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The present research employed sodium alginate (SA) and pea protein isolate (PPI) as primary materials to explore the impact of pre-gelation time on the rheological properties, 3D printability, and swallowing properties of SA-PPI composite gel. Additionally, in vitro release capabilities of 3D printed products carrying curcumin (Cur) were studied. The results illustrated that adjusting the pre-gelation time could enhance the rheological properties, 3D printability, swallowing ability, encapsulation efficiency, and slow-release capabilities of the composite gel. Specifically, the SA-PPI composite gel (SA-PPI22) with pre-gelled for 22 min, displayed the optimal viscosity and recovery, which facilitated extrusion and shape retention during the 3D printing process. Moreover, SA-PPI22 exhibited a smooth surface quality in its 3D printed structures, along with exceptional self-supporting ability and swallowing performance meeting grade 5 fine filling food standards. Furthermore, SA-PPI22 delayed its release rate in vitro. This study could contribute to the advancement of hydrogel applications in the field of 3D printing and offer the theoretical groundwork for the development of SA-PPI composite gels in dysphagia-friendly food products.

In this study, sodium alginate (SA), locust bean gum (LBG) and mung bean starch (MBS) were used as raw materials. Dynamic rheometer, texture analyzer, differential scanning calorimeter, X-ray diffractometer and low-field nuclear magnetic resonance were used to explore the effects of SA, LBG and SA-LBG mixtures with different compounding ratios on MBS aging and their influence mechanisms. The results showed that adding SA, LBG and SA-LBG mixture can reduce the hardness, aging enthalpy value, recrystallization rate constant (k), relative crystallinity and water mobility of aged MBS gel, and increase its loss factor. Low-field NMR results found that the SA-LBG mixture increased the T2 of MBS gel. The results show that SA, LBG and SA-LBG mixture can delay the aging of MBS gel, among which the anti-aging effect of SA-LBG mixture is more significant. SA-LBG mixture at mass ratio of 1:1 exhibited a strongest synergistic effect on inhibiting MBS gel retrogradation. This may be due to that the synergistic effects between SA and LBG, as well as hydrogen binding among SA, LBG and starch, which could prevent interactions between starch molecules and inhibit starch recrystallization. These findings might provide useful information for improving MBS-based products’ shelf-life with introduction of SA-LBG.

Sodium alginate-porous starch complex gels were prepared by calcium chloride dripping method and calcium carbonate internal gelation method. Furthermore, hardness, syneresis, swelling characteristics, crystalline structure and microstructure of the complex gels were analyzed. The results showed that the gel properties were significantly affected by calcium source and sodium alginate to porous starch ratio (mass ratio defined as r value). At high r value (r =4∶2 or 5∶1), calcium carbonate caused the formation of gel curds with uniform shape and dense structures, which also showed high gel hardness and low syneresis. Meanwhile, calcium chloride caused the formation of gel beads with uniform shape and hard shell. Due to different gel structures, the initial swelling speed of gel beads was slow and the final swelling ratio was high, while the initial swelling speed of gel curds was fast and the final swelling ratio was relatively low. The gels prepared by these two methods showed high swelling ratio in simulated colonic fluid and low swelling ratio in simulated gastric fluid, indicating good pH response. Microstructure analysis showed there was good compatibility between sodium alginate and porous starch. The results of the present research could provide useful information to develop pH responded delivery system for bioactive substances.

To further improve the gel properties of wheat starch, the effects of sodium alginate (AG) to locust bean gum (LBG) ratio on the viscoelasticity and gel texture of wheat starch were investigated by dynamic rheology, steady rheology and diffusing wave spectroscopy. The results showed that storage modulus, loss modulus and consistency coefficient of wheat starch gel were increased, while loss factor was decreased with the addition of AG and LBG with different ratio. The viscosity of wheat starch-gum blends decreased with the increase of shear rate, showing pseudoplastic behavior of shear thinning. This was in line with the power law model. The results of diffusing wave spectroscopy confirmed that elastic index and viscosity index of wheat starch gel were increased, while solid-liquid index was decreased with the addition of AG and LBG. When the mass ratio of AG to LBG was 1∶1, there was a synergistic effect between AG and LBG that could cause wheat starch forming dense and elastic gels with optimal viscoelasticity.

In order to explore the oil reducing mechanism of sodium alginate (AG) and low methoxyl pectin (LMP) on the fried sweet potato starch, the oil content, distribution and thermal properties of fried sweet potato starch with 0.5% (W/W), 2% (W/W) AG or 2% (W/W) LMP were investigated by low field nuclear magnetic resonance, confocal laser scanning microscopy, X-ray diffractometer, Fourier transform infrared spectroscopic analysis and differential scanning calorimetric analysis, respectively. The results showed that the total oil content of fried sweet potato starch significantly decreased with adding AG or LMP, while most of the oil was distributed on the starch surface. The crystallization pattern of fried sweet potato starch with adding AG or LMP changed from A+V type to V type, as well as the gelatinization enthalpy and relative crystallinity significantly decreased. The fried sweet potato starch with AG showed an obviously lower total oil content, relative crystallinity and gelatinization enthalpy than that with LMP. The fried sweet potato starch with 2% AG exhibited the highest gelatinization degree to form a continuous and dense lamellar structure, while showed the lowest total oil content and surface oil content. The result of this study could provide a reference for processing the fried starchy foods with low oil content.

To enhance the physicochemical properties and extend the release duration of sodium alginate (SA) hydrogels, this study explored the impact of acidifier type and the number of cross-linking on the physicochemical characteristics and in vitro anthocyanin release from SA hydrogels, utilizing calcium carbonate as the cross-linking agent. The findings revealed that the utilization of gluconolactone (GDL) as an acidifying agent in the preparation of SA hydrogels, as opposed to hydrochloric acid, resulted in a deceleration of the hydrolysis process of calcium carbonate. This deceleration led to the strengthening of hydrogen-bonding interactions and the development of a more compact network structure within the SA hydrogels. Consequently, there was a noticeable enhancement in the hardness, relaxation time, and anthocyanin encapsulation efficiency of the gels. Additionally, the release of anthocyanins in simulated intestinal fluid was delayed. Secondary cross-linking was found to facilitate ionic interactions between SA and Ca2+, further intensifying the denseness of the network structure and enhancing the physicochemical characteristics of the SA hydrogels. Overall, SA hydrogels processed with GDL as the acidifier and subjected to secondary cross-linking exhibited improved physicochemical properties, delayed release effects, and proved to be an efficient system for the delayed release of anthocyanins. • GDL is a more suitable acidifying agent for SA hydrogel. • Secondary cross-linking enhances the ionic interaction of the hydrogel. • Secondary cross-linked hydrogels can slow down the rate of anthocyanin release • The release of anthocyanin follows both the first-order model and Higuchi's model. [ABSTRACT FROM AUTHOR]

Background and Objectives: Strengthening effects of sodium alginate (AG, anionic gum) and locust bean gum (LBG, neutral gum) on dough's network structures were investigated. Findings: Among all samples, dough containing 0.6% AG showed the longest development and stability time, which was longer than that containing 0.6% LBG by 7.8% and 15.5%, respectively. The relative elastic part of maximum creep compliance (36.26%–59.13%), zero‐shear viscosity (3.69–6.35 × 106 Pa s), elasticity index (0.17–0.44 nm−2), and macroscopic viscosity index (0.14–0.39 nm−2 s) significantly increased with adding AG and LBG. Results of extensograph and dynamic rheology suggested that adding NaCl decreased the tensile energy, storage modulus, and loss modulus of dough containing AG, which might be related to the presence of electrostatic interactions between dough and AG. The bread containing 0.6% AG had a higher specific volume (3.30 ml g−1), height/width ratio (0.74), and springiness (0.93) compared with the bread containing 0.6% LBG. Conclusions: These results showed denser gluten networks were formed in dough containing AG with electrostatic interactions than in dough containing LBG with hydrogen‐bonding interactions, indicating that electrostatic interactions had a more pronounced effect on dough's network structures than hydrogen‐bonding interactions. Significance and Novelty: This investigation could provide useful information for the potential application of AG in the development of whole wheat bread. [ABSTRACT FROM AUTHOR]

In the present work, sodium alginate-based complex (flaxseed protein-sodium alginate) electrostatic complexes (FP-AG) were fabricated, acting as an effective emulsifier for the first time to stabilize Pickering high internal phase emulsions (HIPE). Interactions between FP and AG were evaluated by isothermal titration calorimeter and quartz crystal microbalance with dissipation monitoring. These results suggested that electrostatic interactions played a dominant role in FP-AG complexation, and stronger interactions between FP and AG occurred under acidic conditions, forming more viscoelastic layers. FP-AG complexes at pH 4.0 (FP-AG4) exhibited appropriate wettability (87.9°). HIPEs were prepared using FP-AG4 (HIPE-C), contrasted with FP at pH 8.0 (HIPE-P) as a control. Rheological results suggested that HIPE-C exhibited shear-thinning behavior (extrusion), high thixotropy (recovery), and high viscoelasticity (self-supporting), which possessed a great potential for 3D printing. Moreover, 3D printing and the stability of curcumin of HIPE were explored simultaneously for the first time. These results showed that HIPE-C exhibited outstanding printability and printing models presented smooth surfaces, regular shapes, and distinct resolution. HIPE-C showed a better protection for curcumin against ultraviolet and thermal treatments than HIPE-P. FP-AG complexes could be used as an effective HIPE stabilizer and novel edible ink with good 3D printability in food industry. [Display omitted] • FP-AG complexes could act as an effective emulsifier to stabilize HIPE. • Electrostatic interactions played a dominant role in FP-AG complexation. • Addition of AG could strengthen HIPE's network structure and mechanical strength. • HIPE-C showed outstanding extrudability and printability during 3D printing. • HIPE-C significantly protected Cur from degradation against UV and heat treatments. [ABSTRACT FROM AUTHOR]

The gelatinization and retrogradation properties of wheat starch (WS) with the addition of the combination of stearic acid and sodium alginate (C-SA-AG) were investigated in this study. The results of differential scanning calorimetry (DSC) showed that C-SA-AG significantly increased the gelatinization onset temperature of WS by 2.6–3.4 °C, whereas decreased the gelatinization enthalpy of WS by 5.7–6.7 J/g. This suggested that C-SA-AG could obviously delay the gelatinization process of WS. The gel firmness, retrogradation enthalpy, the ratio of intensity at the band of 1047 cm −1 to 1022 cm −1 (R 1047/1022 ), and the relative crystallinity (RC) of WS were significantly decreased with the addition of C-SA-AG by 322–346 g, 0.51–1.78 J/g, 0.06–0.12, and 7.12–9.05% after stored for 7 days at 4 °C, respectively. However, the loss factor (tanδ t /tanδ 0 ) was increased by 0.49–0.54 after sweeping for 120 min. This suggested that C-SA-AG could effectively retard the retrogradation of WS. During storage, the retrograded WS containing SA showed V-type crystal structure, which lost the A-type crystal structure of native WS. [ABSTRACT FROM AUTHOR]

Background and objectives: The inherent properties of native starches are undesirable for the industrial applications because of the high tendency of retrogradation. Tuber starches are widely used in starchy foods. However, the gelatinization and retrogradation properties of tuber starches are not much known. This study mainly investigated the gelatinization and retrogradation properties of two tuber starches, potato starch (PS) and sweet potato starch (SPS), with or without the addition of sodium alginate (AG), using rapid visco analyzer, texture analyzer, differential scanning calorimeter, dynamic rheometer, and X‐ray diffractometer. The AG‐starch mixture gel was stored at 4°C for 1–21 days. Findings: The results showed that the addition of AG increased the gelatinization temperature of the two tuber starches, suggesting the gelatinization process was delayed by the addition of AG. The addition of AG obviously decreased the setback (SB) value, while increased the tanδ values of the two tuber starches. This suggested that addition of AG could retard the short‐term retrogradation of starch. AG also significantly reduced the gel firmness, retrogradation ratio, and relative crystallinity of the two tuber starch gels during storage, indicating that the long‐term retrogradation was retarded with the addition of AG. Meanwhile, the retrograded starch with or without the addition of AG showed B‐type crystallinity pattern. Although PS contains phosphate groups, AG exerted a similar effect on the retrogradation of PS and SPS. Conclusions: Results suggest that the addition of AG could retard the retrogradation and delay the gelatinization process of the two tuber starches. Significance and novelty: This result can provide available information about the interactions between negative polysaccharide and negative/neutral starch, which also can provide an effective method to retard the starch retrogradation. [ABSTRACT FROM AUTHOR]

The effect of sodium alginate (AG) on the retrogradation properties of normal cornstarch (NCS) and its anti-retrogradation mechanism were investigated by determining the pasting parameters, gel firmness, gelatinization parameters, retrogradation enthalpy, glass transition temperature, dynamic rheological properties, interaction force, leached amylose content, swelling power, X-ray diffraction patterns and relative crystallinity, respectively. The sodium alginate-normal cornstarch (AG-NCS) blends were treated with different ratio of NCS to AG (ranging from 10:0–9.6: 0.4) and stored at 4 °C and 25 °C for 1d or 3d, respectively. The addition of AG significantly decreased the setback value, which suggested that the short-term retrogradation of NCS was inhibited. AG obviously reduced the retrogradation enthalpy, storage modulus, and relative crystallinity of NCS, which decreased with the increase in the AG concentration. The aforementioned results suggested that addition of AG could retard the retrogradation of NCS, and the retardation effect exhibited positive correlation of AG concentration. The changes in the storage modulus after the addition of NaCl and urea suggested that the hydrogen bonding might be the main force involved in the formation and stability of the AG-NCS blends. The X-ray diffraction patterns showed that the transformation of the A-type to B-type of NCS occurred after gelatinization and retrogradation. [ABSTRACT FROM AUTHOR]

Modified starch is considered to be an important ingredient in the application of food industry. The present study investigates the physicochemical properties of normal cornstarch (NCS) treated with a single heat-moisture treatment (SHMT) or a dual heat-moisture treatment (DHMT) with an interval storage temperature of 25 °C (DHMT25), 4 °C (DHMT4) and −20 °C (DHMT-20) in the presence of sodium alginate (AG). The results showed that both SHMT and DHMT combined with AG increased the pasting temperature (PT), gelatinization conclusion temperature (T c ), gelatinization temperature range (T c –T o ), and gel hardness of NCS, but they decreased the pasting viscosities, gelatinization onset temperature (T o ), gelatinization enthalpy (ΔH), and relative crystallinity (RC) of NCS. Neither SHMT nor DHMT combined with AG addition changed the crystalline type of NCS. Sodium alginate–normal cornstarch (AG-NCS) mixtures after SHMT showed the highest PT value and gel hardness, and they showed the lowest breakdown (BD) and setback (SB) values, indicating that AG-starch mixtures with SHMT had superior mechanical and thermal stability. AG-NCS after DHMT-20 showed the highest T c and T c –T o values as well as the lowest ΔH and RC values, suggesting that the hydrothermal treatment had an effect on the structure changes of starch molecules. Above all, both SHMT and DHMT had effects on the properties of AG-NCS. [ABSTRACT FROM AUTHOR]