Effect of hydrocolloids on physical, thermal and microstructure properties of par-baked baguette during frozen storage

Construction of sodium alginate/trehalose/wheat starch ternary complex and its effects on storage stability of frozen dough system

In order to improve the quality of frozen dough, a calcium alginate-coated sodium alginate/trehalose/wheat starch ternary complex was designed in this paper. The ternary complex was added to dough, and the dough quality were measured after 0-30 d of frozen storage. The XRD and FT-IR results showed the ternary complex was mainly starchy crystal. The TGA curves showed the starting (To), peak (Tp) and termination temperature (Tc) were increased. The interaction between sodium alginate and trehalose enhanced the thermal performance of ternary complex. As the ternary complex addition to dough increased, the maximum ice crystal formation zone of the frozen dough passed faster, resulting in more uniform and smaller ice crystals. The dough with 0.8% addition contained more bound water and had better hardness, springiness and cohesiveness. In conclusion, the study provides a novel insight and understanding for the development of ternary complex as food additives in frozen food industry.

Mitigating effect of fucoidan versus sodium alginate on quality degradation of frozen dough and final steamed bread

The impact of fucoidan (FD) and sodium alginate (SA) addition (0.3, 0.6, and 0.9 g/100 g wheat flour, dry basis) and freezing time on the rheology, water, structural characteristics of dough, and the quality of end steamed bread was explored in this study. The results showed FD was more effective in improving the textural characteristics of frozen dough compared with SA. Meanwhile, the freezable and free water content of SA dough were lower than those of FD dough, with the most pronounced effect observed at 0.9%. Adding SA increased the storage modulus, loss modulus, and disulfide bond content of the dough. The addition of FD induced a denser gluten protein network with fewer pores. Furthermore, the addition of FD reduced the hardness and chewiness of steamed bread and increased its specific volume and lightness. Overall, FD could alleviate the quality deterioration of frozen dough and the corresponding steamed bread.

Effects of freeze-thaw cycles on the quality of Hot-dry noodles: From the moisture, starch, and protein characteristics

Freeze-thaw cycles (FTC) could cause damage to food during storage. The effects of different FTC on Hot-dry noodles (HDN) in terms of quality, moisture, starch, and protein characteristics were studied. This study showed that FTC decreased the texture properties and water absorption of HDN. Meanwhile, cooking loss was significantly increased after FTC. The water content of HDN was decreased and water migration was increased during FTC. In addition, results showed that FTC destroyed the order structure and increased the crystallinity of starch in HDN. Under FTC, the disulfide bond of HDN was broken, the free sulfhydryl group was increased, and the electrophoretic patterns confirmed the protein depolymerization. The microstructure also showed that the gluten network became incomplete and starch was exposed outside the substrate. This study expounded the mechanism of HDN quality deterioration during FTC, which laid a foundation for the development and improvement of frozen and freeze-thaw noodles.

Effects of apple fiber on the physicochemical properties and baking quality of frozen dough during frozen storage

The effects of apple fiber on gluten structure and corresponding frozen dough quality during frozen storage were studied. The addition of 0.50% and 0.75% apple fiber effectively preserved gluten structure by inhibiting the breakage of disulfide bonds and promoting the formation of hydrogen bonds. Notably, the presence of 0.75% apple fiber increased the β-turn of gluten from 29.60% to 33.84%. Fiber-enriched frozen dough exhibited a smoother and more compact microstructure, but excessive fiber addition (more than 1.00%) had adverse effects. The freezable water content of frozen dough decreased as fiber addition increased. Correspondingly, the addition of 1.50% apple fiber resulted in a 56.08% increase in storage modulus, indicating improved viscoelasticity of the dough. Consequently, the addition of 0.50% and 0.75% apple fiber alleviated the quality deterioration of frozen dough bread in terms of larger specific volume, softer and more uniform crumb.

Effects of oat β-glucan on the retrogradation behavior of rice starch and its potential mechanism

In this study, to minimize the quality deterioration caused by the retrogradation of starch-based food, the effect and mechanism of oat β-glucan (OG) on the retrogradation of rice starch was investigated. OG effectively decreased storage modulus (G'), syneresis, and retrogradation enthalpy, indicating the inhibition of short-term and long-term retrogradation of rice starch. The competition for water molecules between the OG and rice starch resulted in partial swelling of the starch granules, consequently reducing particle size, lowering amylose leaching, and decreasing the proportion of short-amylose chains. The microstructure characterization showed that the OG-treated rice starch group (ST-OG) exhibited a smoother and denser surface. Particularly, no notable alterations were observed in the structure of the ST-OG sample during storage, owing to the improved water-holding capacity of starch gel and reduced proportion of free water caused by OG. Furthermore, the ordered structure results confirmed the occurrence of hydrogen bonding between OG and rice starch, which hindered the rearrangement of starch molecules. Therefore, OG is an effective natural additive for controlling the retrogradation of starch-based foods.

Effects of Wheat Oligopeptide on the Baking and Retrogradation Properties of Bread Rolls: Evaluation of Crumb Hardness, Moisture Content, and Starch Crystallization

Delaying the deterioration of bakery goods is necessary in the food industry. The objective of this study was to determine the effects of wheat oligopeptide (WOP) on the qualities of bread rolls. The effects of WOP on the baking properties, moisture content, and starch crystallization of rolls during the storage process were investigated in this study. The results showed that WOP effectively improved the degree of gluten cross-linking, thereby improving the specific volume and the internal structure of rolls. The FTIR and XRD results showed that the addition of WOP hindered the formation of the starch double helix structure and decreased its relative crystallinity. The DSC results revealed a decrease in the enthalpy change (ΔH) from 0.812 to 0.608 J/g after 7 days of storage with 1.0% WOP addition, further indicating that WOP reduced the availability of water for crystal lattice formation and hindered the rearrangement of starch molecules. The addition of WOP also improved the microstructure of the rolls that were observed using SEM analysis. In summary, WOP is expected to be an effective natural additive to inhibit starch staling and provide new insights into starchy food products.

Extracts with Nutritional Potential and Their Influence on the Rheological Properties of Dough and Quality Parameters of Bread

Formulating basic food to improve its nutritional profile is one potential method for food innovation. One option in formulating basic food such as bread is to supplement flours with specified amounts of non-bakery raw materials with high nutritional benefits. In the research presented here, we studied the influence of the addition of curcumin and quercetin extracts in amounts of 2.5% and 5% to wheat flour (2.5:97.5; 5:95). The analysis of the rheological properties of dough was carried out using a Mixolab 2. A Rheofermentometer F4 was used to assess the dough's fermentation, and a Volscan was used to evaluate the baking trials. The effect of the extracts on the rheological properties of dough was measured and found to be statistically significant, with curcumin shortening both dough development time and dough stability. Doughs made with greater quantities of extract had a greater tendency to early starch retrogradation, which negatively affects the shelf life of the end products. The addition of extracts did not significantly affect either the ability to form gas during fermentation or its retention, which is important because this gas is prerequisite to forming a final product with the required volume and porosity of crumb. Less favourable results were found on sensory evaluation, wherein the trial bread was significantly worse than the control wheat bread. The panel's decision-making might have been influenced by the atypical colour of the bread made with additives, and in case of a trial bread made with quercetin, by a bitter taste. From the technological point of view, the results confirmed that the composite flours prepared with the addition of extracts of curcumin and quercetin in amounts of 2.5% and 5% can be processed according to standard procedures. The final product will be bread with improved nutritional profile and specific sensory properties, specifically an unconventional and attractive colour.

Retrogradation inhibition of wheat starch with wheat oligopeptides

Starch staling greatly reduces the cereal products quality, and the staling retardation becomes a focus in current research. The effect of wheat oligopeptide (WOP) on anti-staling properties of wheat starch (WS) was studied. Rheology property indicated that WOP reduced WS viscosity, showing more liquid-like behavior. WOP improved the water holding capacity, inhibited swelling power, and reduced the hardness of WS gels, which decreased from 1200 gf to 800 gf compared with the control after 30 days storage. Meanwhile, the water migration of WS gels were also reduced with WOP incorporation. The relative crystallinity of WS gel with 1% WOP was reduced by 13.3%, and the pore size and the microstructure of gels was improved with WOP. Besides, the short-range order degree reached the lowest value with 1% WOP. In conclusion, this study explained the interaction between WOP and WS, which was beneficial to the application of WOP in WS-based food.

The Effect of Terminal Freezing and Thawing on the Quality of Frozen Dough: From the View of Water, Starch, and Protein Properties

Frozen dough is suitable for industrial cold chain transportation, but usually experiences temperature fluctuations through the cold chain to the store after being refrigerated in a factory, seriously damaging the product yield. In order to analyze the influence mechanism of temperature fluctuation during the terminal cold chain on frozen dough, the effects of terminal freezing and thawing (TFT) on the quality (texture and rheology) and component (water, starch, protein) behaviors of dough were investigated. Results showed that the TFT treatment significantly increased the hardness and decreased the springiness of dough and that the storage modules were also reduced. Furthermore, TFT increased the content of freezable water and reduced the bound water with increased migration. Additionally, the peak viscosity and breakdown value after TFT with the increased number of cycles were also increased. Moreover, the protein characteristics showed that the low-molecular-weight region and the β-sheet in the gluten secondary structure after the TFT treatment were increased, which was confirmed by the increased number of free sulfhydryl groups. Microstructure results showed that pores and loose connection were observed during the TFT treatment. In conclusion, the theoretical support was provided for understanding and eliminating the influence of the terminal nodes in a cold chain.

Effect of Lactylated Gluten and Freeze-Thaw Cycles on Frozen Dough: From Water State and Microstructure

The influence of lactylated gluten and Freeze-Thaw Cycles on the water state, microstructure, and quality of frozen steamed bread dough was investigated. After three freeze-thaw cycles (3F/T), the specific volume of steamed bread with sodium lactate-treated gluten increased by 18.34% compared with the blank group and 5.73% compared with the wheat gluten (WG) group. Compared with wheat gluten, the texture properties of steamed bread with lactylated gluten increased significantly. Changes in rheological properties demonstrated that the frozen dough's viscoelasticity increased significantly. The lactylated gluten could reduce water mobility and decrease the content of freezable water in frozen dough. Moreover, the free sulfhydryl (SH) content increased, revealing that the protein was depolymerized. Based on the microstructure and corresponding protein network analysis (PNA), the total area and the number of protein network connection points of the dough adding lactylated gluten were significantly higher than those of the blank group and the WG group. In conclusion, lactylated gluten enhanced the freeze-thaw tolerance of frozen dough.

Classification, gelation mechanism and applications of polysaccharide-based hydrocolloids in pasta products: A review

Polysaccharide-based hydrocolloids (PBHs) are a group of water-soluble polysaccharides with high molecular weight hydrophilic long-chain molecules, which are widely employed in food industry as thickeners, emulsifiers, gelling agents, and stabilizers. Pasta products are considered to be an important source of nutrition for humans, and PBHs show great potential in improving their quality and nutritional value. The hydration of PBHs to form viscous solutions or sols under specific processing conditions is a prerequisite for improving the stability of food systems. In this review, PBHs are classified in a novel way according to food processing conditions, and their gelation mechanisms are summarized. The application of PBHs in pasta products prepared under different processing methods (baking, steaming/cooking, frying, freezing) are reviewed, and the potential mechanism of PBHs in regulating pasta products quality is revealed from the interaction between PBHs and the main components of pasta products (protein, starch, and water). Finally, the safety of PBHs is critically explored, along with future perspectives. This review provides a scientific foundation for the development and specific application of PBHs in pasta products, and provides theoretical support for improving pasta product quality.

Combined effect of konjac glucomannan addition and ultrasound treatment on the physical and physicochemical properties of frozen dough

The effects of dual sequential modification using konjac glucomannan and ultrasound treatments at power densities of 15-37.5 W/L on the hydration, rheology and structural characteristics of frozen dough were investigated in this study. The results revealed that the konjac glucomannan and ultrasound treatments improved the textural properties of frozen dough, but had a negative impact on its viscoelasticity. Furthermore, konjac glucomannan and ultrasound treatments increased the content of free sulfhydryl group and disulfide bond, as well as improved the freeze tolerance of dough. The results exhibited that the enthalpy of frozen dough decreased by 20.42 % compared with the frozen blank control dough under ultrasonic power density of 22.5 W/L. The network structure of frozen dough treated by konjac glucomannan and ultrasound was more ordered and integral than that of frozen blank control dough. These results provide valuable knowledge on the application of konjac glucomannan and ultrasound to frozen wheat-based foods.

Insight into the effect of garlic peptides on the physicochemical and anti-staling properties of wheat starch

The staling of wheat starch in storage seriously damages the quality of starch-based foods, and how to delay the staling has become a topic focus. To solve the problem, this study analyzed the effect of garlic peptides on the physical and retrogradation behaviors of wheat starch during storage. The rheological, pasting, swelling properties, molecular order, water migration, and microstructure of wheat starch gels were evaluated. Our results showed that garlic peptides effectively reduced the storage and loss modulus of wheat starch. The physical properties indicated that garlic peptides suppressed the swelling and gelatinization of starch, which exhibited higher water holding capacity and lower water migration. In addition, garlic peptides incorporated wheat starch exhibited the lowest gel hardness during storage. X-ray diffraction and Fourier Transform Infrared Spectroscopy analysis indicated that garlic peptides could reduce the crystallinity and inhibit the formation of ordered structures in wheat starch gel. The microstructure observation showed that the gel with garlic peptides maintained the integrity of the network structure. Consequently, garlic peptides are expected to be an effective natural additive to inhibit starch staling and provide new insights for starch-based foods.

Biofunctional soy-based sourdough for improved rheological properties during storage

Frozen dough storage, along with its thawing process, negatively affects the quality of the final product. Thus, fermentation with selected cultures and the enrichment of wheat-based dough using a specific soy powder could optimize the viscoelastic quality of frozen dough and increase its nutritional characteristics. Based on these aspects, the present study's objective was to examine the effects of soy powder addition to wheat flour with single cultures of Fructilactobacillus florum DSM 22689 or Saccharomyces cerevisiae and coculture with these two microorganisms for 72 h of fermentation. Additionally, the fermentation process was monitored, and viscoelastic behavior and physical-chemical analyses of the fermented sourdough before and after frozen storage were assessed, as soy protein has been proposed to hinder water migration throughout frozen storage. As observed, soy powder, an essential functional ingredient, had a favorable impact on the water-starch-gluten system, and enhanced the viscoelastic behavior before and after 4 weeks of frozen storage.

Effect of mulberry leaf polysaccharides on the baking and staling properties of frozen dough bread

BACKGROUND

Deterioration in frozen dough bread easily occurs in store, resulting in tremendous economic waste. Therefore, it is imperative to find natural additives to improve storage staling. The effects of mulberry leaf polysaccharides (MLP) were studied in terms of baking, retrogradation and microstructural aspects in frozen dough bread.

RESULTS

The incorporation of MLP improved the specific volume and reduced the hardness of bread during room storage, with 1% MLP showing the best results. The results of X-ray diffraction and Fourier transform infrared spectroscopy showed that crystallinity was decreased and the formation of double helical structure was inhibited with the incorporation of MLP. Meanwhile, the results of low-field nuclear magnetic resonance demonstrated that the addition of MLP was advantageous for retarding water migration and distribution, with reduced water loss. It can be seen intuitively from scanning electron microscopy that MLP improved the gluten network with a smoother and flatter system.

CONCLUSION

MLP improved the quality of bread during storage and delayed the degradation of internal structure, and can be used as an effective natural additive to improve the storage stability of baked food. 1% MLP showed the best results. © 2022 Society of Chemical Industry.

Effect of freeze-thaw cycles on the physicochemical properties and frying performance of frozen Youtiao dough

The impact of freeze-thaw cycles on the physicochemical properties and frying performance of frozen Youtiao dough with chemical leavening agent was investigated. The specific volume of Youtiao made from frozen dough decreased by 66% after 4 freeze-thaw cycles. Meanwhile, the hardness and puncture force showed increasing trends, and the fibrous structure became unclear. The extensibility, storage modulus (G') and loss modulus (G'') of frozen Youtiao dough decreased during freeze-thaw cycles, while the creep compliance increased. Changes in rheological properties demonstrated that frozen Youtiao dough was more deformable and its strength was weakened. Moreover, the sodium dodecyl sulfate (SDS) extractable protein and free sulfhydryl content increased, revealing that protein was depolymerized. The loose structure with large pores and fractured protein network were observed by micromorphology. Freeze-thaw cycles had a detrimental effect on the Youtiao quality, which was related to the deterioration of rheological properties and protein structure of frozen Youtiao dough.

Assessment of Physicochemical and Rheological Properties of Xylo-Oligosaccharides and Glucose-Enriched Doughs Fermented with BB-12

Simple Summary

Xylo-oligosaccharides (XOS) are considered indigestible fibers that could support the growth of potentially beneficial gut microbes, thus classified as “prebiotics”. Prebiotics are “a substrate that is selectively utilized by host microorganisms conferring a health benefit” as defined by the International Scientific Association for Probiotics and Prebiotics. The current work aimed to study the effect of XOS and glucose addition on wheat flour sourdough fermented with Bifidobacterium animalis subsp. lactis (BB-12) strain in terms of organic acid production and on the rheological properties of the doughs. The effect of XOS addition increased the production of organic acids, and positively influenced the rheological properties of the dough. Additionally, after frozen storage, there were no significant viscoelastic changes in the dough structure, which indicates that xylo-oligosaccharides improved the water retention capability of the dough. Through fermentation carbohydrates like, glucose, xylose, maltose, and XOS were consumed, and a high quantity of lactic and acetic acid were produced, organic acids with roles in the flavor generation and sensorial properties of the final product. This study showed the potential use of XOS as food ingredient in sourdoughs for bakery products manufacturing with improved quality and rheological properties.

Abstract

Xylo-oligosaccharides (XOS) are considered non-digestible fibers produced mainly from agricultural biomass and are classified as “emerging prebiotic” compounds. Since XOS were shown to promote the growth of bifidobacteria in the gut with potential effects on one’s health, scientists used them as food ingredients. For example, the addition of XOS in bakery products could improve their physicochemical characteristics. The current work aimed to investigate the effect of XOS and glucose addition on wheat flour sourdough fermented with Bifidobacterium animalis subsp. lactis (BB-12) strain in terms of organic acid production. The effect on viscoelastic changes during frozen storage and after the thawing process was also studied. The results showed that the viability of BB-12 increased slightly with the increase in XOS and glucose concentrations, which determined dough acidification due to accumulation of organic acids, that positively influenced the dough’s rheological properties such as a higher elasticity before and after frozen storage. With 10% XOS-addition, the acetic acid quantity reached 0.87 ± 0.03 mg/L, and the highest lactic acid concentration was found in the 10% XOS-enriched doughs, the glucose-enriched doughs and in the control sample (100% wheat dough). The quantity of glucose, maltose, XOS, and xylose decreased until the end of fermentation.

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.