb (the typical LOD level S/N is about 3). The S/N for aloins A and B and aloe-emodin at the 20 ppb level were 17, 14, and 16, respectively, indicating our conservative LOQ level at 20 ppb (the typical LOQ level S/N is about 10). The stock standard solution of a mixture of aloins and aloe-emodin and a working standard solution were found to be stable for at least 19 days when stored refrigerated at 2-8°C, with a recovery of 100 ± 5%.