Polydextrose Research Articles

Mechanism of emulsion stabilized by an ultrasonically prepared protein-polyphenol-polysaccharide complex: structure, functional properties and interfacial behavior.

Polydextrose (PDX), as a prebiotic, is an extensively branched glucose polymer that can promote the growth of beneficial bacteria in the gut. Recent research indicates that PDX regulates intestinal function and supports immune balance, which helps to protect the gut from pathogenic bacteria. However, scarce research has been found that PDX prevents the host infection through the direct effects on the pathogen. In this study, we developed a mouse model infected with Klebsiella pneumoniae by pretreating with PDX, assessed the effect of PDX on K. pneumoniae acute infection in mice, and explored its potential mechanisms. We developed a mouse model that is infected with K. pneumoniae by pretreating with PDX. Colony counting quantified the K. pneumoniae bacterial load in the parenchymal organs of mice. A scanning electron microscope was used to investigate the morphological characteristics of K. pneumoniae. The expression level of TamA (translocation and assembly module A) was detected by reverse transcription-polymerase chain reaction (RT-PCR) and western blotting. The CRISPR-Cas9 technique was applied to construct the tamA mutant strains (ΔtamA) and the tamA complement strain (C-ΔtamA). The biofilm formation capacity was evaluated by the crystal violet assay. The capsule production was quantified by measuring uronic acid content. In the PDX pretreated model, PDX did not alter the growth characteristics and morphological structure of K. pneumoniae. However, it significantly reduces the load of K. pneumoniae in the lung, liver, spleen, and intestinal tract of mice, which is related to inhibiting the expression of the outer membrane TamA protein by PDX. In an in vitro study, the results indicated that deletion of tamA significantly inhibited capsule production and biofilm formation of K. pneumoniae, weakened interspecific and intraspecific competitive abilities with other members of the Enterobacteriaceae family, and reduced the adhesion ability to Caco-2 and murine lung epithelial (MLE) cells. Compared with the wild strain, PDX treatment and the deletion of tamA inhibit the expression of adhesion factors (including FimH, FimC, FimD, and MrkD) and the capsule synthesis genes (including galF, wzi, and manC) in K. pneumoniae. PDX can prevent the infection of K. pneumoniae in mice. The potential mechanism may involve downregulating TamA expression and inhibiting adhesion-related molecules. Therefore, PDX can serve as a potential prebiotic to reduce K. pneumoniae infections in both humans and animals.IMPORTANCEOur findings revealed that polydextrose (PDX) could significantly reduce the load of Klebsiella pneumoniae in the lung, liver, spleen, and intestinal tract of mice. The potential mechanism is related to inhibiting the expression of the outer membrane TamA protein by PDX. The deletion of tamA significantly inhibited the capsule production and biofilm formation of K. pneumoniae, weakened the interspecific and intraspecific competitiveness ability with other members of the Enterobacteriaceae family, and reduced the adhesion ability to Caco-2 and MLE cells. Our data suggest that PDX may act as a prebiotic to reduce K. pneumoniae infections in humans and animals.

Background/Objectives: Environmental stressors, including spaceflight and altered gravity, can negatively affect the symbiotic relationship between the gut microbiome and host health. Dietary prebiotics, which alter components of the gut microbiome, show promise as an effective way to mitigate the negative impacts of stressor exposure. It remains unknown, however, if the stress-protective effects of consuming dietary prebiotics will extend to chronic altered-gravity exposure. Methods: Forty female C57BL/6 mice consumed either a control diet or a prebiotic diet containing galactooligosaccharides (GOS) and polydextrose (PDX) for 4 weeks, after which half of the mice were exposed to 3 times the gravitational force of Earth (3g) for an additional 4 weeks. Fecal microbiome samples were collected weekly for 8 weeks, sequenced, and analyzed using 16S rRNA gene sequencing. Terminal physiological endpoints, including immune and red blood cell characteristics, were collected at the end of the study. Results: The results demonstrate that dietary prebiotic consumption altered the gut microbial community structure through changes to β-diversity and multiple genera across time. In addition, consuming dietary prebiotics reduced the neutrophil-to-lymphocyte ratio (NLR) and increased red blood cell distribution width (RDW-CV). Importantly, the prebiotic diet prevented the impacts of altered-gravity on β-diversity and the bloom of problematic genera, such as Clostridium_sensu_stricto_1 and Turicibacter. Furthermore, several prebiotic diet-induced genera-level changes were significantly associated with several host physiological changes induced by 3g exposure. Conclusions: These data demonstrate that the stress-protective potential of consuming dietary prebiotics extends to environmental stressors such as altered gravity, and, potentially, spaceflight.

Consumer scrutiny of fat content in foods is becoming a notable trend in health concerns. This study aims to develop a novel functional low-fat goat feta cheese by utilizing polydextrose (PDX) and inulin as dietary fiber-based fat replacers to improve its overall characteristics. The physicochemical and textural properties, along with consumer acceptance, of the feta cheese were evaluated across three fat levels (full-fat [FFC], reduced-fat [RFC], low-fat [LFC]) and three fibers: PDX, inulin, and their combination. The intercorrelation of all characteristics was assessed through principal component analysis and Pearson’s correlation. Fat reduction significantly altered the cheese’s visual properties, increasing lightness and the total color difference, which inversely correlated with a* and b* values. Lower-fat cheeses exhibited decreased pH and increased lactic acid, with salinity playing a crucial role in both lactic acid development and texture. Under Scanning Electron Microscopy (SEM), PDX yielded a cheese matrix with a finer pore structure than inulin or the combined fibers. Lower-fat cheeses exhibited greater hardness, with PDX resulting in the highest hardness among the fiber treatments. Crucially, the RFC with PDX was as well-received by consumers as the FFC. These findings not only empower goat farmers and cheese entrepreneurs to increase their product value for niche market but also contribute to sustainability by providing a healthier food option for functional benefits.

Abstract Introduction Insufficient sleep and circadian misalignment dysregulate glucose homeostasis. Interventions are needed for when insufficient sleep and circadian misalignment cannot be avoided (e.g., military operations, emergency responders, shift work). Prebiotics, defined as a substrate that is selectively utilized by host microorganisms conferring a health benefit, have been shown to beneficially affect glucose metabolism in non-human preclinical models and in humans. Here, we examined in a pilot study the effects of a combined Polydextrose (PDX) and Galacto-oligosaccharide (GOS) prebiotic supplement on 24-hour glucose levels during combined sleep restriction and circadian misalignment. Methods 5 healthy adults (aged 25.4±3.5, 2 females) completed a 39-day randomized, double-blind, placebo-controlled, cross-over study comparing a prebiotic–7.5g/day each of GOS [Frieslad Campina] and PDX [Dupont Nutrition & Biosciences] or placebo (maltodextrin [Grain Processing Corporation]) sachets dissolved in water with breakfast. Participants consumed 14 days of prebiotic or placebo at home while maintaining regular mealtimes and ~8h habitual sleep each night. Participants then completed an ~4-day in-laboratory study of combined sleep restriction and circadian misalignment with 3h sleep opportunities; the first at night and the second and third during the daytime. Prebiotic and placebo conditions continued in-laboratory. Timing and composition of food intake was identical during the in-laboratory segment for each condition and designed to maintain energy balance. Glucose levels were monitored every 15 min for ~60h using a continuous glucose monitor (FreeStyle Libre Pro [Abbott]). Participants had a 3-day washout period prior to repeating the protocol with the second condition. Mixed model ANOVA with condition and time as fixed factors were performed. Results Mean 24-hour glucose level over the ~60h of recording was significantly lower during prebiotic versus placebo treatment (p< 0.00001; Small effect size, Hedges’ g bias corrected). Conclusion Preliminary findings from this pilot study suggest that a combination of prebiotic fibers taken prior to and during insufficient sleep and circadian misalignment may have some benefits for glucose metabolism. Support (if any) Office of Naval Research MURI N00014-15-1-2809, NIH CTSA Grant Ul1-TR002535, NIH T32-HL149646, and Undergraduate Research Opportunities Grant University of Colorado Boulder.

Soy allergy is an important nutritional and health issue that needs to be addressed. Lactic acid bacteria (LAB) fermentation is an effective approach to reduce soy protein allergy. Polysaccharides are commonly used in LAB-fermented products to enhance their textural properties. This study proposes a new strategy for developing hypoallergenic soy protein products. We prepared a soy protein isolate (SPI) through fermentation with LAB (FSPI) and with five types of polysaccharides supplementation, namely polydextrose (PDX), inulin (IN), long-chain inulin (LCIN), soluble soy polysaccharides (SSPS), and β-glucan (BG). The texture and microstructure of different samples were analyzed. Antigenicity and IgE-binding capacity were determined using ELISA. Finally, peptide sequencing was used to identify the degradation degree and frequency of allergenic epitopes. Samples with added PDX (F-PDX) and IN (F-IN) exhibited lower hardness; smaller, irregular pores; and a honeycomb structure, whereas samples with SSPS (F-SSPS) and BG (F-BG) had higher hardness; large, regular pores; and strong sheet structures. The antigenicity and IgE-binding capacity of F-PDX and F-IN were lower both before and after 120 min of in vitro dynamic gastrointestinal digestion. The peptidomics results indicated that F-PDX and F-IN primarily facilitated the degradation of the glycinin G1 and G2 subunits, β-conglycinin α, and the β subunit. Moreover, it increased the frequency of destruction of allergenic epitopes, and further promoted the degradation of epitopes in the external α-helix structures of glycinin and β-conglycinin compared to FSPI. The addition of polysaccharides had a significant impact on the structure and allergenicity of the soy protein gel, especially PDX and IN.

Different dietary fibers have distinct structures, leading to significant variations in their laxative effects. To explore how these structural differences impact constipation intervention, a 14-day study was conducted on loperamide-induced constipated mice using five dietary fibers: soluble dietary fiber from steamed sweet potato (SDF-S), oat β-glucan (OB), polydextrose (PD), arabinogalactan (AG), and inulin (IN). The results showed that four fibers, excluding PD, significantly improved gastrointestinal (GI) transit rate (p < 0.05), although PD had the highest fecal moisture, it was significantly different from the lowest IN (p < 0.05). AG and IN resulted in higher 6 h fecal weights compared to other fibers. SDF-S and OB were more effective in modulating serum levels of gastrointestinal hormones. The different monosaccharide compositions and glycosidic bonds of these fibers led to distinct changes in gut microbiota composition and SCFA profiles. Galactose and arabinose in AG were linked to increased abundance of Lachnospiraceae_UCG-006, Bacteroides, and Odoribacter, promoting butyrate fermentation, which is positively correlated with GI transit rate. Glucose in SDF-S, OB, and PD favored acetate fermentation positively correlated with fecal moisture. Fructose in IN encouraged the proliferation of Muribaculaceae_unclassified and Ruminococcus, associated with butyrate fermentation and increased 6 h stool weight, respectively. The β-glycosidic bonds in OB may lead to high butyrate production through the selective proliferation of Lachnospiraceae_unclassified. Minor components like fucose, rhamnose, and ribose were positively correlated with the abundance of Oscillospiraceae_unclassified, Anaerotignum, and Lachnospiraceae_unclassified. In conclusion, the unique monosaccharide compositions and glycosidic bond differences in dietary fibers selectively promote the proliferation of fiber-degrading and butyrate-producing bacteria, resulting in varied effects on constipation relief.

The prevalence of childhood diabetes has been increasing, with diagnoses occurring at younger ages. Since excessive sugar intake is a key dietary risk, there is growing interest in reducing sucrose in foods by using low-glycemic alternatives. This study evaluated the effects of replacing sucrose with isomalto- oligosaccharides (IMO), fructo-oligosaccharides (FOS), and polydextrose (PDX) in soft milk candy on its physicochemical properties and consumer acceptance. A two-phase single-factor randomized block design was used, first testing each substitute, then evaluating the best candidate (IMO) at 50:50, 25:75, and 0:100 sucrose-to-substitute ratios. Measurements included moisture content, water activity, hardness, and color. Sensory attributes - aroma, texture, taste, color, and overall liking - were rated using a 9-point hedonic scale. Results showed that IMO increased moisture and water activity. PDX produced a softer texture, while FOS resulted in firmer candies. All substitutes reduced lightness (L value) compared to sucrose. Among all formulations, 50 % IMO replacement had the highest sensory scores, with overall liking similar to the sucrose control. Thus, partial substitution with IMO, particularly at 50 %, is a promising strategy to reduce sucrose while maintaining desirable sensory and physicochemical properties in soft milk candy.

Ergothioneine (EGT) is an effective antioxidant that animals cannot produce and has an important anti-inflammatory role in cell protection, which can help lower the risk of various diseases. In this study, we investigated the potential role of gut microbiota in the production of EGT, which was found to increase in the mouse liver after dietary supplementation with betaine (BET) or polydextrose (PDX). The effects of BET and PDX on the gut microbiota and tissue EGT content were investigated using a diet-induced obese mouse model and simulated fermentation in the human colon. Male C57BL/6J mice were fed a high-fat diet (HFD) for 8 weeks to induce obesity and related metabolic disorders, and for the last 4 weeks of this study, the mice continued on the same diet, supplemented with BET, PDX, or their combination. The potential function of BET and PDX in microbial EGT production was further studied in an in vitro human colon model. The quantity of Bifidobacterium spp. and Bacteroidota were significantly higher in the feces of mice on diets supplemented with PDX or BET + PDX, and Enterobacteriaceae levels were significantly higher in PDX-supplemented mice than in HFD-fed mice. Untargeted metabolomic analysis of the liver revealed a significant increase in EGT in mice fed HFDs with BET or BET + PDX. Microbial analysis from samples collected from the human in vitro model showed significant changes in Neglecta timonensis, Blautia faecis, Lachnospiracea incertae sedis, Faecalibacillus, and Stenotrophomonas maltophilia species, along with an increase in microbial metabolites, namely, acetic, propionic and butyric acids, and a decrease in 2-methylbutyric acid. Although PDX and BET or their combination affected microbial composition and metabolites in the human colon simulation model, the model used was not able to detect a significant change in microbiota-based EGT production and, therefore, could not explain the increase in EGT in the liver of betaine-fed mice.

The gut microbiome is impacted by certain types of dietary fibre. However, the type, duration and dose needed to elicit gut microbial changes and whether these changes also influence microbial metabolites remain unclear. This study investigated the effects of supplementing healthy participants with two types of non-digestible carbohydrates (resistant starch (RS) and polydextrose (PD)) on the stool microbiota and microbial metabolite concentrations in plasma, stool and urine, as secondary outcomes in the Dietary Intervention Stem Cells and Colorectal Cancer (DISC) Study. The DISC study was a double-blind, randomised controlled trial that supplemented healthy participants with RS and/or PD or placebo for 50 d in a 2 × 2 factorial design. DNA was extracted from stool samples collected pre- and post-intervention, and V4 16S rRNA gene sequencing was used to profile the gut microbiota. Metabolite concentrations were measured in stool, plasma and urine by high-performance liquid chromatography. A total of fifty-eight participants with paired samples available were included. After 50 d, no effects of RS or PD were detected on composition of the gut microbiota diversity (alpha- and beta-diversity), on genus relative abundance or on metabolite concentrations. However, Drichlet’s multinomial mixture clustering-based approach suggests that some participants changed microbial enterotype post-intervention. The gut microbiota and fecal, plasma and urinary microbial metabolites were stable in response to a 50-d fibre intervention in middle-aged adults. Larger and longer studies, including those which explore the effects of specific fibre sub-types, may be required to determine the relationships between fibre intake, the gut microbiome and host health.

Maillard reacted wheat gluten and polydextrose complex enhances the emulsifying properties and stability of pickering emulsion

Real-time monitoring of peptic and tryptic digestions of immunoglobulin G and the impact of dietary hydrocolloids on digestion

Despite substantial evidence supporting the efficacy of prebiotics for promoting host health and stress resilience, few experiments present evidence documenting the dynamic changes in microbial ecology and fecal microbially modified metabolites over time. Furthermore, the literature reports a lack of reproducible effects of prebiotics on specific bacteria and bacterial-modified metabolites. The current experiments examined whether consumption of diets enriched in prebiotics (galactooligosaccharides (GOS) and polydextrose (PDX)), compared to a control diet, would consistently impact the gut microbiome and microbially modified bile acids over time and between two research sites. Male Sprague Dawley rats were fed control or prebiotic diets for several weeks, and their gut microbiomes and metabolomes were examined using 16S rRNA gene sequencing and untargeted LC-MS/MS analysis. Dietary prebiotics altered the beta diversity, relative abundance of bacterial genera, and microbially modified bile acids over time. PICRUSt2 analyses identified four inferred functional metabolic pathways modified by the prebiotic diet. Correlational network analyses between inferred metabolic pathways and microbially modified bile acids revealed deoxycholic acid as a potential network hub. All these reported effects were consistent between the two research sites, supporting the conclusion that dietary prebiotics robustly changed the gut microbial ecosystem. Consistent with our previous work demonstrating that GOS/PDX reduces the negative impacts of stressor exposure, we propose that ingesting a diet enriched in prebiotics facilitates the development of a health-promoting gut microbial ecosystem.

Life in space presents significant challenges to mammalian physiology and the longer one is in space, the greater the impact. Three major stressors are present in space: 1) changes in gravitational environment, 2) psychological/physiological stress, and 3) constant low dose radiation. It is critical, therefore, to discover interventions that promote stress resilience. Dietary prebiotics selectively increase the relative abundances of probiotic bacterial species in the gut. We have previously reported that a diet enriched in galactooligosaccharide (GOS) and polydextrose (PDX) compared to control diet robustly elevates parabacteroides distasonis, clostridium leptum, and reduces the negative impact of acute and chronic stress. Interoceptors (e.g., baroreceptors) sense gravity-induced changes in blood pressure and cardiac function/structure. There is evidence that hypergravity disrupts autonomic and cardiovascular homeostasis and function. Cardiovascular homeostasis depends on a sympathetic and parasympathetic balance reflected in heart rate variability (HRV), a measure of cardiovascular stress. The following study was designed to test the hypothesis that GOS+PDX reduces the cardiovascular impacts of living in an altered gravitational environment. Adult female mice were housed in 1G or 3G and were fed GOS+PDX or a matched control diet for 4 weeks on the NASA Ames 1.22-meter radius centrifuge. We recorded electrocardiograms (ECG) in animals from all four groups immediately before, halfway through, and immediately after centrifugation. We analyzed HRV data using a Python-based Jupyter notebook and R. R was used to perform a 1F-LD-1F ANOVA with pair-wise comparisons to quantify changes in HRV longitudinally. Classic time domain based HRV metrics, standard deviation of the successive differences between adjacent R-R intervals and standard deviation of NN intervals, showed little change over time. Instead, frequency domain measures showed results were housing in 3G compared to 1G reliably changed Shannon entropy, Sample entropy, and low to high frequency ratio at each time-point. The changes across time reflected adaptation to hypergravity and a consequent reduction in HRV. Poincare plot analysis and low to high frequency ratio metrics showed divergent compensatory reactions between diets at 3G. Overall, 3G impacted HRV less in mice that were fed the prebiotic diet compared to the control diet. Further longitudinal studies with greater temporal resolution are needed to assess changes in HRV caused by gravitational changes. However, our data suggests the prebiotic diet significantly reduces 3G activation of sympathetic drive and increases parasympathetic drive, potentially reducing cardiovascular stress in animals exposed to high gravity. NASA grant 80NSSC19K1038 funded this project. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Comparison of the in-vitro effect of five prebiotics with different structure on gut microbiome and metabolome

Single nutrient likes polyphenol or dietary fiber have been exhaustively investigated to validate their positive intervention in health or disease. Meanwhile, the common interaction of inner systems with the nutrient complex has not been well elucidated, which raises the scientific issue of the modulatory effect of the nutrient complex on immunity. The representative prebiotics of epigallocatechin-3-gallate (EGCG), ginseng extract, and polydextrose (PDX) were selected on behalf of the classification of polyphenol, flavone or polysaccharides, and dietary fiber to generally cover the daily food intake in this study to explore their intervention in inflammation and macrophage polarization. The intervention of selected nutrients on inflammation and macrophage polarization has been evaluated against macrophages to unveil their comprehensive effects. The synergistic effect of selected nutrients was demonstrated by inhibiting M1 macrophage polarization and the promotion of M2 macrophage polarization. Then, the nutrient formula was set up to verify the intervention effect, and the results revealed the significant inhibition of cell inflammation and the effect on cell proliferation through promoting the cell cycle in the G2 phase. The nutrient complex could inhibit M1 macrophage polarization to inhibit M1-mediated inflammation and promote M2 macrophages for anti-inflammatory effect and enhance cell phagocytosis. Moreover, the varied intervention effects of the nutrient complex with different formulas could be summarized. In general, the formula containing EGCG, ginseng extract, and PDX was demonstrated to possess an enhanced immunomodulatory effect on cell inflammation and macrophage polarization, which could potentially inspire the investigation of complex nutrients in health and diseases.

To explore the protective effect of different ratios of galactose oligosaccharide(GOS) and polydextrose(PDX) on intestinal cell barrier damage model of Caco-2. The same batch of Caco-2 cells were cultured to form a cell barrier model and randomly divided into damaged model group without calcium, calcium-containing blank control group(1.8 mmol/L Ca~(2+)), low-ratio/low-dose group(1.8 mmol/L Ca~(2+)+2 mg/mL GOS+2 mg/mL PDX) and low-ratio/medium-dose group(1.8 mmol/L Ca~(2+)+4 mg/mL GOS+4 mg/mL PDX), low-ratio/high-dose group(1.8 mmol/L Ca~(2+)+8 mg/mL GOS+8 mg/mL PDX) and high-ratio/low-dose group(1.8 mmol/L Ca~(2+)+0.8 mg/mL GOS+3.2mg/mL PDX), high-ratio/medium-dose group(1.8 mmol/L Ca~(2+)+1.6 mg/mL GOS+6.4 mg/mL PDX), high-ratio/high-dose group(1.8 mmol/L Ca~(2+)+3.2mg/mL GOS+12.8 mg/mL PDX), a total of 8 groups, three parallel groups were performed in each group. The Trans Epithelial Electrical Resistance value and apparent permeability coefficient value of each group were determined after 4 d culture, and the morphology of tight junction proteins ZO-1, Occludin and Claudin-1 were observed by immunofluorescence method, and the expression levels of inflammatory related factors in each group were determined by protein microarray method. Compared with damaged model group, TEER ratio in calcium-containing blank control group was significantly increased(P&lt;0.05), while Papp value was significantly decreased(P&lt;0.05);Compared with calcium-containing blank control group, TEER ratio in low-ratio/medium-dose group and high-ratio/high-dose group was significantly increased(P&lt;0.05) while Papp value was significantly decreased(P&lt;0.05), and they could significantly down-regulate some inflammatory response related cytokines. The cell barrier was intact in all groups except for the compact junction protein structure in the model group. Compared with Ca~(2+) alone, the combination of two prebiotics can enhance the density of Caco-2 cell barrier and reduced the permeability of cell bypass. And it can significantly reduce the expression level of some inflammatory cytokines and effectively protect the intestinal cell barrier.

The impact of prebiotics on the structural characteristics of yogurt is an important aspect of evaluating its functional properties. This study aimed to evaluate and compare the effects of several commonly used prebiotics, including fructooligosaccharide (FOS), galactooligosaccharide (GOS), inulin (INU), polydextrose (PDX), and xylooligosaccharide (XOS), on the gel properties of milk protein and the structural features, with respect to the texture and rheology, of stirred yogurt during and after fermentation. The results revealed that the supplementation of INU, PDX, and XOS was involved in the construction of protein networks during fermentation, promoting a viscous and more elastic gel structure, due to the enhanced protein–water interactions. This resulted in a significant increase (p < 0.05) in structural stability (higher critical strain (γc) and greater thixotropy), firmness, cohesiveness, and rheology (G′ and G″) and a significant decrease (p < 0.05) in the loss of yogurt during centrifugation. Conversely, the supplementation of GOS and FOS did not appear to be involved in the construction of the protein network and barely affected the rheological properties of the gel during fermentation. However, a significant increase (p < 0.05) in viscosity and firmness, and a slight decrease (p > 0.05) in loss during centrifugation were still observed in the yogurt. These findings could be useful for a comprehensive assessment of the application potential of these prebiotics in yogurt, when combined with their respective prebiotic properties.

The surimi-like material made from duck (DSLM) was investigated on the freeze-thaw stability during 4 months of frozen storage using different low-sweetness cryoprotectants such as palatinose (PAL), trehalose (TRE), polydextrose (PLD), maltodextrin (MAL), sucrose and sorbitol (SS), and lactitol (LAC) at a 6% concentration. As compared to the CON, the inclusion of cryoprotectants significantly improved the water-holding capacity of all treated samples. Particularly, as compared to all of the cryoprotectants evaluated, the PLD and PAL samples displayed greater stability concerning Ca2+-ATPase activity, sulfhydryl concentration, and protein solubility. All samples' endothermic peaks declined over time, showing changes in thermal characteristics during storage. A scanning electron microscope (SEM) observation of the CON and LAC-treated samples after 4 months of frozen storage revealed an increase in the number of pores. These findings imply that low-sweetness PLD and PAL outperformed the usual cryoprotectant combination of sucrose and sorbitol (SS) and that they could be used in frozen DSLM. They provide greater water-holding capacity, anti-freezing characteristics, lowered sulfhydryl oxidation, increased protein solubility, and structural integrity, which renders them useful components for innovation in the frozen surimi-like material industry.

The characteristics and the functions of Maillard reaction products (MRPs) produced by polydextrose (PD), a new type of prebiotic, and α-lactalbumin (α-LA) were valued. PD and α-LA were incubated at 60 °C and 79% relative humidity for up to 72 h to prepare MRPs. The results showed that the absorbance and fluorescence intensity of heated α-LA-PD increased, and the amount of free amino groups reduced as the reaction progressed, which confirmed the formation of different stages of MRPs. Electrophoresis revealed an increase in molecular mass and the degree of covalent cross-linking. The secondary structure of MRPs experienced no significant changes with the measurement of circular dichroism (CD), while the tertiary structure gradually unfolded, exposing hydrophobic groups. Furthermore, a significant increase was detected in the radical-scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the ferric reducing/antioxidant power (FRAP) of MRPs. The findings offer a foundation for understanding the structural and functional features of MRPs in formula milk powder.