Casein micelle/iota carrageenan interactions in milk: influence of temperature

Effect of xanthan gum (XG) and carrageenan (CG) ratio on casein (CA)-XG-CG ternary complex: Used to improve the stability of liquid diabetes formula food for special medical purposes

Poor storage stability limits the application of liquid diabetes formula food for special medical purposes (L-D-FSMP) in maintaining blood sugar stability in diabetic patients. This work aims to improve the stability of L-D-FSMP by adjusting the ratio of xanthan gum (XG) and carrageenan (CG) in casein (CA)-XG-CG ternary complex. The centrifugal sedimentation rate results showed that the compound ratio of XG and CG had a greater impact on L-D-FSMP storage stability. Transmission electron microscopy (TEM) results showed that the combination of CA, XG and CG occurred. Fourier transform infrared spectroscopy (FTIR) results showed that CA, XG and CG were mainly combined through hydrogen bonds and ionic bonds to form a CA-XG-CG ternary complex. When the ratio of XG and CG was 1:1, the number of disulfide bonds was the largest. The results of three-phase contact angle and emulsifying ability confirmed that when the ratio of XG and CG was 1:1, CA-XG-CG had the strongest emulsifying ability. The particle size distribution and zeta-potential results showed that when the ratio of XG and CG was 1:1, L-D-FSMP had the narrowest particle size distribution range and the strongest stability. These results may provide valuable information for the production of stable L-D-FSMP.

Heat-Induced Changes in κ-Carrageenan-Containing Chocolate-Flavoured Milk Protein Concentrate Suspensions under Controlled Shearing

Milk protein dispersions containing added cocoa powder (1.5% (w/w)) and sucrose (7% (w/w)) and varying levels of κ-carrageenan (0.01, 0.03, or 0.05% w/w) were subjected to combined heat treatment (90 °C/5 min or 121 °C/2.6 min) and shear (100 or 1000 s-1) to investigate the heat stability of milk proteins. The application of shear led to a notable reduction in non-sedimentable proteins, resulting in an increase in the average particle size and apparent viscosity of the dispersions, particularly at high concentrations of k-carrageenan and elevated temperatures. This indicates that shear forces induced prominent protein aggregation, especially at higher κ-carrageenan concentrations. This aggregation was primarily attributed to the destabilisation of micelles and presence of loosely bound caseins within the κ-carrageenan network, which exhibited increased susceptibility to aggregation as collision frequencies increased due to shear.

Influence of Some Hydrocolloids and Sterilization Conditions on the Physical Properties of Texture-Modified Foods Developed for the Swallow Training of Dysphagia Patients

This research aimed to develop jelly soup for dysphagia patients at the International Dysphagia Diet Standardization Initiative (IDDSI) Framework levels 4 (puree) and 5 (minced and moist), who require swallow training to regain normal swallowing ability due to neurological issues. The study comprised three main parts: (1) an investigation of hydrocolloid types and concentrations for texture-modified foods to aid dysphagia patients during training; (2) a study of sterilization conditions and ascorbic acid's impact on physical properties (e.g., texture, viscosity, color) of the texture-modified foods; and (3) an evaluation of changes in physical, chemical, and microbial properties of the product during storage. Results revealed that the ideal recipe involved using pork bone broth with 1% κ-carrageenan for texture modification, which closely matched the properties of hospital jelly samples in terms of hardness, adhesiveness, and viscosity. Sterilization at 110 °C for 109 min effectively eliminated microorganisms without affecting the product's appearance or texture, albeit causing a slight increase in brownness. Adding ascorbic acid helped to prevent the Maillard reaction but reduced the gel strength of the sample and induced milk protein denaturation, leading to aggregation. During storage at room temperature for 9 weeks, the product became browner and less firm. Notably, no bacteria were detected throughout this period. In conclusion, this heating process is suitable for producing jelly soup to support swallow training for dysphagia patients with neurological problems. It offers invaluable assistance in their daily training to regain normal swallowing function.

The Impact of Divergent Algal Hydrocolloids Addition on the Physicochemical, Viscoelastic, Textural, and Organoleptic Properties of Cream Cheese Products

The aim of the current study was to evaluate the addition of different algal hydrocolloids (κ-carrageenan, ι-carrageenan, furcellaran, and sodium alginate) at three different concentrations (0.50, 0.75, and 1.00% w/w) on the physicochemical, viscoelastic, textural, and organoleptic properties of model cream cheese (CC) samples. On the whole, the highest viscoelastic moduli and hardness values of the CC samples were reported when κ-carrageenan was used. Furthermore, increasing the concentrations of the tested hydrocolloids led to increases in the viscoelastic moduli and hardness values of CC. Recommendations for softer-consistency CC production include the application of κ-carrageenan at a concentration of 0.50-0.75% (w/w) or the use of furcellaran and sodium alginate at a concentration of 1.00% (w/w). For the production of CC with a more rigid consistency, it is recommended to apply κ-carrageenan at a concentration higher than 0.75% (w/w).

Photo-Phytotherapeutic Gel Composed of Copaifera reticulata, Chlorophylls, and k-Carrageenan: A New Perspective for Topical Healing

Chronic wound healing represents an impactful financial burden on healthcare systems. In this context, the use of natural products as an alternative therapy reduces costs and maintains effectiveness. Phytotherapeutic gels applied in photodynamic therapy (PDT) have been developed to act as topical healing medicines and antibiotics. The bioactive system is composed of Spirulina sp. (source of chlorophylls) and Copaifera reticulata oil microdroplets, both incorporated into a polymeric blend constituted by kappa-carrageenan (k-car) and F127 copolymer, constituting a system in which all components are bioactive agents. The flow behavior and viscoelasticity of the formulations were investigated. The photodynamic activity was accessed from studies of the inactivation of Staphylococcus aureus bacteria, the main pathogen of hospital relevance. Furthermore, in vivo studies were conducted using eighteen rabbits with dermatitis (grade III and IV) in both paws. The gels showed significant antibiotic potential in vitro, eliminating up to 100% of S. aureus colonies in the presence or absence of light. The k-car reduced 41% of the viable cells; however, its benefits were enhanced by adding chlorophyll and copaiba oil. The animals treated with the phytotherapeutic medicine showed a reduction in lesion size, with healing and re-epithelialization verified in the histological analyses. The animals submitted to PDT displayed noticeable improvement, indicating this therapy's viability for ulcerative and infected wounds. This behavior was not observed in the iodine control treatment, which worsened the animals' condition. Therefore, gel formulations were a viable alternative for future pharmaceutical applications, aiming at topical healing.

Interaction Between Caseinate and Carrageenans Results in Different Physical and Mechanical Properties of Edible Films

Edible films were elaborated with sodium caseinate and different types of carrageenans (iota, kappa or lambda), and glycerol as plasticizer, to determine the different specific interactions between caseinate and carrageenans on physical and mechanical properties via a response surface methodology approach. The different sulphate groups content in the different carrageenans affected differentially edible films properties. The use of lambda carrageenan in edible film formulation resulted in more soluble and permeably film, with a concomitantly both less rigid and more elastic structure. The edible film formulation was optimized to 8.0 % of caseinate, 0.4% of carrageenan (irrespectively of the type) and 0.3% of glycerol.

Revisiting the carrageenan controversy: do we really understand the digestive fate and safety of carrageenan in our foods?

An overview of evidence on Carrageenan (CGN), a family of marine polysaccharides, their characteristics and digestive fate that highlight various gaps in our understanding.

Dental enamel irradiated with a low-intensity infrared laser and photoabsorbing cream: a study of microhardness, surface, and pulp temperature

OBJECTIVE

The aim of this study was to assess the effect of low-intensity infrared laser light (λ=810 nm, 100 mW/cm(2), 90 sec, 4.47 J/cm(2), 9 J) with or without indocyanine green cream fluorinated or not fluorinated, using Knoop surface microhardness analysis.

BACKGROUND DATA

Lasers can be used as tools for the prevention of tooth enamel demineralization.

METHODS

The surface and pulp temperatures of the human deciduous tooth enamel were measured. For the analysis of surface hardness, a total of 48 specimens were prepared and randomly assigned into six groups (n=8/group): C (+), which received laser light; C(-), which received no treatment; cream (IV); cream and fluoride (IVF); cream and light (IVL); and cream and fluoride and light (IVFL). The specimens were subjected to treatment before demineralizing challenge by pH cycling. To analyze the surface and pulp temperatures, the samples were divided into the following groups (n=10): C(+), IVL, and IVFL.

RESULTS

The hardness analysis indicated that the groups that received irradiation had less hardness reduction following the demineralizing challenge (p<0.001), with IVFL and IVL presenting the lowest percentages of surface microhardness loss at 3.98% and 9.3%, respectively. Surface temperature analysis indicated a maximum increase of 74°C and a mean of 45.25°C and 45.95°C for the IVL and IVFL groups, respectively. Pulp temperature analysis indicated a higher mean increase of 2.40°C±0.65 in the IVL group.

CONCLUSIONS

These results suggest that the combination of cream and laser light possibly promoted protein denaturation of the tooth enamel organic matrix, which possibly decreased the loss of hardness without causing pulp damage.

High pressure homogenization to improve the stability of casein - hydroxypropyl cellulose aqueous systems

The effect of high pressure homogenization on the improvement of the stability hydroxypropyl cellulose (HPC) and micellar casein was investigated. HPC with two molecular weights (80 and 1150 kDa) and micellar casein were mixed in water to a concentration leading to phase separation (0.45% w/v HPC and 3% w/v casein) and immediately subjected to high pressure homogenization ranging from 0 to 300 MPa, in 100 MPa increments. The various dispersions were evaluated for stability, particle size, turbidity, protein content, and viscosity over a period of two weeks and Scanning Transmission Electron Microscopy (STEM) at the end of the storage period. The stability of casein-HPC complexes was enhanced with the increasing homogenization pressure, especially for the complex containing high molecular weight HPC. The apparent particle size of complexes was reduced from ~200nm to ~130nm when using 300 MPa, corresponding to the sharp decrease of absorbance when compared to the non-homogenized controls. High pressure homogenization reduced the viscosity of HPC-casein complexes regardless of the molecular weight of HPC and STEM imagines revealed aggregates consistent with nano-scale protein polysaccharide interactions.

Interactions between Carrageenans and Milk Proteins: A Microstructural and Rheological Study

Gels were produced using kappa-, iota-, or hybrid-carrageenan at a low (0.2-0.25%) and a high (0.7-1.0%) dosage in skim milk. The microstructure of carrageenan and protein was observed by confocal laser scanning microscopy using direct immunostaining. Additionally, rheology was used to characterize the gels. The low kappa- and iota-carrageenan dosages resulted in gels with a fine stranded carrageenan-protein microstructure and emulsion-like inclusions, while the high dosages resulted in strongly flocculated microstructures. Hybrid-carrageenan exhibited flocculation at both dosages. When using iota- and hybrid-carrageenan at a high dosage and kappa-carrageenan at both dosages, the gel characteristics were dominated by carrageenan-carrageenan interactions. On the other hand, the gel with a low dosage of iota-carrageenan in milk was barely fusible, indicating the presence of a true coupled network. We suggest that kappa-, iota-, and hybrid-carrageenan all interact with casein micelles but that the impact of this interaction on the total gel properties varied.

Production and characterization of oil-in-water emulsions containing droplets stabilized by multilayer membranes consisting of beta-lactoglobulin, iota-carrageenan and gelatin

The influence of environmental conditions (pH, NaCl, CaCl2, and temperature) on the properties and stability of oil-in-water (O/W) emulsions containing oil droplets surrounded by one-, two-, or three-layer interfacial membranes has been investigated. Three oil-in-water emulsions were prepared with the same droplet concentration and buffer (5 wt % corn oil, 5 mM phosphate buffer, pH 6) but with different biopolymers: (i) primary emulsion: 0.5 wt % beta-Lg; (ii) secondary emulsion: 0.5 wt % beta-Lg, 0.1 wt % iota-carrageenan; (iii) tertiary emulsion: 0.5 wt % beta-Lg, 0.1 wt % iota-carrageenan, 0-2 wt % gelatin. The secondary and tertiary emulsions were prepared by electrostatic deposition of the charged biopolymers onto the surfaces of the oil droplets so as to form two- and three-layer interfacial membranes, respectively. The stability of the emulsions to pH (3-8), sodium chloride (0-500 mM), calcium chloride (0-12 mM), and thermal processing (30-90 degrees C) was determined. We found that multilayer emulsions had better stability to droplet aggregation than single-layer emulsions under certain environmental conditions and that one or more of the biopolymer layers could be made to desorb from the droplet surfaces in response to specific environmental changes (e.g., high salt or high temperature). These results suggest that the interfacial engineering technology used in this study could lead to the creation of food emulsions with improved stability to environmental stresses or to emulsions with triggered release characteristics.

Influence of environmental stresses on stability of oil-in-water emulsions containing droplets stabilized by β-lactoglobulin–ι-carrageenan membranes

An oil-in-water emulsion (5 wt% corn oil, 0.5 wt% beta-lactoglobulin (beta-Lg), 0.1 wt% iota-carrageenan, 5 mM phosphate buffer, pH 6.0) containing anionic droplets stabilized by interfacial membranes comprising of beta-lactoglobulin and iota-carrageenan was produced using a two-stage process. A primary emulsion containing anionic beta-Lg coated droplets was prepared by homogenizing oil and emulsifier solution together using a high-pressure valve homogenizer. A secondary emulsion containing beta-Lg-iota-carrageenan coated droplets was formed by mixing the primary emulsion with an aqueous iota-carrageenan solution. The stability of primary and secondary emulsions to sodium chloride (0-500 mM), calcium chloride (0-12 mM), and thermal processing (30-90 degrees C) were analyzed using zeta-potential, particle size and creaming stability measurements. The secondary emulsion had better stability to droplet aggregation than the primary emulsion at NaCl </=500 mM, CaCl(2) </= 2 mM, and holding temperatures </= 60 degrees C for 20 min. The interfacial engineering technology used in the study could therefore lead to the creation of food emulsions with improved stability to environmental stresses.