Investigating appropriate molecular and chemical methods for ingredient identity testing of plant-based protein powder dietary supplements

Abstract

Plant-based protein powders are rapidly growing in popularity, and outdated quality assurance tools expose vulnerabilities to adulteration via different methods of “protein spiking”. Adequate diagnostic tools are urgently needed to be able to authenticate protein source ingredients and screen for potential adulterants. We explored the application of three diagnostic tools for ingredient identification: targeted PCR with Sanger sequencing, NGS, and LC-MS/MS. We collected 33 samples of common commercial products from the plant-based protein powder market and sought to identify botanical components using the three technologies. We found success in detection with all approaches, with at least one main protein source being identified by at least one approach in all samples. The investigation uncovered challenges to data collection or result interpretation with each technology including but not limited to amplification biases with PCR technologies, potential influence of DNA degradation, and issues with protein solubility during isolation. Ultimately, each platform demonstrated utility along with certain caveats, which epitomized the importance of orthogonality of testing.

Flower Species Ingredient Verification Using Orthogonal Molecular Methods

“…Targeted DNA methods have been validated and utilized within the food, herbal, and supplement industries [ 51 ]. These DNA-based tools have been used successfully by these industries to verify plant species in sourced ingredients when samples have a sufficient quantity of good-quality DNA [ 52 , 53 ]. Although there is considerable research published on DNA-based identification and authentication that utilize leaves, fruit/seeds, and roots, there are only a few published studies that have used DNA methods on flowers to identify plant species [ 54 , 55 ].…”

Flower Species Ingredient Verification Using Orthogonal Molecular Methods

“…Targeted DNA methods have been validated and utilized within the food, herbal, and supplement industries [52]. These DNA-based tools have been used successfully by the industry to verify plant species in sourced ingredients when samples have su cient quantity of good quality DNA [53,54]. Although there is considerable research published on DNA-based identi cation and authentication that utilize leaves, fruit/seeds and roots, there are only a few published studies that have used DNA methods on owers to identify plant species [55,56].…”

On the Applicability of Electrophoresis for Protein Quantification

“…Protein chemistry methods are currently used to control, optimize, and elaborate novel technologies in molecular biology, pharmacology, bioengineering, and food technology [1][2][3][4][5]. Such efficient, fast, illustrative, and reproducible methods as HPLC, HPLC-MS, and PCR coupled with Sanger sequencing are used for protein quantification [6][7][8][9]. Despite the rapid progress in fast and efficient techniques employed for protein identification and quantification, simpler and more accessible analytical techniques (e.g., the conventional colorimetric measurements) also remain relevant [4,10,11].…”