Combination of κ-Carrageenan and Soy Protein Isolate Effects on Functional Properties of Chopped Low-Fat Pork Batters During Heat-Induced Gelation

Characterization and in vitro digestibility of soybean tofu: Influence of the different kinds of coagulant

This study explored the effect of diverse coagulants (glucono-δ-lactone (GDL), gypsum (GYP), microbial transglutaminase (MTGase), and white vinegar (WVG)) on microstructure, quality, and digestion properties of tofu. The four kinds of tofu were significantly different in their structure, composition, and digestibility. Tofu coagulated with MTGase had the highest springiness and cohesiveness while GDL tofu had the highest enthalpy (6.54 J/g). However, the WVG and GYP groups outperformed others in terms of thermodynamic, and digestion properties. The WVG group exhibited the highest nitrogen release (84.3%), water content, denaturation temperature, and the highest free-SH content but the lowest S-S content. Compared to WVG, the GYP group had the highest ash content, hardness, and chewiness. Results demonstrated that the tofu prepared by WVG and GYP show high digestibility. Meanwhile, the former has better thermal properties and the latter has better texture properties.

Effects and mechanisms of ultrasound-assisted emulsification treatment on the curcumin delivery and digestive properties of myofibrillar protein-carboxymethyl cellulose complex emulsion gel

Different emulsion gel systems are widely applied to deliver functional ingredients. The effects and mechanisms of ultrasound-assisted emulsification (UAE) treatment and carboxymethyl cellulose (CMC) modifying the curcumin delivery properties and in vitro digestibility of the myofibrillar protein (MP)-soybean oil emulsion gels were investigated. The rheological properties, droplet size, protein and CMC distribution, ultrastructure, surface hydrophobicity, sulfhydryl groups, and zeta potential of emulsion gels were also measured. Results indicate that UAE treatment and CMC addition both improved curcumin encapsulation and protection efficiency in MP emulsion gel, especially for the UAE combined with CMC (UAE-CMC) treatment which encapsulation efficiency, protection efficiency, the release rate, and bioaccessibility of curcumin increased from 86.75 % to 97.67 %, 44.85 % to 68.85 %, 18.44 % to 41.78 %, and 28.68 % to 44.93 % respectively. The protein digestibility during the gastric stage was decreased after the CMC addition and UAE treatment, and the protein digestibility during the intestinal stage was reduced after the CMC addition. The fatty acid release rate was increased after CMC addition and UAE treatment. Apparent viscosity, storage modulus, and loss modulus were decreased after CMC addition while increased after UAE and UAE-CMC treatment especially the storage modulus increased from 0.26 Pa to 41 Pa after UAE-CMC treatment. The oil size was decreased, the protein and CMC concentration around the oil was increased, and a denser and uniform emulsion gel network structure was formed after UAE treatment. The surface hydrophobicity, free SH groups, and absolute zeta potential were increased after UAE treatment. The UAE-CMC treatment could strengthen the MP emulsion gel structure and decrease the oil size to increase the curcumin delivery properties, and hydrophobic and electrostatic interaction might be essential forces to maintain the emulsion gel.

Investigating Texture and Freeze-Thaw Stability of Cold-Set Gel Prepared by Soy Protein Isolate and Carrageenan Compounding

In this study, the purpose was to investigate the effects with different concentrations of carrageenan (CG, 0-0.30%) on the gel properties and freeze-thaw stability of soy protein isolate (SPI, 8%) cold-set gels. LF-NMR, MRI, and rheology revealed that CG promoted the formation of SPI-CG cold-set gel dense three-dimensional network structures and increased gel network cross-linking sites. As visually demonstrated by microstructure observations, CG contributed to the formation of stable SPI-CG cold-set gels with uniform and compact network structures. The dense gel network formation was caused when the proportion of disulfide bonds in the intermolecular interaction of SPI-CG cold-set gels increased, and the particle size and zeta potential of SPI-CG aggregates increased. SG20 (0.20% CG) had the densest gel network in all samples. It effectively hindered the migration and flow of water, which decreased the damage of freezing to the gel network. Therefore, SG20 exhibited excellent gel strength, water holding capacity, freeze-thaw stability, and steaming stability. This was beneficial for the gel having a good quality after freeze-thaw, which provided a valuable reference for the development of freeze-thaw-resistant SPI cold-set gel products.

Effect of High-Pressure Homogenization on the Properties and Structure of Cold-Induced Chiba Tofu Gel in Soy Protein Isolate

In the actual production process of soy protein isolate (SPI), most of the homogeneous operating pressure is controlled below 20 MPa due to the consideration of production safety and the limitation of the pressure control capability of homogeneous equipment. In order to improve the functional properties of SPI and adapt it to actual production, the effects of different homogeneous pressures (4, 8, 10, 12, and 14 MPa) on the structure and gel properties of SPI were studied from the perspective of production control. Compared to the control group, the modified SPI improved the hardness, springiness, cohesiveness, chewiness, and water holding capacity (WHC) of the protein gel (p < 0.05). Rheological analysis shows that both G' and G″ increase with increasing frequency, reaching a maximum at 12 MPa. The gel intermolecular force results show that the disulfide bond, hydrophobic interaction, and non-disulfide bond are important molecular forces for gel formation. The particle size distribution uniformity of modified SPI was high, and scanning electron microscopy (SEM) analysis showed that the protein gel with a continuous uniform and dense network structure could be formed by high-pressure homogeneous modification. Overall, high-pressure homogenization technology has the potential to improve SPI gel structure and WHC, and 12 MPa modified SPI gel has the most significant effect.

Investigation of 3D printing product of powder-based white mushroom incorporated with soybean protein isolate as dysphagia diet

The elderly people are prone to dysphagia due to weakened muscle strength. 3D food printing could modify the nutritional ratio and shape design to produce personalized nutritious food suitable for patients with dysphagia. White mushroom (Agaricus bisporus) is rich in a variety of active ingredients such as polysaccharides and polyphenols which are beneficial to human body, but its unique texture is not suitable for patients with dysphagia to chew. This study investigated the impact of different concentrations of soybean protein isolate (SPI, 3%, 5%, 7%, w/w) on 3D food printing of white mushroom powder and carried out the hierarchical representation of dysphagia diet within the framework of International Dysphagia Diet Standardization Initiative (IDDSI). The results illustrated that SPI addition to white mushroom gel reduced water mobility and promoted hydrogen bond formation, which significantly improved the mechanical strength and cohesiveness of printing inks, including yield stress, viscosity and hardness. IDDSI tests showed that the SPI addition of 3% and 5% helped the printing ink pass the spoon tilt test and the fork drip test, which could be classified as level 5 minced and moist food under the consideration of the fork pressure test. The 3D printing results indicated that the 7% SPI addition made the yield stress too high and was not easy for extrusion, resulting in the appearance defects of the printed sample. The addition of 3% SPI could make the printed sample have smooth surface and excellent self-supporting capacity. This work provides insights of white mushroom 3D printing technology as a more visually appealing dysphagia diet.

Physiochemical characteristics and sensory properties of plant protein isolates-konjac glucomannan compound gels

In this study, the effects of konjac glucomannan (KGM) at different concentrations on the physiochemical and sensory properties of soy protein isolate (SPI), pea protein isolate (PPI), or peanut protein isolate (PNPI) compound gels were investigated. The results revealed that when the ratio of PNPI to KGM was 90:10, the denaturation temperature of PNPI could be significantly enhanced to 119.32°C by KGM modification. Concerning the textural and microstructural features, the amount of KGM addition had positive correlation with the hardness and chewiness of each compound gel, however, too much KGM addition will cause the unstable internal structure of the PNPI/KGM compound gels (70:30 and 60:40). Furthermore, sensory results indicated that PNPI/KGM (80:20), PPI/KGM (80:20), SPI/KGM (80:20) had great potential to be considered as prototypes for novel plant-based products, which generated the highest acceptance scores of 5.04, 5.94, and 5.36 in each group, respectively.

Suppression mechanism of L-lysine on the Epigallocatechin-3-gallate-induced loss of myofibrillar protein gelling potential

As a natural antioxidant, Epigallocatechin-3-gallate (EGCG) needed to be added in high doses to maintain the quality of meat products. However, high doses of EGCG caused the excessive aggregation of myofibrillar protein (MP), which damaged the gel properties of MP gels. Therefore, the purpose of this study was to investigate the mitigation of EGCG-induced loss of MP gelling potential by L-Lysine (L-Lys). The results showed that the addition of 20 mM L-Lys induced excessive unfolding and loose aggregation of MP at 10 µmol/g EGCG, and hence, reducing the solubility (14.5%) and the tryptophan fluorescence, and forming a network structure with a large aperture. Therefore, the cooking loss was decreased from 29.20% to 15.13%, and the strength of MP gels was decreased from 0.35 N to 0.17 N. However, L-Lys hindered the hydrogen bonding interactions and hydrophobic interactions between MP and EGCG by competing the binding sites of MP at 50 µmol/g EGCG, which was supported by the Zeta potential, surface hydrophobicity, FTIR and molecular docking analysis. Thus L-Lys mitigated the protein aggregation caused by 50 µmol/g EGCG, improved the solubility (23.02%∼86.99%) and apparent viscosity, which were beneficial for the formation of a continuous network structure in MP gels. Therefore, the cooking loss of MP gels was decreased from 52.40% to 41.30%, and the gel strength was enhanced from 0.13 N to o.22 N with 20 mM L-Lys addition. The present study could provide a new strategy for increasing the amounts of EGCG in meat products without damaging the gel properties of meat products.

Structural, functional properties of protein and characteristics of tofu from small-seeded soybeans grown in the Loess Plateau of China

The structural, functional properties of protein isolated from small-seeded soybeans were investigated and characteristics of tofu were studied. Small-seeded soybean protein had obvious α', α, β, acidic and basic subunits bands and two endothermic peaks (76.02-76.63℃ and 91.94-94.25℃). Small-seeded black soybean protein isolates (SBSPI) had more β-sheet (31.90-33.54%) structure, while small-seeded yellow soybean protein isolates (SYSPI) had more α-helix (18.89-20.72%) structure. SYSPI had higher fluorescence intensity (839.10-847.80) than SBSPI (482.70-565.10). SBSPI exhibited higher surface hydrophobicity (939.51-1252.75) and water absorption capacity (8.07-8.50 g/g). Tofu made from small-seeded yellow soybeans had higher yield (549.46-560.23 g/100 g soybean) and was brighter (L*, 74.61-77.48) and more yellowish (b*, 14.83-14.95) in color. Tofu made from Fugu small-seeded black soybean (FGSBS) had the highest hardness (178.52 g), adhesiveness (-25.77 g.sec), chewiness (87.45 g) and resilience (0.26), signifying a more compact structure.

Mechanical Properties, Microstructure, and In Vitro Digestion of Transglutaminase-Crosslinked Whey Protein and Potato Protein Hydrolysate Composite Gels

The production of animal protein usually leads to higher carbon emissions than that of plant protein. To reduce carbon emissions, the partial replacement of animal protein with plant protein has attracted extensive attention; however, little is known about using plant protein hydrolysates as a substitute. The potential application of 2 h-alcalase hydrolyzed potato protein hydrolysate (PPH) to displace whey protein isolate (WPI) during gel formation was demonstrated in this study. The effect of the ratios (8/5, 9/4, 10/3, 11/2, 12/1, and 13/0) of WPI to PPH on the mechanical properties, microstructure, and digestibility of composite WPI/PPH gels was investigated. Increasing the WPI ratio could improve the storage modulus (G') and loss modulus (G″) of composite gels. The springiness of gels with the WPH/PPH ratio of 10/3 and 8/5 was 0.82 and 0.36 times higher than that of the control (WPH/PPH ratio of 13/0) (p < 0.05). In contrast, the hardness of the control samples was 1.82 and 2.38 times higher than that of gels with the WPH/PPH ratio of 10/3 and 8/5 (p < 0.05). According to the International Organization for Standardization of Dysphagia Diet (IDDSI) testing, the composite gels belonged to food level 4 in the IDDSI framework. This suggested that composite gels could be acceptable to people with swallowing difficulties. Confocal laser scanning microscopy and scanning electron microscopy images illustrated that composite gels with a higher ratio of PPH displayed thicker gel skeletons and porous networks in the matrix. The water-holding capacity and swelling ratio of gels with the WPH/PPH ratio of 8/5 decreased by 12.4% and 40.8% when compared with the control (p < 0.05). Analysis of the swelling rate with the power law model indicated that water diffusion in composite gels belonged to non-Fickian transport. The results of amino acid release suggested that PPH improved the digestion of composite gels during the intestinal stage. The free amino group content of gels with the WPH/PPH ratio of 8/5 increased by 29.5% compared with the control (p < 0.05). Our results suggested that replacing WPI with PPH at the ratio of 8/5 could be the optimal selection for composite gels. The findings indicated that PPH could be used as a substitute for whey protein to develop new products for different consumers. Composite gels could deliver nutrients such as vitamins and minerals to develop snack foods for elders and children.

The effects of modified quinoa protein emulsion as fat substitutes in frankfurters

In the current study, the effects of replacing different proportions of pork back fat (0, 25, 50, 75, and 100%) with high-pressure homogenization-modified quinoa protein emulsions (HMQE) on the physicochemical, water distribution, and rheological properties of low-fat frankfurters were investigated. HMQE incorporation significantly increased the moisture, ash, protein content, pH and L^⁎ values and decreased the a^⁎ and b^⁎ values and T₂ relaxation time of the low-fat frankfurters (P < 0.05). Of note, 50% fat substitution by HMQE yielded higher WHC, textural properties, gel strength, immobilized water percentage and G' value of the frankfurters than others. HMQE incorporation changed the protein secondary structure from α-helix to β-sheet, forming a compact and uniform gel network structure with small cavities. Moreover, 50% fat substitution by HMQE did not affect sensory characteristics and improved the fat oxidative stability during storage. Therefore, the incorporation of HQME as a partial fat substitute resulted in nutritional benefits and quality enhancements, indicating that HQME could serve as a promising fat alternative in manufacturing low-fat frankfurters with desirable attributes.

Application of Emulsion Gels as Fat Substitutes in Meat Products

Although traditional meat products are highly popular with consumers, the high levels of unsaturated fatty acids and cholesterol present significant health concerns. However, simply using plant oil rich in unsaturated fatty acids to replace animal fat in meat products causes a decline in product quality, such as lower levels of juiciness and hardness. Therefore, it is necessary to develop a fat substitute that can ensure the sensory quality of the product while reducing its fat content. Consequently, using emulsion gels to produce structured oils or introducing functional ingredients has attracted substantial attention for replacing the fat in meat products. This paper delineated emulsion gels into protein, polysaccharide, and protein–polysaccharide compound according to the matrix. The preparation methods and the application of the three emulsion gels as fat substitutes in meat products were reviewed. Since it displayed a unique separation structure, the double emulsion was highly suitable for encapsulating bioactive substances, such as functional oils, flavor components, and functional factors, while it also exhibited significant potential for developing low-fat or functional healthy meat products. This paper summarized the studies involving the utilization of double emulsion and gelled double emulsion as fat replacement agents to provide a theoretical basis for related research and new insight into the development of low-fat meat products.

Textural and gel properties of frankfurters as influenced by various κ-carrageenan incorporation methods

The influence of different addition forms of κ-carrageenan, including powder, pre-suspended in water, and pre-suspended in brine, on the textural and gel properties of frankfurters were investigated. Compared with the control group, each addition form of κ-carrageenan led to a lower cooking loss, as well as higher emulsion stability with more trapped water within frankfurters (P < 0.05). Moreover, κ-carrageenan powder or κ-carrageenan water suspension addition could render higher hardness, adhesiveness, springiness, chewiness, fracturability, and resilience of frankfurters than control group (P < 0.05), which was verified by dynamic rheology analysis. However, κ-carrageenan brine suspension addition had negative effects on the above characteristics. Microstructural images indicated that κ-carrageenan could help form finer and denser protein matrices. However, the interaction modes between the meat protein matrix and each addition form of κ-carrageenan were distinct. Additionally, the addition of κ-carrageenan water suspension had the best effect on the improvement of the textural and gel properties of frankfurters with an enhanced overall acceptability.

Development of soy protein isolate/κ-carrageenan composite hydrogels as a delivery system for hydrophilic compounds: Monascus yellow

The aim of the present study was to develop soy protein isolate (SPI) and κ-carrageenan (KC) composite hydrogels as a delivery system for hydrophilic compounds. The pigment of monascus yellow was used as a model. A systematic study was performed to characterize the rheological, textural, microstructural properties and in vitro digestion release profile of monascus yellow of the composite gels. The results of power law modeling, electrophoresis patterns and fourier transform infrared spectroscopy (FTIR) confirmed that non-covalent interactions were involved in the formation of SPI/KC composite hydrogels. Compared to pure κ-carrageenan hydrogels, the incorporation of SPI could promote the formation of tougher, more uniform and compact composite gels with sustained-release property. In addition, the release behaviors of monascus yellow entrapped in the hydrogel network can be well described by the Ritger-Peppas mathematical model. Overall, our study provided a promising strategy to enhance the sustained release performance of hydrogels in digestive conditions.

Cooking loss, texture properties, and color of comminuted beef prepared with breadfruit (Artocarpus altilis) flour

Cooking loss, texture properties, and color of comminuted beef when prepared with breadfruit (Artocarpus altilis) flour or other flour sources was evaluated using 2 separate studies. Flour sources tested in these studies (against a negative control with no added flour) were breadfruit flour, soy flour, corn flour, wheat flour, and tapioca flour. Study 1: Finely minced, comminuted beef batters (extra lean beef targeted to 97% lean and 3% fat, salt, and ice/water) prepared with inclusion levels of 0, 1, 2, 3, 4, and 5% flour were evaluated for cooking loss and texture. Cooking loss was reduced (P < 0.05) in comminuted beef prepared with breadfruit flour compared with those not prepared with flour and cooking loss decreased as breadfruit flour inclusion level increased (Linear P < 0.01). Hardness was not different (P = 0.49) in comminuted beef prepared with breadfruit flour compared with soy flour, and was much less (P < 0.01) compared with the 3 other flour sources at each inclusion level. Study 2: Comminuted beef (lean beef targeted to 90% lean and 10% fat, salt, and ice/water) with inclusion levels of 0, 2.5, and 5% flour were formed into patties and were evaluated for color over a simulated retail display period. Redness values (a*) of comminuted beef prepared with breadfruit flour were the greatest (P < 0.05) during the 7-d simulated retail display compared with all other treatments, including control samples with no flour. Overall, the results indicated that breadfruit flour could be effectively used as an ingredient in comminuted beef to produce similar texture as observed with soy flour, while actually improving redness values beyond that of other flour sources.

Effect of nano-scaled rabbit bone powder on physicochemical properties of rabbit meat batter

BACKGROUND

To explore a new method of deep processing and to improve the value of rabbit bone, we prepared a nano-scaled rabbit bone powder by dry ball milling and compared the effect of different particle sizes of rabbit bone powder [fine-scaled (236.01 ± 5.99 μm), superfine-scaled (65.92 ± 1.71 μm), nano-scaled (502.52 ± 11.72 nm)] on the nutritional characteristics, pH, color, water-holding capacity, textural and rheological attributes of rabbit meat batter.

RESULTS

The rabbit bone powder significantly affected nutritional characteristics of meat batters; in particular, the contents of calcium were increased, regardless of particle size. Additionally, the rabbit meat batter, which contained 20 g kg^-1 nano-scaled rabbit bone, had the lowest centrifugal and cooking losses among the treatments.

CONCLUSION

Based on the textural and rheological attributes of the rabbit meat batters, the addition of 20 g kg^-1 nano-scaled rabbit bone was the best treatment. This represents an important finding with respect to the deep processing of rabbit bone in the rabbit meat industry. © 2018 Society of Chemical Industry.

Structural changes evaluation with Raman spectroscopy in meat batters prepared by different processes

A comprehensive study was conducted to evaluate the structural changes of meat and protein of pork batters produced by chopping or beating process through the phase-contrast micrograph, laser light scattering analyzer, scanning electronic microscopy and Raman spectrometer. The results showed that the shattered myofibrilla fragments were shorter and particle-sizes were smaller in the raw batter produced by beating process than those in the chopping process. Compared with the raw and cooked batters produced by chopping process, modifications in amide I and amide III bands revealed a significant decrease of α-helix content and an increase of β-sheet, β-turn and random coils content in the beating process. The changes in secondary structure of protein in the batter produced by beating process was thermally stable. Moreover, more tyrosine residues were buried, and more gauche-gauche-trans disulfide bonds conformations and hydrophobic interactions were formed in the batter produced by beating process.

Technological demands of meat processing-An Asian perspective

A rapid increase in the economy, population, industrialization, and urbanization of Asian countries has driven the fast development of their meat industries over recent decades. This consistent increase in meat production and consumption in Asia has been the major cause for the development of the global meat industry. Meat production methods and consumption are very diverse across different regions and countries in Asia, and thus, it is impossible to cover the technological demands of all Asian countries in this review. Here, we have mainly highlighted the differences in meat production methods and consumption in Asia during recent decades and the meat technology demands of three east Asian countries, namely China, Korea, and Japan, and one south Asian country, India. A brief introduction of the meat industry, in particular the production and consumption trend in these countries, is provided in this article. The technology demands for fresh and processed meat products are then reviewed.