Effect of starch-based emulsion with different amylose content on the gel properties of Nemipterus virgatus surimi

Effect of water redistribution on the rheological behavior of MP-PSs and 3D printability of surimi: An investigation using LF-NMR

This study explored the effect of interaction between starch and water on 3D printing adaptability of surimi, a topic that has received limited attention in previous research. The 3D printability of surimi-starch systems was examined under controlled moisture conditions, and notable enhancements in printing quality were observed when starch concentrations were adjusted to 8-12 % (with a fixed water content of 70 %) or reduced to 4 % with a corresponding increase in water to 80 %. To gain further insights, we investigated myofibrillar protein-potato starch blend system and manipulated the proportions of the constituents and water content, using LF-NMR technology to analyze the competitive adsorption of water molecules among the components. Our findings, validated through polymer blending theory, revealed that within a water content range of 60-80 % and a protein-to-starch mass ratio of 9/1 to 4/6, the system exhibited a bicontinuous phase structure characterized by pronounced competition for water molecules between protein and starch. This competitive adsorption facilitated the redistribution of water within the system, ultimately altering its rheological properties and influencing the 3D printability of the surimi. Moreover, by employing a full factorial design approach, we explored the influence of protein, starch, and water content on the rheological characteristics. To capture these variations, we constructed regression models that underscored the predictive probability of nonlinear surface regression fitting. Our work not only establishes a theoretical foundation for optimizing formulations of 3D-printed minced products but also has profound practical implications for broadening the application of 3D printing technology within the food industry.

Enhanced gel properties of low-salt (1 %) silver carp surimi via combined starch addition and 915 MHz microwave pasteurization treatment

The optimization of gel properties in low-salt surimi is critical for producing high-quality, health-oriented products. The objective of this study was to reveal the combined effects of starch addition and 915 MHz microwave pasteurization treatment on the low-salt (1 %) silver carp surimi gel properties. Surimi samples with and without starch were processed using either microwave pasteurization or water bath, and water bath processed surimi without starch served as the control. Gel strength, texture, water-holding capacity (WHC), whiteness, water molecules distribution and mobility, protein secondary structure, and gel network were used to assess the gel properties and microstructure of the samples. Results demonstrated that microwave treatment and starch addition each improved gel properties, while their combination yielded the most significant enhancements. For surimi with starch treated by microwave, the gel strength increased by 93.50 % (406.93 g·cm to 787.42 g·cm), and WHC rose from 0.72 to 0.91, compared to controls. Additionally, this combination promoted ordered protein structure formation, which was characterized by increased β-sheet content to 60.92 % and decreased α-helix content to 10.74 %. These results indicated that microwave treatment and starch have a synergistic effect on improving the surimi gel properties. The alternative electric fields and faster heating rate of microwaves enhanced the starch-protein cross-linking and interaction forces, which contributed to the formation of a more compact and uniform microstructure. These results provided practical data for producing high-quality, low-salt surimi products.

Effect of β-sitosterol+γ-oryzanol-based oleogels on protein conformation and gel properties of Nemiperus virgatus surimi

BACKGROUND

The impact of β-sitosterol+γ-oryzanol-based oleogels or peanut oil on the protein conformation and gel quality of Nemiperus virgatus surimi was evaluated.

RESULTS

A significant reduction in gel strength, texture parameters and water holding capacity (WHC) of surimi was found as oil concentration increased (P < 0.05). However, compared with peanut oil, the gel strength, hydrophobic interaction and disulfide bond content of surimi gel containing oleogels increased by 6.919%, 32.635% and 12.409%, respectively, when the oil concentration was 10 g kg-1. Both oleogels and peanut oil could enhance the whiteness of surimi gel. Oleogels induced the unfolding of surimi proteins, and promoted the conformational shift from α-helix to β-sheet structure. Furthermore, oleogels filled the gaps of protein networks to make the microstructure of surimi gel more compact and uniform, improving the WHC and reducing the cooking loss.

CONCLUSION

γ-Oryzanol+β-sitosterol-based oleogel alleviated the adverse influences of direct addition of peanut oil on the gel and textural properties of surimi products. © 2024 Society of Chemical Industry.

Ovalbumin/sodium alginate Pickering emulsion: Structural characteristics and its contribution to enhancing the gel properties of Hairtail (Trichiurus haumela) surimi

In this study, ovalbumin (OV) and sodium alginate (SA), two macromolecular complexes, were coagulated into the emulsifier (OV/SA), which stabilized soybean oil by electrostatic interaction, hydrophobic interactions, and hydrogen bonding. The structure of OV/SA and properties of OV/SA Pickering emulsion were investigated. Additionally, the effect of emulsions on the gel and protein properties of hairtail surimi was studied. The results revealed that with the increasing concentration of OV/SA, the particle size and zeta potential value (negative value) of the emulsion initially decreased and then increased, while the rheological properties gradually improved. Compared with the surimi gel directly supplemented with soybean oil, the addition of emulsion enhanced gel strength, whiteness, water holding capacity, and hydrophobic interactions, resulting in a more stable gel network structure. In summary, incorporating emulsion into surimi at the same lipid content not only maintained its gel properties but also improved its color and compensated for lipid loss.

Evaluation of the performance of low-fat (oil-fat) dressings based on chemically modified Guayabo plantain starch (Musa paradisiaca L.)

Guayabo plantain (GP) starch was chemically modified by acetylation to evaluate its role as a stabilizer and emulsifier in low-fat dressings. Native starch (NS) from GP was chemically modified starch (MS), and its functional properties, such as water absorption index, water solubility index, swelling power, gelatinization temperature (Tg), were evaluated. Additionally, functional groups and morphology were identified using Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy. Low-fat dressings were prepared using NS and MS at two concentrations, 2% and 3% (NS2, NS3, MS2, MS3), and the stability of the dressings was evaluated over a storage period of 28 days at 4 °C ± 2.0 °C. The percentage of acetylation and the degree of substitution obtained were 2.48% and 0.01, respectively, complying with current regulations. MS showed a higher amylose content (23.62 ± 1.89%) than NS (16.01 ± 0.43%). The Tg of MS decreased, and the appearance of bands at 1012 and 1723 cm-1 in the FT-IR spectra suggested a modification in the functional characteristics of starch due to acetylation. Emulsions of MS at 2% and 3% (MS2 and MS3) showed a smaller droplet size and higher interfacial dispersion. However, MS3 had higher viscosity, which contributed to an increase in hydrophobicity and delays in flocculation and subsequent coalescence. This research study provides useful information on the use of 3% MS dressings in new food formulations, reducing fat content while preserving functional characteristics, thus ensuring greater stability.

Preparation of cod protein composite gels for dysphagia by high-pressure homogenization: Egg white microgels-based high-phase emulsion as a texture modifier

The rising prevalence of dysphagia among the aging population presents significant challenges in developing specialized diets that combine soft textures with high nutritional value. This study investigates the formulation of cod protein composite gels (CPCGs) using egg white based microgels-high internal phase emulsions (HIPEs, 5-25 %). The CPCGs were prepared via high-pressure homogenization at 400 bar for 10 min. The texture, water retention, rheological properties, and network structure of the CPCGs were analyzed. Results demonstrated that incorporating HIPEs increased the hardness and whiteness of CPCGs. The water holding capacity peaked at 98.52 % with 15 % HIPEs. Additionally, as the concentration of HIPEs increased, the apparent viscosity, support properties, and thermal stability of CPCGs improved, although the critical strain point decreased from 475.33 % (control) to 199.33 % (25 % HIPEs). The network structure of CPCGs became denser and more uniform with higher HIPE concentrations, with noticeable changes in the gel skeleton when HIPEs exceeded 15 %. According to the International Dysphagia Diet Standardization Initiative (IDDSI) tests, all CPCG formulations met Level 6 - soft and bite-sized criteria. This study offers valuable insights into the development of fish protein-based dysphagia diets that are both nutritious and safe for swallowing.

Fabrication and characterization of novel curcumin-loaded thermoreversible high amylose maize starch emulsion gel

This study developed a novel thermoreversible emulsion gel system based on high amylose maize starch (HAMS) and investigated the impact of the oil-to-water ratio on its physicochemical properties and encapsulation performance (using curcumin as model guest molecule). Electron microscopy showed a tightly porous network structure of the HAMS-based emulsion gels. Thermal results revealed a sol-gel transition occurring in the range of 59.41 to 67.64 °C for the prepared emulsion gels. Rheological analysis suggested that all samples displayed shear-thinning behavior and HAMS-based emulsion gels exhibited typical gel-like behavior with the gel strength bolstered by higher aqueous phases. Particle size analysis showed that droplet size of emulsion gel decreased from 245 to 184 nm with increased starch aqueous phase content. Texture profile analysis indicated enhanced strength, hardness, and chewiness of the emulsion gel with increased aqueous phases. Curcumin encapsulation efficiency in the HAMS-based emulsion gel also improved with higher aqueous phase content, reaching up to 93.82 %, which attributed to the smaller droplets caused increased interfacial area. The novel HAMS-based emulsion gel system showed considerable encapsulation capacity and desirable mechanical properties. It provided valuable insights into the application of starch-based emulsion gels in food and medical area.

Effect of starch and peanut oil on physicochemical and gel properties of myofibrillar protein: Amylose content and addition form

Starch and peanut oil (PO) were widely used to improve the gel properties of surimi, however, the impact mechanism of addition forms on the denaturation and aggregation behavior of myofibrillar protein (MP) is not clear. Therefore, the effect of starch, PO, starch/PO mixture, and starch-based emulsion on the physicochemical and gel properties of MP was investigated. The results showed that amylose could accelerate the aggregation of MP, while amylopectin was conducive to the improvement of gel properties. The addition of PO, starch/PO mixture, or starch-based emulsion increased the turbidity, solubility, sulfhydryl content of MP, and improved the gel strength, whiteness, and texture of MP gel. However, compared with starch/PO mixture group, the gel strength of MP with waxy, normal and high amylose corn starch-based emulsion increased by 22.68 %, 10.27 %, and 32.89 %, respectively. The MP containing emulsion had higher storage modulus than MP with starch/PO mixture under the same amylose content. CLSM results indicated that the oil droplets aggregated in PO or starch/PO mixture group, while emulsified oil droplets filled the protein gel network more homogeneously. Therefore, the addition of starch and PO in the form of emulsion could effectively play the filling role to improve the gel properties of MP.

Artificial saliva induced structural breakdown of surimi gels with starch under continuous compressive motions

Food texture perception is dynamic, influenced by food properties and oral processing. Using the Repeatable Dual Extrusion Cell (RDEC), the oral processing dynamics of surimi gel with different corn starch concentrations (0-15%) in the presence of 1 ml artificial saliva or water were studied. The force-time curve showed increased peak forces with higher corn starch concentrations, peaking significantly at 10%, then decreasing at 15%. Salivary amylase played a crucial role in gel sample degradation, especially in samples with 5% starch, with a work value depletion ratio of 0.535 for sample with 1 ml water (SGW-5) and 0.406 for sample with 1 ml saliva (SGS-5). SEM analysis confirmed the formation of a continuous starch network with reduced intermolecular spaces in SGS-5. The starch-iodine complex showed decreasing order with increasing starch concentration, and SGS-5 exhibited the highest degradation rate (61.61 ± 0.92%). Mathematical modeling revealed that initial decay rates (k1) in gel sample decreased with increasing starch concentration, and samples with starch and artificial saliva had higher initial degradation rates. These findings highlight the intricate interplay between saliva and starch in the surimi gel matrix under continuous compressive motions by RDEC apparatus, providing insights for formulating food products with tailored textures properties.