Validation of HPLC-UV Methods for the Quantification of Betaine in Foods by Comparison with LC-MS

Betaine as a Functional Ingredient: Metabolism, Health-Promoting Attributes, Food Sources, Applications and Analysis Methods

Betaine is a non-essential amino acid with proven functional properties and underutilized potential. The most common dietary sources of betaine are beets, spinach, and whole grains. Whole grains-such as quinoa, wheat and oat brans, brown rice, barley, etc.-are generally considered rich sources of betaine. This valuable compound has gained popularity as an ingredient in novel and functional foods due to the demonstrated health benefits that it may provide. This review study will provide an overview of the various natural sources of betaine, including different types of food products, and explore the potential of betaine as an innovative functional ingredient. It will thoroughly discuss its metabolic pathways and physiology, disease-preventing and health-promoting properties, and further highlight the extraction procedures and detection methods in different matrices. In addition, gaps in the existing scientific literature will be emphasized.

Comparison of the Retention and Separation Selectivity of Aromatic Hydrocarbons with Polar Groups in RP-HPLC Systems with Different Stationary Phases and Eluents

In this manuscript, the retention of aromatic hydrocarbons with polar groups has been compared for systems with various nonpolar columns of the types from C3 to C18 and different mobile phases composed of methanol, acetonitrile, or tetrahydrofuran as modifiers. The selectivity separation of the solutes in systems with different adsorbents, when one eluent modifier is swapped by another, has been explained, taking into account molecular interactions of the solutes with components of the stationary phase region (i.e., extracted modifier depending on the chain length of the stationary phase).

The impact of processing on the phenolic acids, free betaine and choline in Triticum spp. L. whole grains and milling by-products

Wheat (Triticum spp. L.) is an important source of nutrients and bioactive compounds with recognized beneficial effects. Wheat undergoes several processes with the final aim of separating the endosperm from the outer layers, usually discarded. In this study, free and bound phenolic acids (PAs) profile, betaine and choline contents were quantified in six different wheat species (durum and bread wheat, turanicum wheat, einkorn, emmer and spelt), the corresponding milling by-products (bran, middlings, aleurone and I, II and III steps of debranning) and flour/semolina, using UHPLC-MS/MS methods. The bound form of phenolics was the component present in higher concentration (80% of the total, in average) and ferulic acid was the most abundant compounds, representing between 67 and 73 % of total PAs. Among the species, bread wheat grain totalized the highest content of total PAs (1209.31 ± 7.3 µg g^-1 d.w.). Betaine and choline are abundantly present in wheat species. In general, the highest content of bioactive compounds was found in bran (3 times higher than whole grains), emphasizing the good nutritional profile of these by-products. The milling process leads to a severe reduction of phenolic acids and methyl-donors in the end-products.

Development and optimization of a method for determining betaine and trigonelline in the fruits of Lycium species by using solid-phase extraction combined with high-performance liquid chromatography-diode array detector

Betaine is an essential nutrient for humans and a source of methyl donors for methionine and S-adenosylmethionine formation, and it is used as a biomarker for pharmacological activities and to evaluate the quality of Lycium species and common foods. However, because of its special structural features, poor ultraviolet-chromophore, and high polarity, the existing methods for betaine extraction and quantification cannot provide higher extraction efficiency, better sensitivity, or resolution degree. A simple, fast, and efficient high-performance liquid chromatography-diode array detector coupled with solid-phase extraction was adopted for simultaneous separation and quantification of betaine in four types of Lycium species. The results revealed that after degreasing with dichloromethane, extraction with 80% ethanol (pH adjusted to 1.0 with hydrochloric acid), and elution with aluminum oxide (OH^- form), the improvement in the average yield rate of betaine was thrice of that of the existing methods. In addition, trigonelline was identified as the interfering substance of betaine for the first time in Lycium species, and betaine and trigonelline were simultaneously separated and quantified. Furthermore, their chemical characteristics and content distribution in different Lycium species were carried out.

Betaine in Cereal Grains and Grain-Based Products

Betaine is a non-essential nutrient which performs several important physiological functions in organisms. Abundant data exist to suggest that betaine has a potential for prevention of chronic diseases and that its dietary intake may contribute to overall health enhancement. Several studies have pointed out that the betaine status of the general population is inadequate and have suggested nutritional strategies to improve dietary intake of betaine. Cereal-based food has been implicated as the major source of betaine in the Western diet. This review summarizes the results on the betaine content in various cereals and related products. Attention has been given to the betaine content in gluten-free grains and products. It also discusses the stability of betaine during processing (cooking, baking, extrusion) and possibilities to increase betaine content by fortification.

New approaches for extraction and determination of betaine from Beta vulgaris samples by hydrophilic interaction liquid chromatography-tandem mass spectrometry

Betaine is one of most studied biologically active compounds, due its role in the main biological processes. Although it may be found in several plants and roots, such as the Beta vulgaris family, present in typical diets, just a few analytical methods have been developed for its extraction from roots. A new, quick and effective procedure for the isolation and determination of betaine from two different varieties of B. vulgaris (red and gold) is presented. For betaine extraction, an accelerated solvent extraction (ASE) was coupled with solid-phase extraction. For betaine determination, a separation method based on hydrophilic interaction chromatography coupled with tandem mass spectrometry was optimized for a sensible detection of betaine by means of experimental design. Recoveries were about 93%, with RSD <5%, for both the matrices, without evidence of interfering species. The total content of betaine in extracts of various parts of plants (juice, peel, root) have been determined, obtaining concentrations in the range 3000–4000 mg/L for the juice and in the range 2–5 mg/g for the pulp and for the peel. The B. vulgaris gold species exhibited a higher concentration of betaine, compared to the red variety. Additionally, a micro extraction by packed sorbent technique and a modified quick, easy, cheap, rugged and safe (QuEChERS) procedure, were also tested and compared. Despite the lower recoveries of the latter, with respect to the ASE/SPE procedure (75–89%, RSD <1.5%), the ease of the method, which can be applied without the SPE purification procedure, can represent a positive improvement.

Graphical abstract