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.

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.

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.

Effect of drying methods on the structure, thermo and functional properties of fenugreek (Trigonella foenum graecum) protein isolate.

BACKGROUND: Different drying methods due to protein denaturation could alter the functional properties of proteins, as well as their structure. So, this study focused on the effect of different drying methods on amino acid content, thermo and functional properties, and protein structure of fenugreek protein isolate. RESULTS: Freeze and spray drying methods resulted in comparable protein solubility, dynamic surface and interfacial tensions, foaming and emulsifying properties except for emulsion stability. Vacuum oven drying promoted emulsion stability, surface hydrophobicity and viscosity of fenugreek protein isolate at the expanse of its protein solubility. Vacuum oven process caused a higher level of Maillard reaction followed by the spray drying process, which was confirmed by the lower amount of lysine content and less lightness, also more browning intensity. ΔH of fenugreek protein isolates was higher than soy protein isolate, which confirmed the presence of more ordered structures. Also, the bands which are attributed to the α-helix structures in the FTIR spectrum were in the shorter wave number region for freeze and spray dried fenugreek protein isolates that show more possibility of such structures. CONCLUSION: This research suggests that any drying method must be conducted in its gentle state in order to sustain native structure of proteins and promote their functionalities. © 2017 Society of Chemical Industry.

Thermodynamic compatibility and interactions between Speckled Sugar bean protein and xanthan gum for production of multilayer O/W emulsion.

Thermodynamic compatibility and probable interactions between Speckled Sugar been protein (SSBP) and xanthan gum for production of multilayer O/W emulsion (30% oil) were investigated. Different interactions were observed between SSBP and xanthan at different pH (3-7) including electrostatic interactions and hydrogen bonding. These interactions were predominant at pH 3. When low xanthan gum concentration (0.1%) was used, phase separation and complex coacervation observed at this pH (negative effect of interactions). However, at pH 5, only 0.1% xanthan was enough to drastically reduce non-dissolved protein and its precipitation which normally occurs at this pH. In addition, incompatibility or segregative phase behavior which normally occurs when protein and polysaccharide have same charges was not observed (positive effects of interactions). Protein-gum interactions influenced emulsion properties (zeta potential, particle size, PDI, rheology, emulsion capacity, heat stability and creaming rate). Interactions had considerable influence on emulsion shelf life and produced completely stable emulsions at all pH values. Results confirmed that SSBP-xanthan gum mixture has a high potential for production of multilayer emulsions.

Proteome Changes in biceps femoris Muscle of IranianOne-Humped Camel and Their Effect on Meat Quality Traits.

In this study physicochemical and quality traits of biceps femoris and longissimus thoracis muscles of male and female Iranian one-humped camel were determined during 14 days of refrigeration storage. Analysis of variance of the results showed that only shear force and temperature were affected by the gender (p<0.05). Anatomical location of the muscle influenced the meat properties except for drip loss (p<0.05). Also, except for cooking loss, ageing influenced the physicochemical and quality properties of meat; during 14 days of storage, proteolysis resulted in an increase of L* and b* values, drip loss and myofibrillar fragmentation index, and the decrease of a* value, expressed juice, shear force and sarcomere length. Proteome changes (myofibrillar proteins) during storage were investigated. Gel analysis revealed that 19 protein spots were significantly changed during 24, 72 and 168 h post-mortem. Fifteen spots were identified by MALDI-TOF/TOF mass spectrometer. Correlation analysis revealed significant correlations of actin, troponin T, capping protein, heat shock proteins (HSP) and desmin with physicochemical and quality properties of meat (p<0.05). Actin might be a potential protein marker for colour, tenderness and water-holding capacity, and HSP27 and desmin are good candidate markers for colour and tenderness, respectively.

Fenugreek (Trigonella foenum graecum) seed protein isolate: extraction optimization, amino acid composition, thermo and functional properties.

BACKGROUND: With increasing demand for new protein sources, research on plant protein extraction and evaluation of the functional properties of protein isolates is necessary. In this study, pH and NaCl concentration, as two parameters affecting protein extraction of fenugreek seed, was investigated and the condition of fenugreek protein isolate (FPI) extraction was optimized using response surface methodology. RESULTS: FPI had significantly (P< 0.05) higher protein and essential amino acid content (891.00 and 387.41 g kg(-1) , respectively) compared with soy protein isolate (SPI). FPI was rich in Asp and Glu, confirming the presence of bands in the acidic region (30-39 kDa) of its electrophoretic pattern. Differential scanning calorimeter thermography of both FPI and SPI showed two peaks with high denaturation temperature, confirming the presence of high protein content and hydrophobic amino acids. Protein solubility, foaming capacity, foam stability and emulsion stability of FPI were higher than SPI; moreover, both FPI and SPI showed pH-dependent protein functionalities. CONCLUSION: Fenugreek seed protein extraction was optimized by control of pH and NaCl concentration. FPI could be used as a protein source with remarkable functional properties.

Antioxidant and antibrowning properties of Maillard reaction products in food and biological systems.

Oxidative damage refers to the harm caused to biological systems by reactive oxygen species such as free radicals. This damage can contribute to a range of diseases and aging processes in organisms. Moreover, oxidative deterioration of lipids is a serious problem because it reduces the shelf life of food products, degrades their nutritional value, and produces reaction products that could be toxic. Antioxidants are effective compounds for preventing lipid oxidation, and synthetic antioxidants are frequently added to foods due to their high effectiveness and low cost. However, the safety of these antioxidants is a subject that is being discussed in the public more and more. Synthetic antioxidants have been found to have potential negative effects on health due to their ability to accumulate in tissues and disrupt natural antioxidant systems. During thermal processing and storage, foods containing reducing sugars and amino compounds frequently produce Maillard reaction products (MRPs). Through the chelation of metal ions, scavenging of reactive oxygen species, destruction of hydrogen peroxide, and suppression of radical chain reaction, MRPs exhibit excellent antioxidant properties in a variety of food products and biological systems. Also, the capacity of MRPs to chelate metals makes them as a potential inhibitor of the enzymatic browning in fruits and vegetables. In this book chapter, the methods used for the evaluation of antioxidant activity of MRPs are provided. Moreover, the antioxidant and antibrowning activities of MRPs in food and biological systems is discussed. MRPs can generally be isolated and used as commercial preparations of natural antioxidants.

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.

Effect of verjuice (Vitis vinifera L.) on physicochemical and textural properties of beef M. biceps femoris.

The objective of this study was to investigate the effect of verjuice on beef M. biceps femoris (BF). BF blocks were marinated with 30%, 70%, and 100% verjuice solutions containing 2% NaCl, for different marination times (12, 24, 48, and 72 h). Verjuice marination reduced the pH values of BF samples from 6.77 in control sample to 3.66 in 100% of verjuice for 72 h. The decreased values of water holding capacity (from 54.06% to 47.46%) with increasing verjuice concentration (from 30% to 100% for 72 h) confirmed the drop of proteins isoelectric point of the muscle due to salt presence preventing fibers swelling. Less cookout was observed with increasing acid concentration. Marination time had no significant effect on L* and a* coordinates of uncooked samples while acidification made the samples lighter and less red. Enzymatic proteolysis of myosin and troponin-T concomitant with increase in myofibrillar fragmentation index contributed to the decrease of shear force in a way dependent on verjuice concentration and marination time. Sensory panelists gave the highest score to cooked samples marinated with 70% verjuice solution.

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.

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.

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.

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.

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.

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).

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.

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.

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.