Simultaneous extraction of oil, protein and polysaccharide from Idesia polycarpa Maxim cake meal using ultrasound combined with three phase partitioning.

This study explored the potential of ultrasonic-assisted three-phase partitioning (UTPP) to simultaneously extract lipids, proteins, and polysaccharides from Idesia polycarpa Maxim (IPM) cake meal, a significant byproduct of oil extraction. The impact of variables such as inorganic salt type, solid-liquid ratio, salt concentration, pH, ultrasonic time, temperature, and volume of dimethyl carbonate was examined. Based on the single-factor tests and response surface methodology (RSM), optimal conditions were identified as 30 % ammonium citrate, a 1:26 solid-liquid ratio, pH 3, 31 min of ultrasonic time, 30 °C temperature, and 15 mL of dimethyl carbonate. These conditions achieved extraction rates of 8.10 % for lipids, 5.03 % for proteins, and 10.03 % for polysaccharides, with recovery rates of 91.62 %, 83.08 %, and 93.95 % respectively. Chemical analysis showed the lipid fraction rich in linoleic acid, and the protein fraction high in glutamic acid, aspartate, and serine. The polysaccharide fraction, mainly RG-I pectin with a molecular weight of 226.58 kDa, exhibited strong thermal stability and inhibitory effects on α-glucosidase and glycation, suggesting potential for functional food and dietary supplement applications. This highlights UTPP as a sustainable method for effectively utilizing valuable compounds from IPM cake meal, outperforming traditional extraction techniques.

Polysaccharides from Seedless Chestnut Rose (Rosa sterilis) Fruits: Insights into Innovative Drying Technologies and Their Structural Characteristics, Antioxidant, Antiglycation, and α-Glucosidase Inhibitory Activities.

The selection of an optimal drying method is essential for extending the shelf life and enhancing the quality of Rosa sterilis fruits. This study investigated the effects of both innovative (microwave vacuum drying and infrared drying) and traditional (freeze-drying and hot air drying) techniques on the structural characteristics and bioactivities of polysaccharides from R. sterilis fruits (RSPs). Four different RSPs were obtained from fruits dried using these methods. Results demonstrated that the structural characteristics and bioactivities of RSPs varied significantly with the drying method. Notable differences were observed in extraction yield, total sugar, uronic acid content, monosaccharide molar ratios, molecular weight distribution, particle size, thermal stability, and microstructures of RSPs. Despite these variations, the types of constituent monosaccharides and major glycosidic linkages remained consistent across all methods. Notably, RSPs obtained via microwave vacuum drying (RSPs-MVD) showed a higher uronic acid content and lower molecular weight, and exhibited stronger in vitro antioxidant, α-glucosidase inhibitory, and antiglycation activities. These findings suggest that microwave vacuum drying is an effective pre-drying technique for extracting RSPs, making them suitable as bioactive ingredients in functional foods and pharmaceuticals for managing diabetes mellitus and its complications.

Effects of Different Drying Methods on the Structural Characteristics and Multiple Bioactivities of Rosa roxburghii Tratt Fruit Polysaccharides.

Drying conditions significantly impact the compositions and microstructures of polysaccharides, leading to various effects on their chemical characteristics and bioactivities. The objective of this study was to investigate how different industrial drying techniques, i.e., hot air drying, infrared drying, microwave vacuum drying, and freeze drying, affect the structural properties and biological activities of polysaccharides extracted from Rosa roxburghii Tratt fruit (RRTP). Results revealed that these drying methods significantly altered the extraction yield, molecular weights, monosaccharide ratios, contents of uronic acid and total sugars, gelling properties, particle sizes, thermal stability, and microstructures of RRTPs. However, the monosaccharide composition and functional groups of polysaccharides remained consistent across the different drying techniques. Biological activity assays demonstrated that RRTPs, particularly those processed through microwave vacuum drying (MVD-RRTP), exhibited excellent anti-linoleic acid oxidation, robust anti-glycosylation effects, and significant α-glucosidase inhibition in vitro. The outcomes of this research demonstrate that microwave vacuum drying serves as an effective pre-extraction drying method for RRTPs, enhancing their biological activities. This technique is particularly advantageous for preparing RRTPs intended for use in functional foods and pharmaceuticals, optimizing their health-promoting properties for industrial applications.

In vitro digestion and fermentation characteristics of soluble dietary fiber from adlay (Coix lacryma-jobi L. var. ma-yuen Staft) bran modified by steam explosion.

Adlay bran is known for its nutrient-rich profile and multifunctional properties, and steam explosion (SE) is an emerging physical modification technique. However, the specific effects of SE on the activity composition and antioxidant capacity of adlay bran soluble dietary fiber (SDF) during in vitro digestion, as well as its influence on gut microbiota during in vitro fermentation, remain inadequately understood. This paper reports the in vitro digestion and fermentation characteristics of soluble dietary fiber from adlay bran modified by SE (SE-SDF). Compared with the untreated samples (0-SDF), most of the phenolic compounds and antioxidant capacity were significantly increased in the SE-SDF digests. Additionally, SE was beneficial for adlay bran SDF to increase the content of acetic acid, propionic acid and total short-chain fatty acids (SCFAs) in fermentation broth during in vitro fermentation. SE-SDF could promote the growth of beneficial bacteria while inhibiting the proliferation of pathogenic microbes. Our research indicates that SE-SDF shows strong antioxidant properties after in vitro digestion and plays a pivotal role in regulating gut microbiota during in vitro fermentation, ultimately enhancing human intestinal health.

Ultrasonic-Assisted Decoloration of Polysaccharides from Seedless Chestnut Rose (Rosa sterilis) Fruit: Insight into the Impact of Different Macroporous Resins on Its Structural Characterization and In Vitro Hypoglycemic Activity.

Pigments within polysaccharides pose significant challenges when analyzing their structural characteristics and evaluating their biological activities, making decolorization a crucial step in purifying these biomolecules. In this research, a novel approach using ultrasound-assisted static adsorption with macroporous resins was employed to decolorize polysaccharides extracted from seedless chestnut rose (Rosa sterilis S. D. Shi) fruit (RSP). Among the fourteen tested resins, AB-8, D101, D4020, HPD100, and S8 were identified as the most effective, demonstrating superior decoloration efficiency and polysaccharide recovery. Further examinations of RSPs treated with these five resins revealed distinct effects on their uronic acid levels, monosaccharide makeup, molecular weight, surface structure, and hypoglycemic properties. The RSP treated with HPD100 resin stood out for having the highest uronic acid content, smallest particle size, and lowest molecular weight, leading to the most notable inhibition of α-glucosidase activity through a mixed inhibition model. The application of HPD100 resin in the decolorization process not only potentially preserved the macromolecular structure of RSP but also enhanced its hypoglycemic efficacy. These findings provide a solid theoretical basis for further exploring RSP as a component of functional foods, underscoring the effectiveness of the ultrasound-assisted resin adsorption method in polysaccharide purification.

Comparative Study on the Impact of Different Extraction Technologies on Structural Characteristics, Physicochemical Properties, and Biological Activities of Polysaccharides from Seedless Chestnut Rose (Rosa sterilis) Fruit.

Seedless chestnut rose (Rosa sterilis S. D. Shi, RS) is a fresh type of R. roxburghii Tratt with copious functional components in its fruit. Polysaccharides are recognized as one of the vital bioactive compounds in RS fruits, but their antioxidant and hypoglycemic properties have not been extensively explored. Hence, in this study, accelerated solvent extraction (RSP-W), citric acid (RSP-C), 5% sodium hydroxide/0.05% sodium borohydride (RSP-A), and 0.9% sodium chloride (RSP-S) solution extraction were individually utilized to obtain RS fruit polysaccharides. The physicochemical properties, structural characteristics, and biological activities were then compared. Results indicated that extraction methods had significant influences on the extraction yield, uronic acid content, monosaccharide composition, molecular weight, particle size, thermal stability, triple-helical structure, and surface morphology of RSPs apart from the major linkage bands and crystalline characteristics. The bioactivity tests showed that the RSP-S, which had the greatest amount of uronic acid and a comparatively lower molecular weight, exhibited more potent antioxidant and α-glucosidase inhibitory property. Furthermore, all RSPs inhibited α-glucosidase through a mixed-type manner and quenched their fluorescence predominantly via a static quenching mechanism, with RSP-S showing the highest binding efficiency. Our findings provide a theoretical basis for utilizing RSPs as functional ingredients in food industries.

Effects of agro-forestry systems on the physical and chemical characteristics of green coffee beans.

Twenty agroforestry systems consisting of different management practices (conventional and organic) and shade types were set up for coffee plantations in 2,000 at the Tropical Agricultural Research and Higher Education Center (CATIE), Turrialba, Costa Rica. The physical (density, bulk density, moisture content, and roasting loss) and chemical attributes (mineral, total lipid, fatty acids, caffeine, and carbohydrate contents) of harvested green coffee beans were investigated. The full sun and Erythrina shade tree systems significantly improved (p < 0.05) the density of the green coffee beans and decreased (p < 0.05) the moisture content and roasting loss of the green coffee beans. The intensive organic (IO) management practice significantly increased some mineral contents, such as K, P, and Ca, in green coffee beans. The full sun system also significantly promoted (p < 0.05) some mineral contents, such as Ca and Mn, in green coffee beans. In terms of total lipid and fatty acids (FAs), compared with the moderate conventional (MC) management practice, the IO management practice was beneficial as it significantly increased (p < 0.05) the total lipid and FAs contents in the green coffee beans, while the Erythrina shade tree system significantly increased (p < 0.05) the total lipid and FAs contents of green coffee beans more efficiently than the other shade types. The caffeine content of green coffee beans was significantly higher (p < 0.05) under the intensive conventional (IC) and IO management practices than under the MC management practice and higher under the full sun system than under the shaded system. The Erythrina shade tree system significantly improved (p < 0.05) the carbohydrate content of green coffee beans. Overall, in consideration of sustainability, the IO management practice associated with the Erythrina shade tree system would be a useful combination for the local farmers to grow coffee trees.

Comparison of different drying technologies for brocade orange (Citrus sinensis) peels: Changes in color, phytochemical profile, volatile, and biological availability and activity of bioactive compounds.

This study evaluated the effects of freeze drying (FD), heat pump drying (HPD), microwave drying (MD), and far-infrared drying (FID) on the quality of brocade orange peels (BOPs). Although the most attractive appearance, maximum levels of ascorbic acid (0.46 mg/g dry weight (DW)), carotenoids (total 16.34 µg/g DW), synephrine (15.58 mg/g DW), limonoids (total 4.60 mg/g DW), phenols (total 9142.80 µg/g DW), and antioxidant activity were observed in FD-BOPs, many aroma components in FD-BOPs were in the minimum levels. HPD-, and MD-BOPs depicted similar trends to FD-BOPs, but they contained the highest concentrations of limonene and ß-myrcene. Phenols and ascorbic acid in MD-BOPs generally featured the highest levels of bioavailability, being to 15.99% and 63.94%, respectively. In comparison, FID was not beneficial for the preservation of bioactive compounds and volatile. Therefore, considering time and energy costs, HPD and particularly MD are more appropriate for the commercial production of dried BOPs.

Physicochemical, structure properties and in vitro hypoglycemic activity of soluble dietary fiber from adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) bran treated by steam explosion.

To enhance the content of adlay bran soluble dietary fiber (SDF) and improve its functionality, we investigated the influences of steam explosion (SE) on the physicochemical, structural properties, and in vitro hypoglycemic activities of adlay bran SDF. The cellulose, hemicellulose, and lignin contents of adlay bran decreased significantly after SE treatment. When the SE strength was 0.8 MPa for 3 min, the SDF content was 9.37%, which was a significant increase of 27.48% compared to the control. Under these conditions, SDF showed the highest oil-holding capacity (OHC) (2.18 g/g), cholesterol adsorption capacity (CAC) (27.29 mg/g), glucose adsorption capacity (GAC) (15.54 mg/g), glucose dialysis retardation index (GDRI) (36.57%), and α-Amylase activity inhibition ratio (α-AAIR) (74.14%). Compared with SDF from untreated adlay bran, SDF from SE-treated adlay bran showed lower weight molecular. In addition, differential scanning calorimetry (DSC) measurement showed that the peak temperature of SDF from adlay bran treated by SE increased by 4.19°C compared to the untreated SDF sample. The structure of SDF from adlay bran treated by SE showed that the SDF surface was rough and poriferous and the specific surface areas increased. In conclusion, SE pretreatment increases the content of SDF in adlay bran and improves its physicochemical, structural properties, and biological activities, which will be beneficial for the further exploitation of adlay bran.

Characterization of sonicated gluten protein and subsequent rheological properties of model dough and noodles.

BACKGROUND: The present study aimed to investigate the effects of the thermo-mechanical and rheological properties of a wheat gluten-sonicated model dough and noodles, as well as the effects of ultrasonic frequency (20, 28, 40, 68 and 80 kHz) on the functional properties and structural features of gluten. RESULTS: Water absorption, stability and developmental time, and viscoelastic behavior of gluten-sonicated model dough were all found to be improved. Water absorption, tensile resistance and stretching distance of noodles increased markedly, whereas cooking loss decreased. Ultrasonication at different frequencies also significantly affected gluten structure, including its surface hydrophobicity, micro-network structure, and secondary and tertiary structures. These alterations then caused changes in its functional characteristics. Compared to untreated gluten, sonicated gluten exhibited significantly increased oil and water capacities (8.75-15.26% and 100.65-127.71% higher than the untreated gluten, respectively), foaming and emulsifying properties, and increased solubility (63.46-98.83% higher than control). In addition, these findings indicated that 40 kHz was the likely resonance frequency of the cavitation bubble in the gluten solution. However, sodium dodecyl sulfate-polyacrylamide gel electrophoresis electropherograms revealed that such treatments did not affect the molecular weight of gluten, which was also consistent with its unchanged disulfide bond content. CONCLUSION: The present study clarified the impact of frequency on the properties of gluten and model dough. The best frequency for modification of gluten was 40 kHz. Collectively, these findings suggest that ultrasonic technology has the potential for use in modifying wheat gluten and commercial noodle processing. © 2022 Society of Chemical Industry.

lncRNA BBOX1-AS1 silencing inhibits esophageal squamous cell cancer progression by promoting ferroptosis via miR-513a-3p/SLC7A11 axis.

Long noncoding RNA BBOX1 antisense 1 (BBOX1-AS1) has been demonstrated to play important roles in several tumors. However, the expression and function of BBOX1-AS1 in esophageal squamous cell cancer (ESCC) have not been defined. Here, BBOX1-AS1 expression in 78 collected ESCC tissues, paired adjacent normal tissues, and ESCC cell lines were analyzed using quantitative real-time polymerase chain reaction. The overall survival of the patients was also studied. Cell proliferation, invasion, and migration were verified by constructing in vitro models. Additionally, cell apoptosis was determined by flow cytometry, and ferroptosis was examined using Ptgs2 detection and lipid-reactive oxygen species assays. The relationship between BBOX1-AS1 and downstream molecules was evaluated using RNA immunoprecipitation, western blotting, and luciferase reporter assays. The function of BBOX1-AS1 was studied in vivo using a xenograft model and immunohistochemistry. BBOX1-AS1 expression was significantly higher in ESCC tissues, indicating poor prognosis. Inhibition of BBOX1-AS1 reduced cell proliferation, slowed cell invasion and migration, and promoted apoptosis and ferroptosis in vitro. miR-513a-3p was verified as a specific target of BBOX1-AS1 in ESCC, whereas knockdown of miR-513a-3p reversed the suppressive function of BBOX1-AS1 silencing in TE-1 cells. Moreover, solute carrier family 7 member 11 (SLC7A11) is regulated by miR-513a-3p, which is mediated by BBOX1-AS1 in ESCC cells. In conclusion, downregulation of BBOX1-AS1 inhibits cell proliferation, and metastasis accelerates cell apoptosis and ferroptosis in ESCC by upregulating miR-513a-3p to reduce SLC7A11 expression. These findings may provide novel insights into the diagnosis and treatment of ESCC.

Characterization and in vitro simulated gastrointestinal digestion and fermentation of Mentha haplocalyx polysaccharide.

An acidic polysaccharide (PMHP-3) obtained from the Mentha haplocalyx was structurally characterized, and in vitro simulated digestion and fermentation were investigated. PMHP-3 was mainly composed of mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose and arabinose with molecular weight of 21.82 kDa. After digestion in saliva and simulated gastric juice, the molecular weight, reducing sugar, total sugar and uronic acid contents of PMHP-3 did not change significantly (p > 0.05). After digestion in simulated intestinal juice, the molecular weight and uronic acid content of PMHP-3 did not change significantly, and there was no free monosaccharide production, but the total sugar and reducing sugar contents slightly decreased. During fermentation, the molecular weight, carbohydrate residue and free monosaccharides of PMHP-3 were decreased, suggesting that PMHP-3 could be degraded by microorganism and metabolized into a variety the short-chain fatty acids (SCFAs) such as acetic, propionic. Meanwhile, PMHP-3 modulated the gut microbiota by reducing the ratio of Firmicutes/Bacteroidetes, promoting the proliferation of beneficial bacteria such as Bacteroidaceae and Bifidobacteriaceae, and inhibiting harmful bacteria such as Lachnospiraceae and Enterobacteriaceae. These results indicate that PMHP-3 is beneficial to the gut health and can be developed as a potential prebiotic to prevent diseases by improving intestinal health.

Kinetic study on soybean hydration during soaking and resulting softening kinetic during cooking.

This work evaluated the hydration kinetics of three yellow soybeans and one black soybean (Glycine max (Linn.) Merr.) at five temperatures (5-40°C), as well as the softening kinetics of steamed and boiled soybeans after hydration. The results showed that high temperature promoted water absorption and solids loss. Dongbei large soybean had the fastest water absorption than all others and its water diffusivities varied from 4.4×10-11 (m2 /s) to 2.6×10-10 (m2 /s) at the tested temperatures. Page model provided the best prediction of moisture content of four varieties of soybeans at five temperatures. The thermodynamic coefficient indicated that hydration is a nonspontaneous phenomenon. In addition, results showed that four soybeans exhibited no significant differences in softening rate during the cooking process, although the black soybean had the highest ultimate hardness relative to the yellow soybeans. Taken together, these new results will provide theoretical support for industrial soaking and cooking approaches for soybeans.

The immunomodulatory effects of Carapax Trionycis ultrafine powder on cyclophosphamide-induced immunosuppression in Balb/c mice.

BACKGROUND: There are abundant resources of Carapax Trionycis from soft-shelled turtle processing wastes each year in China. Our preliminary work showed that Carapax Trionycis ultrafine powder (CTUP) obtained using ball-milling with a particle size of 2.24 µm (D0.025) contained more active ingredients. The CTUP D0.025 has a good bioaccessibility, but there has been no report about the immunomodulatory function of CTUP. Therefore, using a cyclophosphamide-induced immunosuppression mice model, we investigated the immunomodulatory effects of CTUP D0.025. RESULTS: The results indicated that CTUP D0.025 administration significantly improved the immune organ (bone marrow, thymus and spleen) indices, ameliorated spleen tissue morphology and increased the capacity of splenocyte proliferation and the activity of macrophage phagocytosis. CTUP D0.025 also significantly promoted the secretion of cytokines (IL-2, IL-4, IL-10, IFN-γ and TNF-α), improved the related mRNA expression levels of IL2, IFN-γ, T-bet and GATA3 in immunosuppressed mice and increased the production of serum hemolysin and the levels of IgG, IgM as well as complement C3 . Moreover, CTUP D0.025 administration enhanced the antioxidant capacity of mice, exhibited a moderating effect on the damage of bone and skeletal muscle and improved the recovery of bone mineral density and calcium metabolism. CONCLUSIONS: These findings demonstrated that CTUP D0.025 had an effective immune-enhancing function in immunosuppressive Balb/c mice and also exhibited anti-osteoporosis properties. © 2020 Society of Chemical Industry.

Assessment of fresh star anise (Illicium verum Hook.f.) drying methods for influencing drying characteristics, color, flavor, volatile oil and shikimic acid.

In order to evaluate the effects of drying methods on the drying characteristics, quality (color, volatile oil (VO) content, shikimic acid (SA) content, trans-anethole content in the star anise volatile oil (TA-O)) and flavor components of star anise (Illicium verum Hook.f.), we tested five different methods (hot air drying (HAD), heat pump drying (HPD), far infrared radiation drying (FIRD), microwave drying (MD), and sun drying (SD)) with or without blanching to dry fresh star anise. Results showed MD had a shorter drying time than others, as well as the highest SA content (125.56 mg/g d.b.). HPD sample exhibited higher VO content (12.27% d.b.) and TA-O (113.30 mg/g d.b.) than those dried with other methods. HPD can improved the dominant flavor compounds of star anise, including trans-anethole (4165.46 mg/100 g d.b.), estragole (176.50 mg/100 g d.b.), linalool (280.69 mg/100 g d.b.), and (+)-limonene (471.18 mg/100 g d.b.). Samples treated with HPD-B had the highest comprehensive score (4.59) in the flavor principal component analysis. Therefore, HPD was more suitable for star anise drying as it maintaining quality. The better quality (higher flavor quality and better appearance) was found in HPD-B.

Insights into the stability of carotenoids and capsaicinoids in water-based or oil-based chili systems at different processing treatments.

Ultrasonication, microwave, heat, and light treatments, as well as storage conditions, were investigated for their effects on the stability of carotenoids and capsaicinoids in water/oil chili systems. The stability of carotenoids and capsaicinoids were found to vary in response to different processing treatments. Carotenoid and capsaicinoid contents in chili juice (CJ, water system) were increased by low-power ultrasonic and microwave treatments, but decreased by high-power treatments. The thermal stability of carotenoids and capsaicinoids in hot pot bottom (HPB, oil system) were superior to those in CJ. Moreover, ultraviolet light significantly reduced the contents of carotenoids and capsaicinoids in both CJ and HPB. It was also demonstrated that low temperature conditions (4 °C) significantly delayed the degradation of carotenoids and capsaicinoids in chili-based food. In conclusion, our findings suggest that the stability of carotenoids and capsaicinoids can be tuned using different processing and storage techniques appropriate to different systems.

Zanthoxylum alkylamides improve amino acid metabolism in type 2 diabetes mellitus rats.

To investigate the effect of Zanthoxylum alkylamides (ZA) on amino acid metabolism of type 2 diabetes mellitus (T2DM), the present study was performed with T2DM rats model induced with high fat and sugar fodder combined with low-dose of streptozotocin. ZA were fed to rats at three different doses of 2, 4, and 8 mg/kg for 28 days and metformin was fed to rats at 135 mg/kg as positive control. The results showed that compared with the normal control, the amino acid levels and the expression of related carrier genes were disordered in T2DM rats. Compared with the model, different doses of ZA could significantly resist (p < .05) the decrease in body weight of T2DM rats and improve hyperglycemia, with the best result observed with the high dose (8 mg/kg). Different doses of ZA could ameliorate the levels of 19 kinds of amino acid in the plasma, jejunum, liver, and skeletal muscle of T2DM rats by regulating the expression of related amino acid transporters including LAT1, SNAT2, CAT1, et al. to thereby ameliorating amino acid metabolism disorder in T2DM rats. PRACTICAL APPLICATIONS: Previous studies showed that Zanthoxylum alkylamides (ZA) could promote the amino acid metabolism in the jejunum of healthy SD rats, improve protein metabolism disorder of type 1 diabetic rats, and also reduce the risk of metabolic syndrome in fat rats model. Herein, we investigated the effect of ZA on amino acid metabolism in type 2 diabetes mellitus (T2DM) rats. The results indicated that ZA could remarkably improve the abnormal expression of amino acid carriers in the jejunum, liver, and skeletal muscle, thereby ameliorating the disorder of amino acid metabolism in the plasma, jejunum, liver, and skeletal muscle of T2DM rats. Therefore, ZA are potential antidiabetic food/medicine product for the T2DM treatment.

Influences of different drying methods on the structural characteristics and prebiotic activity of polysaccharides from bamboo shoot (Chimonobambusa quadrangularis) residues.

In the present study, in order to assess the influences of drying methods on the chemical structures, in vitro digestibility and prebiotic potential of polysaccharides extracted from Chimonobambusa quadrangularis shoot (CPSs), four drying methods, including hot air-, vacuum-, freeze-, and spray-drying, were utilized to dry CPSs. Results revealed that the physicochemical characteristics and prebiotic activity of CPSs varied by different drying methods. In comparison with the other drying methods, freeze-dried CPSs had higher uronic acid content (9.58%), lower medium-high molecular weight (117.63 kDa), smaller particle size (115.97 nm) and better solubility. All four CPSs fractions exhibited low degree of digestibility to pretended human gastric juice (< 2%) and α-amylase (< 5%). The freeze-dried CPSs showed the greatest prebiotic activity as this polysaccharide induced the strongest proliferation effect of probiotic bacteria and the highest production of total short chain fatty acids. Our results collectively provided substantial evidence that the freeze-drying method proposed in this study could be an effective technique in improving the prebiotic potentiality of CPSs.

Effects of multi-frequency ultrasound on physicochemical properties, structural characteristics of gluten protein and the quality of noodle.

In this study, the influence of multi-frequency ultrasound irradiation on the functional properties and structural characteristics of gluten, as well as the textural and cooking characteristics of the noodles were investigated. Results showed that the textural and cooking characteristics of noodles that contain less gluten pretreated by multi-frequency ultrasonic were ultrasonic frequency dependent. Moreover, the noodles that contain a smaller amount of sonicated gluten could achieve the textural and cooking quality of commercial noodles. There was no significant difference in the cooking and texture characteristics between commercial noodles and noodles with 12%, 11%, and 10% gluten pretreated by single-frequency (40 kHz), dual-frequency (28/40 kHz), and triple-frequency sonication (28/40/80 kHz), respectively. Furthermore, the cavitation efficiency of triple-frequency ultrasound was greater than that of dual-frequency and single-frequency. As the number of ultrasonic frequencies increased, the solubility, water holding capacity and oil holding capacity of gluten increased significantly (p < 0.05), and the particle size was reduced from 197.93 ± 5.28 nm to 110.15 ± 2.61 nm. Furthermore, compared to the control group (untreated), the UV absorption and fluorescence intensity of the gluten treated by multi-frequency ultrasonication increased. The surface hydrophobicity of gluten increased from 8159.1 ± 195.87 (untreated) to 11621.5 ± 379.72 (28/40/80 kHz). Raman spectroscopy showed that the α-helix content of all sonicated gluten protein samples decreased after sonication, while the ß-sheet and ß-turn content increased, and tryptophan and tyrosine residues were exposed. Through scanning electron microscope (SEM) analysis, the gluten protein network structure after ultrasonic treatment was loose, and the pore size of the gluten protein network increased from about 10 µm (untreated) to about 26 µm (28/40/80 kHz). This work elucidated the effect of ultrasonic frequency on the performance of gluten, indicating that with increasing frequency combination increases, the ultrasound effect became more pronounced and protein unfolding increased, thereby impacting the functional properties and the quality of the final product. This study provided a theoretical basis for the application of multi-frequency ultrasound technology in the modification of gluten protein and noodle processing.

Comparison on characterization and biological activities of Mentha haplocalyx polysaccharides at different solvent extractions.

This study aimed to compare the effects of four solvent extractions on the physicochemical properties, antioxidant and hypoglycemic activities of polysaccharides from Mentha haplocalyx (MHPs). The solvent extractions included hot water, citric acid (pH 3.0), 5% NaOH/0.05% NaBH4 and 0.9% NaCl. Four corresponding MHPs named as MHP-W, MHP-C, MHP-A and MHP-S were obtained, respectively. The experimental results showed that the extraction yields, basic chemical components, monosaccharide contents, molecular weights, antioxidant and hypoglycemic activities of four MHPs were significantly different. However, their thermal stabilities, preliminary structural characteristics and monosaccharide types were similar. MHP-A possessed the highest extraction yield of 9.37 ± 0.24% and the smallest molecular weight. MHP-W had the highest uronic acid content and the largest molecular weight. More specifically, MHP-C exhibited the highest sugar content, the most remarkable antioxidant abilities of DPPH radical scavenging activity and ferric reducing power, and the strongest inhibitory activities on α-glucosidase and α-amylase. The above results indicated that MHP-C extracted with citric acid could be served as a promising bioactive substance for applications in the functional food and medicine industries.