Coordinated improvement of frozen shrimp surimi gel quality by soybean protein isolate and transglutaminase: The role of building a bridge.

Effects of pre-heating soybean protein isolate and transglutaminase treatments on the properties of egg-soybean protein isolate composite gels

Effect of high intensity ultrasound on the structure and physicochemical properties of soy protein isolates produced by different denaturation methods

Investigating the role of calcium ions in modulating the physicochemical and gel properties of myofibrillar protein-soybean protein isolate binary composites.

Effect of transglutaminase and laccase on pea protein gel properties compared to that of soybean

Transglutaminase (TG) is an alternative coacervate cross-linking agent to aldehydes due to its safety. In this work, the cross-linking conditions of soybean protein isolate (SPI)–chitosan coacervates with TG-utilizing capsanthin as the model core were optimized and its cross-linking effectiveness was compared with that of glutaraldehyde. Results indicated that the optimum capsanthin microcapsule cross-linking conditions were as follows: a suspension pH of 6.0, an incubation duration of 3 h, a TG concentration of 18.75 U/g SPI and a reaction temperature of 45 °C. Under these conditions, TG provided a cross-linking effectiveness comparable with that of glutaraldehyde in regards to microcapsule stability against swelling in 80 °C water and heating at 150 °C. Differential scanning calorimetry analysis revealed that TG cross-linking increased the integrity of the microcapsule walls. It was concluded that the SPI–chitosan coacervation pair has potential applications in the food industry in terms of cross-linker safety and effectiveness.

Reformulation of traditional food systems to introduce new ingredients may change their structure and perceived texture. Interactions between proteins and starch during processing can markedly influence starch gel network structure and rheological profile. The present work aimed to study the effects of soybean protein and the products of enzymatic modification on the pasting and rheological profile of corn and cassava starch. The behavior of those protein‐enriched gels during storage was also assessed. Soybean protein isolate (SPI) was incubated with endopeptidase (AL) or food grade microbial transglutaminase (TG). Pasting and rheological behavior, water retention capacity, and structure of protein– and hydrolyzed protein–starch gels were analyzed. Protein incorporation increased the viscosity of starch suspension during and after heating. SPI‐modified proteins increased peak viscosity. Only the structural modifications brought by TG on SPI increased the final viscosity during starch pasting and the storage modulus (G′). This modulus (G′) of the gelled systems decreased with the addition of AL‐treated protein isolate. Light and fluorescence microscopy showed that SPI formed a continuous phase, like a network, in the gelled system. Different network structures and rheological properties can be obtained when SPI are modified by protease and TG enzymes, which may be very useful for designing new food products.

Transglutaminase treatment and pH shifting to manipulate physicochemical properties and formation mechanism of cubic fat substitutes

Advancing soy protein isolate-ulvan film physicochemical properties and antioxidant activities through strategic high-pressure homogenization technique

Changes induced by high pressure (HP) treatment (200-600 MPa) on soybean protein isolates (SPI) at pH 3 (SPI3) and pH 8 (SPI8) were analyzed. Changes in protein solubility, surface hydrophobicity (Ho), and free sulfhydryl content (SH(F)) were determined. Protein aggregation and denaturation and changes in secondary structure were also studied. An increase in protein Ho and aggregation, a reduction of free SH, and a partial unfolding of 7S and 11S fractions were observed in HP-treated SPI8. Changes in secondary structure were also detected, which led to a more disordered structure. HP-treated SPI3 was partially denatured and presented insoluble aggregates. A major molecular unfolding, a decrease of thermal stability, and an increase of protein solubility and Ho were also detected. At 400 and 600 MPa, a decrease of the SH(F) and a total denaturation were observed.

Effects of combined enzymatic and ultrasonic treatments on the structure and gel properties of soybean protein isolate

The processing instability and strong pungent smell limit the use of allicin. To overcome these shortcomings, emulsion gels loaded with allicin were constructed using soybean protein isolate (SPI) and gum Arabic (GA) through ultrasound treatment and transglutaminase (TG) induction. The effect of ultrasonic modification and GA concentration on the physical properties of emulsion gels was investigated, and the protective effect of emulsion gel on allicin was evaluated. The results showed that ultrasonic pretreatment of SPI can significantly improve the water holding capacity, hardness, viscosity, and elasticity modulus of emulsion gels, forming denser homogeneous network structure, and these properties were best when GA concentration was 0.3%. In the process of gel formation, ultrasound can change the spatial structure of protein, the introduction of polysaccharide can enhance the hydrogen bond between molecules, and TG can promote the intramolecular crosslinking, the three worked together to form a gel network. The encapsulation efficiency of the ultrasonic SPI-GA emulsion gel can reach 70.84%, while it was only 26.63% for the SPI emulsion gel. The degradation of allicin was inhibited under strong light and high temperature. This study provides a new idea for the development of functional food rich in allicin.

Effects of moderate electric field on the structural properties and aggregation characteristics of soybean protein isolate

In this study, rice noodles were developed with the goal of improving texture, cooking quality, sensory attributes, and reducing glycemic impact by adding transglutaminase (TG), soybean protein isolate (SPI), and konjac glucomannan (KGM) to indica rice flour using a single-screw extruder. Compared to the control group without these additives, the textural analysis results showed that the addition of 0.5 % TG, 0.5 % KGM, and 3 % SPI significantly improved chewiness. For cooking and sensory quality, this formulation exhibited the lowest cooking loss rate (CLR), a reduced iodine blue value, the highest water absorption rate (WAR), and superior overall acceptability in comparison to the control. In terms of color properties, this group showed a 1.66 % increase in L* (lightness) and a 0.78 % decrease in a* (red-green value) compared to the control. Furthermore, the in vitro digestion results revealed a decrease of 3.87 % in estimated glycemic index (eGI) and an 8.03 % reduction in glycemic load (GL) for the 0.5 % TG + 0.5 % KGM + 3 % SPI group relative to the control. This study demonstrates the potential to enhance rice noodle quality while lowering glycemic impact.

The effect of soybean soluble polysaccharide (SSPS) on the formation of glucono-δ-lactone (GDL)-induced soybean protein isolate (SPI) gel was investigated. Electrophoretic analysis showed the SSPS did not change the electrophoretic behavior of SPI during the formation of SPI gel. However, infrared analysis indicated the β-sheet content increased, and the contents of random coil and α-helix decreased in both cooked SPI and SPI gel. The SSPS and SPI might conjugate via the Maillard reaction according to the results of grafting degree, color change, and infrared analyses. The main interactions during the formation of SPI gel changed from non-covalent to electrostatic interaction after adding SSPS. Sulfhydryl group content also increased in both cooked SPI and SPI gel. The water-holding capacity and gel strength of SPI gel decreased as the SSPS concentration increased. Larger aggregate holes were observed in the microstructure of SPI gel at higher SSPS concentration. Thus, SSPS could covalently conjugate with SPI and influence the formation of hydrogen bonds, disulfide bonds, and electrostatic interaction among SPI molecules to eventually form a loose gel network.

Improving gel properties of soy protein isolate through alkaline pH-shifting, mild heat treatment, and TGase cross-linking