Locust Bean Gum Research Articles

Purification and Characterization of β-Mannanase Derived from Rhizopus microsporus var. rhizopodiformis Expressed in Komagataella phaffii.

The demand for food-grade β-mannanases, ideal for high-temperature baking, is increasing. Using the Komagataella phaffii (P. pastoris) expression system for β-mannanase production, this study aimed to enhance purification methods. We evaluated better conditions for production and purification of β-mannanase (PpRmMan134A) from recombinant P. pastoris X-33, focusing on a higher purity and reducing the production of endogenous secretory proteins in fermentation. By adjusting carbon and nitrogen sources, culture time, and temperature, we controlled cell growth to reduce the production of endogenous secretory proteins. The better-evaluated conditions involved culturing recombinant P. pastoris in 70 mL buffered glycerol complex medium for 24 h at 30 °C, then in modified buffered methanol-complex medium with 0.91% (w/v) methanol, 0.56% (w/v) sorbitol, and 0.48% (w/v) mannitol for another 24 h, which improved the PpRmMan134A yield and reduced endogenous secretory proteins, shortening the fermentation time by 72 h. An affordable purification method using ultrafiltration and salt-out precipitation was utilized. PpRmMan134A showed thermostability up to 100 °C and effectively degraded locust bean gum into smaller fragments, mainly producing mannotriose. In conclusion, with its enhanced purity due to reduced levels of endogenous secretory proteins, purified PpRmMan134A emerges as a promising enzyme for high-temperature baking applications.

Effect of food hydrocolloids on 3D meat-analog printing and deep-fat-frying

Three-dimensional (3D) printing of food product is an emerging technology. This study investigated the effects of hydrocolloid addition on 3D printing of plant-protein based meat-analogs. Meat-analog inks were formulated with soy protein isolate, gluten, canola oil, and water. Hydrocolloids (xanthan gum, pectin, hydroxypropyl methylcellulose, guar gum, locust bean gum) were added to meat-analogs formulation. The influence of hydrocolloid addition and deep-fat-frying on 3D printing process parameters, thermal, structural, and physicochemical properties of meat-analogs, were investigated. Formulated inks were used to create a specific 3D cylindrical model geometry and the printed structure were subjected to deep-fat-frying (at 180 °C, 90sec) in canola oil. Results showed that the meat-analog ink's viscosity (3871–5482 Pa s), 3D printing rate (0.34–0.39 g s−1), printing error (2.51–10.37%), printing precision (81.97–97.27%), dimensional stability (91.22–98.61%), and cooking loss (5.69–14.23%) were significantly (p < 0.05) impacted by the incorporation of hydrocolloid. Moisture-fat profile of uncooked 3D printed meat-analogs were identical, however, differences in color attributes (L∗, a∗, b∗) among the hydrocolloids added samples were observed. Moisture, fat, and color traits of 3D printed meat-analogs were substantially impacted by deep-fat-frying. During deep-fat-frying, the loss of moisture, absorption of fat, and changes in color attributes were associated with the types of hydrocolloids incorporated in formulating the meat-analog's ink. Overall, surface's structure, chemical profile, and glass-transition-temperature of 3D printed deep-fat-fried meat-analogs were extremely impacted by the addition of hydrocolloids as well as by the types of used hydrocolloids in meat-analog ink.

Development and evaluation of locust bean gum based in situ gel for ocular delivery of ofloxacin for treatment of bacterial keratitis

One of the drawbacks of conventional ocular dosage forms is their short residence time in the eye. To address this, we propose an ocular in situ gel that adheres to the eye surface for a prolonged period. Locust bean gum (LBG), a galactomannan polysaccharide, exhibits the desired characteristics to serve as a drug carrier for ocular application. However, the gum has not yet been investigated for ocular drug delivery. In this work, we have developed an LBG based in situ gel loaded with ofloxacin and evaluated its drug delivery efficacy through in vitro and ex vivo tests. To confer temperature sensitivity, LBG was grafted with N-isopropyl acrylamide (NIPAAm), and a series of solutions were made with ofloxacin (0.03 % w/v). The solution turned into a gel when the temperature was raised to 37 °C. The safety and efficacy of the developed in situ gels were validated through experiments on rat eyes infected with clinical strains of bacteria. The developed keratitis was completely healed indicating that the grafted LBG can be used as a potential candidate for the development of ocular in situ gel.

Effects of galactomannans of varied structural features on the functional characteristics and in vitro digestibility of wheat starch

This study explores the effects of four natural galactomannans (GMs) with varying degrees of branching (fenugreek gum, guar gum, tara gum and locust bean gum) on the functional properties and in vitro digestibility of wheat starch (WS). Results from rapid viscosity analysis (RVA) and low-field nuclear magnetic resonance (LF-NMR) analysis revealed that GMs with lower branching degrees were correlated with higher paste viscosity, peak viscosity, and greater water-holding capacity in the WS-GM mixtures. Additionally, these lower branching GMs more effectively inhibited amylose leaching during starch gelatinization, leading to a softer gel texture and increased transparency of the mixtures. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analysis demonstrated that starch mixtures containing lower branching GMs exhibited reduced relative crystallinity and enthalpy values during aging. Furthermore, the incorporation of lower branching GMs resulted in decreased starch digestibility in vitro, thereby enhanced resistant starch content. These findings highlight the potential of selectively branched GMs to modulate the functional properties and nutritional profile of WS, providing a promising approach for the development of starch-based products with improved health benefits.

Modification of gel properties of Meretrix meretrix (clam) with polysaccharides: physical characterization and interaction mechanism.

This study investigated the contribution of 11 polysaccharides (2%, w/w), including pectin (PC), κ-carrageenan (KC), ι-carrageenan (IC), gellan gum (GG), guar gum (GM), sodium alginate (SA), konjac gum (KG), gum arabic (GA), fucoidan (FC), locust bean gum (LBG), and curdlan (CD), to the gel and microstructural properties of Meretrix meretrix clam gel (MMG). The hardness, springiness and chewiness of MMG with KC, IC, GG, SA and FC addition increased by ~10%-250%, while PC, GM, KG and LBG groups decreased by ~0.6% to 69%. KC, IC, SA, GG and FC decreased the cooking loss rate (CLR) by 69.4% to 88.7% and correspondingly enhanced the water holding capacity (WHC) by 10.2% to 21.4%, which was accompanied by an increased bound water and immobilized water area and high hydrogen proton density. The addition of KC transformed the MMG microstructure from a loose network with large pores to a compact, dense network, reducing lacunarity by 57.9%. The primary intermolecular forces in MMG with the incorporation of KC, IC, GG, SA and FC were hydrophobic interactions and disulfide bonds, which increased by 32.8%-105.3% and 45.6%-114.5% than MMG alone, respectively. Collectively, KC, IC, GG, SA and FC could improve the gel properties of MMG and the strongest synergistic combination was found in the MMG/KC system. This study suggests that the incorporation of polysaccharides is a strategy with potential for modifying the gel properties of shellfish surimi products. © 2024 Society of Chemical Industry.

Acid resistance of different polysaccharide hydrocolloids: pH effects

The acid resistance of polysaccharide hydrocolloids is very important for its application in food industry. In this study, the acid resistance of tamarind seed polysaccharide (TSP), xanthan gum (XG), and locust bean gum (LBG) at different pH was investigated. Results showed that the shear viscosity of TSP and LBG was significantly decreased at pH 1. Structural analyses showed that molecular degradation on the side chain of TSP and LBG occurred at pH 1, whereas the composition of the monosaccharides of XG showed no significant difference. Molecular degradation led to a decrease in the molecular weight of TSP and LBG with the gradual decrease of pH, accompanied by a shift in solution conformation, i.e., from semi-flexible chain to rigid rod for TSP and LBG, whereas XG did not undergo significant structural changes with the gradual decrease of pH. In addition, the SEM results showed that with the gradual decrease of molecular weight, the structures of TSP and LBG were gradually broken and showed fragmentation, while XG only showed slight cracks. These results show that the structure of the polysaccharides changes with the gradual decrease of pH, resulting in a change in the solution conformation and a decrease in viscosity. This study provides a new theoretical basis for the application of these polysaccharide hydrocolloids in food processing.

Impact of hydrocolloids on 3D meat analog printing and cooking

This study investigated the effects of hydrocolloid addition on three-dimensional (3D) printing and cooking of plant ingredients-based meat analog (MA). The MA inks were formulated with soy protein isolate, wheat gluten, canola oil, water, and hydrocolloids (xanthan gum, pectin, hydroxypropyl methylcellulose, guar gum, locust bean gum) at a ratio of 22:12:15:88:2. Formulated inks were used to create a specific 3D cylindrical model geometry and the printed structure were subjected to air frying (AF:180°C, 15 min) and infrared heating (IR:180°C, 15 min). Results showed that the MA ink’s viscosity (3871–5482 Pa. s), 3D printing rate (0.34–0.39 g.sec−1), printing error (2.51–10.37 %), and printing precision (81.97–97.27 %) were significantly (p<0.05) impacted by the incorporation of hydrocolloids. The dimensional stability (63.17–98.58 %), and cooking loss (6.70–17.41 %) were greatly impacted by both the hydrocolloids and post-printing cooking methods. Moisture (1.71 db) and fat (0.28 db) content of uncooked 3D printed MA were identical, whereas, differences in color attributes (L value:80.21–98.88, a value:0.01–0.13, b value:0.11–2.11) among the studied hydrocolloid added samples were observed. Moisture, fat, and color traits of 3D printed meat-analogs were significantly (p<0.05) impacted by post-printing cooking methods (AF, IR). During post-printing cooking, the loss of mass (moisture, fat) and changes in color tones were associated with the types of hydrocolloids incorporated in formulating the 3D printing ink. Surfaces and internal structure, mass loss, chemical profile, and glass-transition-temperature of 3D printed meat-analogs were significantly (p<0.05) impacted by both the type of incorporated hydrocolloids and post-printing cooking methods.

Locust bean gum glutarate nanocomposite hydrogel microspheres of gliclazide: Optimization by box-Behnken design and preclinical evaluation of anti-diabetic efficacy

In this study, carboxymethyl locust bean gum was synthesized and nanocomposite hydrogel microspheres (GHMs) of gliclazide were produced based on nanosilicate reinforcement and aluminium-ion driven gelation process, followed by covalent crosslinking with glutaric anhydride (GA). The effect of three independent variables (polymer and GA concentration, incubation time) on the drug entrapment efficiency (DEE%) and percent drug release at 8 h, was optimized using Box-Behnken design. The highest DEE (%) and lowest drug release was achieved at the following optimized conditions: polymer (2.43 %), GA (0.34 %), and incubation (27 min). The nanoscilicate-enriched matrix provided a maximum of 75.13 % DEE, 92.33 % gel fraction, and excellent flowability. The optimized microspheres had virtually spherical morphology, according to FE-SEM analysis. FTIR study indicated a hydrogen bonding interaction between the drug and other formulation components. X-ray and DSC measurements suggested that the crystallinity of the drug decreased following integration into the matrix. The optimized GHM demonstrated anomalous diffusion of gliclazide in simulated gastrointestinal fluids for 12 h without disintegration. In streptozotocin (50 mg/kg BW)-induced diabetic rats, the optimized formulation diminished blood glucose level by about 72 % in 12 h. Thus, the nanocomposite GHMs created by combining nanosilicate with GA had an outstanding potential for long-term control of diabetes.

Locust Bean Gum/κ-Carrageenan Film Containing Blueberry or Beetroot Extracts as Intelligent Films to Monitoring Hake (Merluccius merluccius) Freshness.

The main goal of this work was to develop bio-based and ecofriendly intelligent films as freshness indicators to monitor European hake (Merluccius merluccius) quality during storage by using a visual, non-destructive, and real-time technique. Locust bean gum (LBG)/κ-carrageenan (Car) films incorporating blueberry extract (BLE) or beetroot extract (BEE) were developed and their effectiveness to detect hake deterioration during 7 days of storage at 4 °C was evaluated. A visible color response from pink to blue was observed on the BLE films at the end of hake storage, which correlated with the hake deterioration profile, namely an increase in pH values (from 6.60 ± 0.04 to 8.02 ± 0.03), total viable count (TVC, from 4.61 ± 0.36 to 8.61 ± 0.21 log CFU/g), and total volatile basic nitrogen content (TVB-N, from 10.21 ± 1.97 to 66.78 ± 4.81 mg/100 g) beyond the spoilage threshold. The results of this study are very promising, since it was possible to develop a new effective intelligent bio-based responsive indicator film incorporating natural dye BLE, which has the potential to contribute to food waste reduction and improve food safety by detecting the hake freshness status.

Sensory Evaluation and Consumers' Acceptance of a Low Glycemic and Gluten-Free Carob-Based Bakery Product.

Carob pulp flour has antidiabetic and antioxidant activities, is naturally sweet, and is rich in fibers. It is obtained from carob pod pulp from the evergreen tree Ceratonia siliqua L., which is grown in Mediterranean areas and is known for locust bean gum production. Despite its valuable effects on health, such as the modulation of the glycemic index, this ingredient has a tremendous impact on technological and hedonic features, mainly on color, flavor, and texture. In this paper, the qualitative features and consumers' acceptance of a carob-based gluten-free bakery product where rice flour was substituted at 40% with carob pulp flour were studied. A panel group of experts described the bread as dark, quite dense, sweet, aromatic, and with a limited bubble dispersion. On the other hand, the sensory assessment and the willingness to pay of consumers were assessed in two groups (a fully informed one about heathy attributes of the food and a blind one). The results indicated a moderate appreciation of the overall quality of the product (average score between 4 and 5 points on a 9-point Likert scale). The information about the food's healthy properties and the ability to maintain a low glycemic index did not enhance the consumers' perception of the product, while previous knowledge and involvement in the product consumption were perceived to have primary importance regarding the final consumers' choice. Finally, an accelerated shelf-life test was run on the packaged snack to evaluate the general quality and stability. The protective packaging helped in limiting bread decay and maintaining the textural characteristics.

Mediterranean Diet gastronomic experiences using olive oil and goat cheese

The present study aims to develop three food formulations, spreadable olive oil, goat cream cheese, and a cold dessert made of carob and goat cheese, using local elements of the Mediterranean diet (MD), namely, olive oil, fresh goat cheese, and carob derivatives in addition to hydrocolloids. The final products, with the best spreadability, texture and consistency, were obtained using: a) methylcellulose 6% (w/v) for the spreadable olive oil; b) Locust Bean Gum (LBG) (0.5% w/w) for goat cream cheese; and c) Goat cream cheese (43.4%), carob flour (8.7%), glucose syrup (26.1%), olive oil (14.6%), powdered goat milk (3.8%), chia seeds (0.5%), LBG (0.7%), and cinnamon for the cold dessert. Subsequently, foods were refrigerated until evaluated by a consumer panel of 101 untrained tasters aged between 15 and 49 years. All the attributes were assessed on a scale from 1 to 5. The products were well accepted by the tasters with no significant differences registered among the different age groups regarding the food attributes, except for the sweetness of the dessert. The goat cream cheese obtained the highest acceptability (4.09 ± 1.16–3.88 ± 0.86) and creaminess (4.22 ± 0.80–4.33 ± 0.65) among the youngest consumers (<30 years), while the acceptability of spreadable olive oil was evaluated with values of 3.24 ± 1.33–3.17 ± 1.14 by the same age group, indicating the need to add seasonings, as salt substitutes, to improve the attributes flavour and aroma. The results highlight the potential of the three formulations to expand the range of food products and processing strategies in the hospitality, catering, and food industry, as well as to provide alternative foods associated with the MD food pattern.

The dissolution of galactomannans in type II/III deep eutectic solvents: Effect of polysaccharide structure and interaction mechanism

Deep eutectic solvents (DESs) have garnered increasing attention as sustainable solvents for natural polysaccharides. Galactomannans (especially guar and locust bean gums) are abundant natural compounds used in food, medicine, agriculture and daily chemical products, whereas their high molecular weight and randomly distributed non-linear structures remain a huge challenge in solubilization and high value-added utilization. In this study, the dissolution of galactomannans in type II/III DESs was comprehensively investigated using density functional theory (DFT) calculation, experimental results, and molecular dynamics simulation (MD). The results indicated that immense anionic and neutral H-bonds supported by type II DESs (consisting of a quaternary ammonium salt and a metal chloride hydrate) could break and rebuild galactomannan H-bond networks, thereby exhibiting remarkable physical solubilization. A large number of active acid sites in type III DESs (consisting of a quaternary ammonium salt and a hydrogen bond donor) greatly improved solubility and cleaved the glycosidic bond, enabling the recovery of polysaccharides with a target molecular weight. Furthermore, significant correlations between solubility and the structure of galactomannans had been established, which meant that high molecular weight and rich galactose side-chains produced repulsive interactions with DESs, directly hindering dissolution. Overall, this work not only offered a framework for enhancing the dissolution of polysaccharides, but also proposed a promising strategy for development of task specific DESs promoting green chemistry and the use of sustainable bioresources.

Influence of different hydrocolloids on the pasting, rheological, and morphological characteristics of heat gelatinized cassava starch

Heat-gelatinized starch (HGS), which is prepared via heat treatment, enhances viscosity and provides suitable thickening properties, which improve water retention in products. This study aimed to investigate the potential of blending gelatinized starch with edible hydrocolloids (guar gum, carrageenan (C), locust bean gum, konjac powder, and sodium alginate) to assess their effect on the stabilization of starch gelatinization and reduction of retrogradation. Optical microscopic observations revealed the disrupted structures of gelatinized starch after heat treatments, along with diminished or absent birefringence. Adding C to the gelatinized starch reduced its peak viscosity, breakdown and setback value. For the rheological analysis, heat gelatinization and hydrocolloid addition contributed to the increased elasticity and viscosity of samples. Gelatinization and hydrocolloid addition emerged as effective strategies for improving starch quality. Although it still warrants further exploration, the introduced approach holds potential for applications in the development of convenience and canned food products.

Improvement of casein / κ-carrageenan composite gel properties: Role of locust bean gum concentration

Processed cheese analogues (PCA) are popular among consumers worldwide for their diverse flavors and forms. Casein/κ-carrageenan (CA/KC), as the main structural basis of common PCA, suffers from syneresis and thermal instability, which could be well ameliorated by locust bean gum (LBG) as a thickening, non-gelatinizing polysaccharide. However, the mechanism by which LBG improves the gel properties of CA/KC composites has not yet been clarified. In this study, the CA/KC/LBG ternary composite gels were constructed and the effect of LBG concentrations (0–0.5%) on the CA/KC binary gel properties were investigated. Compared with the control CA/KC gel, the addition of low LBG concentrations (0.1–0.3%) significantly increased the water-holding capacity, strength and thermal stability of gels (P < 0.05), while the addition of high LBG concentrations (0.4%–0.5%) weakened the gel properties. To reveal the influence mechanism of LBG, the water migration, molecular interactions and microstructure of gels were compared. The results confirmed that the addition of LBG induced the migration of water molecules from free state to bound state and enhanced the hydrogen bonding interactions between CA/KC gel molecules. In addition, scanning electron microscopy results showed that the addition of low concentrations of LBG induced the unfolding of KC macromolecules into chains, which optimized the gel network structure of KC. The formed CA/KC/LBG ternary composite gels showed more homogeneous and denser gel network structure than the control. In conclusion, the addition of an appropriate amount of LBG could well improve the thermal stability of CA/KC binary gel and the sense of storage stability of PCA products.

Injectable Carrageenan/Green Graphene Oxide Hydrogel: A Comprehensive Analysis of Mechanical, Rheological, and Biocompatibility Properties.

In this work, physically crosslinked injectable hydrogels based on carrageenan, locust bean gum, and gelatin, and mechanically nano-reinforced with green graphene oxide (GO), were developed to address the challenge of finding materials with a good balance between injectability and mechanical properties. The effect of GO content on the rheological and mechanical properties, injectability, swelling behavior, and biocompatibility of the nanocomposite hydrogels was studied. The hydrogels' morphology, assessed by FE-SEM, showed a homogeneous porous architecture separated by thin walls for all the GO loadings investigated. The rheology measurements evidence that G' > G″ over the whole frequency range, indicating the dominant elastic nature of the hydrogels and the difference between G' over G″ depends on the GO content. The GO incorporation into the biopolymer network enhanced the mechanical properties (ca. 20%) without appreciable change in the injectability of the nanocomposite hydrogels, demonstrating the success of the approach described in this work. In addition, the injectable hydrogels with GO loadings ≤0.05% w/v exhibit negligible toxicity for 3T3-L1 fibroblasts. However, it is noted that loadings over 0.25% w/v may affect the cell proliferation rate. Therefore, the nano-reinforced injectable hybrid hydrogels reported here, developed with a fully sustainable approach, have a promising future as potential materials for use in tissue repair.

K-Carrageenan/Locust Bean Gum Gels for Food Applications-A Critical Study on Potential Alternatives to Animal-Based Gelatin.

Among hydrocolloids used in the food industry, gelatin (an animal protein) is remarkably known for its unique gel forming ability. Creating a perfect, green substitute for animal gelatin is extremely difficult if not impossible, because this versatile hydrocolloid offers many special properties that are not easily imitated by other vegetable-based systems. The combination of more than one type of hydrocolloid is commonly used in food either to bridge the above-mentioned gap or to impart novel organoleptic characteristics (such as mouthfeel) to food products, to modify rheological characteristics, and to satisfy processing requirements in the industry. In this work, we study the rheology and the texture of water mixtures of κ-Carrageenan (κ-C) and Locust Bean Gum (LBG). By fixing different κ-C concentrations and varying the LBG/κ-C ratio, we explore a wide range of potentially useful textures. The results obtained for the green systems are also compared to those exhibited by animal gelatin formulations.

The potential of hydrocolloid-modified fish gelatine in substituting non-halal gelatine for halal dessert cuisine

Gelatine is one of the essential ingredients in dessert making that enhances product development. As porcine and bovine gelatines are exquisite ingredients in many food products, especially in desserts, religious and cultural restrictions need to be considered. The limits in religions on porcine and bovine gelatine consumption contribute to mammal gelatine substitutes such as fish gelatines. However, the fish gelatine has lower thermal and rheological properties compared to mammalian gelatines. The lower rheological properties decrease the mechanical strength, gelling mechanism, and capability to stabilize in dessert products. Hydrocolloid-modified fish gelatines can overcome such drawbacks by improving their gel properties. This study reviewed the physical and chemical properties of different hydrocolloids used to modify fish gelatines which are agar with locust bean gum, carrageenan with locust bean gum, and gellan with calcium chloride, and their potential to emulate the texture and sensory properties of non-halal gelatine in dessert products. The study of modified fish gelatine with hydrocolloids can be a learning paradigm among food service establishments to intensify the need to explore the components used in food manufacturers and food industries. The new research that introduces hydrocolloid-modified gelatine will give various selections in creating new products without the intervention of non-halal or forbidden substances, especially in the gelatine-based dessert.

Date nawah powder as a promising waste for β-mannanase production from a new isolate Aspergillus niger MSSFW, statistically improving production and enzymatic characterization

β-Mannanase producing fungus was isolated from coffee powder waste and identified as Aspergillus niger MSSFW (Gen Bank accession number OR668928). Dates nawah powder as industrial and agricultural waste was the most inducer of β-mannanase production. The Plackett–Burman and Central Composite designs were used to improve β-mannanase titer. Optimization studies enhanced the enzyme yield with approximate 13.50-times. β-Mannanase was purified by Sephadex G-150 gel filtration column and the molecular weight was estimated to be 60 kDa by SDS–PAGE. Crude and purified β-mannanase displayed maximum activity at temperature 60 °C and 50 °C, respectively. Crude β-mannanase showed an activation energy value 2.35-times higher than the purified enzyme. Activation energy for thermal denaturation of the purified β-mannanase was 1.08-times higher than that of the crude enzyme. Purified β-mannanase exhibited higher deactivation rate constant (Kd) and lower half-life (t0.5) and decimal reduction time (D-value) compared with the crude enzyme. Thermodynamic parameters of enthalpy, entropy, and free energy values for crude and purified β-mannanase were calculated. Substrate kinetic parameters suggested that the purified β-mannanase had a strong affinity toward locust bean gum by showing 3.44-times lower Km and 1.99-times higher Vmax compared to the crude enzyme.

Exploring the Potential of Anthocyanin-Based Edible Coatings in Confectionery-Temperature Stability, pH, and Biocapacity.

This study aims to develop purple-coloured polymeric coatings using natural anthocyanin and desoxyanthocianidins (3-DXA) colourants for application to chocolate almonds. The objective is to achieve a stable and uniform colour formulation throughout processing and storage, enhancing the appearance and durability of the almonds to appeal to health-conscious consumers and align with market demands. Plant materials like sweet potato pulp, sweet potato peel, radish peel, black carrot, and sorghum were employed to obtain the desired purple hue. Anthocyanidins and 3-DXA were extracted from the matrices using solvent extraction and ultrasound-assisted methods at different pH values. High-performance liquid chromatography with diode array detection (HPLC-DAD) and high-resolution tandem mass spectrometry (HRMS/MS) were used to identify the compounds in the extracts. The highest antioxidant capacities, as measured by the DPPH• and FRAP methods, were observed in purple sweet potato and dye factory extracts, respectively; meanwhile, sorghum extract inhibited both α-amylase and α-glucosidase, indicating its potential for managing postprandial hyperglycemia and type 2 diabetes. The degradation kinetics of coloured coatings in sugar syrup formulations with anthocyanins and 3-DXA revealed that locust bean gum offered the best colour stabilization for plant extracts, with sorghum extracts showing the highest and black carrot extracts the lowest colour variation when coated with Arabic gum. Sweet potato pulp extracts exhibited less colour variation in sugar pastes, both with and without blue spirulina dye, compared to factory dye, highlighting their potential as a more stable and suitable alternative for colouring purple almonds, particularly over a five-month storage period. This study supports sustainable practices in the confectionery industry while aligning with consumer preferences for healthier and environmentally friendly products.

Synthesis of locust bean gum/titanium dioxide hydrogel nanocomposites for efficient removal of methylene blue from aqueous solution

In this study, we are interested in preparing novel hydrogel and hydrogel nanocomposite-based adsorbents for removing methylene blue (MB) dye based on grafted locust bean gum (LBG). LBG hydrogel and hydrogel nanocomposite were synthesized using a radical polymerization technique in the absence and presence of TiO2 with LBG-cl-(acrylic acid (AA)-co-acrylamide (AAm)). Various analytical instruments Fourier transform infrared (FTIR), X-Ray diffraction (XRD), Scanning electron microscopy (SEM), and High-resolution transmission electron microscopy (HRTEM) were used to elucidate the chemical structure and surface morphology of the prepared samples. Using a batch adsorption experiment, the Langmuir isotherm model showed that LBG-cl-p(AA-co-AAm) hydrogel had a maximum adsorption capacity of 1540.9 mg/g and LBG-cl-(AA-co-AAm)/TiO2 hydrogel nanocomposites had a maximum adsorption capacity of 1273.4 mg/g at neutral pH. The thermodynamic data demonstrated that MB dye was removed via spontaneous adsorption. Furthermore, the regeneration study showed good recyclability for the obtained hydrogel nanocomposites through six consecutive reusable cycles. Therefore, the hydrogel nanocomposites are an effective adsorbent for the removal of MB dye from aqueous solutions.