Water migration depicts the effect of hydrocolloids on the structural and textural properties of lotus seed starch

Influence of highland barley β-glucan on textural, structural, and rheological characteristics of corn starch

Non-starch polysaccharides are added to grains as dietary fiber to enhance their processing characteristics. This study investigates the influence of highland barley β-glucan (HBBG) on the gelatinization, texture, rheological, structural, and retrogradation characteristics of corn starch (CS). The pasting analysis revealed that the trough, peak, and final viscosities of the CS gel were markedly decreased after HBBG addition. Rheological analysis indicated reduced viscosity, flow behavior, and elasticity of the gels following HBBG addition. Fourier Transform Infrared Spectroscopy (FTIR) displayed a red shift in wavenumber, suggesting increased hydrogen bonding interactions induced by HBBG. HBBG increased water holding in CS and reduced hardness by forming hydrogen bonds with the starch. Specifically, the hardness of CS containing 20 % HBBG decreased from 290.32 g to 66.1 g. X-ray diffraction indicated 7.98 and 8.58 % reductions in CS gels with 20 % HBBG after 24 h and 7 days of retrogradation, respectively. These findings offer valuable insights for the formulation of functional foods designed for elderly individuals.

Effects of Porphyra haitanensis polysaccharides on the short-term retrogradation and simulated digestion in vitro of three crystalline starches

In this study, the effects of Porphyra haitanensis polysaccharides (PHP) (0.4 %, 0.8 % and 1.2 %) on the short-term retrogradation and simulated digestion in vitro properties of starches with corn starch (CS), potato starch (PS) and lotus seed starch (LS) and their potential mechanism of PHP were constructed. 0.4 % and 0.8 % PHP promoted the formation of ordered structures in PS, and all PHP suppressed short-range ordered structure rearrangements in CS and LS. PHP promoted PS-PHP complex while retarding water migration of CS-PHP and LS-PHP complex. XRD showed that all PHP inhibited the short-term retrogradation of CS and LS while facilitating PS. Finally, compared to native starch, CS-0.4%PHP, CS-0.8%PHP, LS-0.8%PHP and LS-1.2%PHP had higher hydrolysis rate, but PHP could decrease that of PS. All of PHP were decreased the RS proportion of CS and LS, especially CS-0.8%PHP, LS-0.8%PHP and LS-1.2%PHP. While PHP were increased that of PS. These results will provide a scientific basis for the development of starch-based foods.

Chlamydomonas reinhardtii polysaccharides retard rice starch retrogradation by weakening hydrogen bond strength within starch double helices

This study investigated the effects of Chlamydomonas reinhardtii polysaccharides (CRPs) on retarding the retrogradation of japonica rice starch (JS) and glutinous rice starch (GS). Structure characterization revealed that CRPs, with an average molecular weight of 505 kDa, mainly consisted of glucose, mannose, and galactose and featured a triple-helix structure. CRPs could reduce the storage modulus increment of JS during the cooling process by interacting with amylose, thereby inhibiting gel network formation. After long-term storage, CRPs decreased the hardness of JS and GS gels, limited the mobility of water molecules, and inhibited dehydration of gels. In addition, CRPs restricted starch recrystallization through interactions with amylopectin, resulting in reduced retrogradation enthalpy and relative crystallinity in JS and GS gels. Further investigation revealed that CRPs could weaken hydrogen bond strength within double helices in JS and GS after 14 days, with bond energies of 10.270 kJ for JS-0.4%CRPs and 10.241 kJ for GS-0.4%CRPs, which are lower than those of native starches (10.464 and 10.500 kJ). Moreover, the energy increments of hydrogen bonds within double helices in complexes were smaller than those of native rice starches during storage, which emerges as the essential reason behind the retardation of rice starch retrogradation by CRPs.

Effects of glycosylated whey protein isolate on gelatinization, gel properties, and microstructure of wheat starch

Glycated whey protein isolate (gWPI) was produced by dry thermal reaction between whey protein isolate (WPI) and lactose, and its influence on the gelatinization, gel properties, and microstructure changes of wheat starch (WS) was systematically studied. Results showed that gWPI significantly inhibited starch gelatinization and improved starch gel properties. RVA and DSC analysis showed that gWPI decreased viscosity and gelatinization enthalpy (ΔH) in a concentration-dependent manner. When gWPI concentration was 12 %, the peak viscosity and ΔH decreased by 36 cP and 3.11 J/g, respectively. gWPI competed with WS for water and inhibited WS water absorption and expansion. Rheological results showed that the viscoelasticity of the gel decreased by adding gWPI and that of WS-gWPI was a pseudoplastic fluid with shear-thinning behavior. In addition, gWPI covered the WS surface in the form of hydrogen bonds, which inhibited the leaching of amylose, thereby reducing the particle size of the gelatinized starch and its iodine binding ability. AFM results showed that gWPI combined with WS weakened the aggregation of starch molecular chains and decreased the height of starch. In conclusion, gWPI can be used as a gelatinizing regulator to improve starch properties.

Influence of different hydrocolloids on the pasting, rheological, and morphological characteristics of heat gelatinized cassava starch

Heat-gelatinized starch (HGS), which is prepared via heat treatment, enhances viscosity and provides suitable thickening properties, which improve water retention in products. This study aimed to investigate the potential of blending gelatinized starch with edible hydrocolloids (guar gum, carrageenan (C), locust bean gum, konjac powder, and sodium alginate) to assess their effect on the stabilization of starch gelatinization and reduction of retrogradation. Optical microscopic observations revealed the disrupted structures of gelatinized starch after heat treatments, along with diminished or absent birefringence. Adding C to the gelatinized starch reduced its peak viscosity, breakdown and setback value. For the rheological analysis, heat gelatinization and hydrocolloid addition contributed to the increased elasticity and viscosity of samples. Gelatinization and hydrocolloid addition emerged as effective strategies for improving starch quality. Although it still warrants further exploration, the introduced approach holds potential for applications in the development of convenience and canned food products.

Effect of frozen storage on the quality of frozen instant soup rice noodles: From the moisture and starch characteristics

This study aimed to simulate frozen instant soup rice noodles (FISRN) and investigate the effects of long-term frozen storage (-18 °C, 180 days) on the quality characteristics, moisture status, and starch retrogradation of FISRN. The findings indicated that the extent of starch retrogradation gradually increased over 90 days, which elevated the RS rate and inhibited starch digestibility. However, recrystallization resulted in a gradual increase in ice crystal size after 90 days, which disrupted the ordered structure formed by starch retrogradation, reduced the degree of starch order, and accelerated the rate of starch digestion. Furthermore, a longer relaxation time (T24) was detected by NMR with increasing storage time. The weakly bound water in FISRN was gradually converted to free water. Texture results suggested that the hardness of FISRN experienced a general decrease. The cooking loss increased progressively from 3.66 % to 8.10 %. Scanning electron microscope demonstrated that the internal porous network structure of FISRN became inhomogeneous, and a significant number of apertures were formed on the surface. Overall, starch retrogradation and ice recrystallization significantly impact the quality of FISRN during long-term frozen storage. The findings may potentially influence the consumption and market circulation of FISRN positively.

Lycium barbarum pulp addition improves the dough properties and gluten protein structure

This study investigated the effects of Lycium barbarum pulp (LBP) on the properties of mixed dough and gluten protein. The results showed that appropriate addition of LBP (5 %) significantly improved the performance of the dough, promoted the aggregation of gluten protein, enhanced the water binding ability, and delayed the gelatinization of starch during cooking. Compared with the control group, the peak temperature (Tp) of the LBP sample gradually increased from 63.23 °C to 65.56 °C, the expansion force reduced by about 21.56 %, the absolute Zeta potential lowered by about 18.4 %, and the α -helix content and β -folding increased by 32.36 % and 10.23 %, respectively, indicating the more orderly and stable overall structure. However, LBP did not change the crystal configuration of starch and still showed typical type A line diffraction. Moreover, the addition of LBP increased the polyphenol content, which further improved the antioxidant properties and provided the possibility to improve the health potential of the flour.

Freezing rate's impact on starch retrogradation, ice recrystallization, and quality of water-added and water-free quick-frozen rice noodles

The study evaluated the effect of freezing rate on the quality of water-added quick-frozen rice noodles and water-free quick-frozen rice noodles. Results indicated that the retrogradation enthalpy, relative crystallinity, freezable water content, and cooking loss of water-added quick-frozen rice noodles were higher than those of water-free quick-frozen rice noodles with increasing storage time. Furthermore, ice recrystallization accelerated the deterioration of the quality of the rice noodles, resulting in the enlargement of the pores within the rice noodles and the formation of many pores on the surface. This phenomenon was particularly evident in the rice noodles of Y-40 °C (freezing with water at -40 °C) and Y-60 °C (freezing with water at -60 °C). After 28 days of frozen storage, the hardness increased by 83.83 % for rice noodles of Y-20 °C (freezing with water at -20 °C), while the hardness decreased by 51.68 % and 45.80 %, respectively, for rice noodles of Y-40 °C and Y-60 °C. Consequently, the impact of the freezing rate on the quality of water-added quick-frozen rice noodles is more pronounced than that of water-free quick-frozen rice noodles. Moreover, a higher freezing rate can delay the deterioration of the quality of frozen rice noodles by postponing starch retrogradation and inhibiting ice recrystallization.

Interaction of anthocyanins, soluble dietary fiber and waxy rice starch: Their effect on freeze-thaw stability, water migration, and pasting, rheological and microstructural properties of starch gels

This study aimed to investigate the effect of the interaction of black rice anthocyanins (BRA), soluble dietary fiber from extruded rice bran (ES) and waxy rice starch (WRS) on the physicochemical properties of starch gels, including gelatinization properties, rheological properties, freeze-thaw stability, water migration, molecular structure and gel microstructure. The results showed that the pasting temperature (PT) of the mixtures was increased, and the peak viscosity (PV), trough viscosity (TV), final viscosity (FV) and setback viscosity (SV) were significantly reduced when ES and BRA were added to WRS in different proportions (ES:BRA, 4:0, 4:0.4, 4:1, 4:2, 8:0, 8:0.8, 8:2, 8:4). Both ES and BRA could enhance the viscosity of WRS gels, and ES exhibited strong ability on improving the strength of gels. The presence of ES and BRA improved the water retaining capacity of WRS gels, but weakened the freeze-thaw stability. ES, BRA and WRS formed non-covalent bonds (hydrogen bonds) through hydrophilic groups during gelatinization, which improved the gel properties. In addition, the steric hindrance formed by ES and BRA inhibited starch retrogradation. These results might contribute to the development of starch-based food formulations with good quality.

Structural analysis of type 3 resistant starch from Canna edulis during in vitro simulated digestion and its post-digested residue impact on human gut microbiota

Introduction

Resistant starch (RS) has garnered attention for its health benefits, including modulating the gut microbiota and promoting the production of short-chain fatty acids (SCFAs).

Methods

This study investigates structural changes of type 3 resistant starch from Canna edulis (CE) during in vitro simulated digestion and explores its health-relevant properties using healthy individuals' fecal microbiota.

Results

CE, prepared with a RS content of 59.38%, underwent a comprehensive analysis employing X-ray diffraction (XRD), fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). During simulated digestion, XRD analysis demonstrated a significant rise in CE's relative crystallinity from 38.92 to 49.34%. SEM illustrated the transition of CE from a smooth to a rough surface, a notable morphological shift. Post-digestion, CE was introduced into microbial fermentation. Notably, propionic acid and valeric acid levels significantly increased compared to the control group. Furthere more, beneficial Bifidobacterium proliferated while pathogenic Escherichia-Shigella was suppressed. When comparing CE to the well-known functional food fructo-oligosaccharide (FOS), CE showed a specific ability to support the growth of Bifidobacterium and stimulate the production of short-chain fatty acids (SCFAs) without causing lactic acid accumulation.

Discussion

CE demonstrates potential as a functional health food, with implications for gut health enhancement and SCFAs production.

New insights into the interaction between bamboo shoot polysaccharides and lotus root starch during gelatinization, retrogradation, and digestion of starch

In this study, the interaction between bamboo shoot polysaccharides (BSP) and lotus root starch (LS) during gelatinization, retrogradation, and digestion of starch was investigated. The addition of BSP inhibited the gelatinization of LS and decreased the peak viscosity, valley viscosity, and final viscosity. Amylose leaching initially increased and then decreased with the increase in BSP addition. The apparent viscosity and viscoelasticity of LS decreased with the increase in BSP addition. Moreover, 3 % BSP increased the hardness and cohesiveness of LS gel, whereas 6 %-15 % BSP decreased them. In addition, 3 %-6 % BSP promoted the uniform distribution of water molecules in the starch paste, whereas the addition of 12 % and 15 % BSP resulted in the inhomogeneous distribution of the water. The retrogradation degree of LS gel gradually increased with the increase in BSP addition from 3 % to 6 %, whereas 9 %-15 % BSP restricted the short-term and long-term retrogradation of LS. After 12 % BSP was added, the RDS content reduced by 11.6 %, the RS content significantly increased by 75 %, and the digestibility of starch decreased. This work revealed the interaction between BSP and LS during starch gelatinization, retrogradation, and digestion to improve the physicochemical properties and digestive characteristics of LS.

Modifications of native lotus (Nelumbo nucifera G.) rhizome starch and its overall characterization: A review

Lotus (Nelumbo nucifera G.) rhizomes are an under-utilized and sustainable starch source that constitutes up to 20 % starch. The review mainly focused on the extraction methods of starch, the chemical composition of LRS, and techno-functional characteristics such as swelling power, solubility, in vitro digestibility, pasting property, and gelatinization is highlighted in LRS review. Lotus rhizome starch (LRS) is also used as a water retention agent, thickening, gelling, stabilizing, and filling in food and non-food applications. Native starch has limited functional characteristics in food applications so by modifying the starch, functional characteristics are enhanced. Single and dual treatment processes are available to enhance microstructural properties, resistant starch, techno-functional, morphological, and, film-forming properties. Compared with other starch sources, there is a lack of systematic information on the LRS. Many industries are interested in developing food products based on starch such as nanoparticles, hydrogels, edible films, and many others. Additionally, there are several recommendations to improve the applications in the food industry. Finally, we provide an outlook on the future possibility of LRS.

Effect of Soy Wax/Rice Bran Oil Oleogel Replacement on the Properties of Whole Wheat Cookie Dough and Cookies

This study investigated the replacement of butter with soy wax (SW)/rice bran oil (RBO) oleogel in varied proportions in cookie dough and the resulting cookies. The study mainly evaluates the physical, textural, and chemical properties of the butter cookie dough and cookies by replacing butter with SW/RBO oleogel. The dough was assessed using moisture analysis, microscopy, FTIR Spectroscopy (Fourier Transform Infrared) and impedance spectroscopies, and texture analysis. Micrographs of the dough showed that D-50 (50% butter + 50% oleogel) had an optimal distribution of water and protein. D-0 (control sample containing 100% butter) showed the lowest impedance values. Moisture content ranged between 23% and 25%. FTIR spectroscopy suggested that D-50 exhibited a consistent distribution of water and protein, which CLSM and brightfield microscopy supported. Texture analysis revealed that the dough samples exhibited predominantly fluidic behavior. As the amount of oleogel was raised, the dough became firmer. The prepared cookies showed a brown periphery and light-colored center. Further, a corresponding increase in surface cracks was observed as the oleogel content was increased. Cookies moisture analysis revealed a range between 11 and 15%. Minute changes were observed in the texture and dimensions of the cookies. In summary, it can be concluded that replacing butter with oleogel by up to 50% seems to be feasible without significantly compromising the physicochemical properties of cookie dough and cookies.

Effect of hydroxypropyl distarch phosphate on the retrogradation properties of sterilized pea starch jelly and its possible mechanism

Due to the high content of amylose in pea starch (PS), PS jelly is prone to retrogradation during storage and its quality reduces subsequently. Hydroxypropyl distarch phosphate (HPDSP) shows a potential inhibitory effect on the retrogradation of starch gel. Based on this, five retrograded PS-HPDSP blends containing 1 %, 2 %, 3 %, 4 % and 5 % (w/w, based on the weight of PS) of HPDSP were prepared, and their long-range, short-range ordered structure and retrogradation properties, and the possible interaction between PS and HPDSP were investigated. The addition of HPDSP significantly reduced the hardness of PS jelly and maintained its springiness during cold storage, and this effect was enhanced with HPDSP dosage being from 1 % to 4 %. The presence of HPDSP destroyed both short-range ordered structure and long-range ordered structure. Rheological results indicated that all the gelatinized samples were typical non-Newtonian fluids with shear-thinning characteristics and HPDSP increased their viscoelasticity in a dose-dependent manner. In conclusion, HPDSP delays the retrogradation of PS jelly mainly by combining with amylose in PS through hydrogen bonds and steric hindrance.

Starch-guar gum-ferulic acid molecular interactions alter the ordered structure and ultimate retrogradation properties and in vitro digestibility of chestnut starch under extrusion treatment

Molecular interactions among starch and multiple-components during food processing determine the retrogradation properties and digestibility of starch. Here, the effects of starch-guar gum (GG)-ferulic acid (FA) molecular interactions on retrogradation properties, digestibility and ordered structural changes of chestnut starch (CS) under extrusion treatment (ET) were investigated by structural analysis and quantum chemistry. Due to the entanglement behaviors and hydrogen bond interactions, GG could inhibit the formation of helical and crystalline structures of CS. When FA was introduced simultaneously, FA could weaken the interactions between GG and CS as well as enter the spiral cavity of starch to increase the single/double helix and V-type crystalline structures while reducing A-type crystalline. Based on the above structural changes, ET with starch-GG-FA molecular interactions resulted in resistant starch content of 20.31% and anti-retrogradation rate of 42.98% for 21-day storage. Overall, the results could provide basic data for creation of chestnut-based food with higher value.

Stale bread waste recycling as ingredient for fresh oven-baked white bread: effects on dough viscoelasticity, bread molecular organization, texture, and starch digestibility

BACKGROUND

Wasted food produced for human consumption is estimated at 33% globally, and bread is the food product with the highest percentage. There is an ongoing drive to reincorporate food waste still useful and safe into the production chain of food for human consumption. This work aims to contribute to the study of the feasibility of recycling stale bread waste flour (BWF) into fresh oven-baked white bread, by replacing 0, 20, 40, 60, 80, and 100 g/100 g of the wheat flour with BWF.

RESULTS

Storage and loss moduli increased as the BWF content increased. The baked loaf exhibited decreased lightness and yellowness but increased redness. Increasing BWF contents produced decreased loaf volume and hardness but increased moisture content. Fourier-transform infrared analysis showed that the BWF addition induced important changes in the water, protein, and starch molecular organization. Therefore, starch digestibility showed reductions in both rapidly and slowly digestible starch fractions. Principal component analysis revealed that replacements of up 20 g/100 g can produce white bread with textural, colour, and starch digestibility characteristics like that of the control bread.

CONCLUSION

The fresh oven-baked white bread variation produced by replacing 20 g/100 g of the wheat flour with BWF exhibited comparable colour, volume, texture, and starch digestibility features as a control bread did made with 0 g/100 BWF. Higher replacement percentages of wheat flour by stale BWF produced unsuitable drawbacks in the white bread characteristics, but those might be deemed as convenient in other types of bakery products. © 2023 Society of Chemical Industry.

Comparative study on the effect of inhibitory methods on the color and gelation properties of alkali induced heat-set konjac gel from Amorphophallus bulbifer

As a newly superior konjac variety, the Amorphophallus bulbifer (A. bulbifer) was easily browning during the alkali-induced process. In this study, five different inhibitory methods, such as citric-acid heat pretreatment (CAT), mixed with citric acid (CA), mixed with ascorbic acid (AA), mixed with L-cysteine (CYS), and mixed with potato starch (PS, containing TiO2), were separately used to inhibit the browning of alkali-induced heat-set A. bulbifer gel (ABG). The color and gelation properties were then investigated and compared. Results showed that the inhibitory methods had significant influences on the appearance, color, physicochemical properties, rheological properties, and microstructures of ABG. Among them, the CAT method not only significantly inhibited the browning of ABG (ΔE value dropped from 25.74 to 14.68) but also improved the water-holding capacity, moisture distribution, and thermal stability without damaging the textural properties of ABG. Moreover, SEM revealed that both CAT and adding PS methods could exhibit the more dense gel network structures of ABG than other methods. It was reasonable to conclude that ABG-CAT offered a superior method to prevent browning compared to the other methods based on the texture, microstructure, color, appearance, and thermal stability of the product.

Effects of different hydrocolloids on the water migration, rheological and 3D printing characteristics of β-carotene loaded yam starch-based hydrogel

The effects of guar gum (GG), xanthan gum (XG), carrageenan gum (CG), xanthan-guar gum blend (XG-GG), chitosan (CS), gum arabic (GA) on the water migration, rheological and 3D printing properties of β-carotene loaded yam starch-based hydrogel (BCH) were investigated to expand product form of β-carotene. The results showed that CS addition promoted the migration of weakly bound water to tightly bound water in BCH. Addition of GG, CG, XG-GG, CS and GA enhanced apparent viscosity, G', G'', hardness and gumminess of BCH. CG, XG-GG, CS and GA addition improved printing stability of BCH. The printed objects added with GG and CS displayed smooth lines with fine resolution and higher formability, which showed a more uniform pore distribution and thinner gel skeleton structure. The results of XRD showed that hydrocolloids addition decreased the relative crystallinity of BCH. A combination of physicochemical parameters could be used to discriminate samples through hierarchical cluster analysis.

Effects of Konjac Glucomannan on Retrogradation of Amylose

The effect of konjac glucomannan (KGM) on the retrogradation of amylose was explored during storage. The color, rheological properties, texture, water-holding capacity (WHC), low-field nuclear magnetic resonance (LF-NMR), and X-ray diffraction (XRD) were investigated. Results of color and rheological measurements showed that with the increasing amount of KGM, the L value of the system decreased, but the elastic modulus, viscous modulus, and tangent value of loss angle increased. The textural result presented that KGM obviously inhibited the growth rate of gel strength of amylose. Results from WHC and XRD suggested after 14 days of storage, when the concentration of KGM increased from zero to 0.3% in the mixture, the WHC grew from 80% to 95% and the crystallinity degree declined from 35.3% to 25.6%. The LF-NMR result revealed that KGM limited the conversion of free water to bound water in the system. In general, a small amount of KGM in a mixed system could inhibit the short-term and long-term retrogradation of amylose. This research could provide a theoretical reference for the influence of hydrophilic colloids on the retrogradation of starch, and it could also provide support for the processing and production of starch-based food.

Effect of Tremella fuciformis and Different Hydrocolloids on the Quality Characteristics of Wheat Noodles

To improve the quality characteristics of noodles and enrich nutritional value, Tremella fuciformis (TF) powder was incorporated into noodles. Tremella fuciformis (TF) is an edible fungus with rich nutritional value, and TF gel has good viscosity properties. This paper explored the effect of TF on noodle quality, and compared the difference between TF and three hydrocolloids: sodium alginate (SA), guar gum (GG) and xanthan gum (XG). The results showed that TF could significantly (p < 0.05) increase the hardness, adhesiveness and chewiness of noodles, and showed a decreasing trend for additions greater than 3%. The addition of 3% TF enhanced storage modulus (G′), loss modulus (G″) and elasticity of dough. The addition of 3% TF also increased α-helix and β-sheet content, and degradation temperature in noodles. Meanwhile, it elevated the deeply bound water content and retarded water mobility. In addition, the content of slowly digestible starch and resistant starch in the noodles increased with the addition of 3% TF. It was found that the effect of 3% TF on the above data was not different from the effects of the three hydrocolloids (respectively, their optimal additions), and improved the quality characteristics of the noodles. The results provide guidance for the application of TF and the development of a new natural hydrocolloid and nutritionally fortified noodles.

Effects of konjac glucomannan on the long-term retrogradation and shelf life of boiled wheat noodles

BACKGROUND

Starch retrogradation and moisture migration of boiled wheat noodles (BWNs) result in quality deterioration and short shelf life. The objective of this research was to investigate whether konjac glucomannan (KGM) could improve the quality of BWNs and further establish the shelf-life prediction model.

RESULTS

The moisture distribution, recrystallization, and thermal properties of BWNs during refrigerated or ambient temperature storage were determined. Low-field nuclear magnetic resonance data showed that KGM addition induced left-shifts of T₂₁ and T₂₂ values, indicating that KGM limited the mobility of bound and immobile water among noodle matrices. X-ray diffraction spectra revealed that KGM did not change the crystal patterns of BWNs but could inhibit the starch recrystallization after refrigerated storage. The T_p and ΔH values of retrograded samples notably (P < 0.05) decreased with the increase of KGM addition, suggesting the hinderance of starch retrogradation behavior by KGM. The shelf life of BWNs was predicted by accelerated storage test combined with the Arrhenius equation. The present data displayed that the predicted shelf life of vacuum-packed and sterilized BWNs with 10 g kg^-1 KGM at 25 °C was 733 days, 2.4-fold that of the control group.

CONCLUSION

BWNs with KGM addition could inhibit starch retrogradation and improve the storage stability, consequently promoting noodle quality. © 2021 Society of Chemical Industry.

Water Behavior of Emulsions Stabilized by Modified Potato Starch

Starch is a widely known and used emulsion stabilizer. In order to improve its properties, various types of modifications are made that change its ability to emulsify and stabilize. This paper describes the analysis of the molecular dynamics of water using low-field nuclear magnetic resonance (LF NMR) in oil-in-water emulsions obtained with the use of physically or chemically modified potato starch. The analysis of changes in spin-spin and spin-lattice relaxation times depending on the temperature allowed the activation energy value of water molecules in the analyzed emulsions to be determined. It has been shown that the presence of starch influences the values of spin-lattice T₁ and spin-spin T₂ relaxation times, both in the water and the oil phase, and the observed changes largely depended on the type of starch modification. Both types of analyzed starches also differently influenced the energy of activation of rotational movements of water molecules. On the basis of the analyses carried out with the use of LF NMR, it can be concluded that physically modified starch acts not only as a stabilizer, but also as an emulsifier, while acetylated starch does not exhibit good emulsifying properties.

Ordered structural changes of retrograded starch gel over long-term storage in wet starch noodles

Temperature-induced structural variations of retrograded starch gel during long-term storage were investigated in a real food system (wet starch noodles). Fresh starch noodles presented a B-type XRD pattern containing 8.82% crystallinity and 16.04% double helices. In the first 2 weeks, double helices of starch chain formed long-range ordered structure leading to increased crystallinity, and such structural transformation was positively correlated with increasing storage temperature (from 4 °C to 35 °C) and storage time. However, with the extension of storage time to 12 weeks, the disorganization of supra-molecular structure was likely to be observed by decreased crystallinity, double helix and water mobility. Besides, we propose that the area and intensity of Raman band at 2910 cm^-1 can be a good indicator for evaluating perfection of crystallinity in starch noodles. These results contributed to a better understanding of mechanisms underlying molecular order changes of retrograded starch gel product during long-term storage.

Contribution of starch to the flavor of rice-based instant foods

Increased consumption of instant foods has led to research attention, especially rice-based instant foods. Starch, one of the most important components of rice, significantly affects food quality. However, the mechanisms by which starch contributes to rice-based instant foods flavor are poorly understood in many cases. The review aims to describe the common mechanisms by which starch contributes to food flavor, including participating in flavor formation, and affecting flavor release throughout starch multiscale structure: particle morphology, crystal structure, molecular structure. Five specific examples of rice-based instant foods were further analyzed to summarize the specific contribution of starch to flavor, including instant rice, fermented rice cake, rice noodles, fried rice, and rice dumplings. During foods processing, reducing sugars produced by heating or enzymatic hydrolysis of starch participate in Maillard reaction, caramelization and thermal degradation, which directly or indirectly affect the formation of flavor compounds. In addition, adsorption by granules, encapsulation by retrograded V-type crystal, and controlled release by starch gel all contribute to rice-based instant food flavor qualities. These mechanisms jointly contribute to flavor compounds formation and release. Proper theoretical application and improved processing methods are needed to promote the high-quality, mechanization, and automation of rice-based instant foods production.

Effect of four viscous soluble dietary fibers on the physicochemical, structural properties, and in vitro digestibility of rice starch: A comparison study

The effect of carboxymethyl cellulose (CMC), high-methoxyl pectin (HMP), konjac glucomannan (KGM), and xanthan gum (XG) on the physicochemical, structural properties, and digestibility of rice starch were investigated and compared. The four viscous soluble dietary fibers (VSDFs) increased the viscosity, storage modulus and loss modulus while decreased the pasting temperature and gelatinization enthalpy. Moreover, XG produced the lowest peak viscosity and dynamic modulus compared with the other VSDFs. Furthermore, the degree of short-range ordered structure of starch with KGM increased from 0.8448 to 0.8716; and the relative crystallinity of starch with XG increased by 12%. An ordered and reunited network structure was observed in SEM. In addition, VSDF inhibited the digestibility of rice starch and significantly increased the resistant starch content. This study compared the effect of four VSDFs on the physicochemical, structural and digestion properties of rice starch to fully understand and develop their application to starchy foods.

Effects of freeze-thaw treatment and pullulanase debranching on the structural properties and digestibility of lotus seed starch-glycerin monostearin complexes

The effects of multiple cycles of freeze-thaw treatment, combined with pullulanase debranching, on the structural properties and digestibility of lotus seed starch-glycerin monostearin complexes were investigated. The formation and melting of ice crystals during freeze-thaw treatment disrupted the crystalline structure of the starch granules, creating pores which facilitated access of pullulanase to the interior of the granules. Pullulanase debranching increased the free amylose content of the starch, which promoted the formation of starch-lipid complexes, which, in turn, increased the proportion of resistant starch and the overall resistance of the starch to digestive enzyme action. These effects increased with the number of freeze-thaw cycles, because more cycles increased both the disruption of the granule structure and the extent of pullulanase debranching. These findings provide a basis for the preparation of functional foods with low glycemic indices, which have strong potential for management of type II diabetes.

The Influence of Konjac Glucomannan on the Physicochemical and Rheological Properties and Microstructure of Canna Starch

The addition of hydrocolloid is an effective method to improve the properties of native starch. However, few studies have investigated the effects of konjac glucomannan (KGM) on canna starch (CS). In this study, the effects of various KGM concentration on the pasting, rheological, textural, and morphological properties of CS were investigated. The addition of KGM significantly increased CS’s pasting viscosities. Incorporation of KGM in CS at a relatively high level (1.2% w/w) exerted a significant influence on the pasting properties of CS. The consistency coefficient of CS was notably increased by KGM (from 43.6 to 143.3 Pa·sⁿ) and positively correlated positive with KGM concentration. KGM concentration at a relatively high level (1.2% w/w) increased the elasticities and cohesiveness of CS by 53.3% and 88.0%, respectively, in texture profile analysis. The polarized optical microscope images indicated that KGM played an important part in protecting the crystalline structure of CS during heating. A denser porous microstructure with a filamentous network was observed in gelatinized KGM/CS mixtures as compared with the CS control. This research advances the knowledge of interactions between KGM and CS and opens possibilities to improve rheological properties of CS and to develop its new functionalities with KGM addition.

The impact of various exogenous type starch on the structural properties and dispersion stability of autoclaved lotus seed starch

In order to investigate the effects of exogenous V-type starch on the structural properties and dispersion stability of lotus seed starch after autoclave treatment, the crystal structure, molecular structure, and dispersion stability were analyzed and discussed, as well as compared with exogenous A-type and B-type starches. Analysis of structural properties indicated that the addition of different crystal nuclei led the crystallization of disordered helices to a specific direction. The B- and V-type starch addition increased the crystallinities of starch and enhanced the ordered arrangement of disordered helices, whereas A-type starch had no significant positive influence on the stability of starch system. The microstructure observation showed that A- and B-type starch addition led to a rough and porous morphology of starch particles; the presence of V-type starch retarded the agglomeration and retrogradation of starch after autoclaving. Analysis of contact angle and dispersion stability revealed that the addition of various exogenous starch increased the contact angle of starch particles in different extent, suggesting the enhancement of hydrophobicity. But B-type starch addition resulted in the poor dispersion stability compared to A-type starch, instead V-type starch addition improved the dispersion stability of starch in aqueous solution, allowing the particles to stay dispersed for 141.12 ± 6.52 min. These results provided a theoretical basis for the effects of exogenous type starch on original starch properties, and revealed the potential of V-type starch as dispersion stabilizer.