Retrogradation Properties Research Articles

Starch and Protein Characteristics of Chestnut Flours and Their Applications in Gluten-Free Products.

In the context of valorizing underutilized crops, this study investigated the starch and protein characteristics of chestnut varieties (Balestrera and Rossera) and their potential for use at 15% and 25% in reformulating gluten-free baked snacks and fresh pasta. Chestnut varieties differ in protein and starch content (Balestrera > Rossera), as well as in amylose, dietary fiber, and lipids (Balestrera < Rossera). Differences in starch and amylose content affected starch gelatinization (Balestrera < Rossera), pasting and retrogradation properties, and water absorption capacity at 90 °C (Balestrera > Rossera). No differences in water and oil absorption capacity and mixing properties were observed, neither in the protein profile nor in the nature of protein aggregates. Both varieties exhibited a good aptitude for producing gluten-free baked snacks and fresh pasta, even at enrichment levels of 25%. Overall, this study could provide valuable information for the development of gluten-free products using sustainable, underutilized crops.

Effect of the critical melting treatment on the short/long-term retrogradation behaviour of maize starch

The shortand long-term retrogradation properties in normal maize starch (N-S) by critical melting treatment (CMT; including TO (onset temperature) melting (OM), TP (peak temperature) melting (PM), and TC (conclusion temperature) melting (CM)) were studied. Results indicated that CMT promoted short-term (1 day) and long-term (7 days) retrogradation of N-S in the following order: PM > CM > OM. After storage for 7 days, following the PM treatment, the gel hardness, the retrogradation degree, and relative crystallinity increased to 4.67 N, 13.191%, 8.58% from 2.87 N, 9.972%, and 6.20%, respectively. PM treatment resulted in harder starch granules, promoting the rearrangement of the starch crystalline structure during cold storage. This was confirmed by the increased storage modulus, decreased iodine blue value, reduced gap in the gel network, and compact aggregate formation. Results indicated that CMT can promote the retrogradation properties of N-S.

Effect of glyceryl monopalmitate on the gelatinization, rheological and retrogradation properties of Japonica rice starch.

Starch-based food is easy to retrograde during cold storage after gelatinization, which leads to quality fission and a relatively short shelf life. Some lipids can effectively enhance the storage stability of starch gels by the formation of starch-lipid complexes. The present study aimed to investigate the effects of glyceryl monopalmitate (GMP) on gelatinization, rheological and retrogradation properties of Japonica rice starch (JS) at different conditions and to analyze the correlation between the physical-chemical properties and structural characteristics of the JS-GMP complex. The addition of GMP to JS could retard the process of starch gelatinization through forming JS-GMP complexes. The resulting JS-GMP pastes were typical pseudoplastic fluids with shear thinning, and their solid-like properties were prominent (tan δ < 1). In addition, the retrogradation of JS-GMP complex was more inhibited during storage at -18 than at 4 °C. The added amount of GMP was negatively and highly associated with the minimum viscosity, consistency coefficient, hardness and elasticity, whereas it was positively and highly correlated with the breakdown value, fluid characteristic index and relative crystallinity. The relative crystallinity of JS was affected by GMP in an approximate dose-dependent manner. The addition of GMP can influence the gelatinization properties, rheological properties and retrogradation characteristics of JS, and the formation of JS-GMP complex could improve the quality and storage stability of starch gel, which provides ideas for the quality control of starch-based food. © 2024 Society of Chemical Industry.

Rapid preparation of anti-retrogradation starch by choline chloride based deep eutectic solvents: A comparative study

Legumes are a widespread and cheap source of starch. However, legume starches are prone to retrogradation in applications. Therefore, enhancing the resistance to retrogradation is important to ensure the quality of starch products. In this study, the effects of amines, alcohols, and carboxylic acids deep eutectic solvents (DESs) on the retrogradation properties of pea starch (PS) were investigated. The results showed that the starches treated with carboxylic acid DESs for only 30 min exhibited low paste viscosity, high paste clarity and anti-retrogradation. The carboxylic acid DESs treatment resulted in holes or cracks appearing on the starch surface, a decrease in molecular ordering, relative crystallinity, and amylose content. The thermal enthalpy of starch as well as the pasting viscosity were substantially reduced after the treatment. The paste clarity and the resistance to retrogradation were significantly improved. Conversely, the structure, pasting and retrogradation properties of starch treated with amine and alcohol DESs exhibited only slight differences compared to PS. The carboxylic acid DESs took a short time for the starch modification, and the modified starch paste with low viscosity, high clarity, and resistance to retrogradation. The study could provide an environmentally-friendly and cost-effective method for the preparation of starch with well anti-retrogradation properties.

Structural and property characterization of low-molecular-weight novel reuterans synthesized from pea starch by Limosilactobacillus reuteri N1 GtfB with 4,6-α-glucanotransferase II activity

Promising novel α-glucanotransferases with starch-converting activity have recently emerged from the CAZy GH70 GtfB subfamily. In this study, we thoroughly investigated and elucidated the impact of the newly characterized 4,6-α-glucanotransferase II Limosilactobacillus reuteri N1 GtfB (LrN1 GtfB), which was capable of synthesizing linear (α1 → 6) and branched (α1 → 4,6) linkages, on the fine structure, rheology, and retrogradation properties of pea starch (PS). The results revealed that as the reaction time increased, the total (α1 → 6) linkages in linear chains and branching points of PS increased from 5.6 % to 18.7 %, the molecular weight decreased from 7.3 × 106 g/mol to 7.4 × 104 g/mol, and the percentage of short chains (DP ≤ 12) increased from 47.4 % to 92.7 %, thereby producing low-molecular-weight, short-clustered novel reuterans with new (α1 → 6) linkages in both linear chains and branches. Additionally, LrN1 GtfB-modified PS exhibited lower storage/loss modulus and weaker creep property, indicating a significant attenuation of the strength and rigidity of the modified gel structure. Moreover, products derived from pea starch and LrN1 GtfB exhibited notably low retrogradation properties. These findings provide insights into the potential application of GtfB-type α-glucanotransferases in starch-based products, thereby producing unique-structured α-glucans with versatile properties from starch.

Effect of cooling rate on the retrogradation properties and quality of refrigerated dry-steamed fried rice

The cooling rate is an important factor affecting the quality of refrigerated fried rice. The effect of the cooling rate (0.16°C/min, 0.78°C/min, 1.66°C/min) on the retrogradation properties of dry-steamed fried rice during the refrigeration period (0-3 d) was investigated. The increased cooling rate from 0.16 to 1.66°C/min led to a weakening of stability of the fried rice gel and an increase in the loss of moisture content of the fried rice from 0.86% to 7.11% after 3 d of refrigeration. The cooling rate of 0.78°C/min slowed the increase in hardness of fried rice and resulted in a lower short-range ordering (0.85) as well as the least increase in relative crystallinity (9.51%) after 3 d of refrigeration. However, a cooling rate of 1.66°C/min resulted in a crispy texture and the worst sensory quality of the fried rice after reheating. Both the 0.16°C/min and the 1.66°C/min cooling rates increased the viscosity and reduced the thermal stability of the fried rice paste system. In contrast, a cooling rate of 0.78°C/min is the most suitable cooling rate for refrigerated dry-steamed fried rice. These results will be of guiding significance for regulating the regrowth of dry-steamed fried rice by changing the cooling rate.

Regulating effect of glycated rice bran protein aggregates and resultant emulsions on the gelatinization and retrogradation properties of rice starch

The effects of the rice bran protein aggregates (RBPAs), glycated rice bran protein aggregates (gRBPAs) and resultant emulsions on the gelatinization and retrogradation characteristics of rice starch (RS) were investigated. The gelatinization and retrogradation properties of RS were determined by rapid viscosity analyzer (RVA), differential scanning calorimetry (DSC), dynamic rheology, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The addition of the protein aggregates and the emulsions reduced the swelling of starch during the gelatinization process and the enthalpy change (ΔH) of RS. Meanwhile, during the long-term storage (4 °C for 21 d), the existence of the protein aggregates and the emulsions decreased the storage modulus (G′) and hardness of RS gel, thereby decelerating the retrogradation of RS. Besides, XRD analysis proved that when heated for 2 h, the relative crystallinity of the RS-gRBPAs mixture decreased by 6.08%, and the relative crystallinity of the corresponding RS-emulsions mixture reduced by 6.85%, which indicated the grafting of Dex could impede the retrogradation of RS. The inhibitory effect of adding the emulsions was more pronounced than that of adding corresponding protein aggregates. Furthermore, SEM analysis confirmed that the gel network structures of mixture were more uniform and compact compared with RS, which resulted from the protein aggregates and the emulsions inhibiting the internal combination through hydrogen bonds between starch molecules. Overall, these findings suggested that the protein aggregates and the emulsions prevented the retrogradation of RS, and could be potently used as a natural substitutes to enhance the quality and nutrition of starch-based foods.

Modulation of retrogradation properties by removal and retention of starch granule-associated lipids: A case study on buckwheat and wheat starches

The objective of this research was to investigate the influence of starch granule-associated lipids (SGALs) on retrogradation properties of buckwheat and wheat starches. According to the results, the removal of SGALs led to remarkable increase in the retrogradation enthalpy change of all starches and the strength of starch gels, as well as the density and short-range ordered structure of starch aggregates. The strength of starch gel experienced a rise from 3139.39 g to 3718.18 g in Tartary buckwheat, 2924.12 g to 3551.13 g in common buckwheat, and 1887.55 g to 2555.24 g in wheat, respectively. The removal of SGALs contributed to a decrease in the thermal stability of starches and an augmentation of amylose leaching during gelatinization process, which would strengthen the hydrogen bond interaction between starch molecules during cooling process, and promoting the rearrangement of the order structure of starch molecules. In general, these results indicated that the retention of SGALs could limit amylose leaching, then inhibited rearrangement and recrystallization of dissolved starch molecules, and ultimately delayed the short-term and long-term retrogradation process. This work further supplemented theoretical knowledge about SGALs in buckwheat and wheat starches, also provided a new perspective for regulating the physicochemical properties of starches.

The high molecular weight and large particle size and high crystallinity of starch increase gelatinization temperature and retrogradation in glutinous rice

The gelatinization and retrogradation properties of glutinous rice starch are important factors that affect its quality. In this study, the thermal properties, viscosity properties and retrogradation of starch from 152 natural glutinous varieties were investigated, and further explored the effects of starch structure on gelatinization temperature (GT) and retrogradation. The results demonstrated a strong positive linear correlation between thermal properties and retrogradation of glutinous rice. The high molecular weight, high crystallinity and large particle size of starch have significant positive effects on the thermal properties and retrogradation of amylopectin. Varieties of glutinous rice with high molecular weight starch, large starch particle sizes, and high crystallinity exhibited high GT and retrogradation rates (R%). Additionally, there was a significantly negative correlation between the range of gelatinization temperature and gelatinization enthalpy in raw starch, while a larger temperature range in retrograded starch corresponded to greater gelatinization enthalpy. The recrystallization of retrograded starch exhibited higher crystal heterogeneity and a broader range of melting points compared to raw glutinous starch. These findings provide valuable insights for breeding glutinous rice varieties with desirable retrogradation traits, particularly those with low R%.

Effect of different chain-length fatty acids on the retrogradation properties of rice starch

In order to delay the retrogradation of rice starch, the effects of three different chain length fatty acids (lauric acid, myristic acid and palmitic acid) on rice starch were studied. The fatty acids with longer carbon chains had strong steric hindrance and hydrophobicity, which formed a more compact structure in the helical cavity of amylose, and significantly reduced degree of expansion, migration of water, short-range ordered structure, number of double helical structures and crystallinity. These structural changes endowed the rice starch-long chain fatty acid complexes with better gel viscosity, liquid fluidity and thermal stability than in the rice starch-short chain fatty acid complexes. The results showed that fatty acids with longer chain length inhibited the retrogradation of rice starch, most obviously when 5% palmitic acid was added. This study provides an important reference for the processing of rice starch-based foods.

Effects of alginate synergized with polyphenol compounds on the retrogradation properties of corn starch

This study aimed to investigate the impact of alginate (AG) on the retrogradation properties of corn starch (CS) in conjunction with three phenolic compounds, including naringin (NA), rutin (RT), and soy isoflavones (SI). The findings indicated that AG, NA, RT, and SI collectively resulted in a significant reduction in the hardness, retrogradation enthalpy, and relaxation time of CS gel. This effect was more pronounced when compared to NA, RT, and SI individually. The findings suggested that the elemental system comprising AG, phenolic compounds, and CS yielded enhanced water retention capacity and thermal stability. Moreover, a noticeable decrease in the short-range ordered structure and crystallinity was observed, indicating that AG and phenolic compounds effectively inhibited the retrogradation of CS; notably, the synergistic interaction between AG and SI resulted in the most favorable outcome. The results of this study provide new ideas for the design, development, and quality improvement of starch-based food.

Physicochemical characteristics of tea seed starches from twenty-five cultivars

The physicochemical features of starches separated from tea seeds of 25 cultivars were analyzed. The distinct characteristic of tea seed starches was that they had high apparent amylose content (AAC, 28.94–39.91 %) and resistant starch contents (4.64–8.24 %), suggesting that tea starch can be used for production of low glycemic index food. One cultivar (T12) had smallest breakdown (74.2 RVU) and highest gel hardness, indicating it performed stably during shear thinning, resulting in a firm texture. Another cultivar (T25) had a peak viscosity of 417.6 RVU, a large breakdown and small setback, suggesting a low tendency for retrogradation. There was a range of 61.6 °C to 77.5 °C for the peak gelatinization temperature and 0.163 to 0.390 for the flow behavior index values. These parameters could serve for selecting suitable starches with minor differences in physicochemical properties for food use. Correlation analysis indicated that AAC is a key factor determining starch retrogradation properties. The broad genetic diversity in the tea seed starch physicochemical features provided potentially versatile applications in the food industry. The results gained from the present study contribute to a better understanding of tea seed starch quality, and encourage its application in many value-added food products.

Starch chain-length distributions affect the processing and digestion characteristics of proso millet starch

Starch chain-length distributions play a key role in regulating the processing and digestion characteristics of proso millet starch. Waxy proso millet starch has higher endothermic enthalpy (13.06–16.73 J/g) owing to its higher relative crystallinity (27.83%–32.04%), while nonwaxy proso millet starch has lower peak viscosity (1.0630–1.1930 Pa∙s) and stronger viscoelasticity owing to its higher amylose content (21.72%–24.34%). Non-waxy proso millet starch exhibited two different digestion phases and its resistant starch content (18.37%–20.80%) was higher than waxy proso millet starch. Correlation analysis showed proso millet starch with longer amylopectin B1 chains and more amylopectin B2 chains exhibited excellent thermal ability and retrograde resistance, whereas proso millet starch with shorter and more amylose medium/long-chains not only reduced the digestion rate and increased the resistant starch content but also exhibited stronger viscoelasticity and excellent retrogradation properties. These results could provide more insights into efficient utilization of proso millet starch.

Retrograde Conduction in Left Bundle Branch Block: Insights From Left Bundle Branch Pacing.

Biventricular pacing is a well-established therapy for patients with heart failure (HF), left bundle branch block (LBBB) and left ventricular (LV) dysfunction. Left bundle branch pacing (LBBP) has emerged as an alternative to biventricular pacing. The aim of this study was to assess the retrograde conduction properties of the left bundle branch in patients with nonischemic cardiomyopathy and LBBB during LBBP and its clinical implications. Patients undergoing successful LBBP for nonischemic cardiomyopathy with LV ejection fraction (LVEF)≤35% and LBBB were included. Continuous recording of His potential was performed using a quadripolar catheter. Unidirectional block was defined as retrograde His bundle activation during LBBP with stimulus to His potential (SH) duration less than or equal to antegrade HV interval and bidirectional block as VH dissociation or SH duration greater than HV interval. HF hospitalization, ventricular arrhythmias, and mortality were documented. A total of 165 patients were included. The mean follow-up duration was 21.8 ± 13.1months. Bidirectional block (group I) was observed in 82% (n=136), and these patients were noted to have advanced HF stage and prolonged baseline QRS duration. Unidirectional block (group II) with intact retrograde conduction was observed in 18% (n=29) and was associated with narrow paced QRS duration and higher LVEF during follow-up. Super-response (LVEF≥50%) was observed in 54.4% (n=74) in group I compared with 73.3% (n=22) in group II (P=0.03). The OR for LVEF normalization was 4.1 (95%CI: 1.26-13.97; P=0.02), with unidirectional block compared with bidirectional block in patients with LBBB and LV dysfunction. Adverse clinical outcomes as measured by a composite of HF hospitalization, ventricular arrhythmias, and mortality were significantly higher in group I compared with group II (12.5% vs 0%; P=0.04). Bidirectional block in LBBB was characterized by advanced HF symptoms, while unidirectional block was associated with better clinical outcomes after cardiac resynchronization therapy by LBBP.

Insight into the multi-scale structure and retrogradation of corn starch by partial gelatinization synergizing with epicatechin/epigallocatechin gallate

Starch retrogradation is of great importance to the quality of starch-based food. This study investigated the effect of partial gelatinization (PG) synergizing with polyphenol (epicatechin, EC; epigallocatechin gallate, EGCG) on the multi-scale structure and short/long-term retrogradation of corn starch (CS). The PG synergizing with EC/EGCG substantially suppressed the short/long-term retrogradation properties of CS. These could be confirmed by the decreased storage modulus and viscosity, the relative crystallinity (1.54%, 3.56%), and the retrogradation degree (9.99%, 20.18%) of CS during storage for 1, 14 days after PG synergizing with EGCG and EC, respectively. This is because PG treatment promoted the hydrogen bond interaction between disordered starch molecules and EC/EGCG. These were proven by the larger aggregation, more and brighter fluorescents, and the reduced long/short-range order structures in CS after PG synergizing with EC/EGCG. This study is helpful for the development of foods with enhanced nutrition and low-retrogradation.

Effects of dextran molecular weight on starch retrogradation and technological properties of Chinese steamed bread: Based on the rubber/glass transition

From the perspective of rubber/glass transition, this study clarified that the impact of dextran on retarding hardening behavior and slowing starch retrogradation of Chinese Steamed Bread (CSB) depended on its molecular weight and concentration level. Guggenheim-Anderson-de Boer (GAB) model was fitted to explore critical behavior changes in rubber/glass transition of CSB. Incorporation of high molecular weight dextran enhanced the elasticity of dough and porosity of CSB, reduced the aging and hardening degree of CSB at appropriate addition levels. CSB hardness showed a growing tendency during storage, while macromolecular dextran reduced the hardness and retrogradation degree by 22.87 % and 67.53 %. Dextran with high molecular weights lowered the glass transition temperature (Tg) and improved the moisture sorption and molecular mobility of CSB under various relative humidity (RHs) conditions by providing hydrophilic sites or intermolecular space to bind water molecules. Meanwhile, it reinforced the binding between denatured gluten and gelatinized starch. Both of them devoted to starch retrogradation inhibition and stable quality maintenance of CSB. CSB is suggested to maintain stable quality at room temperature with RHs ≤33 % to prevent rubber/glass transition. This work provided theoretical guidance for fractionation application of dextran to regulate the quality and extend the shelf-life of flour products.

Purple rice starch in wheat: Effect on retrogradation dependent on addition amount

While individual starch types may not possess the ideal gelatinization and retrogradation properties for specific applications, the amalgamation of multiple starch varieties might bestow desirable physicochemical properties upon resulting starch-based products. This study explored the impact of incorporating purple rice starch (PRS), as a novel starch variant (up to 15 % PRS), on the gelatinization and retrogradation (within 14 days) of regular wheat starch (WS). Rheological and texture assessments demonstrated that the introduction of PRS diminished the viscoelasticity and hardness of fresh WS paste. Additionally, in the case of retrograded WS pastes stored at 4 °C for 1–14 days, the incorporation of 10 % or 15 % PRS effectively retarded the reduction in transparency and significantly reduced hardness, retrogradation degree, the ratio of absorbance at 1047/1017 cm−1, and relative crystallinity. Notably, 10 % PRS results in a more pronounced effect. Conversely, 5 % PRS induced an opposing impact on retrograded WS post-storage. Moreover, scanning electron microscopy revealed that as the proportion of PRS increased, the microstructure of gelatinized WS-PRS closely resembled that of pure PRS. In conclusion, the diverse effects of varying PRS proportions on WS alter the texture and characteristics of starch-based foods, underscoring the potential of starch blending for improved applications.

The role of C18 fatty acids in improving the digestion and retrogradation properties of highland barley starch

In this study, five C18 fatty acids (FA) with different numbers of double bonds and configurations including stearic acid (SA), oleic acid (OA), elaidic acid (EA), linoleic acid (LA), and α-linolenic acid (ALA), were selected to prepare highland barely starch (HBS)-FA complexes to modulate digestibility and elaborate the underlying mechanism. The results showed that HBS-SA had the highest complex index (34.18 %), relative crystallinity (17.62 %) and single helix content (25.78 %). Furthermore, the HBS-C18 FA complexes were formed by EA (C18 FA with monounsaturated bonds) that had the highest R1047/1022 (1.0509) and lowest full width at half-maximum (FWHM, 20.85), suggesting good short-range ordered structure. Moreover, all C18 FAs could form two kinds of V-type complexes with HBS, which can be confirmed by the results of CLSM and DSC measurements, and all of them showed significantly lower digestibility. HBS-EA possessed the highest resistant starch content (20.17 %), while HBS-SA had the highest slowly digestible starch content (26.61 %). In addition, the inhibition of HBS retrogradation by fatty acid addition was further proven, where HBS-SA gel firmness (37.80 g) and aging enthalpy value were the lowest, indicating the most effective. Overall, compounding with fatty acids, especially SA, could be used as a novel way to make functional foods based on HBS.

Characterization of Starch Properties in Diverse Pea Accessions: Structural, Morphological, Thermal, Pasting, and Retrogradation Analysis

AbstractThe present work evaluates starch from 29 diverse pea accessions for structural (amylose content and amylopectin chain length distribution), granule size distribution, thermal, pasting, and retrogradation properties. Amylose content and the proportion of amylopectin chains with the degree of polymerization (DP) of 6–10, 11–20, and &gt;20 vary in the range from 21.4% to 57.0%, 17.9% to 25.8%, 64.0% to 66.5%, and 9.4% to 16.7%, respectively. Starches with a higher proportion of small granules (&lt;5 µm) have a greater proportion of amylopectin chains with DP &gt; 10 and exhibit higher transition temperatures/enthalpy and vice versa. Retrogradation in starch pastes relates negatively to the proportion of amylopectin chains with DP &lt; 10. Paste viscosities relate negatively with amylopectin chains with DP &gt; 10, amylose content, and retrogradation while positively with transition temperatures/enthalpy and the potential of granules to swell.

Effect of soybean polysaccharide and soybean oil on gelatinization and retrogradation properties of corn starch

This investigation stems from the wide interest in mitigating starch retrogradation, which profoundly impacts the quality of starch-based food, garnering significant attention in the contemporary food industry. Our study delves into the intricate dynamics of soluble soybean polysaccharide (SSPS) and soybean oil (SO) when added individually or in combination to native corn starch (NCS), offering insights into the gelatinization and retrogradation phenomena. We observed that SSPS (0.5 %, w/w) hindered starch swelling, leading to an elevated gelatinization enthalpy change (∆H) value, while SO (0.5 %, w/w) increased ∆H due to its hydrophobicity. Adding SSPS and/or SO concurrently reduced the viscosity and storage modulus (G′) of starch matrix. For the starch gel (8 %, w/v) after refrigeration, SSPS magnified water-holding capacity (WHC) and decreased hardness through hydrogen bonding with starch, while SO increased hardness with limited water retention. Crucially, the combination of SSPS and SO maximized WHC, minimized hardness, and significantly inhibited starch retrogradation. The specific ratio of SSPS to SO was found to significantly influence the starch properties, with a 1:1 ratio resulting in the most desirable quality for application in starch-based foods. This study offers insights for utilizing polysaccharides and lipids in starch-based food products to extend shelf life.