OUP accepted manuscript

Improved analysis of grape seed extract by liquid chromatography-high resolution mass spectrometry (LC-HRMS) reveals that proanthocyanidin-protein interaction mechanisms in cream depend on degree of polymerization

This study aimed to comprehensively characterize chemical profiles of proanthocyanidins (PACs) from grape seed extract (GSE), examine their interactions with proteins in a cream system, and define the mechanisms mediating PAC-protein interactions. GSE PACs were fractionated and characterized by thiolysis followed by liquid chromatography-high resolution mass spectrometry (LC-HRMS) analysis. New PACs with a degree of polymerization (DP) up to 16 were identified by improved HRMS data processing methods. In the model cream system, high-DP PACs exhibited greater precipitation capacity and protein binding than low-DP PACs. Low-DP PACs primarily engaged in hydrogen bonding, while high-DP PACs predominantly utilized multiple hydrophobic interaction sites to form cream protein aggregates. Furthermore, particle size and viscosity measurement of cream revealed a progressively DP-dependent increase in aggregated fat globules and cream viscosity. These findings enhanced our understanding of PACs' structural intricacies and highlighted their functional role as PAC-rich natural ingredients in creating structured cream systems.

Definition of system suitability and proficiency testing acceptance criteria for the standardization of quality control methodologies of botanical bioactives: A case study for the development of AOAC Official Method of Analysis 2020.05 flavanols and procyanidins

Flavanols and procyanidins are bioactives found in many foods including cocoa. The characterization of cocoa flavanols and procyanidins (CF) has historically been challenged by the lack of commercially available standards and weak chromatographic separation performances. The recent release of a reference material and the final authorization of an AOAC Official Method of Analysis (AOAC 2020.05) technically enables the standardization of CF testing. However, the practical implementation of CF testing for routine testing remains challenging for new laboratories, highlighting the need to define guidelines and acceptance criteria to verify normal method performance and user proficiency. This study leveraged the data generated from the recent multi-laboratory validation to define normal method performances. While the challenges associated with HILIC separation can be alleviated through a thorough system equilibration, monitoring system performances remains critical to routine operation and a laboratory's ability to generate reliable data. Guidelines for routine analysis were developed for system precision and bracketing standard recovery, as well as acceptance criteria for the analysis of the reference material. These guidelines not only complete a body of work that provide accessible, reliable, and robust CF analysis solution to research and quality laboratories, but also provide an example to facilitate the establishment and implementation of future international testing standards for botanical bioactives.

Eco-Efficient Quantification of Glucosinolates in Camelina Seed, Oil, and Defatted Meal: Optimization, Development, and Validation of a UPLC-DAD Method

Camelina sativa (camelina) seed, oil, and defatted meal are widely used for food, animal feed, and other purposes. The accurate quantification of camelina glucosinolates is critical as their functionalities are highly dose-dependent. The classic quantification of glucosinolates in camelina products involves tedious desulfation steps, toxic reagents, and a lengthy instrument time because glucosinolates are easy to degrade and subject to interference in the liquid chromatography. Thus, we developed and validated an eco-efficient UPLC-DAD method for determining glucoarabin (GS9), glucocamelinin (GS10), and homoglucocamelinin (GS11) in camelina seed, oil, and defatted meal. Glucosinolates were extracted using 80% cold methanol to denature myrosinase, and were separated by an HSS T3 column without desulfation. Glucotropaeolin was used as an internal standard to track analyte degradation and loss during sample preparation. The method has shown high precision (relative standard deviations ranging from 4.12% to 6.54%) and accuracy (>94.4% spike recovery) for GS9-11, and all validation parameters passed the industry-consensus AOAC Appendix F criteria. To our best knowledge, this is the first eco-efficient and low-cost analytical method that is validated against strict AOAC criteria for the quantification of intact camelina glucosinolates. The method is suitable to be adopted as a new industrial testing standard to assist in the quality control of camelina products.

Label compliance for ingredient verification: regulations, approaches, and trends for testing botanical products marketed for "immune health" in the United States

During the COVID-19 pandemic, the botanical product market saw a consumer interest increase in immune health supplements. While data are currently insufficient to support public health guidance for using foods and dietary supplements to prevent or treat COVID-19 and other immune disorders, consumer surveys indicate that immune support is the second-most cited reason for supplement use in the United States. Meanwhile, consumers showed increased attention to dietary supplement ingredient labels, especially concerning authenticity and ingredient claims. Top-selling botanical ingredients such as elderberry, turmeric, and functional mushrooms have been increasingly marketed toward consumers to promote immune health, but these popular products succumb to adulteration with inaccurate labeling due to the intentional or unintentional addition of lower grade ingredients, non-target plants, and synthetic compounds, partially due to pandemic-related supply chain issues. This review highlights the regulatory requirements and recommendations for analytical approaches, including chromatography, spectroscopy, and DNA approaches for ingredient claim verification. Demonstrating elderberry, turmeric, and functional mushrooms as examples, this review aims to provide industrial professionals and scientists an overview of current United States regulations, testing approaches, and trends for label compliance verification to ensure the safety of botanical products marketed for "immune health."

Assessing Variability in Vascular Response to Cocoa With Personal Devices: A Series of Double-Blind Randomized Crossover n-of-1 Trials

Controlled clinical intervention studies have demonstrated that cocoa flavanols (CF) can decrease blood pressure and arterial stiffness in healthy humans, although a large variability in the effect size across trials has been reported. In this study, we evaluated the intra- and inter-individual variability of responses to CF in everyday life using a series of n-of-1 trials in healthy free-living individuals with normal blood pressure carrying personal devices. In total, eleven healthy young humans participated in a repeated crossover randomized controlled double-blind n-of-1 trial. On 8 consecutive days, each volunteer consumed on alternating days 6 CF capsules (862 mg CF) on 4 days and 6 matched placebo capsules (P, 0 mg CF/day) on another 4 days in one of the two randomized sequences (CF-P-CF-P-CF-P-CF-P or P-CF-P-CF-P-CF-P-CF). On each day, the capsules were taken at the same time in the morning with breakfast after baseline measurements. Each subject was provided with an upper arm blood pressure monitor and a finger clip that measures pulse wave velocity (PWV). Measurements of blood pressure, heart rate, and PWV were taken at least hourly over 12 h during the day by the participants. On the first 2 days, measurements were performed under supervision to provide training. The overall mixed model analysis showed that CF significantly decreased 12-h systolic blood pressure and PWV by −1.4 ± 0.3 mmHg and −0.11 ± 0.03 m/s, respectively. Peak effects were observed within the first 3 h (1.5 h SBP: −4.9 ± 2.2 mmHg, PWV: −0.32 ± 0.17 m/s) and again after 8 h post-ingestion. Large inter-individual variation in responses was found [intra-cluster correlation coefficients (ICC): 0.41, 0.41]. When analyzing single individuals’ datasets, there was also considerable between-day variation in individual responses that varied greatly between subjects (ICC: 0–0.30, 0–0.22, 0–0.45). Effect sizes inversely correlated with baseline blood pressure values both between- and within-subjects. The data confirm that cocoa can decrease blood pressure and arterial stiffness in everyday life when elevated within the normal range. The large inter- and intra-individual variation in responses calls for more personalized nutritional intervention strategies.