Search Results (41)

Peptidoglycan (PG) is a polymer that makes up the cell wall of most bacteria. In this study, the peptidoglycan of Lactobacillus casei ATCC 393 was extracted, and its prebiotic function as well as its effects on intestinal health and inflammation reduction in a colitis murine model were investigated. PG was extracted from L. casei ATCC 393 using the ultrasonic-assisted enzymatic method. A structural characterization and assessment of its antioxidant capacity were subsequently performed to evaluate its functional properties. In a dextran sulfate sodium (DSS)-induced colitis model, dietary supplementation with PG (100 mg/kg) demonstrated significant protective effects. Specifically, the PG intervention group exhibited reduced inflammatory symptoms, improved disease activity indices, suppressed weight loss, and colon shortening compared to the DSS-induced group. Intestinal barrier injury was reversed and the Firmicutes/Bacteroidetes ratio was increased. These clinical improvements were accompanied by decreased circulating levels of pro-inflammatory cytokines (IL-6, TNF-α, and IL-1β). These findings revealed that PG modulated gut microbial ecology by enhancing bacterial diversity and promoting the enrichment of beneficial taxa, particularly the Lachnospiraceae and Lactobacillus species. Additionally, PG intervention increased fecal short-chain fatty acid (SCFA) concentrations, especially the concentration of propionic acid and butyric acid, which increased by 13% and 42%, respectively, compared to the DSS-induced group, suggesting enhanced microbial metabolic activity. Furthermore, these findings emphasize the potential of peptidoglycan as a functional component for preventing colitis through microbial-mediated pathways. This study underscores the prebiotic promise of peptidoglycan in the development of interventions targeting intestinal inflammation and supports its further exploration as a functional agent for promoting human health. Full article

Pumpkin seed proteins are underutilized plant proteins with a balanced content of essential amino acids and health benefits. Benefit from the functional properties and low-cost character, pumpkin seed proteins exhibit great potential for applications as alternative food ingredients. This paper reviews the composition of pumpkin seed proteins, as well as the extraction methods, including the alkaline method, ultrasonic-assisted method, and enzymatic-assisted approach. Functional properties of pumpkin seed proteins, such as solubility, foamability, gelling, and emulsification, are described. Additionally, several modification methods were emphasized to enhance the functionality of pumpkin seed proteins, including physical, chemical, enzymatic, and combined approaches. Food applications of pumpkin seed proteins, including food packaging films, meat analogs, carriers, protein supplements, and functional food additives, are also systematically introduced. Finally, the challenges and solutions that limit the widespread utilization of pumpkin seed proteins are discussed. Full article

The crystalline structure of cellulose plays a crucial role in its reactivity, which is particularly important in biomass processing involving enzymatic hydrolysis. This study investigates the effect of low-frequency ultrasound (40 kHz) on the efficiency of enzymatic hydrolysis of cellulose in poplar wood and its structure, with a focus on its crystallinity and susceptibility to enzymatic hydrolysis. Two experimental pathways were explored: ultrasound-assisted hydrolysis of raw wood and isolated cellulose. Structural modifications were assessed using Fourier-transform infrared spectroscopy to determine the Lateral Order Index (LOI) and Total Crystallinity Index (TCI), providing insight into the reorganisation of cellulose microstructure. To evaluate hydrolysis efficiency, glucose yields were quantified by high-performance liquid chromatography. The application of ultrasound to raw wood resulted in minimal improvement in sugar release, whereas pretreatment of extracted cellulose led to a modest acceleration of enzymatic hydrolysis. The results show that ultrasound-assisted hydrolysis of raw wood did not significantly increase glucose yield, reaching only 9.9 ± 0.3% and 10.1 ± 0.8% for two poplar hybrids. Only slight increases in TCI and no significant changes in LOI were observed after 4 h of ultrasonic exposure. It indicates limited disruption of the crystalline structure under the tested conditions. Full article

Green soybean (Glycine max L.), commonly known as edamame, is recognized for its rich phytochemical content and nutritional and functional benefits. However, its limited shelf life and susceptibility to quality degradation restrict its commercial potential in fresh form. To address this, green soybean seeds can be processed into extract and powder forms, which offer greater stability and added value. The preparation of crude procyanidin extract was examined in this study along with the effects of three distinct extraction techniques: enzyme incubation, ultrasonic-assisted extraction (UAE), and enzymatic hydrolysis followed by ultrasonic-assisted extraction (EUAE). Additionally, the effects of two drying methods (drum-drying and spray-drying) on the retention of bioactive compounds and antioxidant activity were assessed. Optimal conditions for each drying method were selected to enhance antioxidant properties by fortifying instant green soybean powder (GSP) with encapsulated crude procyanidin extract (ECPE). The chemical, physical, and sensory properties of ECPE-fortified GSP were analyzed. Results indicated that the EUAE method was the most effective for procyanidin extraction. Encapsulation allowed for procyanidin retention of over 83% after storage at 25 and 35 °C for 12 weeks. The optimal conditions were determined to be drum-drying at 3 rpm and spray-drying at an inlet temperature of 200 °C for the drying techniques. Fortification of GSP with 3–5% ECPE powder positively correlated with increased phytochemical content and antioxidant activity. Both drum- and spray-dried GSP maintained color integrity comparable to the control. Drum-dried GSP preserved greater concentrations of bioactive compounds and exhibited superior antioxidant activity compared to spray-dried GSP. All powdered products had acceptable water activity (≤0.60) and moisture content (≤12%), suggesting suitability for long-term storage. Although spray-dried powders exhibited greater hygroscopicity, they demonstrated lower emulsion stability and solubility compared to drum-dried powders. Drum-dried GSP retained higher levels of carbohydrate, fat, fiber, and ash compared with spray-dried powder, while protein content was similarly preserved by both methods. In conclusion, ECPE powder serves as a promising functional ingredient in instant green soybean powder. Both drum-dried and spray-dried GSP products exhibit potential for application in a variety of functional food products. Full article

In this investigation, pinocembrin and galangin were efficiently extracted from the male inflorescence of Populus alba L. × berolinensis K. Koch through an enzymatic pretreatment–ultrasonic-assisted strategy (EP-UAS), and the feasibility of their pilot-scale application was validated. The optimal parameters (ethanol volume fraction, cellulase dosage, incubation temperature, incubation time, pH, liquid‒solid ratio, ultrasonic irradiation power during incubation, duty cycle, ultrasonic irradiation power and time during extraction) affecting pinocembrin and galangin yields were systematically explored. The Box–Behnken design (BBD) results provided optimal parameters for the EP-UAS process. Under the optimal conditions, the actual yields of pinocembrin and galangin were 2158.33 ± 0.13 μg/g and 1257.96 ± 0.06 μg/g, respectively. Stability, recovery and reproducibility were determined under the above optimized conditions to evaluate the proposed EP-UAS method. Moreover, laboratory-scale experimental results revealed that the conditions selected via single-factor and response surface experiments were also applicable to pilot-scale production, facilitating industrialization. Full article

Tartary buckwheat hulls, a phenolic-rich by-product of buckwheat processing, offer great potential for resource utilization. In this study, ultrasound-assisted enzymatic extraction with two temperatures (40 °C and 50 °C) was employed to obtain phenolics from Tartary buckwheat hulls. Compared with the traditional extraction method (207 mg/100 g), ultrasound-assisted enzymatic extraction increased the total phenolic yield by 91.3% at 50 °C. Numerical simulations based on Fick’s law indicated that enzyme pretreatment concentration positively correlated with the effective diffusion coefficient ($D_e$), which increased from 9.15 × 10⁻⁷ to 2.00 × 10⁻⁶ m²/s at 40 °C. Meanwhile, the neuro-fuzzy inference system (ANFIS) successfully predicted the extraction yield under various ultrasonic conditions (R² > 0.98). Regarding quantitative analysis of phenolic compounds in extracts, the results revealed that catechins and epicatechins were the most abundant in Tartary buckwheat hull. Additionally, phenolic acids rapidly diffused at higher temperatures (50 °C), and flavonoids were highly sensitive to temperature and enzyme synergy. Phenolic extracts exhibit significant potential for value-added applications in food processing, particularly in improving antioxidative stability, prolonging shelf life. This study provides a theoretical basis for green, efficient phenolic extraction from plant residues. Full article

Dragon fruit peel is a by-product rich in bioactive compounds, such as polyphenols and betalains. In this study, ultrasound-assisted enzyme extraction (UAEE) was proposed to exploit this, combining the advantages of the enzymatic hydrolysis and ultrasound extraction. The effect of extraction time, temperature, and enzyme quantity were evaluated using a Box–Behnken design. Total betalains and polyphenol contents were determined spectrophotometrically. The results show that the extraction of total polyphenols was significantly affected (p ≤ 0.05) by the enzyme quantity, while temperature had a significant effect (p ≤ 0.05) on the extracted betalains. The optimal conditions for the extraction of total betalains and polyphenols were a temperature of 20 °C, an extraction time of 20 min, and an enzyme/substrate ratio of 400 mg/g. Under optimized conditions, the extraction efficiency reached 565.6 ± 12.9 µg/g for total betalains and 14.9 ± 2.4 mg/g for total polyphenols. In addition, UAEE showed the best extraction yields compared to other methodologies, such as microwave, ultrasound, and enzymatic hydrolysis extraction (p ≤ 0.05). This study helps us to understand how the temperature, time, and amount of enzymes affect the extraction of total polyphenols and betalains present in the peel of the dragon fruit using the UAEE technique. Full article

Sea buckthorn pomace (SBP) is a rich source of flavonoid compounds with potential healthy properties. This study optimized ultrasonic-enzymatic-assisted extraction (UEAE) of flavonoids from SBP and investigated its chemical composition and biological activities. Under the optimal conditions (pectinase addition of 1500 U/g, ultrasonic power of 300 W, ethanol concentration of 48%, liquid–solid ratio of 34:1, extract temperature of 50 °C, and extraction time of 28 min), the yield of SBP flavonoid extracts (SBFEs) was 21.57 ± 0.45 mg/g, well-matched with the predicted value (21.72 mg/g). The chemical composition was detected by ultrahigh-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS^E) and mainly including isorhamnetin, kaempferol, and quercetin’s derivatives. After purification with AB-8 macroporous resin, the purified product (PSBFE) exhibited a significantly enhanced scavenging capability for 1,1-diphenyl-2-picryl-hydrazyl radical (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (947.17 ± 3.85 and 427.33 ± 0.67 μmol Trolox/g, respectively) and ferric reducing antioxidant power (2.68 ± 0.01 mmol FeSO₄·7H₂O/g). Moreover, PSBFE possessed a pronounced inhibitory rate on α-glucosidase and α-amylase, with the IC₅₀ at 52.89 ± 0.09 and 97.81 ± 0.42 μg/mL, respectively. These findings indicate that it is a reliable, optimal extraction method to obtain potential antioxidant and hypoglycemic flavonoids from SBP for comprehensive development in functional food. Full article

Herein, Elaeagnus angustifolia L. was utilized as a raw material to extract bound polyphenols using an ultrasound-assisted complex enzyme method for the first time. The effects of enzyme ratio, ultrasonic time, liquid-to-solid ratio, and pH value on the bound polyphenol yield were investigated using single-factor experiments. The key parameters were subsequently optimized using the Box–Behnken design. The optimal conditions identified were as follows: enzyme ratio (α-amylase/cellulase = 5:1 mg/mg), ultrasonic time of 50 min, liquid-to-solid ratio of 12:1 mL/g, and pH value of 5. Under these conditions, the bound polyphenol yield was measured at 13.970 ± 0.3 mg/g. A total of 27 phenolic compounds were identified using ultrahigh-performance liquid chromatography–ion mobility quadrupole time-of-flight mass spectrometry (UPLC–IMS-QTOF-MS), including two coumarins, five lignins, 10 polyphenols, nine flavonoids, and one tannin, and specifically containing Angeloylgomisin Q, Yakuchinone A, Furosin, 6-Dehydrogingerdione, and 4′-Methylpinosylvin, and so on. Antioxidant activity was assessed using the 1,1-diphenyl-2-picryl-hydrazil (DPPH) and 2,2′-azino-bis-(3-ethylbenzthiazoline-6-sulfonate) (ABTS) methods, revealing significant antioxidant potential. This study introduced a novel extraction process for bound polyphenols from E. angustifolia L. and provided the first qualitative analysis of bound polyphenols in this species, establishing a scientific foundation for its development and application in the functional food, medicine, and cosmetics industries. Full article

Drought stress is one of the key environmental factors restricting the germination of alfalfa seeds (Medicago sativa L.). Nanopriming is an innovative seed-priming technology able to meet economic, agronomic, and environmental needs in agriculture. However, the use of conventional nanomaterials is hampered by high costs, environmental risks, and biotoxicity. In this study, we synthesized iron oxide nanoparticles (Fe₃O₄NPs) using seasonal Ginkgo biloba leaf extracts (collected from August to November) obtained via an enzymatic ultrasonic-assisted method. The synthesized Fe₃O₄NPs were characterized using SEM, EDS, DLS, FTIR, UV-Vis, and XRD. To investigate the effects of Fe₃O₄NP priming on alfalfa seed germination under drought stress, germination and pot experiments were conducted with five Fe₃O₄NP priming concentrations (unprimed, 0, 20, 40, and 60 mg/L) and three PEG-6000 concentrations (0%, 10%, and 15%) to simulate normal, moderate, and severe drought conditions. The results showed that leaf extracts collected in November exhibited the highest flavonoid content (12.8 mg/g), successfully yielding bioactive-capped spherical Fe₃O₄NPs with a particle size of 369.5 ± 100.6 nm. Germination experiments revealed that under severe drought stress (15% PEG-6000), the 40 mg/L Fe₃O₄NP treatment most effectively enhanced seed vigor, increasing the germination rate, vigor index, and α-amylase activity by 22.1%, 189.4%, and 35.5% (p < 0.05), respectively, compared to controls. Under moderate drought stress (10% PEG-6000), the 20 mg/L Fe₃O₄NP treatment optimally improved germination traits, increasing the germination rate by 25.5% and seedling elongation by 115.6%. The pot experiments demonstrated morphological adaptations in alfalfa seedlings: under moderate drought stress, the 40 mg/L Fe₃O₄NPs significantly increased lateral root numbers, while under severe drought stress, the 60 mg/L Fe₃O₄NPs increased the root surface area by 20.5% and preserved the roots’ structural integrity compared to controls. These findings highlight that Fe₃O₄NPs synthesized via Ginkgo leaf extracts and enzymatic ultrasonic methods exhibit promising agricultural potential. The optimal Fe₃O₄NP priming concentrations enhanced seed vigor, germination traits, and drought resistance by modulating root morphology, with concentration-specific efficacy under varying drought intensities. Full article

Tea saponin is a kind of natural non-ionic surfactant. Saponins were extracted from tea seed cake using an ultrasonic-assisted enzymatic method. The optimization of the tea saponin extraction procedure was conducted by using the response surface method to increase the yield. Study results indicated that the maximum yield of tea saponin was 69.81 mg/g under the optimum conditions of an enzyme concentration of 0.67%, a solvent-to-material ratio of 16.82 mL/g, an extraction temperature of 58.14 °C and an extraction time of 1.89 h. The surface activity experimental study results indicated that the critical micelle concentration of tea saponin was 0.5 g/L at 30 °C, and the lowest surface tension was 39.61 mN/m. The surface tension and CMC of tea saponin remained basically unchanged between 30 °C to 60 °C. When the pH of the solution was slightly acidic, the surface tension of tea saponin decreased significantly, while the CMC remained almost unchanged. Tea saponin has good salt and hard water resistance, and its surface tension decreases to a certain extent in both saltwater and hard water. The foam volume of tea saponin can reach 490 mL, with a half-life of 2350 s, and the foam is relatively stable. The combination of tea saponin and other surfactants has a certain synergistic effect. The critical micelle concentration of its complex system with the natural surfactant rhamnolipids can increase by 69.23%, and the surface tension can be reduced to a minimum of 22.56 mN/m. Moreover, by using the proposed method, the foam performance and stability of the system have been improved to a certain extent. This has significant practical significance for fully utilizing and developing waste camellia dried cake resources. Full article

Ultrasonic-assisted enzymatic extraction (UAEE) was utilized to obtain the polysaccharides from the bark of Cinnamomum cassia Presl. (C. cassia). Taking the yield of the crude polysaccharides from C. cassia (CCCP) as the assessment indicator, response surface methodology (RSM) and a genetic algorithm-back propagation (GA-BP) artificial neural network model were employed to forecast and contrast the optimal parameters for UAEE. The outcomes demonstrated that the GA-BP model, which was superior in prediction accuracy and optimization capabilities to the RSM and BP models, identified the following conditions as optimal for the UAEE of CCCP: cellulase was employed, the temperature for enzymatic hydrolysis was 50.0 °C, the pH value was 5.248, the addition of enzyme was 3%, and the ultrasonic time was 70.153 min. Under these parameters, the yield of CCCP was significantly increased to 28.35%. Then, UAEE-extracted CCCP under optimal conditions was further separated and purified using a DEAE-52 column and SephadexG-100 column, yielding five purified polysaccharides from C. cassia (CCPs). All of these five fractions were acidic polysaccharides with safety at 3 mg/mL. The CCPs did not significantly affect the viability of HaCaT cells affected by UVB exposure. The CCPs demonstrated differential inhibition of nitric oxide production in RAW264.7 cells stimulated by lipopolysaccharide. Full article

Proanthocyanidins have received extensive attention due to their high functional value, but their sources are limited. Therefore, this experiment studied the preparation, biological activities, and characterization of proanthocyanidins from Chinese jujube (Ziziphus jujuba Mill. cv. Muzao) at different periods, aiming to explore a new source of proanthocyanidins and enhance their utilization value. Through ultrasonic-assisted enzymatic extraction, the optimal extraction conditions for PC from Muzao were determined, yielding a proanthocyanidin content of 2.01%. Purification using AB-8 macroporous resin increased the proanthocyanidin content by 11 times. The bioactivity results indicated that proanthocyanidins demonstrated significant in vitro antioxidant activity (scavenging rate ≥ 83.4%) and blood glucose-lowering activity (inhibition rate ≥ 84.7%). Both activities decreased with maturity, while the degree of polymerization also exhibited a positive effect. Mass spectrometry identified a total of 102 compounds, with cyanidin-based compounds being the most abundant, comprising 28 species. The comprehensive research results indicate that the oligomeric proanthocyanidins extracted, purified, and isolated from Muzao during the young fruit stage exhibit diverse biological activities and are abundant in content. They can be utilized for the extraction and purification of proanthocyanidins, offering a reference for the expansion of natural sources of proanthocyanidins and the development of functional foods. Full article

There are millions of tons of fresh soy sauce residue (SSR) by-products created by China’s soy sauce industry every year. Most of the SSR is directly discarded; this not only wastes resources, but also pollutes the environment. As it is rich in dietary fiber, which is beneficial to human health, skimmed SSR was used as a raw material to obtain soluble dietary fiber (SDF) in this study. Firstly, the process of ultrasonic-assisted enzymatic extraction of SDF was optimized through single factor experiments and a response surface test. The extraction rate of the SDF from SSR reached 76.8 ± 0.8% under the optimum extracting conditions of a cellulase/hemicellulase (w/w) 1/1 mixture, an enzyme addition amount of 5.7%, a material–liquid ratio (w/v) of 1/20 g/mL, and a reaction time of 30 min. Then, the physicochemical properties of the SDF extracted using enzymatic and chemical methods were compared; we found that the SDF obtained through ultrasound-assisted enzymatic extraction had a much better appearance and physicochemical properties than that extracted by acid or alkali, with a lighter color, higher extraction rate, higher water-holding capacity, higher oil-holding capacity, higher swelling capacity, and solubility. The microstructure was more uniform and porous. This study will provide theoretical guidance and technical support for the recycling and utilization of SSR, which is beneficial for improving its economic value. Full article

Marine microalgae are emerging as promising sources of polyphenols, renowned for their health-promoting benefits. Recovering polyphenols from microalgae requires suitable treatment and extraction techniques to ensure their release from the biomass and analytical methodologies to assess their efficiency. This review provides a comprehensive comparison of traditional and cutting-edge extraction and analytical procedures applied for polyphenolic characterization in marine microalgae over the past 26 years, with a unique perspective on optimizing their recovery and identification. It addresses (I) cell disruption techniques, including bead milling, high-speed homogenization, pulsed electric field, ultrasonication, microwave, freeze-thawing, and enzymatic/chemical hydrolysis; (II) extraction techniques, such as solid–liquid extraction, ultrasound and microwave-assisted extraction, pressurized-liquid extraction, and supercritical CO₂; (III) analytical methods, including total phenolic and flavonoid content assays and advanced chromatographic techniques like GC-MS, HPLC-DAD, and HPLC-MS. Key findings showed bead milling and chemical hydrolysis as effective cell disruption techniques, pressurized-liquid extraction and microwave-assisted extraction as promising efficient extraction methods, and HPLC-MS as the finest alternative for precise phenolic characterization. Unlike previous reviews, this study uniquely integrates both extractive and analytical approaches in one work, focusing exclusively on marine microalgae, a relatively underexplored area compared to freshwater species, offering actionable insights to guide future research and industrial applications. Full article