Search Results (444)

Repeated heat–moisture treatment (RHMT) is an efficient approach for modifying starch. However, the role of treatment temperature, a critical parameter, remains poorly understood. Therefore, this study investigated the effects of RHMT temperatures (80, 100, 120 °C) and cycles (1, 3, 5, 7) on the multi-scale structure and in vitro digestibility of hard proso millet starch, using native starch as a control. Compared with the severe 120 °C treatment, processing at 100 °C better preserved double-helical organization (supported by moderately retained enthalpy, ΔH) and short-range order, while maintaining granule integrity. These structural retentions restricted swelling, improved pasting stability, and reinforced the macroscopic gel network. Furthermore, multivariate analysis suggested that the rigidified internal granular architecture delayed initial enzymatic hydrolysis, maximizing slowly digestible starch (SDS) formation (47.44% in 100-RHMT-5). Conversely, 120 °C caused severe granular collapse and a drastic drop in ΔH, diminishing gel elasticity and triggering a surge in rapidly digestible starch (RDS, 59%). Overall, 100 °C RHMT yields an SDS-enriched starch, which may be a promising ingredient for the development of starch-based foods with slower in vitro digestibility. Full article

Plant-based food systems increasingly rely on heat-induced gelation of protein–starch mixtures, yet no focused synthesis has linked legume protein composition to mixed gel structure and function. This review critically analyses heat-induced gelation mechanisms in legume protein–starch systems, using the legumin-to-vicilin (L:V) ratio and starch origin as integrating design parameters. Legume storage proteins range from legumin-rich faba bean and Lupinus angustifolius, which form dense, disulfide-stabilised networks with high storage moduli, to vicilin-dominated mung bean, which produces weaker gels reliant on starch reinforcement. Pulse starches, characterised by high amylose content (24–45%), C-type crystallinity, and rapid amylose retrogradation upon cooling, act as a parallel gel-forming phase whose contribution scales inversely with protein network strength. Four protein–starch interaction modes, namely segregative phase separation, water competition, granule filler effects, and molecular complexation, jointly determine microstructure and rheological behaviour. A three-axis compositional framework defined by the L:V ratio, starch amylose content, and protein-to-starch ratio maps the gel design space. Variables favouring plant-based meat analogue performance, including high elastic modulus, yield stress, and hardness, are systematically opposed by dysphagia food requirements, including low yield stress, adequate lubrication, and soft fracture. This demonstrates that both application domains traverse the same compositional space in opposite directions. Critical research gaps include chickpea and lentil performance in meat analogue systems, mechanistic modelling of protein-matrix-mediated starch digestibility, and retrogradation kinetics during food storage. Full article

The aim of this study was to evaluate the possibility of using rapeseed protein–fiber concentrate (RPFC) as a functional ingredient for wheat pasta fortification, with emphasis on dough rheology, gel-like network formation, microstructure, and cooking quality. For this purpose, five formulations of rigatoni pasta were produced by partially substituting wheat flour with 0, 5, 10, 15, and 20% RPFC. Dough rheological behavior was assessed by frequency sweep and creep–recovery tests, while mixing and pasting behavior was evaluated using the Mixolab device. Microstructure was analyzed by scanning electron microscopy (SEM), and pasta technological and chemical parameters were determined using standard methods. All dough systems exhibited viscoelastic, gel-like behavior characterized by the dominance of the storage modulus (G’) over the loss modulus (G”), confirming the formation of a structured gluten-based network. Moderate RPFC incorporation (5–15%) enhanced G′, indicating reinforcement of the continuous protein–starch gel matrix and improved structural integrity and deformation resistance. Mixolab results showed a significant increase in water absorption and dough stability with RPFC addition, reflecting improved hydration and strengthening of the gel-forming protein network. SEM observations confirmed the development of a more compact and continuous starch–protein gel system, associated with reduced stickiness and improved structural cohesion. However, higher RPFC levels (15–20%) disrupted the continuity of the gel network, leading to increased cooking losses (8.8–10.4%), higher fracturability, and reduced firmness of cooked pasta. According to the data obtained, RPFC represents a promising functional protein ingredient for gel-like food systems such as cereal-based products, particularly pasta. These findings offer feasible formulation strategies and support its use as a sustainable, high-quality plant protein ingredient in pasta production. Full article

The objective of this study was to examine the physicochemical properties of maltodextrins derived from starch isolated from red- and purple-fleshed potatoes, in comparison to those obtained from light-fleshed potatoes. The investigation focused on several parameters, including dextrose equivalent (DE), non-carbohydrate components, maltooligosaccharide profile, particle size, surface morphology, water-binding capacity, solubility, rheological properties, structural composition as determined by Fourier transform infrared spectroscopy (FT-IR), and molecular weights. Maltodextrins sourced from the starch of colored potato varieties exhibit superior functional properties, notably nearly 100% solubility and enhanced water absorption capacity. This is attributed to their fine microstructure, which promotes hydration and facilitates the diffusion of water into the interior of the particles, in contrast to maltodextrins derived from the starch of yellow potato varieties. This phenomenon is also influenced by the maltooligosaccharide profile, characterized by a high proportion of low-molecular-weight sugars, lower molecular weights, and polydispersity (Pd), as well as the low SPAN of these maltodextrins. Additionally, maltodextrins derived from the starch of yellow potato varieties (Tajfun and Lord) formed soft gels, whereas those from colored potatoes resulted in hard gels. Full article

Rice starch (RS) is widely consumed, but is usually rapidly digested, which may increase postprandial blood glucose levels. Therefore, regulating RS digestibility is important for development functional starch-based foods. In this study, sodium alginate (NaAlg) was incorporated into RS gels and subsequently crosslinked with Ca²⁺ to form a calcium alginate (CaAlg) network, and its effects on the physicochemical properties, digestion behavior, and physiological responses of RS gels were evaluated. Rheological measurement showed that the Ca²⁺-crosslinked alginate network increased the viscosity and viscoelastic moduli of RS gels. Low-field nuclear magnetic resonance analysis showed that the Ca²⁺-crosslinked alginate network reduced free water mobility. Structural characterization using Fourier-transform infrared spectroscopy, X-ray diffraction, and cold-field scanning electron microscopy shows that the Ca²⁺-crosslinked alginate network was associated with enhanced intermolecular interactions and a more continuous gel network, while all gelatinized samples exhibited predominantly amorphous structures. In vitro digestion experiments showed that the hydrolysis degree at 120 min decreased from 92.3% in RS to 85.6% in HCaAlg/RS. The rapidly digestible starch content significantly decreased from 72.4% to 68.4% (p < 0.05), while resistant starch significantly increased from 7.7% to 14.4% (p < 0.05). First-order kinetic fitting showed that C_∞ significantly decreased from 93.0% to 86.0%, and k significantly decreased from 0.027 to 0.013 min⁻¹ (p < 0.05). In vivo experiments showed that the Ca²⁺-crosslinked alginate/RS gels were associated with a lower postprandial glycemic response, with the incremental area under the curve significantly decreased from 747.2 to 591.7 mmol·min/L (p < 0.05), and the intestinal propulsion rate decreased from 89.6% to 75.3% (p < 0.05). These results suggest that Ca²⁺-crosslinked alginate network formation may modulate the structural properties, digestion behavior, and digestion-related physiological responses of RS gels, providing a basis for the development of starch-based functional foods with improved glycemic control. Full article

The objective of this study was to evaluate the effect of prolonged mild thermal treatment (65 °C, 7 days) in the presence of flaxseed oil (0.16%, w/w), on the structural, pasting, texture, and emulsifying properties of cassava starch (CS). The resulting sample was designated as CS-oil-h. Confocal laser scanning micrographs showed oil on the interface of starch granules promoted granule agglomeration. DSC and FTIR analyses showed no detectable evidence of amylose–lipid complexes or new covalent bonds. Compared to CS, CS-oil-h exhibited slight variations in pasting temperature and peak time, and significantly lower peak, trough, breakdown, final, and setback viscosities. CS-oil-h gel showed higher hardness, adhesiveness, gumminess, and chewiness when compared to the CS gel. Crucially, CS-oil-h exhibited the best emulsifying ability (60.8%, volume of emulsion layer relative to total tube volume after 30 min standing) and emulsion stability (94.1%, after 7 days of storage). The result suggested that the prolonged mild thermal treatment may have promoted putative surface association between flaxseed oil and the surface of starch granules, which resulted in inhibition of pasting viscosity and improved gel properties and emulsifying ability. Full article

This study added two types of resistant dextrin (RD), i.e., Bailong (BL) and Luo Gaite (LGT)) to a Japonica (cv. RXY) and an early indica (cv. IP44) rice during cooking and analysed the functional and structural properties of the cooked rice. Compared with no RD addition, 3–10% RD addition induced a declinein cooking time and an incrementin gruel solid loss. Further, 3–10% RD addition increased the hardness, chewiness, and springiness of cooked rice but decreased the cohesiveness. With increases in the added RD amount, the smell, structural appearance, palatability, taste, cool rice texture, and total score of the cooked rice all increased; the peak time and pasting temperature increased, but the peak, final, breakdown, and setback viscosities all significantly decreased. The enthalpy, conclusion temperature of gelatinisation, and gelatinisation peak width and height all decreased with increasing RD amount, but the peak temperature of gelatinisation increased. The addition of 3–7% RD did not change amylopectin ageing, but 10% RD significantly increased amylopectin ageing. RD addition reduced the protein weakness degree and starch breakdown torque of rice doughbut appeared to increase the amorphous and crystalline regions of cooked rice. The addition of 10% BL or LGT induced the formation of α-helix and random coil secondary protein structures in cooked rice, with optimal cooking properties and total sensory score. Microstructure analysis further showed that low-viscous RD induced the formation of new gel-like structures. In conclusion, 3–10% RD addition in cooking rice decreases amylose recrystallisation, weakens the protein structure, and induces new gel-like structures, enhancing the hardness, chewiness, adhesiveness, springiness, and sensory score of cooked rice. This study is useful for developing functionalcooked rice. Full article

The increasing demand for sustainable materials in additive manufacturing has driven the development of bioplastics derived from renewable biomass, including microalgae. In this study, the rheological behavior of a 20 wt.% aqueous gel prepared from native Chlorella vulgaris (C. vulgaris) starch, plasticized with 30 wt.% glycerol, was investigated to assess its suitability for extrusion-based 3D printing (direct-ink-writing, DIW). Steady shear analysis revealed a pronounced yield stress (${\tau }_0$ = 271.93 Pa) and strong shear-thinning behavior, described by the Herschel–Bulkley model (K = 59.47 Pa·sⁿ, n = 0.67), indicating structural stability at rest and efficient flow under shear. Oscillatory measurements confirmed a predominantly elastic response, with storage modulus (G′ $\approx$ 13,500 Pa) greatly exceeding loss modulus (G″) and a low loss factor (tan $\delta \approx$ 0.1), demonstrating gel integrity and shape retention. Temperature-dependent analysis indicated enhanced network strength without thermal softening, while thixotropic recovery tests showed rapid structural rebuilding after shear removal. Notably, a $~$50% increase in G′ during recovery highlights improved interlayer adhesion potential. These results show that C. vulgaris starch exhibits the key rheological characteristics required for DIW-type extrusion printing, including yield stress, shear-thinning behavior, viscoelastic stability, and rapid recovery, making it a promising candidate for this application. Full article

This study examined the effect of heat–moisture treatment (HMT) at 100, 110, or 120 °C for 10 min on the multi-scale structure, functional properties, and in vitro digestibility of the starch isolated from low-GI rice. The HMT decreased the leaching rate and swelling power of the starch, compared to those of the untreated starch. The relative crystallinity decreased, and the short-range molecular order increased as the treatment temperature increased from 24.3% to 15.8%. The weight-average molecular weight decreased from 1.7 × 10⁷ g/mol to 0.9 × 10⁷ g/mol with a broad molecular weight distribution and increased particle size. The proportion of the short amylopectin chains (DP 6–12) increased while that of the long chains (DP > 36) decreased. Mild HMT (100 °C) increased gel strength, while higher-intensity HMT (110–120 °C) reduced G′ as measured by rheology. The content of rapidly digestible starch in rice starch was reduced from 68.7% to 57.4%, slowly digestible starch was increased from 24.5% to 26.8%, resistant starch was enhanced from 6.9% to 15.8%, and the digestion lag time was prolonged to 28.62 min. The in vitro digestion assays indicated that the estimated glycemic index of starch treated at 120 °C was 48.80. This sample exhibited the highest suppression of digestibility. It also showed the highest increase in resistant starch content. The results provide a theoretical ground for low-GI product development from HMT modified rice starch. Full article

In this study, citric acid-esterified ginger starches with different esterification degrees (EGSC10, EGSC20, and EGSC30) were prepared via a dry-heat method by adjusting the dosage of citric acid (10%, 20%, 30%, w/w). Their multi-scale structures were systematically characterized, and Pickering high internal phase emulsions (Pickering HIPEs) synergistically stabilized by EGSC30 and β-cyclodextrin (β-CD) were constructed. The results showed that esterification modification reduced the relative crystallinity and short-range order of starch but significantly increased the content of resistant starch (RS) and thermal processing stability, indicating that the ordered regions of starch molecules were reconstructed to form a structural system with better anti-digestion properties. With the increase in the degree of esterification substitution, the surface of starch granules gradually became rough, the particle size increased, the solubility and swelling power decreased, and the contact angle increased. EGSC30 could synergistically stabilize Pickering HIPEs with β-CD. As the total concentration of composite particles increased and the β-CD/EGSC30 mass ratio was optimized to 3:1, the droplet size of Pickering emulsions decreased, the gel strength and storage modulus increased significantly, and the system exhibited typical elastic-dominant gel properties and shear-thinning behavior, with the most compact and stable network structure. The obtained results can promote the deep processing of ginger and provide a reference for the construction of novel food-grade Pickering emulsions. Full article

This study investigated the effects of curdlan (CUR) on the structural stability and thermal processing properties of Pleurotus eryngii mycelium–soy protein isolate–cassava starch gels used as bio-ink scaffolds for 4D-printed meat analogs. Bio-inks containing different CUR concentrations (0–5%, w/w) were prepared, and their rheological properties, 3D printability, microstructure, and water distribution were systematically evaluated. The fermented meat analogs were then subjected to steaming and baking to assess cooking loss, dimensional shrinkage, and textural properties. The results showed that CUR significantly increased the yield stress and structural recovery of the bio-inks while maintaining high height retention (>87%), thereby providing a favorable scaffold for mycelial growth and subsequent product formation. During thermal processing, CUR effectively mitigated structural collapse, which may be attributed to its heat-induced thermally irreversible gelation and the formation of an internal supporting network that resisted matrix contraction and dehydration. In particular, the addition of 5% CUR reduced cooking loss from 12.83% to 7.35% during steaming and from 42.52% to 38.59% during baking, while reducing shrinkage to 9.29% and 18.00%, respectively. In addition, hardness, springiness, and chewiness were significantly improved after cooking. Overall, CUR functioned not only as a rheological modifier for extrusion printing but also as a heat-activated internal supporting network during cooking, owing to its thermally irreversible gelation. Full article

Nitrogen fertilizer application rate and storage duration are critical agronomic and environmental factors affecting rice quality stability. The milling appearance, eating and nutritional quality, physicochemical properties, microstructure, and volatile metabolic profiles during long-term storage were investigated using three indica-japonica hybrid cultivars at four nitrogen fertilizer application levels. High nitrogen fertilizer application (300 kg hm⁻²) promoted an over-filled protein matrix and induced structural defects such as micropores in starch granules, which acted as “trigger points” for accelerated aging. Specifically, storage duration was the dominant factor reshaping volatile profiles and lipid degradation, but high nitrogen amplified these effects by promoting lipid oxidation and the accumulation of off-flavor compounds. Correlation analysis revealed that gel consistency (GC) is a core determinant of eating quality, exhibiting significant negative correlations with amylose content, setback, hardness and fatty acid values, while showing positive correlations with peak viscosity, breakdown value, and adhesiveness. All correlation patterns collectively contributed to the deterioration of rice eating quality after storage, indicating GC might be served as an indirect indicator for evaluating rice deterioration and applied in the breeding of rice varieties with improved storage tolerance. Microstructural analysis via SEM high nitrogen induced distinct cultivar-specific deterioration characteristics after 12 months storage. Full article

In this study, we systematically investigated the concentration-dependent effects of peptides derived from sour jujube kernel peptide (SJKP) on the multiscale structure, physicochemical properties, in vitro digestibility, and antioxidant activity of a complex formed between pea starch (PS) and SJKP. At an optimal SJKP content of 7.5% (w/w, based on starch dry basis), the slowly digestible starch (SDS) and resistant starch (RS) increased by 23.00% and 49.80%, respectively. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT–IR) verified the formation of complexes and enhanced the short-range structural order of starch. Thermal analysis showed that the gelatinization enthalpy increased to 11.73 J/g, accompanied by an elevated gelatinization temperature and improved thermal stability. Conversely, at 15% SJKP content, RDS rebounded to 58.3% due to phase separation and structural collapse of the starch matrix. Intermolecular force analysis revealed that hydrogen bonding dominated at SJKP concentrations ≤ 7.5%, while hydrophobic interactions prevailed at concentrations ≥ 10%. SJKP incorporation also endowed the complexes with antioxidant capacity. These findings illustrate that SJKP interacts with pea starch via non-covalent bonds, forming a mixed gel network. Moderate SJKP levels can effectively modulate starch digestibility and functionality via regulating intermolecular interactions and multi-scale structure, offering promising potential for developing low-glycemic index (LGI) functional foods, including baked snacks, nutritional beverages, and diabetic-specific staple foods. Full article

Native Andean potatoes (Solanum tuberosum subsp. andigenum) are a valuable phytogenetic resource due to their compositional diversity and adaptation to high-altitude environments. Their starch is a key functional polysaccharide widely used in food systems; however, information on the kinematic viscosity of dilute gels under moderate thermal conditions remains limited. This study evaluated the effects of temperature (26, 36, and 46 °C) and starch concentration (1–3% w/v) on the kinematic viscosity of gels from three Andean potato varieties: Imilla Negra, Compis, and Peruanita. Starch was extracted from fresh tubers (Puno, Peru) using a wet extraction method, and gels were prepared by heating dispersions at 85 °C for 5 min under controlled conditions. Viscosity (0.61–34.47 cSt) decreased with increasing temperature and increased with concentration, confirming the sensitivity of these systems to thermal and compositional factors. The Arrhenius model adequately described temperature dependence, with activation energies of 15.19–29.75 kJ·mol⁻¹, showing an increasing trend with concentration. At 3% and 26 °C, viscosity followed Compis > Imilla Negra > Peruanita, indicating varietal differences in thickening capacity. These results provide useful rheological data for the design and optimisation of food processes involving dilute Andean potato starch dispersions. Full article

Oat starch, β-glucan, and protein are the primary components in oats with high nutritional value, and the interactions among these three constituents markedly influence the starch properties. High hydrostatic pressure (HHP), recognized as a non-thermal processing technique, is primarily employed for the modification of starch and protein in food processing applications. This study aimed to elucidate the interactions among oat β-glucan, protein, and oat starch under 300 MPa HHP treatment and their effects on starch properties. The results showed that at ambient pressure, β-glucan and protein mainly restricted starch swelling and gelatinization through water competition, leading to reductions in pasting viscosity, gelatinization enthalpy, and relative crystallinity. In contrast, HHP treatment significantly enhanced the intermolecular interactions among the three components, thereby improving the freeze–thaw stability, gel elasticity, short-range ordered structure, and thermal stability of the composite system. The study demonstrates that HHP modifies the physicochemical properties of starch by intensifying interactions among its components, providing a theoretical basis and strategy for the development of novel functional starch-based foods using HHP technology. Full article