Bioactive foamulsion gels: a unique structure prepared with gellan gum and Acanthophyllum glandulosum extract.

BACKGROUND: Foamulsions have become increasingly popular in the food industry due to their ability to enhance the textural, sensory and health-promoting properties of food products. This study was therefore aimed to design and prepare a novel gelled structure, foamulsion gel containing 0-600 g L-1 oil, with gellan gum (GG; 7, 10 and 13 g L-1) and saponin-rich antioxidant Acanthophyllum glandulosum extract (AGE; 2, 6 and 10 g L-1). RESULTS: The interaction between components was confirmed by infrared spectroscopy. The overrun and porosity of the foamulsion gels increased with antioxidant AGE (1.30 times) and reduced with oil (up to ca 70% and 30%, respectively) and GG levels. The systems were highly stable, and no water or oil was released during the physical stability experiments. Microscopic images showed that the size of air cells was significantly larger than that of oil droplets. The foamulsion gels based on 13 g L-1 GG and 10 g L-1 AGE had markedly higher elastic (G') and viscous (G'') moduli than other samples, and exhibited an elastic and solid-like behavior (G' > G''). The highest gel firmness was found in oil-free sample, and the presence of oil resulted in a lower firmness induced by the larger size and lubrication effect of oil droplets. CONCLUSION: As a result, the interactions between AGE, GG and oil could lead to the creation of new aerated structures known as bioactive foamulsion gels. These gels exhibit excellent foamability, stability and viscoelasticity and may find applications in the development of novel, healthy and low-calorie aerated foods. © 2024 Society of Chemical Industry.

Natural oleogelators for the formulation of oleogels by considering their rheological and textural perspective; a review.

A well-known method for reducing or swapping out undesirable and controversial fats in food is oleogelation. To quantify the effects of droplets-particle inclusion on the textural aspects of gelled systems, a thorough understanding of rheological behavior of oleogels (OGs) is necessary. Otherwise stated, a rational grasp of rheological characterization is essential for food development, optimization, and processing (when touching or putting food into the mouth, rheological flow qualities influence our perception). This narrative review primarily intends to investigate rheological and textural characteristics of various oleogelator-based OGs, such as operative connection between hardness, distortion, stresses, and rheological parameters like viscosity, elasticity, and viscoelasticity, as well as flow behavior and recovery. Expanding oleogelators concentration and synergistic interactions between them increase robustness and moduli values, as compared to single oleogelators. However, given the lack of information on the connection between the OGs' macroscopic rheological characteristics and their microstructural characteristics, this review presents state-of-the-art overview of various oleogelator-based OGs, highlighting the importance of structure-rheology relationships of OGs to provide advanced knowledge on the development of innovative OGs.

Producing superior oleofoams: Unraveling the impact of oil type, surfactant concentration, and production temperature on foam stability and functional characteristics.

This study explores the impact of oil type, surfactant concentration, and production temperature on oleofoam properties. Oleofoams were prepared using different concentrations (5, 8, and 10 % w/w) of monoglyceride (MG) in olive, soybean, and sunflower oils at temperatures of 25 °C and 5 °C. The results indicate that higher surfactant concentrations and lower production temperatures enhance the stability, foamability, melting behavior, and hardness of the oleofoams, while minimizing oil drainage. Microscopic analysis reveals that lower production temperatures result in smaller bubble sizes in all oil blends which reduces oil loss and increases the hardness of the oleofoam. Also, oleofoams derived from different oils exhibit solid-like behavior. Among the oils studied, the oleofoam prepared with sunflower oil, at a concentration of 10 % MG and a production temperature of 5 °C, demonstrates superior properties. These findings provide valuable insights into optimizing oleofoam properties by controlling the oil type, surfactant concentration, and production temperature.

Hydro- and aerogels from quince seed gum and gelatin solutions.

The composite hydro/aerogels were designed using gelatin and quince seed gum (QSG) at total polymer concentration (TPC) of 1, 1.5 and 2% and gelatin/QSG ratio of 1:0, 1:0.5 and 1:1. The gel syneresis decreased significantly with increase in TPC and QSG. Although, hydrogels with 2% TPC had remarkably higher gel strength and elasticity than 1% TPC ones, the addition of high levels of QSG to the gelatin (i.e., gelatin/QSG 1:1) led to a decrease in its gel strength (∼0.97-fold) and elasticity (∼3,463-fold). The temperature-sweep test showed higher melting points in gelatin/QSG hydrogels (>60 °C) compared to the gelatin ones (∼58 °C). Additionally, QSG addition to the gelatin led to more porous networks with higher gel strength, thermal stability, and crystallinity, as observed by scanning electron microscopy, differential scanning calorimetry, and X-ray diffractometer. Therefore, QSG could be used as a natural hydrocolloid to modify gelatin functionality.

Behavior of protein-polysaccharide conjugate-stabilized food emulsions under various destabilization conditions.

The sensitivity of protein-stabilized emulsions to flocculation, coalescence, and phase separation under destabilization conditions (i.e., heating, aging, pH, ionic strength, and freeze-thawing) may limit the widespread use of proteins as effective emulsifiers. Therefore, there is a great interest in modulating and improving the technological functionality of food proteins by conjugating them with polysaccharides, through the Maillard reaction. The present review article highlights the current approaches of protein-polysaccharide conjugate formation, their interfacial properties, and the behavior of protein-polysaccharide conjugate stabilized emulsions under various destabilization conditions, including long-term storage, heating and freeze-thawing treatments, acidic conditions, high ionic strength, and oxidation. Protein-polysaccharide conjugates are capable of forming a thick and cohesive macromolecular layer around oil droplets in food emulsions and stabilizing them against flocculation and coalescence under unfavorable conditions, through steric and electrostatic repulsion. The protein-polysaccharide conjugates could be therefore industrially used to design emulsion-based functional foods with high physicochemical stability.

Retracted: Preparation and optimization of soy (Katul cultivar) protein isolate cold-set gels induced by CaCl2 and transglutaminase.

Preparation and optimization of soy (Katul cultivar) protein isolate cold-set gels induced by CaCl2 and transglutaminase. Food Science & Nutrition, https://doi.org/10.1002/fsn3.3158. The above article, published online on December 8, 2022 in Wiley Online Library (https://wileyonlinelibrary.com), has been retracted by agreement between the journal Editor in Chief Y. Martin Lo, and Wiley Periodicals LLC. The retraction has been agreed upon due to an error in which the incorrect version of the article was published.

How can plant-based protein-polysaccharide interactions affect the properties of binary hydrogels? (A review).

The last two decades have seen a growing trend toward gels thanks to their attractive sensory properties, low calories, and modification ability. Plant-derived proteins have outstanding potential to replace animal proteins as they are more affordable and eco-friendly. Polysaccharide addition can improve the gelation properties of plant proteins. This paper aimed at critically analyzing the effect of the plant protein-polysaccharide compatibility on the characterization of composite hydrogels. H-bonds and ß structures, increased by polysaccharides, greatly correlated with the gelation rate, superior structural integrity, and textural/rheological properties. Indeed, polysaccharides favored the transition of α-helices to ß-sheets followed by the shift of amide I which made the microstructure dense, regular, and homogeneous. Subsequently, the water-holding capacity, hardness, and elastic modulus increased but the porosity, swelling ratio, and digestibility decreased. High protein concentrations increased the water-holding capacity while the swelling ratio was mostly dependent on polysaccharides. Polysaccharides had a protective role against protease penetration and gel digestibility.

Changes in fat uptake, color, texture, and sensory properties of Aloe vera gel-coated eggplant rings during deep-fat frying process.

There is a widespread use of deep-fat frying in both domestic and industrial sections, and deep-fat fried foods are extremely popular due to their taste, color, and crispy texture. Human health can be, however, seriously compromised by the excessive consumption of oil, especially saturated fats and trans fatty acids. The use of hydrocolloids in inhibiting oil absorption has garnered considerable attention. This study was therefore aimed to lower the oil absorption in eggplant rings during the deep-fat frying process with the aid of Aloe vera gel coating. The effects of gel concentration (0%, 50%, and 100%), frying time (2, 5, and 8 min), and frying temperature (160°C and 180°C) on the oil uptake, moisture content, texture, color, and sensory properties of the eggplant rings were evaluated. The gel coating led to a decrease in oil uptake (up to 50%), hardness (up to 0.98-fold), ΔE (up to 0.89-fold), and overall acceptance (up to 0.85-fold), and an increase in moisture content (up to 1.47-fold) and lightness (up to 1.14-fold) of the samples. The frying time and temperature also influenced the physiochemical and sensory properties of the eggplant rings. The sample coated with 50% gel and fried at 180°C for 8 min had lower oil content and water loss with the highest acceptance rate in terms of taste, color, odor, texture, and appearance. The Aloe vera gel could be, therefore, a good candidate with high nutritional and economic value to reduce oil uptake in fried food products.

Gellan gum conjugation with soy protein via Maillard-driven molecular interactions and subsequent clustering lead to conjugates with tuned technological functionality.

Soy proteins are frequently used in the food industry; however, they have rigid and compact structure with relatively poor interfacial properties and solubility. This study was therefore aimed to modify techno-functional characteristics of soy protein isolate (SPI; 0.1% w/v) by conjugating to low acyl gellan gum (LAGG; 0.1, 0.2, and 0.3% w/v), through the Maillard reaction (at 90 °C for 90 min). The SPI-LAGG conjugates were confirmed by changes in pH, glycation degree (DG; up to 48%), Fourier transform infrared spectroscopy, and sodium dodecyl sulphate polyacrylamide electrophoresis. The conjugates were then classified into three clusters of low, medium, and high DG, via K-means clustering method. The low DG conjugate had lower surface hydrophobicity and foaming capacity, and higher thermal stability, solubility, emulsifying properties, foam stability, and antioxidant activity compared to the other clusters. This indicated that a low DG is required to enhance the functional properties of proteins.

Quinoa flour as a skim milk powder replacer in concentrated yogurts: Effect on their physicochemical, technological, and sensory properties.

Milk standardization with solids (i.e., nonfat milk solids, MSNF) for yogurt manufacture is traditionally achieved by the addition of skim milk powder (SMP). However, the addition of SMP to milk-based yogurt increases lactose content and decreases both protein content and gel firmness. Thus, in this work, quinoa flour (QF; 0%, 25%, 50%, 75%, and 100% w/w) was used to replace SMP in concentrated yogurt. The physicochemical, textural, and sensory properties and microstructure of the yogurt were evaluated during cold storage. Generally, protein content, water-holding capacity, and L* value decreased, while syneresis, textural attributes, and viscosity increased with increasing QF content. The substitution of high levels of QF (>25%, w/w) for SMP led to significantly shorter fermentation times, as compared to the control sample. The scanning electron microscopy observations showed significant changes in the yogurt microstructure as a consequence of QF replacement. Samples with 25% (w/w) substitution of QF and control had the highest scores in overall acceptance. According to the results, QF could be applied as an interesting raw material for concentrating the milk-based yogurt at substitution level of 25% (w/w).

Effect of heat treatment on the structure and stability of Grass pea (Lathyrus sativus) protein isolate/Alyssum homolocarpum seed gum nanoparticles.

In the present study, Grass pea protein isolate (GPPI)- Alyssum homolocarpum seed gum (AHSG) complex nanoparticles were formed through two fabrication methods and their physicochemical properties, structure and stability against sodium chloride and different pHs were investigated. Type 1 particles were formed by creating GPPI nanoparticles, and then coating them with AHSG; while Type 2 particles were fabricated through the heat treatment of GPPI-AHSG complexes at 85 °C for 15 min. The preparation methods did not influence the magnitude of electrical charges on biopolymer particles. The particle size analysis revealed that Type 2 particles had lower mean diameter (d = 360.20 nm) compared to Type 1 particles (d = 463.22 nm). Structural properties of Type 1 and Type 2 particles were determined using Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), Differential scanning calorimetry (DSC), Atomic force microscopy (AFM), and transmission electron microscopy (TEM). Hydrogen bonding, electrostatic and hydrophobic interactions were the main driving forces contributed to the formation of both GPPI-AHSG complex particles. Assessments of morphological and structural properties also indicated that both Type 1 and 2 particles had spherical shapes and heat treatment increased the ordered intermolecular structures in biopolymer particles. Type 2 particles had higher denaturation temperature and better pH and salt stability when compared to Type 1 particles. These results indicate that thermal treatment was effective for the fabrication of stable GPPI-AHSG complex nanoparticles.

Optimization of Microbial Rennet Encapsulation in Alginate - Chitosan Nanoparticles.

The milk-coagulating enzyme, rennet, is widely used in cheese making. Recently stabilization of rennet, especially in accelerated cheese ripening, has received considerable interest. As we know encapsulation is one of the enzyme immobilization methods, which could increase enzyme stability. In this study, the effects of alginate, chitosan and, CaCl2 on rennet encapsulation were evaluated and optimized using RSM. Under the optimal conditions alginate, chitosan, and CaCl2 were 0.04%, 0.1%, and 0.1% respectively. At the optimum point, encapsulation efficiency, particle size, and zeta potential were evaluated to be 61.8%, 323 nm, and 25 mV, respectively. The effect of temperature and pH on the enzyme activity was evaluated, and the results showed that encapsulated enzyme had higher activity at various pH and temperature in comparison with the free enzyme. Also, the enzyme release data in all pH values were fitted to Korsmeyer-Peppas model and the n exponent indicated that the release mechanism was Fickian. The electrostatic interactions between enzyme, alginate, and chitosan were confirmed by infrared spectroscopy. No statistical difference was found between the Km and Vmax of encapsulated and free enzymes.

Physicochemical stability and gastrointestinal fate of ß-carotene-loaded oil-in-water emulsions stabilized by whey protein isolate-low acyl gellan gum conjugates.

This study aimed to examine the effect of whey protein isolate-low acyl gellan gum (WPI-GG) conjugate on the physicochemical properties and digestibility of ß-carotene-loaded oil-in-water emulsions. The WPI-GG conjugate-stabilized emulsions had lower droplet sizes with more homogenous distribution, more negative surface charge, and higher interfacial protein concentration and viscosity, compared to those stabilized by WPI-GG mixture and WPI. The emulsion droplets coated by the conjugate were also generally more stable to environmental stresses (i.e., storage, pH changes, ionic strength, freeze-thaw cycles, and thermal treatment) along with higher ß-carotene retention than other systems. The stability to droplet aggregation during in vitro digestion was remarkably increased for the conjugate-stabilized emulsion. However, the ß-carotene bioaccessibility was significantly affected when the conjugate was used to stabilize the emulsions, likely due to the thick interfacial layer, high viscosity, and negative charge of the corresponding emulsions that could inhibit droplet digestion and mixed micelle formation.

Efficiency of milk proteins in eliminating practical limitations of ß-carotene in hydrated polar solution.

The objective of this work was to study ß-carotene functionalities (color and antioxidant activity) and practical limitations (aggregate formation, poor solubility and low stability) when included in the aqueous systems containing milk proteins. According to the results, self-association constant of ß-carotene in the presence of casein is 1.7-fold of that calculated for WPI. Casein and WPI were capable of conserving ß-carotene against chemical oxidation up to 15 and 12%, respectively, at 1:5 M ratio of ß-carotene to protein. While, WPI reduced its photodegradation quantum yield from 0.03 to 0.012 compared to 0.017 obtained for casein. A 2.7- and 3.6-fold enhancement in ß-carotene solubility was observed in the presence of 1.5 mg/mL of casein and WPI, respectively. The study of ß-carotene interaction with proteins showed, on the one hand, a negative effect on electron transfer and, on the other hand, improved hydrogen transfer to the radical species in the solution.

Replacement of nitrite with lupulon-xanthohumol loaded nanoliposome in cooked beef-sausage: experimental and model based study.

Replacement of nitrite with hop components in cooked beef-sausage (CBS) was studied. For this purpose, lupulon-xanthohumol loaded nanoliposome (L-X-NL) was produced using sonication at optimized condition (time = 10.8 min, power = 72.7 W, lecithin concentration = 140 mg/mL). The release of lupulon and xanthohumol to liquid meat extract followed the Rigter-Peppus model. Samples of CBS (60% meat) supplemented by different ratios of nitrite/L-X-NL were produced. Microbial analysis and lipid oxidation measurement were carried out to evaluate the safety of CBS samples. The formulation consisted 30 ppm of nitrite and 150 ppm of L-X-NL remained microbiologically safe during 30-d storage at 4 °C. It was observed that L-X-NL could postpone the oxidation. Addition of L-X-NL has not impaired the sensory properties of final product, while the presence of nitrite for inducing the demanding color of CBS was important. Considering the results, partial removal of nitrite in formulation of CBS (up to 50%) and replacing with L-X-NL as a new promising preservative is recommended.

Functional and biological properties of Maillard conjugates and their potential application in medical and food: A review.

Protein and peptides are usually sensitive to environmental stresses, such as pH changes, high temperature, ionic strength, and digestive enzymes amongst other, which limit their food and medicinal applications. Maillard reaction (also called Maillard conjugation or glycation) occurs naturally without the addition of chemical agents and has been vastly applied to boost protein/peptide/amino acid functionalities and biological properties. Protein/peptide-saccharide conjugates are currently used as emulsifiers, antioxidants, antimicrobials, gelling agents, and anti-browning compounds in food model systems and products. The conjugates also possess the excellent stabilizing ability as a potent delivery system to enhance the stability and bioaccessibility of many bioactive compounds. Carbonyl scavengers such as polyphenols are able to significantly inhibit the formation of advanced glycation end products without a significant effect on early Maillard reaction products (MRPs) and melanoidins, which are currently applied as functional ingredients. This review paper highlights the technological functionality and biological properties of glycoconjugates in food model systems and products. Recent applications of MRPs in medical sciences are also presented.

Innovative method for analysis of safranal under static and dynamic conditions through combination of HS-SPME-GC technique with mathematical modelling.

INTRODUCTION: Saffron (Crocus sativus L.) is a well-known spice which is used as the colourant and flavouring agent in food products. Safranal could act as an indicator for saffron grading, authentication and adulteration, as well as for quality evaluation of saffron flavoured products; since it is the main odourant and the most aroma-active compound of saffron. OBJECTIVES: Firstly, determination of the optimum static conditions for safranal extraction through headspace solid-phase micro-extraction combined with gas chromatography (HS-SPME-GC) technique. Secondly, safranal measurement in different saffron flavoured products under the optimised static conditions. Thirdly, elucidation of the method efficiency for safranal measurement under non-equilibrium conditions for a saffron drink sample. METHODS: Different equilibrium times, pH and salt concentrations were applied on aqueous solutions of safranal. Accordingly, the optimised static conditions were determined for safranal extraction through HS-SPME-GC approach using polydimethylsiloxane (PDMS) fibre. RESULTS: Under static conditions, a linear response was obtained for standard curve within the safranal concentration range of 0.08-30 ppm, with R2 = 0.9999. The limits of detection and quantification were 0.04 and 0.08 ppm, respectively. Despite the fact that safranal peak area was an efficient parameter for quantifications under static conditions; its poor reproducibility was proved under dynamic conditions for the saffron drink sample. This observation necessitated application of kinetic studies on real food samples. CONCLUSIONS: Safranal extraction was successfully performed from aqueous matrices through HS-SPME-GC, under static conditions. Mathematical modelling resulted in kinetic parameters that improved the efficiency of safranal measurement under dynamic conditions, using PDMS fibre.

Characterization of the binding of cyanidin-3-glucoside to bovine serum albumin and its stability in a beverage model system: A multispectroscopic and chemometrics study.

Anthocyanins as one of the main natural groups of food colorants undergo quick color fading, which can be diminished through protein association. The stabilization of cyanidin-3-glucoside (CYG) through binding to bovine serum albumin (BSA) was investigated at pH 3.0 using atomic force microscopy and differential scanning calorimetry along with UV-Vis absorption, steady-state fluorescence, circular dichroism, and three-dimensional emission spectral analyses merged with the multivariate curve resolution-alternative least square method. The stabilized CYG molecules were found at the site II of BSA with combined static and dynamic quenching mechanisms. Approximately 93% of the BSA binding sites were occupied in the BSA-CYG complex through hydrogen bonds and van der Waals forces with the binding constant and stoichiometry ratio of 1.88 × 105 M-1 and 1:13, respectively. The results also revealed that CYG molecules caused partial unfolding of the BSA structure, while it was not enough for significant alteration of denaturation temperature. The binding results also indicated that the reduction of H2O2-induced-CYG oxidation rate (34.78%) at pH 3.0 was mainly driven via the BSA-hemiketal association, although the colored species of CYG had a greater affinity towards BSA in the equilibrated system at pHs 1.0 and 5.0.

Modeling of osmotic treatment of ostrich meat coated by tragacanth and salep.

This study involved coating of ostrich meat pieces (30 × 30 × 20 mm) with tragacanth gum (0.25%, 0.5%, and 1%) and salep gum (1%, 2%, and 3%) before osmotic treatment with salt solution (5, 15, and 27%) with the immersing duration of 1, 2, 4, 12, and 24 h to accelerate the transfer of moisture and minimize solid gain. This study also involved the investigation of the efficiency of the Peleg's model, Azuara's model, and diffusion equation in modeling water gain/loss and solid gain in meat pieces. Water gain/loss and solid gain were significantly affected by osmotic and coating concentrations during osmotic treatment. The Peleg's model had the best efficiency in the prediction of water loss at 5% and 27% concentrations and solid gain at 27% concentration. Diffusion model showed a favorable performance in the prediction of water loss and solid gain at 27% and 15% concentrations, respectively. It can be concluded that coating pre-treatment could control solid gain and facilitate water loss/gain.

Binding of safranal to whey proteins in aqueous solution: Combination of headspace solid-phase microextraction/gas chromatography with multi spectroscopic techniques and docking studies.

The objective of this work was to study molecular binding of safranal to whey proteins by taking advantage of headspace solid-phase microextraction combined with gas chromatography (HS-SPME/GC), fluorescence and circular dichroism (CD) spectroscopies, and docking studies. The results of HS-SPME/GC indicated that bovine serum albumin (BSA) had the highest affinity toward safranal, with binding constant of 3.196 × 103 M-1. Also, binding strength was reduced in the order of α-lactalbumin (α-Lact), whey protein isolate (WPI), and ß-lactoglobulin (ß-Lg). Although there was a good agreement between results of HS-SPME/GC and fluorescence spectroscopy regarding the safranal binding site on whey proteins, the order of their binding affinity toward safranal was not consistent for both techniques. According to docking studies, conformational alterations in secondary and tertiary structures of whey proteins induced by safranal association resulted from hydrophobic interactions and hydrogen bonds.