Structural characterization of red beet fiber and pectin

The Impact of Red Beetroot Products on Glycemic Profiles: A Systematic Review of Human Evidence

PURPOSE OF REVIEW

Low-glycemic diets are crucial, particularly for individuals with diet-related diseases such as obesity and diabetes. Therefore, observing the impact of multiple forms of red beetroot-based products on the glycemic profiles of humans under various health conditions has arguably become significant due to beetroot's high fiber content, antioxidants, inorganic nitrates, etc., which this review aims to summarize.

RECENT FINDINGS

The relevant articles published between 2000 and 2022 were obtained from PubMed, Scopus, and ScienceDirect by following the PRISMA-P 2020 statement. This systematic review included 18 randomized controlled trials (RCTs), one non-randomized clinical trial (non-RCT), and one quasi-experimental (QE) study, and they covered different health conditions, e.g., type-2 diabetes mellitus (T2DM), obesity, hypertension, etc. The studies produced conflicting results, likely due to differences in the study design, dosage, duration, and population. The risk of bias in most of the RCTs and QE studies included in the review was assessed as low or moderate, and only one non-RCT was assessed as having a high risk of bias. Red beetroot may help maintain the blood sugar levels of humans under different health conditions. However, the existing results on beetroot's potential for glycemic management are unclear due to varied outcomes across studies. Further intervention studies with standardized protocols and diverse participant groups are necessary to assess the role of beetroot products in regulating blood sugar levels before making a definitive judgment.

Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2021-2022

The use of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry for the analysis of carbohydrates and glycoconjugates is a well-established technique and this review is the 12th update of the original article published in 1999 and brings coverage of the literature to the end of 2022. As with previous review, this review also includes a few papers that describe methods appropriate to analysis by MALDI, such as sample preparation, even though the ionization method is not MALDI. The review follows the same format as previous reviews. It is divided into three sections: (1) general aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, fragmentation, quantification and the use of computer software for structural identification. (2) Applications to various structural types such as oligo- and polysaccharides, glycoproteins, glycolipids, glycosides and biopharmaceuticals, and (3) other general areas such as medicine, industrial processes, natural products and glycan synthesis where MALDI is extensively used. Much of the material relating to applications is presented in tabular form. MALDI is still an ideal technique for carbohydrate analysis, particularly in its ability to produce single ions from each analyte and advancements in the technique and range of applications show little sign of diminishing.

Structural characterization of strawberry pomace

Strawberries are a nutrient dense food rich in vitamins, minerals, non-nutrient antioxidant phenolics, and fibers. Strawberry fiber bioactive structures are not well characterized and limited information is available about the interaction between strawberry fiber and phenolics. Therefore, we analyzed commercial strawberry pomace in order to provide a detailed carbohydrate structural characterization, and to associate structures with functions. The pomace fraction, which remained after strawberry commercial juice extraction, contained mostly insoluble (49.1 % vs. 5.6 % soluble dietary fiber) dietary fiber, with pectin, xyloglucan, xylan, β-glucan and glucomannan polysaccharides; glucose, fructose, xylose, arabinose, galactose, fucose and galacturonic acid free carbohydrates; protein (15.6 %), fat (8.34 %), and pelargonidin 3-glucoside (562 μg/g). Oligosaccharides from fucogalacto-xyloglucan, methyl-esterified rhamnogalacturonan I with branched arabinogalacto-side chains, rhamnogalacturonan II, homogalacturonan and β-glucan were detected by MALDI-TOF MS, NMR and glycosyl-linkage analysis. Previous reports suggest that these oligosaccharide and polysaccharide structures have prebiotic, bacterial pathogen anti-adhesion, and cholesterol-lowering activity, while anthocyanins are well-known antioxidants. A strawberry pomace microwave acid-extracted (10 min, 80 °C) fraction had high molar mass (2376 kDa) and viscosity (3.75 dL/g), with an extended rod shape. A random coil shape, that was reported previously to bind to phenolic compounds, was observed for other strawberry microwave-extracted fractions. These strawberry fiber structural details suggest that they can thicken foods, while the polysaccharide and polyphenol interaction indicates great potential as a multiple-function bioactive food ingredient important for gut and metabolic health.

Evaluation of citrus pectin extraction methods: Synergistic enhancement of pectin's antioxidant capacity and gel properties through combined use of organic acids, ultrasonication, and microwaves

The biological potency of pectin is intricately intertwined with its intricate molecular architecture. The fine structure of pectin is influenced by the extraction method, while the specific impact of these methods on the fine structure and the affected attributes thereof remains enigmatic. This study delves into the profound analysis of eight distinct extraction methods influence on the structure and biological activity of citrus peel pectin. The findings demonstrate that citric acid ultrasound-assisted microwave extraction yields pectin (PectinCA-US/MV) with higher viscosity and a dense, rigid chain. Pectin extracted with acetic acid ultrasound (PectinAA-US) and citric acid ultrasound (PectinCA-US) exhibits elevated galacturonic acid (GalA) levels and reduced D-galactose (Gal) content, enhancing antioxidant activity. Eight pectin-chitosan (CS) hydrogels, especially PectinCA-US/MV-CS, demonstrate commendable thermal stability, rheological properties, self-healing capability, and swelling behavior. This study characterizes citrus peel pectin properties from different extraction methods, laying a foundation for its application in food, pharmaceuticals, and industry.

Fractionation and characterisation of pectin-rich extracts from garlic biomass

Polysaccharides from garlic waste leaf and skin biomass have been isolated using a sequential extraction protocol and characterised using constituent sugar composition and linkage analysis, spectroscopy, chromatography and dilute solution viscometry. The results revealed that the isolated polysaccharides were predominantly pectins. The predominant monosaccharide in all samples was galacturonic acid (>61 %), followed by galactose and rhamnose. The pectins extracted from skin biomass were mainly homogalacturonan (83-91 %), whereas those extracted from leaf biomass comprised both homogalacturonan (62-65 %) and rhamnogalacturonan-I (35-38 %). The degree of methyl esterification of uronic acids in all samples was 44-56 %. The peak molecular weight of the main polysaccharide population in each sample was ∼ 350 x103 g/mol, with leaf extracts and the skin acidic extract containing a second, lower molecular weight peak. Overall, waste garlic biomass is a potential resource for commercial pectin extraction for use in food or pharmaceutical industries.

1D and 2D NMR datasets, resonance assignments and coupling constant analysis of red beet fiber and pectin

The datasets presented in this article represent detailed NMR spectral analyses on red beet fiber, including the pomace, water-soluble and water-insoluble fractions, as well as the acid-extracted pectin. The samples were solvated in deuterium oxide and investigated by 1D-¹H, 1D-¹³C NMR, and multiple 2D-NMR experiments, including gCOSY, zTOCSY, HSQC, HMBC, HSQCTOCSY, and H2BC. The NMR chemical shifts, coupling constants and spin-systems were identified for the major carbohydrate residues in each sample. This article provides additional data related to the research article "Structural characterization of red beet fiber and pectin" published in Food Hydrocolloids [1].

Malto-oligosaccharides as critical functional ingredient: a review of their properties, preparation, and versatile applications

Malto-oligosaccharides (MOS) are α-1,4 glycosidic linked linear oligosaccharides of glucose, which have a diverse range of functional applications in the food, pharmaceutical, and other industries. They can be used to modify the physicochemical properties of foods thereby improving their quality attributes, or they can be included as prebiotics to improve their nutritional attributes. The degree of polymerization of MOS can be controlled by using specific enzymes, which means their functionality can be tuned for specific applications. In this article, we review the chemical structure, physicochemical properties, preparation, and functional applications of MOS in the food, health care, and other industries. Besides, we offer an overview for this saccharide from the perspective of prospect functional ingredient, which we feel lacks in the current literature. MOS could be expected to provide a novel promising substitute for functional oligosaccharides.

Simultaneous quantification of cellulose and pectin in tobacco using a robust solid-state NMR method

Cellulose and pectin are the important components of tobacco (Nicotiana tabacum L.) cell wall, which affect the formation of undesirable compounds. Their contents are closely related to the harmfulness of tobacco. But the simultaneous quantitative analysis of cellulose and pectin is hard to be achieved for traditional analytical methods. A solid-state ¹³C cross-polarization by multiple contact periods (multiCP) NMR method was developed for the simultaneous quantification of cellulose and pectin in tobacco. The multiCP spectrum at optimal parameters agreed well with the direct polarization (DP) spectrum within one-thirtieth of the measurement time and provided satisfactory signal to noise ratio (SNR). After three simple procedures of sample preparation and spectra deconvolution, simultaneous quantification of cellulose and pectin extracted from tobacco was effectively achieved. Compared with the chemical method, this interesting method was rapid, practicable, and very promising, which provided the technical support for the simultaneous quantification of cell wall substances in biological sample.

Evaluation of a Novel Phosphorylated Red Dragon Fruit Peel Pectin for Enhancement of Thermal Stability and Functional Activity

Red dragon fruit peel, as a fruit waste, is rich in plant-based nutritional pectins that can be applied as food additives. The present study aims to characterize a novel phosphorylated red dragon fruit peel pectin (PRDFP-P) and to explore its functional activities. The thermal analysis, morphology analysis, antibacterial, antioxidant and antitumor activities of PRDFP-P were evaluated. The results showed that the phosphorylated derivative PRDFP-P had typical phosphate groups. Compared with the native red dragon fruit peel pectin (PRDFP), PRDFP-P possessed superior thermal stability and exhibited significant inhibition effects on Escherichia coli and Staphylococcus aureus. Moreover, the phosphate groups on the derivative PRDFP-P chains remarkably enhanced the scavenging ability of hydroxyl radicals and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. In addition, PRDFP-P showed a significant inhibition effect on growth of human hepatic carcinoma cells (HepG2) and the IC₅₀ value was determined to be 248.69 μg/mL (P < 0.05). Our results suggested that the phosphorylated derivative PRDFP-P might be potentially applied as stabilizing, thickening and gelling agents with functional activities in the food industry.