Search

The traditional starch-based intelligent freshness labels struggle to maintain long-term structural stability when exposed to moisture. To solve this problem, we prepared composite crosslinked labels using phytic acid for double crosslinking of corn starch and soybean isolate proteins, with anthocyanin serving as the chromogenic dye. The mechanical properties, hydrophobic characteristics, and pH responsivity of these crosslinked labels were assessed in this study. The prepared double-crosslinked labels showed reduced moisture content (15.96%), diminished swelling (147.21%), decreased solubility (28.55%), and minimized water permeability, which suggested that they have enhanced hydrophobicity and densification. The crosslinked labels demonstrated the ability to maintain morphological stability when immersed in water for 12 h. Additionally, the mechanical properties of the crosslinked labels were enhanced without compromising their pH-sensing capabilities, demonstrated a color response visible to the naked eye for milk and coconut water freshness monitoring, suggesting great potential for application in beverages freshness monitoring., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Starch is a natural, abundant, renewable and biodegradable plant-based polymer that exhibits a variety of functional properties, including the ability to thicken or gel solutions, form films and coatings, and act as encapsulation and delivery vehicles. In this review, we first describe the structure of starch molecules and discuss the mechanisms of their interactions with guest molecules. Then, the effects of starch-guest complexes on gelatinization, retrogradation, rheology and digestion of starch are discussed. Finally, the potential applications of starch-guest complexes in the food industry are highlighted. Starch-guest complexes are formed due to physical forces, especially hydrophobic interactions between non-polar guest molecules and the hydrophobic interiors of amylose helices, as well as hydrogen bonds between some guest molecules and starch. Gelatinization, retrogradation, rheology and digestion of starch-based materials are influenced by complex formation, which has important implications for the utilization of starch as a functional and nutritional ingredient in food products. Controlling these interactions can be used to create novel starch-based food materials with specific functions, such as texture modifiers, delivery systems, edible coatings and films, fat substitutes and blood glucose modulators.

The formation of amylose-lipid complexes, known as resistant starch type Ⅴ (RS 5 ), is limited by the low content of amylose in natural starch, increasing the amylose content is an effective approach to improve the yield of RS 5 . In this paper, an extrusion-debranching-complexing strategy with two extrusions was proposed to increase the formation of amylose-lipid complexes. A combination of corn starch (CS), pullulanase (60 U/g, w/w), and lauric acid (LA) with different contents of 4 %, 6 % and 8 % (w/w) generated enzymatically debranched extruded corn starch-lauric acid (EECS-LA) complexes after the second extrusion. The EECS-LA complexes were ordered form II complexes, with a significantly improved short-range molecular order. The melting temperature was in the range of 105-145℃. The enthalpy change increased with the increase of LA content and the value was 9.42 J/g for EECS-8 %LA complexes; these complexes could reform after dissociation. Scanning electron microscopy examination of the EECS-LA complexes revealed an irregular lamellar structure. The RS content of EECS-LA complexes increased significantly, achieving a value of 38.34 % for EECS-8 %LA complexes. This extrusion-debranching-complexing strategy is effective for preparing RS 5 and could be useful in industry for the continuous production of RS 5 ., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

High substrate viscosity during the production process suppressed the formation of gamma-cyclodextrin (γ-CD) from starch. Although liquefaction can be carried out by enzymes with high temperature optimum, some CGTases of interest are not suitable due to loss of activity at the gelatinization temperature. In order to apply a gamma-cyclodextrin glucosyltransferase (γ-CGTase) with an optimum temperature of 50 °C to the liquefaction of 10% w/v cassava starch, an improved process combining moderate heat treatment (30 °C increased to 70 °C) with enzymatic treatment was established. The substrate viscosity dropped from 2456 to 23 cP after the pretreatment, and the rate of γ-CD production increased from 10.43 to 26.34%. This process was further applied to the liquefaction of 30% w/v cassava starch, and the pretreated substrate was finally converted into 21.81% γ-CD. In general, evaluation indicators and basic principles of starch pretreatment were established, providing a reference for the production of γ-CD., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Modified potato starch with slower digestion may aid the development of new starch derivatives with improved nutritional values, and strategies to increase nutritional fractions such as resistant starch (RS) are desired. In this study, a correspondence between starch structure and enzymatic resistance was provided based on the efficient branching enzyme AqGBE, and modified starches with different amylose content (Control, 100%; PS1, 90%; PS2, 72%; PS3, 32%; PS4, 18%) were prepared. Through SEM observation, NMR and X-ray diffraction analyses, we identified that an increased proportion of α-1,6-linked branches in potato starch changes its state of granule into large pieces with crystallinity. Molecular weight and chain-length distribution analysis showed a decrease of molecular weight (from 1.1 × 10 6 to 1.1 × 10 5  g/mol) without an obvious change of chain-length distribution in PS1, while PS2-4 exhibited an increased proportion of DP 6-12 with a stable molecular weight distribution, indicating a distinct model of structural modification by AqGBE. The enhancement of peak viscosity was related to increased hydrophobic interactions and pieces state of PS1, while the contents of SDS and RS in PS1 increased by 37.7 and 49.4%, respectively. Our result provides an alternative way to increase the RS content of potato starch by branching modification., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The inhibitory effect of β-CD on pullulanase which hydrolyzes α-1,6 glycosidic bond in starch to release more available linear substrates, limited substrate utilization thus influencing the yield of β-CD. Here, an aspartic acid residue (D465) which interacted with cyclodextrin ligand by hydrogen bond, was mutated to explore its contribution to bind inhibitors and obtain mutants with lower affinity to β-CD. Enzyme activity results showed that mutants D465E and D465N retained higher activity than wild-type pullulanase in presence of 10 mM β-CD. Circular dichroism spectra and fluorescence spectra results showed that D465 was related to structure stability. Chain length distribution results confirmed the improvement of substrate utilization by the addition of D465E. The conversion rate from potato starch, cassava starch, and corn starch into β-CD, increased to 56.9%, 55.4% and 54.7%, respectively, when synchronous using β-CGTase and D465E in the production process., Competing Interests: Declaration of competing interest No conflicts of interest are declared for any of the authors., (Copyright © 2020. Published by Elsevier B.V.)

Since β-cyclodextrin (β-CD) was the competitive inhibitor of pullulanase, substrate utilization and product inhibition were a conflict in β-CD production when using pullulanase for debranching to release more convertible substrate. Here, a phenylalanine complexed with cyclodextrin ligand via classic hydrophobic interaction and hydrogen bond in the crystal structure of pullulanase and absolutely conserved in all homologous, was selected to study its contribution in inhibition and to get mutants with lower affinity to β-CD. Mutants were generated by substituting phenylalanine with tyrosine, valine, histidine, cysteine, aspartic acid or alanine. Enzyme activity assay and ITC data proved that F476 mutants successfully reduced the protein affinity to β-CD. Although circular dichroism spectra and fluorescence spectroscopy results showed F476 mutation affected the secondary structure and microenvironment of pullulanase, mutants F476C and F476H retained relatively higher enzyme activity and significantly decreased affinity to β-CD. The conversion rate of starch into β-CD increased by 6.0% and 6.6%, when adding F476C or F476H in the production process., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interests with the contents of this article., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Enzymatic modification is generally applied to enhance desirable attributes of starch. In this study, β-cyclodextrin glycosyltransferase (β-CGTase) together with a specific cyclodextrinase (CDase) was used to modify corn starch. For single β-CGTase treatment, the molecular weight (M w ) was reduced to 36.7 × 10 5 g/mol and 7.7 × 10 5 g/mol for 1 h and 6 h reaction, and the debranched samples had a high proportion of chains with degree of polymerization (DP) < 13, indicating an apparent depolymerization effect. CDase could hardly act on starch, while it had a high preference for cyclodextrin hydrolysis and produced mainly maltotetraose with β-CGTase. There was a synergistic effect between β-CGTase and CDase in starch degradation. Interestingly, the utilization of dual-enzyme significantly promoted the retrogradation inhibition property of starch, reducing the retrogradation enthalpy from 5.65 J/g to 1.42 J/g. It was proved that β-CGTase and CDase had a great prospect in the future application., Competing Interests: Declaration of Competing Interest No conflicts of interest are declared for any of the authors., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Gelation of starch is a process during short-term retrogradation. However, long-term retrogradation always leads to the quality deterioration of starch-based food. In this work, a new type of modified tapioca starch (MTS) gel with maintained short-term gelation strength and retarded long-term retrogradation was prepared using a novel recombinantly produced and characterized 4-α-glucanotransferase (TuαGT). In the resulting MTS, the exterior chains of the amylopectin part were elongated and the content of amylose was reduced because of the disproportionation activity of TuαGT. The retrogradation analysis demonstrated that the MTS possessed highly weakened long-term retrogradation characteristics as compared to the native starch. Most importantly, the strength of the gel formed by regelatinized MTS is very close to that of gelatinized native tapioca starch when storing below 30 °C. These findings provide a starting point for developing a novel method for the enzymatic modification of the starch-based gels.

Extrusion is a crucial food processing technique that involves mixing, heating, shearing, molding, and other operations to modify the structures and properties of food components. As the primary energy source material, the extrusion process induces significant physical and chemical changes in starch that impact the quality of final products. This review paper discusses novel technologies for starch extrusion and their influence on the physical and chemical properties of starch-based foods, such as gelatinization and retrogradation properties, structural characteristics, and digestion properties. Additionally, it examines the application of extrusion in starch processing and the interactions between starch and other food components during extrusion. This information sheds light on the structural and property alterations that occur during the extrusion process to create high-quality starch-based foods. [ABSTRACT FROM AUTHOR]

Summary: Although different types of starch have been modified with maltogenic α‐amylase (MGA), its behaviour on waxy rice starch (WRS) remains obscure. This study aimed to modify cooked WRS with high concentration using MGA. The molecular weight of WRS decreased from 1.8 × 107 to 4.1 × 106 Da due to the exo–endo activity of MGA, while a high proportion of short branch chain and branching degree were generated as the degrees of hydrolysis (DH) increased. Intriguingly, no retrogradation occurred for the hydrolysates, even at DH 4.65%. Rheology reveal that the hydrolysate systems exhibited better fluidity and thixotropy. Furthermore, the resistant starch content of cooked WRS was elevated by 10.43% after MGA modification. The results indicate that MGA‐modified WRS was superior to other starches that have been reported in terms of inhibition of retrogradation and resistant starch content. Our data demonstrate the potential of enzyme‐based protocol for WRS modification using MGA alone to acquire clean and functional starch. [ABSTRACT FROM AUTHOR]

Fats, as one of the three major nutrients, not only provide energy for the human body but also have a significant impact on the texture and sensory properties of foods. However, excessive fat intake is closely related to the risk of obesity and cardiovascular disease. As people's pursuit of health and wellness gradually increases, people are beginning to favor reduced-fat products. Therefore, it is particularly important to develop fat replacers for use in the production of reduced-fat foods. Starch-based materials exhibit ideal performance in terms of replacing fats. In this review, we introduce the research on the use of starches; modified starches; and starch derivatives, including dextrin, maltodextrin, and cyclodextrin, as fat replacers. In addition, we also reviewed the application of new types of starch-based structured design, such as emulsion gels, oleogels, and bigels, in the replacement of plastic fats. Starch-based fat replacers can simulate the rheological properties and texture of fats and effectively replace partial fats without reducing foods' sensory properties. Moreover, structured starch gels can transform liquid oil into solid plastic fats, which are healthier and safer than industrial hydrogenated oils. Therefore, starch-based fat replacers have enormous development potential for use in the production of reduced-fat foods. • The appropriate size of starch granules provides a taste similar to fat globules. • The application of starch and structured gels as fat replacers was discussed. • Starch-based structured gels have broad development prospects to replace solid fat. • This review will provide reference for the development of starch-based fat replacers. [ABSTRACT FROM AUTHOR]

Cyclodextrinase (CDase) and cyclodextrin glucosyltransferase (CGTase) were synergistically used to provide a novel enzymatic method in lowing in vitro digestibility of waxy maize starch. The molecular structure, malto-oligosaccharide composition, and digestibility properties of the generated products were investigated. The molecular weight was reduced to 0.3 × 105 g/mol and 0.2 × 105 g/mol by simultaneous and sequential treatment with CDase and CGTase, while the highest proportion of chains with degree of polymerization (DP) < 13 was obtained by simultaneous treatment. The resistant starch contents were increased to 27.5% and 36.9% by simultaneous and sequential treatments respectively. Dual-enzyme treatment significantly promoted the content of malto-oligosaccharides (MOSs) by hydrolyzing cyclodextrins from CGTase with CDase. However, the replacement of cyclodextrins by MOSs did not obviously influence the digestibility of the products. The starch digestion kinetics further revealed the hydrolysis pattern of these two enzymes on the starch hydrolysate. It was proved that the starch digestibility could be lowered by modulating the molecular structure and beneficial MOSs content by this dual-enzyme treatment. • A novel method was developed to lower starch digestibility by CDase and CGTase. • The different ways of dual-enzyme treatment had different effect on starch features. • The starch digestibility was modulated by the yielded MOSs and molecular structure. [ABSTRACT FROM AUTHOR]

Cyclodextrins (CDs) are yielded by cyclodextrin glycosyltransferase (CGTase) using starches or their derivatives as substrates. However, how starch fine structure affects it production is still ambiguous. This study aimed to decipher the relevance between the external chain length (ECL) and CD production. The waxy maize starch was hydrolyzed by β-amylase to prepare starchy substrates with regular gradient ECL for CGTase. The HPAEC results reflected that β-amylolysis lower the starch chain fractions with DP range of 13–24 by 30%, while the fractions with DP < 6 promoted by 30%. The molecular weight distribution and iodine binding results reflected that this process had limited impact on overall starch molecular size parameters. After CGTase conversion, it is interesting to find that the ECL was positively correlated with CD contents, which also has a high consistency among α-CD, β-CD, and γ-CD. This research would provide a favorable perspective for CD production improvement. [Display omitted] • The shortening of ECL affects average chain length with DP of 13–24 and DP < 6. • The shortening of ECL has limited impact on the whole starch molecular size. • The positive correlation was established between ECL and the CD contents. [ABSTRACT FROM AUTHOR]

By heterologous expression of a gene from Palaeococcus ferrophilus , a novel recombinant enzyme designated AMPf was obtained and proved to be an amylolytic enzyme with unique catalytic characteristics. The optimal temperature and pH of AMPf were 50 °C and 7.0 respectively. Although sequence analysis and acarbose hydrolysis ability indicated that AMPf belongs to the subfamily GH13_20, interestingly, this enzyme hardly acts on cyclodextrins and pullulan distinguishing it from most enzymes in this subfamily. AMPf hydrolyzes starches to glucose, maltose, maltotriose, and maltotetrose as main products. AMPf mainly liberates glucose from starch with the concentration of 1% (w/v), while it shows malto-oligosaccharide forming ability with higher starch concentration of 4% (w/v). Also, the 4,6-ethylidene-4-nitrophenyl-maltoheptaose hydrolysis ability further indicates the unique combination endo-acting and glucose releasing exo-acting activtity of AMPf. AMPf could utilize maltose and maltotriose to produce malto-oligosaccharides by transglycosylation activity. It was proven AMPf has application protential in malto-oligosaccharides production. [Display omitted] • A novel amylolytic enzyme from Palaeococcus ferrophilus (AMPf) was discovered. • AMPf was fully characterized and proved to be from subfamily GH13_20. • AMPf was amylolytic enzyme with endo- and glucose releasing exo-acting activtity. • AMPf mainly produced malto-oligosacchardes at high starch concentration. • AMPf could use maltose and maltotriose to produce malto-oligosaccharides. [ABSTRACT FROM AUTHOR]

In this study, we successfully prepared Octenyl succinic anhydride debranched starch particles (OSADBSP) and whey protein–coated OSADBSP (WP-OSADBSP) for loading curcumin (Cur) through ethanol precipitation and electrostatic interaction. Compared with the low encapsulation efficiency (EE) (29.50%) obtained by OSADBSP synchronous encapsulation, the encapsulation rate of Cur-loading WP-OSADBSP (WP-Cur-OSADBSP) increased to more than 78%, and when the ethanol settlement ratio was 1:2.5 (10 mL of short amylose solution was dropped into 25 mL of Cur-ethanol solution), the EE was higher (92.04%). The addition of whey protein could increase the DPPH (2, 2-Diphenyl-1-picrylhydrazyl) free radical scavenging rate of OSADBSP-Cur from 24.02% to 62.42%. All of the WP-Cur-OSADBSP (1:1, 1:1.5, 1:2, 1:2.5, 1:3) exhibited sustained release of curcumin, the percentage of the Cur release in the gastric ranges was from 4.34% to 5.65%, and the percentage of the Cur release in the intestine ranges was from 24.91% to 32.07%. The results exhibited that WP-Cur-OSADBSP could be an effective delivery method for curcumin to improve its stability, antioxidant and bioavailability. [Display omitted] • WP-OSADBSP complex had good encapsulation efficiency for Cur. • The addition of WP greatly enhanced the antioxidant activity of OSADBSP-Cur. • The WP-Cur-OSADBSP complex showed good UV stability and pH stability. • The WP-Cur-OSADBSP complex can realize targeted release of Cur in intestinal fluid. [ABSTRACT FROM AUTHOR]

Starch and its derivatives play important roles in food industry. However, the application range of natural starch is limited due to its poor solubility and stability. Enzymatic treatment is one of the most commonly used methods to enhance the functions of starch and broaden its application spheres, which is characterized by strong specificity, high efficiency, and mild conditions. The applications of 4-α-glucanotransferase (4αGT) in the preparation of modified starch and its derivatives were reviewed in this paper, with emphasis on the mechanism of actions of 4αGT, changes of starch structure and properties after 4αGT treatment and the methods to improve the modification effect. Additionally, potential applications of 4αGT-modified starches and its derivatives in the food industry were also discussed and areas that need further researches were pointed out. 4αGT can catalyze disproportionation, coupling, hydrolysis, cyclization reactions. These reactions can be optimized by enhancing the expression level of 4αGT, combining 4αGT with other enzymes or physical and chemical methods, selecting suitable substrates; and optimizing reaction conditions. 4αGT treatments enhanced the properties and functions of starch mainly by changing amylose content, branch chain length distribution and molecular weight distribution. 4αGT modified starch and its derivatives have the potential to be used for encapsulating bioactive agents, creating reduced-calorie foods, sweetener, and prebiotics. Nevertheless, further studies are still needed to develop high-performance and safe 4αGT-modified starches and its derivatives. [Display omitted] • 4αGT catalyze disproportionation, cyclization, coupling, hydrolysis reactions. • The changes mainly focused on side chains, amylose content and molecular weigh. • The digestibility, freeze-thaw stability and gel property were mainly affected. • Further researches are needed to obtain desirable products. • Safety needs to be further explored in order to be widely used in food. [ABSTRACT FROM AUTHOR]

The quality characteristics of rice-based products depend on the properties of their starch component. Maltogenic α-amylase (MA) is extensively used as an anti-staling agent in bakery foods. To expand its application in rice-based products, in the current study, normal rice starch (NRS) was subjected to MA. The enzyme susceptibility of NRS and the impact of starch fine structure changes on its rheological properties was investigated. The results reveal that NRS was less susceptible to MA, and exhibited two hydrolysis phases. As the degree of hydrolysis (DH) increased, the molecular weight of NRS decreased from 3.3 × 107 to 3.4 × 104 g/mol, while the short-chain levels (DP < 13) rose from 44.4% to 88.4%. Furthermore, compared with the control, MA treatment lowered the storage and loss moduli, and the creep properties of NRS, indicating a large attenuation in the rigidity of gel structure. The hydrolyzate pastes exhibited weaker shear thinning behavior and less hysteresis loop areas. Possible models were proposed to illustrate the crucial role of rice starch fine structures in the formation of the gel network after MA hydrolysis. These findings provide insights for exploring novel applications of the MA in rice-based products. [Display omitted] • Enzymatic hydrolysis curves of NRS were fitted to a logarithm of slope plot. • MA amylolysis reduced the Mw of NRS and shortened its outer chains. • The rigidity and creep of NRS decreased but its fluidity and thixotropy enhanced. • The proposed models illustrates the changes in the gel strength during hydrolysis. [ABSTRACT FROM AUTHOR]

The creation of solid fat substitutes using food-grade biopolymers is currently an important focus of food researchers trying to develop healthier food products. In this study, emulsion-templated oleogels assembled from octenyl succinic anhydride starch (OS)-chitosan (CS) electrostatic complexes were prepared. The effects of the OS-CS complexes on the intermediate (emulsion) and final (oleogel) products were investigated. Emulsions stabilized by OS-CS complexes had greater interfacial layer stability and mechanical strength than those stabilized by only OS. The oil loss from the oleogels decreased significantly (p < 0.05) as the chitosan concentration was raised: from 10.28 to 1.5% oil loss for 0.1–1% CS. The rheological measurements showed that CS incorporation improved the viscoelasticity and thixotropy of the oleogels. In addition, adsorption of the OS-CS complexes inhibited lipid oxidation and hydrolysis due to its compact network and stable interfacial structure. Our results show that OS-CS complexes are effective emulsion-template oleogelators, which may be useful for creating new edible functional materials for application in the food industry. [Display omitted] • Octenyl succinic anhydride starch-chitosan complexes are an effective oleogelators. • Oleogels with tunable rheology can be obtained by adjusting chitosan content. • Chitosan significantly (p < 0.05) improved lipid oxidation of oleogels. • Chitosan effectively decreased the rate of lipid digestion of oleogels. [ABSTRACT FROM AUTHOR]

The impact of citric acid, carboxymethyl cellulose, carboxymethyl starch, sodium trimetaphosphate, or soybean protein on the crosslinking of starch-based films was examined. These crosslinking starch films were then used to create pH-sensitive food labels using a casting method. Blueberry anthocyanins were incorporated into these smart labels as a pH-sensitive colorimetric sensor. The mechanical properties, moisture resistance, and pH responsiveness of these smart labels were then examined. Crosslinking improved the mechanical properties and pH sensitivity of the labels. These different crosslinking agents also affected the hydrophobicity of the labels to varying degrees. Soybean protein was the only additive that led to labels that could sustain their structural integrity after immersion in water for 12 h. Because it increased the hydrophobicity of the labels, which decreased their water vapor permeability, moisture content, swelling index, and water solubility by 47 %, 29 %, 52 % and 10 %, respectively. The potential of using these labels to monitor the freshness of chicken breast was then examined. Only the films containing soybean protein exhibited good pH sensitivity, high structural stability, and low pigment leakage. This combination of beneficial attributes suggests that the composite films containing starch and soybean protein may be most suitable for monitoring meat freshness. [Display omitted] • Crosslinking has a significant impact on the performance of intelligent labels. • The mechanical strength and hydrophobicity of composite labels have been improved. • All labels have visible color response to pH changes and chicken breast spoilage. • SPI composite labels can maintain morphological integrity with low pigment leakage. [ABSTRACT FROM AUTHOR]

Starch-based packaging materials are being developed to alleviate environmental pollution and greenhouse gas emissions associated with plastic-based ones. However, the high hydrophilicity and poor mechanical properties of pure-starch films limit their widespread application. In this study, dopamine self-polymerization was used as a strategy to improve the performance of starch-based films. Spectroscopy analysis showed that strong hydrogen bonding occurred between polydopamine (PDA) and starch molecules within the composite films, which significantly altered their internal and surface microstructures. The composite films had a greater water contact angle (> 90°), which indicated that the incorporation of PDA reduced their hydrophilicity. Additionally, the elongation at break of the composite films was 11-fold higher than pure-starch films, indicating that PDA improved film flexibility, while the tensile strength decreased to some extent. The composite films also exhibited excellent UV-shielding performance. These high-performance films may have practical applications in food and other industries as biodegradable packaging materials. [Display omitted] [ABSTRACT FROM AUTHOR]