Ultrasound Treatment Research Articles

An integrated approach to the treatment of a patient with chronic tonsillitis. Clinical case

Chronic tonsillitis (CT) is a common infectious-allergic disease leading to severe general somatic complications, including rheumatic damage of joints and heart, kidney disease. Currently in Russia there is an increase in the number of patients with CT. Therapy for CT in outpatient practice is often limited to only washing the lacunae of the palatine tonsils, without the use of local drugs. We observed a 35-year-old patient with a diagnosis of chronic tonsillitis and a history of the disease of more than 1.5 years. A combined method of therapy was chosen, including treatment with the Tonsillor apparatus using low-frequency ultrasound therapy and local use of Viroxinol for irrigation of the tonsils and mucous membrane. As a result of the complex treatment, pronounced positive dynamics and a decrease in the clinical symptoms of CT were achieved.

Impact of Advanced High-Power Pain Threshold Static Ultrasound and Muscle Energy Technique on Pain Thresholds and Functional Improvement in Myofascial Trigger Points

bands and hypersensitive Trigger Points (TrPs), contributing to musculoskeletal pain. The objective of this study is to investigate and assess the effectiveness of Advanced High-Power Pain Threshold Static Ultrasound (AHPPTSU) and Muscle Energy Technique (MET) in altering pain thresholds and enhancing functional outcomes in individuals with myofascial trigger points. Methods: In this randomized clinical trial involving 86 individuals with TrPs in the upper trapezius muscle, the participants were divided into experimental and control groups. 33 males and 53 females, underwent six sessions of treatment over two weeks. A repeated measure Analysis of variance was used to compare baseline values and altered values at 1 and 2 weeks. Results: The study demonstrated that the Pressure Pain Threshold (PPT) and the Neck Pain Disability Index (NPDI) score, showed a significant improvements in participants receiving AHPPTUS in experimental group compared to the other group. Experimental group showed a significantly greater improvement in PPT (p=0.001) and both groups experienced a significant enhancement in function. However, when comparing the two groups, experimental group showed a significantly greater improvement (p=0.001). Importantly, no adverse effects were reported in either group. Conclusion: In the treatment of myofascial trigger point, AHPPTSU can be considered as an alternative therapy method, which is more effective than previously used High-Power Pain Threshold Static Ultrasound (HPPTSU) therapy and it also shortens the total treatment protocol to 2 weeks.

Comprehensive assessment of heavy slow resistance training and high-dose therapeutic ultrasound in managing patellar tendinopathy, a randomized single-blind controlled trial

BackgroundPatellar tendinopathy (PT) is a common sport injury prone to recurrence. Heavy Slow Resistance Training (HSR) and High-Dose Therapeutic Ultrasound (TUS) are frequently used interventions for PT. However, the combined effectiveness of these therapies remains unclear. This study investigated the impact of combination therapy on functional outcomes in patients with PT.MethodsFifty-one college students aged 18–25, diagnosed with PT via musculoskeletal ultrasound, were randomly assigned to one of three groups (n = 17 per group): combined HSR and high-dose TUS, HSR training alone, or high-dose TUS alone. The eight-week intervention included assessments using the Victorian Institute of Sport Assessment-Patella (VISA-P), Visual Analogue Scale (VAS), Y-balance Test (YBT), Modified Thomas Test (MTT), Horizontal Jumping Distance, Maximum Isometric Muscle Strength Test, and musculoskeletal ultrasound for patellar tendon thickness and blood flow. Assessments were conducted at baseline and post-intervention, with a follow-up VISA-P assessment at week 16. This randomized, single-blind controlled trial was registered on ISRCTN11447397 (www.ISRCTN.com) on February 17, 2024 (retrospectively registered).ResultsAll groups demonstrated significant improvements in VISA-P scores at the end of the intervention compared to baseline (p < 0.01), with the combined group showing the greatest improvement (21 points). Follow-up at week 16 revealed continued improvement in VISA-P scores for the combined and HSR groups, while the TUS group showed a slight decrease (from 74 to 70). All groups displayed significantly reduced VAS scores post-intervention (p < 0.01) compared to baseline, indicating decreased pain. While no significant between-group differences were observed in pre-intervention VAS scores, post-intervention results revealed significant differences between the combined and HSR groups (p < 0.05), as well as between the combined and TUS groups (p < 0.01).ConclusionBoth exercise intervention and high-dose TUS appear effective in reducing pain and improving motor function in individuals with PT. However, the therapeutic effect of high-dose TUS alone seems limited compared to exercise intervention. The combined application of both methods yielded the most significant improvements in pain relief and motor function enhancement.

Human Immunodeficiency Virus Associated Neuropathy Perinatally Infected HIV Children In Calabar, Nigeria. Clinical Features, Treatment and Outcome

Background Renal disease is increasing being recognized as a significant cause of morbidity and mortality in HIV positive patients. Human Immunodeficiency virus associated nephropathy (HIVAN) is the most common type of HIV related renal disease and rapidly progress to end stage renal disease(ESRD). There is paucity of report on true prevalence of HIVAN in African. This study was aimed at determining the prevalence of HIVAN, clinical features, treatment and outcome, in Calabar Nigeria. Methods/Subject This was a retrospective review of all renal patients managed by Pediatric nephrology unit of University of Calabar Teaching Hospital from January 2016 to December 2022 enrolled in the Renal register. During the period of study 215 patients had renal diseases out of which 15 had HIVAN. The following information were extracted from the HIVAN patients; Demographics and clinical data as well as mode of transmission, laboratory investigations, renal Ultrasound scan, treatment and Outcome were obtained and analyzed using SPSS version 20. Results There were 215 cases of renal diseases seen during the study period of which 15 had HIVAN giving a prevalence of 6.9% There were 5 males and 10 females giving a ratio of 1:2, age range 69-192months. with a mean age of 127±43.7months All received HAART and had acquired HIV infection through vertical transmission. 8 (53%) of patient were asymptomatic with 6 (40%) presenting with both legs and facial swelling. Nephrotic range proteinuria was a common presentation seen in 40% of the patients and 5(33.3%) had hypertension. Only 4 (33%) had eGFR&lt;60 ml/min/1.73m2 and 2(16%) had ESRD. Two were lost to follow-up and 4 (26%) died with two requiring dialysis. Conclusion HIVAN is common in patients with renal diseases and there is need to monitor patient at initiation of HAART and at risk patients with low CD4+ count and exposure to nephrotoxic HAART.

The efficacy of power ultrasound treatment in preserving quality of fresh-cut cucumbers

The impact of power ultrasound (PU), antibrowning agents, and hot-water bath at 65?°C on the inhibition of enzymatic browning and 10 days product-life analysis of freshly cut cucumber samples were determined. The observations demonstrated that PU method inhibited the development of bacteria, mold, and yeast in freshly cut cucumber pieces at 4 °C. The PU-treated cucumber pieces exhibited a significant (p &lt; 0.05) developments in bioactive components along with developed weight loss and firmness rather than other methods. In a similar way, PU-treated cucumber slices displayed the best colour parameters accompanying the smallest amount related to enzyme activity meaning lower browning enzymatically. Furthermore, the lowest scores in accordance with decay and off-odor values were determined in the freshly cut cucumbers subjected to PU. It is declared that PU method is an alternative technique to extend the storage conditions and keep the high-quality specifications in freshly cut cucumbers during cold storage.

Influence of mycelial integrity damaged by ultrasonic treatment on product textural properties and in vitro digestibility

This study investigated the effects of ultrasonic treatment with different intensities (200, 400, and 600 W) and durations (15, 30, and 45 min) on the mycelial integrity, product quality, and in-vitro digestibility of mycoprotein. Results showed that the mycelium was damaged to varying degrees under different ultrasonic parameters. The mycelium showed obvious damage when the time of ultrasonic treatment lasted more than 30 min or the power exceeded 400 W. As a result, the particle size, hardness and chewiness of mycoprotein products were decreased significantly. Compared with the control group (CK), ultrasonic treatment increased the proportion of immobile water and changed the secondary structure of the fungal intracellular protein, which may be the reason for improving in-vitro digestibility of mycoprotein products. This result demonstrated that, by damaging the mycelial integrity and changing the protein secondary structure, ultrasound treatment could decrease the texture characteristics, but improve the water-holding capacity and in-vitro digestibility of products. This study would provide a potential application for the minced meat products by mycoprotein treated with ultrasound.

High-intensity focused ultrasound (HIFU) for the treatment of female urinary incontinence: A retrospective analysis.

This study aims to demonstrate the effectiveness of high-intensity focused ultrasound, a noninvasive treatment, for managing urinary incontinence (UI) in women. This is a single-center, retrospective study involving 28 women. Patients, aged between 32 and 65, were included. Patients with insulin-dependent diabetes, neurological disease, active urinary tract infection, undiagnosed vaginal bleeding, who had incontinence surgery, and receiving estrogen therapy were excluded from the study. Incontinence severity was evaluated with the International Incontinence Consultation Questionnaire Short Form (ICIQ-SF). Patients were evaluated before treatment and 6 months after treatment using the ICIQ-SF and the Pelvic Organ Prolapse/Urinary Incontinence Sexual Function Assessment short form. In the analysis of numerical variables independent or paired t test or linear mixed effects models were used. Least square means were used in post hoc comparisons. Mean age of the patients was 45.50 ± 7.59 years. There were 18 (64%) stress urinary incontinence (SUI) and 10 (36%) mixed urinary incontinence (MUI). Six months after treatment, mean ICIQ-SF and Pelvic Organ Prolapse/Urinary Incontinence Short Form Questionnaire scores showed a significant positive change. After the procedure, UI completely disappeared in 43% of the patients. The rate of severe UI decreased from 39% to 8%, and very severe UI decreased from 8% to 0%. Incontinence severity was significantly different in the MUI and SUI groups before and after the procedure. After the procedure, UI completely disappeared in 67% of the patients in the SUI group, while it remained at a mild level in 33%. The decrease in ICIQ-SF score in the SUI group was significantly higher than that in the MUI group. There were no severe adverse events, in 4 patients there was mild vaginal discharge which resolved in 1 week. This study showed that high-intensity focused ultrasound treatment, can be effective and safe even in a single session. Selection and recall biases are potential biases in retrospective studies. Lacking a control group is another limitation. Although advances in technology are very important for medical treatments, their effectiveness and safety need to be proven. Future research in this area with a larger sample size and a prospective design will offer further evidence supporting effectiveness of this treatment model.

Optimization of Non-Thermal Treatment Methods and Extrusion Temperature on Quality of Rice Pasta Enriched with &lt;i&gt;Cirina butyrospermi&lt;/i&gt;

Food security remains a critical global challenge, necessitating the exploration of sustainable and nutrient-rich food alternatives such as edible insects. This study investigated and optimized the effect of treatment methods (boiling, ultrasound, and a combined boiling and ultrasound treatment) on Cirina butyrospermi and extrusion temperature (70℃, 80℃ and 90℃) on some quality (crude protein, in-vitro protein digestibility, calcium, zinc, iron, cooking time, water uptake ratio, lightness, and colour change) of rice pasta. The effect of treatment methods on Cirina butyrospermi powder and extrusion temperature on crude protein ranged from 15.85 to 18.27%, in-vitro protein digestibility (80.42-88.55%), calcium (48.53-56.25 mg/100g), zinc (2.42-3.56 mg/100g), iron (3.34-5.13 mg/100g), cooking time (8.50 - 19.50 min), water uptake ratio (1.15 - 1.90), lightness value (4.19 - 50.73) and colour change (4.47 - 51.13), respectively. The combined boiling and ultrasound treatment on Cirina butyrospermi powder and higher extrusion temperature gave rice pasta the highest protein, calcium, zinc, and iron content while lower extrusion temperature along with boiling treatment, increased in-vitro protein digestibility. Optimum conditions for desirable rice pasta were achieved at 80°C extrusion temperature with combined boiling and ultrasound treatment. Conclusively, exploring edible insects like Cirina butyrospermi under an accurate treatment method and extrusion condition could aid in the development of nutrient-rich rice pasta.

Therapeutic ultrasound: an innovative approach for targeting neurological disorders affecting the basal ganglia.

The basal ganglia are involved in motor control and action selection, and their impairment manifests in movement disorders such as Parkinson's disease (PD) and dystonia, among others. The complex neuronal circuitry of the basal ganglia is located deep inside the brain and presents significant treatment challenges. Conventional treatment strategies, such as invasive surgeries and medications, may have limited effectiveness and may result in considerable side effects. Non-invasive ultrasound (US) treatment approaches are becoming increasingly recognized for their therapeutic potential for reversibly permeabilizing the blood-brain barrier (BBB), targeting therapeutic delivery deep into the brain, and neuromodulation. Studies conducted on animals and early clinical trials using ultrasound as a therapeutic modality have demonstrated promising outcomes for controlling symptom severity while preserving neural tissue. These results could improve the quality of life for patients living with basal ganglia impairments. This review article explores the therapeutic frontiers of ultrasound technology, describing the brain mechanisms that are triggered and engaged by ultrasound. We demonstrate that this cutting-edge method could transform the way neurological disorders associated with the basal ganglia are managed, opening the door to less invasive and more effective treatments.

EFFECT OF PHYSIOTHERAPY ON THE IMPLANTATION POTENTIAL OF THIN ENDOMETRIUM

The article is dedicated to the urgent problem of infertility associated with thin endometrium. The mechanisms of action of various physiotherapeutic methods on the endometrium, such as magnetotherapy, laser therapy, ultrasound therapy, and electrical stimulation, are discussed. The beneficial effects of physiotherapy are described in detail, including improved blood flow, reduced inflammation, and stimulation of tissue regeneration. The results of clinical trials confirming the effectiveness of physiotherapy in increasing the thickness and improving the structure of the endometrium are presented. The article also includes indications and contraindications for the use of physiotherapy and emphasizes the importance of an individualized approach to treatment.

Multi-modal networks for real-time monitoring of intracranial acoustic field during transcranial focused ultrasound therapy

Background and objective:Transcranial focused ultrasound (tFUS) is an emerging non-invasive therapeutic technology that offers new brain stimulation modality. Precise localization of the acoustic focus to the desired brain target throughout the procedure is needed to ensure the safety and effectiveness of the treatment, but acoustic distortion caused by the skull poses a challenge. Although computational methods can provide the estimated location and shape of the focus, the computation has not reached sufficient speed for real-time inference, which is demanded in real-world clinical situations. Leveraging the advantages of deep learning, we propose multi-modal networks capable of generating intracranial pressure map in real-time. Methods:The dataset consisted of free-field pressure maps, intracranial pressure maps, medical images, and transducer placements was obtained from 11 human subjects. The free-field and intracranial pressure maps were computed using the k-space method. We developed network models based on convolutional neural networks and the Swin Transformer, featuring a multi-modal encoder and a decoder. Results:Evaluations on foreseen data achieved high focal volume conformity of approximately 93% for both computed tomography (CT) and magnetic resonance (MR) data. For unforeseen data, the networks achieved the focal volume conformity of 88% for CT and 82% for MR. The inference time of the proposed networks was under 0.02 s, indicating the feasibility for real-time simulation. Conclusions:The results indicate that our networks can effectively and precisely perform real-time simulation of the intracranial pressure map during tFUS applications. Our work will enhance the safety and accuracy of treatments, representing significant progress for low-intensity focused ultrasound (LIFU) therapies.

Effect of Ultrasound Conditions on Germination and Drying Characteristics of Bengal Gram (Cicer arietinum L.) and Determination of Physicochemical and Functional Properties of Flours

ABSTRACTThis study aims to investigate the effect of ultrasound conditions on the germination kinetics and drying characteristics of a germinated Bengal gram at different drying temperatures. Ultrasound treatment was given to the Bengal gram seeds at two different conditions, that is, before (US) and after soaking (SU), which was then followed by germination. This study also determines mass transfer parameters at drying temperatures of 45°C, 55°C, and 65°C and assesses the influence on the physicofunctional characteristics of a germinated Bengal gram. The germination rate behavior was effectively predicted using a zero‐order kinetic model with the highest R2 value of 0.7974–0.8857 in each nontreated (S) and treated (SU, US) Bengal gram seed, respectively. This study showed that the ultrasound treatment effectively enhanced the germination rate in both conditions, and the highest germination rate was found in pretreated ultrasound Bengal gram samples. The logarithmic thin layer drying model, with the highest average R2 of 0.9954 and the lowest average RMSE value of 0.0160, is the best‐fitted model to predict the changes in moisture ratio in both treated and nontreated conditions. The moisture diffusivity values at drying temperatures ranging from 45°C to 65°C were found in treated (US, SU) and nontreated (S) germinated samples ranging from 3.34 × 10−8 to 4.03 × 10−8 m2/s, 1.30 × 10−8 to 2.01 × 10−8 m2/s, and 6.6 × 10−9 to 8.06 × 10−9 m2/s, respectively. The protein content increased in the ultrasound‐treated sample between 12.37% and 13.50%. The solubility ranged from 8% to 10.36% throughout the treated and nontreated germinated Bengal gram flour. This study provides a unified approach to utilizing ultrasound‐treated germinated Bengal gram seeds as an alternative option to develop a functional product with better nutritional and functional properties.

Novel functional carriers based on Spirulina protein for the delivery of curcumin with improved stability and antioxidant efficiency

The potential of sustainably sourced Spirulina protein (SP), and SP nanoparticles (SPNP) obtained by heating gelation and ultrasound treatment as functional carriers for curcumin (Cur) was studied. The antioxidant activity, encapsulation performance, stability and digestive properties of the delivery system were analyzed. Compared with SP, SPNP exhibited higher hydrophobicity, and its antioxidant capacity was enhanced due to increased exposure of chromophores. The encapsulation performance of Cur-loaded complexes was influenced by the protein-Cur mass ratio, and the encapsulation efficiency of SPNP was significantly higher than that of SP (p < 0.05). Because of the better binding affinity, SPNP-Cur complexes showed improved thermal stability and UV protection effect. SP and SPNP all exhibited antioxidant synergism with Cur, and the antioxidant efficiency was closely related to pH, dissociating solvents, UV irradiation and digestion. The bioaccessibility of Cur was also greatly improved. It suggests that Spirulina protein may be an ideal carrier for delivering nutraceutical compounds.

TCT-892 Valvosoft Noninvasive Ultrasound Therapy in Patients With Severe Symptomatic Aortic Valve Stenosis: Safety and Performance Study, 6-Month Follow-Up Update

TCT-892 Valvosoft Noninvasive Ultrasound Therapy in Patients With Severe Symptomatic Aortic Valve Stenosis: Safety and Performance Study, 6-Month Follow-Up Update

Characterization of weakly nonlinear effects in relationship to transducer parameters in focused ultrasound therapy.

Focused ultrasound therapy has been widely used for the treatment of various diseases, employing different types of transducers. The focused ultrasound pressure fields inevitably exhibit nonlinear effects, which can influence the ablation region. However, the nonlinear effects exhibit noticeable variations across different applications. The characterization of the nonlinear pressure fields of ultrasound is important for the effective implementation of focused ultrasound therapy. The traditional angular spectrum method (ASM) was extended to accurately and efficiently simulate the propagation of weakly nonlinear ultrasound in heterogeneous mediums of clinical model. The nonlinear effects were further analyzed in relationship to the transducer parameters that are different in various applications. The pressure fields were simulated using the extended ASM, incorporating calculations for phase aberration in the frequency domain and magnitude compensation in the spatial domain to account for heterogeneous acoustic impedance mismatch. Validation was performed by comparison to k-Wave simulation results using two simplified clinical models, an abdominal soft tissue and a transcranial skull model. The nonlinear effects were then analyzed in relation to the transducer parameters of f-number and effective source area based on the same acoustic output power. The analysis of nonlinear effects was conducted under both homogeneous medium and the clinical models. The simulation results demonstrated a maximum error of 3.93% in the calculated harmonic pressure of the abdominal model, and a maximum error of 4.89% within the transcranial model when comparing the extended ASM simulation results to those obtained from k-Wave simulations. The characterization of the nonlinear effects reveals a strong correlation with the transducer parameters. Specifically, the results indicate that the nonlinear effects intensify with an increase in the effective source area and f-number, under the same acoustic output power of the transducer. However, the clinical model also showed an influence on the nonlinear effects in relation to the f-number. The extended ASM was demonstrated as an accurate and efficient simulation tool, and the simulation results provide a reference for evaluating the intensity of nonlinear effects in various transducer designs.

Ultrasound treatment improved gelling and emulsifying properties of myofibrillar proteins from Antarctic krill (Euphausia superba)

Antarctic krill is a promising source of marine proteins with abundant biomass and excellent nutritional profile, but has poor technological properties. Ultrasonic treatment at power levels of 0, 100, 200, 300, 400 and 500 W was applied to improve the technological properties of Antarctic krill meat, and the changes in physicochemical properties of myofibrillar proteins (MPs) were investigated. The results indicated that proper ultrasonic treatment significantly improved the gelling properties of Antarctic krill meat, in terms of a more uniform and stable gel texture and better water holding capacity, which were related to better cross-linking of MPs. Ultrasonic treatment promoted the conversion of MPs’ secondary structures from α-helix and random coil to β-sheet and β-turn, thereby making the molecular structure soft and loose. In addition, at tertiary structure level, ultrasonic treatment exposed the hydrophobic groups and sulfhydryl groups within MPs, thereby improving the emulsifying properties by changing the intermolecular interactions and interface properties. Furthermore, the particle size of MPs decreased and exhibited a more uniform distribution, aligning with the enhanced interactions observed between MPs and oil. These results provide an insight into the efficient development of Antarctic krill by elucidating how the ultrasonic treatment improves the gelling and emulsifying properties based on structure modulation of myofibrillar proteins.

A Robust ROS Generation and Ferroptotic Lipid Modulation Nanosystem for Mutual Reinforcement of Ferroptosis and Cancer Immunotherapy.

Ferroptosis initiation is often utilized for synergistic immunotherapy. While, current immunotherapy is limited by an immunosuppressive tumor microenvironment (TME), and ferroptosis is limited by insufficient reactive oxygen species (ROS) and ferroptotic lipids in tumor cells. Here, an arachidonic acid (AA) loaded nanosystem (CTFAP) is developed to mutually reinforce ferroptosis and cancer immunotherapy by augmenting ROS generation and modulating ferroptotic lipids. CTFAP is composed of acid-responsive core calcium peroxide (CaO2) nanoparticles, ferroptotic lipids sponsor AA, tetracarboxylic porphyrin (TCPP) and Fe3+ based metal-organic framework structure, and biocompatible mPEG-DSPE for improved stability. Once endocytosed by tumor cells, CTFAP can release oxygen (O2) and hydrogen peroxide (H2O2) in the acidic TME, facilitating TCPP-based sonodynamic therapy and Fe3+-mediated Fenton-like reactions to generate substantial ROS for cell ferroptosis initiation. The immunogenic cell death (ICD) after ferroptosis promotes interferon γ (IFN-γ) secretion to up-regulate the expression of long-chain family member 4 (ACSL4), cooperating with the released AA from CTFAP to accelerate the accumulation of lipid peroxidation (LPO) and thereby promoting ferroptosis in cancer cells.CTFAP with ultrasound treatment efficiently suppresses tumor growth, has great potential to challenges in cancer immunotherapy.

ID: 329069 Change in brain amyloid load in a prodromal alzheimer’s disease patient after low-intensity ultrasound treatment

ID: 329069 Change in brain amyloid load in a prodromal alzheimer’s disease patient after low-intensity ultrasound treatment

Effect of ultrasound-assisted Maillard reaction on functional properties and flavor characteristics of Oyster protein enzymatic hydrolysates

To address the delamination phenomenon during storage and flavor characteristics of Oyster protein hydrolysates (OPH). In this study, xylo-oligosaccharides (XOS) were selected to covalently graft with OPH through ultrasound-assisted Maillard reaction, and the effect of ultrasound-assisted Maillard reaction on the structure, functional properties, and flavor characteristics of OPH were investigated. The results revealed that the ultrasound treatment led to a 1.46-fold increase in the degree of grafting compared with the conventional wet-heat Maillard reaction methods. Structural analyses at various levels indicated substantial alterations in the OPH structure following the ultrasound-assisted Maillard reaction. More ordered α-helical secondary structures were shifting to random coiling, the tertiary structure showed more stretching changes, and the surface structure was characterized by loose and porous features. Compared with OPH, the solubility of the ultrasound-assisted Maillard reaction products (OPH-U-M) increased from 54.67% to 70.14%, leading to a notable enhancement in storage stability. Flavor profile analysis demonstrated a decrease in unsaturated aldehydes and ketones presenting fishy and bitter aromas, while an increase in presenting meat aroma compounds was observed in OPH-U-M. Furthermore, OPH-U-M exhibited superior antioxidant properties with DPPH and ABTS radical scavenging abilities enhancing 46.05% and 42.09% in comparison with OPH, respectively. The results demonstrated that covalently binding with XOS under ultrasonication pretreatment endowed OPH with superior functional properties (including solubility, storage stability, and antioxidant activity), and the improvement of flavor profile. This study can provide theoretical guidance and practical implications for promoting the processing applications of oyster protein.

Limosilactobacillus fermentum CGMCC 1.7434 and Debaryomyces hansenii GDMCC 2.149 synergize with ultrasound treatment to efficiently degrade nitrite in air-dried ducks

Nitrites in meat products are important food additives with coloring, antibacterial and antioxidant effects, but excessive intake of nitrites can pose health risks, including an increased risk of cancer due to the formation of carcinogenic nitrosamines. In the present study, Limosilactobacillus fermentum CGMCC 1.7434 was screened and the effects of it and Debaryomyces hansenii GDMCC 2.149 and their combination on nitrite degradation were investigated. It was found that the co-culture of L. fermentum CGMCC 1.7434 and D. hansenii GDMCC 2.149 significantly enhanced nitrite degradation (99.58%). The findings on salt and ethanol tolerance suggest suitability for application in meat fermentation processes. Scanning electron microscopy and additional data indicate that D. hansenii GDMCC 2.149 facilitates the growth, acid production, adhesion, secretion of AI-2 signaling molecules, and biofilm formation of L. fermentum CGMCC 1.7434. Metabolomics analysis suggests that these microorganisms reduce nitrite levels by converting NH3 derived from nitrite into L-glutamine, which is further transformed into N-nitroso compounds and their downstream derivatives through the ABC transporter pathway, the TCA cycle, and the amino acid metabolism pathway. Microbial community analyses showed that L. fermentum CGMCC 1.7434 and D. hansenii GDMCC 2.149 were successfully inoculated into air-dried ducks, becoming dominant strains and effectively inhibiting the growth of pathogenic bacteria. Furthermore, during the processing of air-dried duck, the combination of ultrasonic cavitation (250 W, 4 min, 30°C, 40 kHz) with the co-fermentation of L. fermentum CGMCC 1.7434 and D. hansenii GDMCC 2.149 effectively reduced nitrite content (84.55%) and TVB-N levels in the meat, without compromising color or TBARS values. This is crucial for understanding the mechanism of nitrite degradation by LAB in synergy with yeast and for the advancement of low-nitrite air-dried duck products.