The luxS deletion reduces the spoilage ability of Shewanella putrefaciens: An analysis focusing on quorum sensing and activated methyl cycle.

The luxS mutant strains of Shewanella putrefaciens (SHP) were constructed to investigate the regulations of gene luxS in spoilage ability. The potential regulations of AI-2 quorum sensing (QS) system and activated methyl cycle (AMC) were studied by analyzing the supplementation roles of key circulating substances mediated via luxS, including S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), methionine (Met), homocysteine (Hcy) and 4,5-dihydroxy-2,3-pentanedione (DPD). Growth experiments revealed that the luxS deletion led to certain growth limitations of SHP, which were associated with culture medium and exogenous additives. Meanwhile, the decreased biofilm formation and diminished hydrogen sulfide (H2S) production capacity of SHP were observed after luxS deletion. The relatively lower total volatile base nitrogen (TVB-N) contents and higher sensory scores of fish homogenate with luxS mutant strain inoculation also indicated the weaker spoilage-inducing effects after luxS deletion. However, these deficiencies could be offset with the exogenous supply of circulating substances mentioned above. Our findings suggested that the luxS deletion would reduce the spoilage ability of SHP, which was potentially attributed to the disorder of AMC and AI-2 QS system.

Nitroarenes and nitroalkenes as potential amino sources for the synthesis of N-heterocycles.

Nitro-compounds are one of the cheapest and most readily available materials in the chemical industry and are commonly utilized as versatile building blocks. Previously, the synthesis of N-heterocycles was largely based on anilines. The utilization of nitroarenes and nitroalkenes for the synthesis of N-heterocyclic compounds can save at least one step, however, as compared to anilines. Thus, considerable attention has been paid to nitroarenes and nitroalkenes as new potential amino sources. Significant progress has been made in the reductive cyclization of nitroarenes or nitroalkenes to access various N-heterocycles in recent years. Herein, we comprehensively summarize the recent progress in the construction of N-heterocycles using nitroarenes and nitroalkenes as potential amino sources. The compatibility of the reaction substrate, its mechanism, applications, advantages, and limitations in this field are also discussed in detail.

Thermochromic Photonic Crystal Microspheres with Uniform Color Display and Wide Coloration Range.

Thermochromic microspheres based on poly(N-isopropylacrylamide) attract much attention in detection and sensor due to the noticeable color response and fast response rate. However, some issues such as uneven color display and narrow coloration range still limit their practical applications. Herein, novel thermochromic microspheres with homogeneous color displays and wide thermochromic range are designed by combining the microfluidic technology with the magnetically-induced self-assembly technique and copolymerizing acrylamide (AM) with N-isopropylacrylamide. The photonic crystal structure with especially even colors is fast and conveniently constructed by magnetic assembly. The addition of AM makes the microspheres more hydrophilic and thus leading to a broader coloration range. The relationship between the structural color display and both the microstructures of photonic crystals and the thermo-responsive properties of gel matrix are elucidated. The detectable temperature of microspheres rises to as high as 60°C, and displays bright iridescent color variations from orange to blue-violet in the heating process. Importantly, their shrinking or swelling equilibrium can be reached in 80 and 105 s. Such microspheres are successfully used to visually indicate the appropriate temperature of enzymatic reaction, and have great potential in practical applications such as visual temperature detection and efficiency monitoring of chemical reactions.

Effect of Ca2+ on 3D printing accuracy and antioxidant efficacy of nano starch-lutein surimi: mechanical properties, chemical bonds and release rate.

BACKGROUND: Nano starch-lutein (NS-L) can be used in three-dimensional (3D) printed functional surimi. However, the lutein release and printing effect are not ideal. The purpose of this study was to facilitate the function and printing properties of surimi by adding the combination of calcium ion (Ca2+ ) and NS-L. RESULTS: Printing properties, lutein release and antioxidation of printed Ca2+ -NS-L-surimi were determined. The NS-L-surimi with 20 mM kg-1 Ca2+ had the best printing effects (fine accuracy, 99 ± 1%). Compared to NS-L-surimi, the structure became denser after adding Ca2+ , the gel strength, hardness, elasticity, yield stress (τ), water holding capacity of Ca2+ -NS-L-surimi increased by about 17 ± 4%, 3 ± 1%, 9 ± 2%, 20 ± 4%, 40 ± 5% respectively. These enhanced mechanical strength and self-supporting ability to resist binding deformation and improve printing accuracy. Moreover, salt dissolution and increased hydrophobic force by Ca2+ stimulated protein stretching and aggregation, leading to enhancement of gel formation. Decreased printing effects of NS-L-surimi with excessive Ca2+ (> 20 mM kg-1 ) caused by excessive gel strength and τ, leading to strong extrusion force and low extrudability. Additionally, Ca2+ -NS-L-surimi had higher digestibility and lutein release rate (increased from 55 ± 2% to 73 ± 3%), because Ca2+ made NS-L-surimi structure porous, which promoted contact of enzyme-protein. Furthermore, weakened ionic bonds reduced electron binding bondage that combined with released lutein to provide more electrons for enhancing antioxidation. CONCLUSION: Collectively, 20 mM kg-1 Ca2+ could better promote printing process and function exertion of NS-L-surimi, facilitating the application of 3D printed functional surimi. © 2023 Society of Chemical Industry.

Clinical and experimental study of a terahertz time-domain system for the determination of the pathological margins of laryngeal carcinoma.

OBJECTIVE: Laryngeal cancer is a common malignancy in otorhinolaryngological head and neck surgery, accounting for approximately one-third of all head and neck malignancies. Terahertz time-domain spectroscopy (THz-TDS) has recently been found to be useful for the detection of tumors. This study was conducted to investigate the application of THz-TDS in the diagnosis of pathological resection margins of laryngeal cancer. METHODS: Fresh laryngeal cancer tissues from 10 patients with laryngeal cancer were extracted, and after simultaneous HE staining and terahertz imaging, the tumor area, paracancerous area, and normal tissue area of each laryngeal cancer tissue sample were located under a microscope according to the pathological results of HE staining. RESULTS: The shape contours of the tumor region revealed by terahertz imaging maps and HE staining were similar. In the terahertz spectrum in the frequency range of 0.5-1.9 THz, both the absorption coefficient and refractive index values followed the order tumor > para cancer > normal tissue, with statistically significant differences (P < 0.01). When the terahertz frequency was 1.5 THz, the absorption coefficient of terahertz light waves by laryngeal cancer tissue and the percentage of nuclei showed an extremely high positive correlation (P < 0.01, r = 0.971). In the frequency ranges of 0.5-1.2 THz and 1.6-1.9 THz, the absorption coefficients of the highly differentiated group were higher than those of the moderately differentiated group. In the frequency range of 1.2-1.6 THz, the results were reversed, with statistically significant differences (P < 0.05). In the frequency range of 0.5-1.9 THz, the highly differentiated group had a higher refractive index than the moderately differentiated group, with a statistically significant difference (P < 0.05). CONCLUSIONS: THz-TDS can be used to determine the pathological margins of laryngeal cancer based on the absorption coefficient and refractive index, and the magnitudes of the absorption coefficient and refractive index are related to the percentage of nuclei. The degree of differentiation of laryngeal cancer tissue can be assessed by THz-TDS. The study shows that the terahertz time-domain system is promising for applications in the diagnosis of laryngeal cancer, especially for the more accurate identification of intraoperative margins.

Microbial colonization on the leaf surfaces of different genotypes of Napier grass.

To address correlations between population sizes of microbes on the leaf surfaces and leaf morphological and physicochemical properties, various leaf morphological and physicochemical features as possible predictors of microbial population sizes on the leaf surfaces of four Napier grass cultivars were assessed. Results indicated microbes except for lactic acid bacteria (LAB) preferred to colonize the leaf surfaces bearing trichomes, and their population sizes were significantly correlated with trichomes, especially for yeasts. The population sizes of microbes were positively correlated with soluble sugar content (p < 0.05). Furthermore, no significant correlation was found between population sizes of microbes and wax content, except for yeasts. The multivariate regression trees (MRT) analysis showed different genotypes of leaf-microbe system could be characterized by four-leaf attributes with soluble sugar of leaf tissues being the primary explanatory attribute. Leaves with soluble sugar content below 9.72 mg g-1 fresh weight (FW) were rarely colonized. For leaves with soluble sugar content above 9.72 mg g-1 FW, water content was the next explanatory leaf attribute, followed by wax content on the leaf surfaces. Leaves with higher water content (> 73%) were more colonized, and small microbial population was associated with higher wax content (> 10.66 mg g-1 dry matter). In conclusion, leaf chemical attributes have a higher contribution than morphological structure properties in determining population sizes of microbes on the leaf surfaces. The exuded soluble sugar and protein promote the development of microbial populations. For different genotypes of leaf-microbe system, the relationship between microbial abundance on their leaf surfaces and leaf morphological structure or physicochemical properties may be predicted by the MRT. Population sizes of microbes are primarily influenced by soluble sugar content under the water-rich conditions.

SO2 Poisoning Mechanism of the Multi-active Center Catalyst for Chlorobenzene and NOx Synergistic Degradation at Dry and Humid Environments.

The performance of fresh (PdV/TiO2), sulfur poisoned (Used-S and Used-H), and regenerated (Used-RS and Used-RH) multi-active center catalysts for chlorobenzene catalytic oxidation and selective catalytic reduction (CBCO + SCR) reaction is investigated. The reaction on the catalyst surface is blocked after sulfur poisoning owing to the occupation and deposition of catalyst active centers (mainly Pd centers) by PdSO4 (and/or PdS in a dry environment) and NH4HSO4 species, especially the CBCO process. Sulfates (mainly NH4HSO4) on the sulfur poisoned catalyst surface are partially decomposed after 400 °C thermal regeneration, while the deactivation caused by the formation of PdSO4 species is irreversible. Density functional theory calculation results show that in the PdSO4 and NH4HSO4 generation paths, each step of the elementary reaction has just a small energy barrier to overcome, and the stability of the product for each elementary reaction increases gradually. Even worse, SO2 is easily combined with H2O gas molecules to form H2SO3 in a humid environment, and the energy barrier for conversion of SO32- to SO42- is just 0.041 eV. The two oxygen vacancies (VOx-1 or TiOx-1) provide adsorption sites for CBCO + SCR reaction gas molecules but do not exhibit adsorption properties for SO2, which gives a possible idea for optimization of sulfur resistance. The present work is favorable for further synergistic removal of CB/NOx by the catalyst for anti-SO2 poisoning modification and application in the manufacture industry.

A novel targeted multifunctional nanoplatform for visual chemo-hyperthermia synergy therapy on metastatic lymph nodes via lymphatic delivery.

BACKGROUND: Distant metastasis to vital organs is the major contributor to breast cancer mortality, and regional lymph node metastasis is an important facilitator of distant metastasis and recurrence in this cancer. The early diagnosis and precise treatment of lymph node metastasis are crucial for staging and prognosis in breast cancer. Herein, we report a visualized precision medicine nanoplatform of metastatic lymph nodes for ultrasonic/photoacoustic (US/PA) dual modal imaging-guided in situ targeted hyperthermia-combined chemotherapy. RESULTS: Carbon nanoparticles (CNs), approved by the China Food and Drug Administration, were loaded with docetaxel and rationally combined with anti-hypoxia-inducible factor 1α antibody-modified poly (lactic-co-glycolic acid) (PLGA) nanoparticles to achieve the combination of passive targeting at the lymph nodes and intracellular targeting at HIF 1α factor. The accumulation and retention of nanoparticles in metastatic lymph nodes via lymphatic delivery were enhanced. Docetaxel could be effectively offloaded by CNs that have active carbon nanoparticles, and the PLGA membrane prevented drug leakage. The nanoparticles exhibited excellent photothermal performance with a photothermal conversion efficiency of 28.9%, killing tumor cells in metastatic lymph nodes through hyperthermia. In vitro and in vivo systematic evaluations revealed that hyperpyrexia triggered the rupture of nanoparticles caused by the phase transition of perfluorohexane, resulting in docetaxel release for achieving in situ hyperthermia-combined chemotherapy. CONCLUSIONS: The laser-triggered highly efficient in situ chemotherapy nanosystem achieves targeted synergistic chemo-hyperthermia treatment of metastatic lymph nodes, and lymphatic delivery represents a strategy to avoid additional injury caused by drugs entering the blood circulation.

Social Work Intervention for Anxiety and Depression among Medical Workers during the COVID-19 Pandemic: "Internet Plus Music Therapy".

BACKGROUND: To explore the effect of social work intervention on psychological intervention of medical workers after the epidemic under the mode of "internet plus Music Therapy". SUBJECTS AND METHODS: The observation objects in this study were all medical workers in fever clinic under the epidemic situation in COVID-19. A total of 60 cases were selected, and the proportion of anxiety and depression of medical workers in fever clinic was investigated by electronic questionnaire. After completing the investigation, social work intervention measures under the mode of "internet plus Music Therapy" were implemented. RESULTS: After implementation, the proportion of anxiety and depression of medical workers were significantly lower than those before intervention (P<0.05). The development of music therapy activities has alleviated the job anxiety of medical workers to a great extent, and the job anxiety test, total score and scores of various factors have all decreased. CONCLUSIONS: Social work intervention under the mode of "internet plus Music Therapy" can relieve anxiety and depression, and ensure the mental health of frontline medical staff during the epidemic.

Aptamer-Pyropheophorbide a Conjugates with Tumor Spheroid Targeting and Penetration Abilities for Photodynamic Therapy.

Pyropheophorbide a (Pyro) is a widely used photosensitizer for photodynamic therapy (PDT). However, poor water solubility, aggregation-induced fluorescence quenching, and lack of selectivity to targeted cells seriously limit its application. In this work, we prepared aptamer-Pyro conjugates (APCs) by linking Pyro to hydrophilic nucleic acid aptamer to enhance its water solubility and endow it with protein tyrosine kinase 7 (PTK7) overexpressed tumor spheroid specific targeting and penetration abilities for photodynamic therapy. The molecular conjugate was successfully synthesized and dissolved well in an aqueous solution. The APCs showed strong near-infrared fluorescence in the aqueous solution and produced singlet oxygen both in the solution and cells under laser irradiation, indicating its generation of singlet oxygen during PDT was guaranteed. Owing to the cancer cell targeting ability of the aptamer, the APCs specifically bound with PTK7 overexpressed cancerous cells and showed fluorescence signal for tumor cell imaging and diagnosis. The APCs exhibited favorable enhanced phototoxicity to target tumor cells compared with control cells. More importantly, due to the small size of the molecular conjugate, the APCs efficiently penetrated into the interior of multicellular tumor spheroids (MCTS) and caused cell damage. All these results indicated that the robust aptamer-Pyro conjugate is a promising selective tumor-targeting and penetrable molecule for cancer photodynamic therapy.

Analysis of risk factors for multiple primary oral squamous cell carcinoma: a cohort study.

OBJECTIVE: Chewing betel quid (CBQ) is popular in Southeast Asia, resulting in a high incidence of oral squamous cell carcinoma (OSCC). The incidence of multiple primary oral cancer (MPOC) has gradually increased and has become one of the main causes of OSCC treatment failure. However, it is unclear whether the high incidence of MPOC is also correlated with the habit of CBQ. MATERIALS AND METHODS: In this retrospective study, 915 OSCC patients were enrolled. MPOC incidence and characteristics were analyzed. CBQ and other risk factors for MPOC were investigated by chi-squared test and logistic stepwise regression analysis. RESULTS: Among 915 patients, 15 were diagnosed with synchronous MPOC. After follow-up, 60 of 915 patients developed a second or third primary lesion site and were diagnosed with metachronous MPOC. The remaining 840 patients were then diagnosed with single primary oral cancer (SPOC). The cumulative incidence of MPOC in all OSCC patients was 8.2%. CBQ and the related oral submucous fibrosis (OSF) were found to be independent risk factors of MPOC (P < 0.001). Both MPOC and SPOC patients with a CBQ habit were much younger than those who did not have a CBQ habit (P < 0.001). The buccal mucosa was the most common primary occurrence site (35.9%) in MPOC cases, and almost all MPOC patients with buccal cancer had previously suffered from OSF (88.9%). CONCLUSION: CBQ and CBQ-related OSF, for the first time, are identified as the independent risk factors of MPOC. Prevention and treatment of OSF as well as cessation of CBQ are expected to become new approaches to reduce the incidence of MPOC. CLINICAL RELEVANCE: More frequent physical examinations should be undertaken in OSCC patients with CBQ or CBQ-related OSF.

Bacterial spore inactivation induced by cold plasma.

Cold plasma has emerged as a non-thermal technology for microbial inactivation in the food industry over the last decade. Spore-forming microorganisms pose challenges for microbiological safety and for the prevention of food spoilage. Inactivation of spores induced by cold plasma has been reported by several studies. However, the exact mechanism of spore deactivation by cold plasma is poorly understood; therefore, it is difficult to control this process and to optimize cold plasma processing for efficient spore inactivation. In this review, we summarize the factors that affect the resistance of spores to cold plasma, including processing parameters, environmental elements, and spore properties. We then describe possible inactivation targets in spore cells (e.g., outer structure, DNA, and metabolic proteins) that associated with inactivation by cold plasma according to previous studies. Kinetic models of the sporicidal activity of cold plasma have also been described here. A better understanding of the interaction between spores and cold plasma is essential for the development and optimization of cold plasma technology in food the industry.

Application of biopolymers for improving the glass transition temperature of hairtail fish meat.

BACKGROUND: Glass transition temperature (Tg ) and food moisture content are closely related, especially in foods with a high moisture content, such as surimi products. In order to improve storage condition and maintain food quality, the influence of six biopolymers on the Tg of hairtail fish meat paste was investigated by differential scanning colorimetry. RESULTS: Samples were stored at -8 °C (>Tg ), -14 °C (Tg ) and -18 °C (

The Effect of the Molecular Architecture on the Antioxidant Properties of Chitosan Gallate.

To elucidate the structure-antioxidant activity relationships of chitosan gallate (CG), a series of CG derivatives with different degrees of substitution (DS's) and molecular weights (MWs) were synthesized from chitosan (CS) and gallic acid (GA) via a free radical graft reaction. A higher MW led to a lower DS of CG. The structures of CG were characterized by FT-IR and ¹H NMR, and results showed that GA was mainly conjugated to the C-2 and C-6 positions of the CS chain. The antioxidant activity (the DPPH radical scavenging activity and reducing power) were enhanced with an increased DS and a decreased MW of CG. A correlation between antioxidant activities and the DS and MW of CG was also established. In addition, a suitable concentration (0~250 µg/mL) of CG with different MWs (32.78~489.32 kDa) and DS's (0~92.89 mg·GAE/g CG) has no cytotoxicity. These results should provide a guideline to the application of CG derivatives in food or pharmacology industries.

Serum vitamin D levels are inversely related with non-alcoholic fatty liver disease independent of visceral obesity in Chinese postmenopausal women.

The aim of the present study was to investigate the association between serum vitamin D levels and both visceral adipose and with non-alcoholic fatty liver disease (NAFLD) in Chinese postmenopausal women. Four hundred and fifty-one postmenopausal women between 45 and 74 years of age (mean (± SD) age 57.3 ± 4.6 years) were enrolled in the study. All subjects participated in the Shanghai Obesity Study between June and August 2011 and underwent abdominal magnetic resonance imaging and an abdominal ultrasonography. Patients with a visceral fat area (VFA) ≥ 80 cm(2) were classified as abdominally obese. Serum 25-hydroxyvitamin D3 (25(OH)D3 ) levels were measured with an electrochemiluminescence immunoassay. The prevalence of NAFLD in the study population was 34.8% (n = 157). Women with abdominal obesity had significantly lower serum 25(OH)D3 levels than those without abdominal obesity (median (interquartile range) 11.23 (8.64-14.12) vs 12.56 (9.41-15.98) ng/mL, respectively; P < 0.01). Regardless of abdominal obesity status, serum 25(OH)D3 levels in patients with NAFLD were lower than those without non-NAFLD (11.14 (8.63-13.81) vs 12.92 (9.48-16.37) ng/mL (P < 0.05) for those without abdominal obesity; 10.86 (8.61-13.56) vs 11.55 (8.82-16.38) ng/mL (P < 0.05) for those with abdominal obesity). Partial correlation analyses demonstrated a negative correlation between serum 25(OH)D3 levels and VFA (P < 0.05). Logistic regression analysis revealed that high serum 25(OH)D3 levels were a protective factor against NAFLD after adjusting for risk factors such as VFA. In conclusion, independent of visceral obesity, vitamin D is inversely correlated with NAFLD in Chinese postmenopausal women.

Serum vitamin D is associated with non-alcoholic fatty liver disease in Chinese males with normal weight and liver enzymes.

AIM: Considering the characterization of vitamin D deficiency as a risk factor of ectopic fat deposition, the association of serum 25-hydroxy vitamin D3 [25(OH)D3] levels with non-alcoholic fatty liver disease (NAFLD) was evaluated in Chinese men with normal body mass index (BMI) and enzyme markers of liver function. METHODS: A total of 514 participants (22 to 79 years old) with normal BMI and liver enzymes were identified for analysis. Abdominal ultrasound was performed to diagnose NAFLD, and the fatty liver index (FLI) was calculated to quantify liver steatosis. Serum 25(OH)D3 levels were determined by an electrochemiluminescence immunoassay. RESULTS: Among the entire study population, the mean levels of serum 25(OH)D3 were 15.32±5.77 ng/mL. However, when serum 25(OH)D3 levels were compared between non-NAFLD subjects (n=438) and NAFLD subjects (n=76), the latter showed significantly lower levels (15.65±5.89 ng/mL vs 13.46±4.65 ng/mL, P=0.002). In addition, serum 25(OH)D3 levels were found to be significantly correlated with FLI after adjustment for age and BMI (r=-0.108, P=0.014). Logistic regression showed that serum 25(OH)D3 levels were independently correlated with NAFLD (OR: 0.937, 95% CI: 0.884-0.993, P=0.028). Furthermore, stepwise regression analysis revealed that serum 25(OH)D3 levels were inversely associated with FLI (ß=-0.055, P=0.040). CONCLUSION: The present study demonstrated that serum 25(OH)D3 levels were inversely associated with NAFLD, even in subjects with normal total body fat, suggesting a potential role of lower levels of vitamin D in the occurrence and development of NAFLD.

Preparation of water-soluble melanin from squid ink using ultrasound-assisted degradation and its anti-oxidant activity.

Water-soluble squid melanin fractions were firstly prepared using ultrasound-assistant degradation method under alkaline condition, which is optimized by response surface methodology. The processing melanin fractions were divided into different molecular weight (Mw) fractions by membrane separation (below 10 kDa, among 10-50 kDa and over 50 kDa). The AFM image and particle-size analysis showed monomer units of the melanin were destroyed, and huge polymers were degraded into smaller soluble particles after ultrasound. While, UV, IR and solid (13)C NMR spectra indicated that the basic structure of melanin fraction was still retained after ultrasound process. Further analysis showed soluble melanin fractions obtained in 0.5 and 1 M NaOH, with Mw above 10 kDa exhibited much higher in vitro antioxidant potency. The IC50 of these fractions (IC50 among 19-80 µg) on scavenging O 2 ∙¯ is more efficient than carnosine (IC50 = 355 µg/ml.), a commercialized antioxidant. They (IC50 mong 115-180 µg/ml) are as efficient as carnosine (IC50 = 110 µg/ml) on scavenging ∙OH. Our research has reported a novel method for preparation of water-soluble melanin fractions from squid ink, which could be a promising free radical scavenger from nature resource.

Differentiation of three commercial tuna species through GC-Q-TOF and UPLC-Q/Orbitrap mass spectrometry-based metabolomics and chemometrics.

Food fraud is common in the tuna industry because of the economic benefits involved. Ensuring the authenticity of tuna species is crucial for protecting both consumers and tuna stocks. In this study, GC-Q-TOF and UPLC-Q/Orbitrap mass spectrometry-based metabolomics were used to investigate the metabolite profiles of three commercial tuna species (skipjack tuna, bigeye tuna and yellowfin tuna). A total of 22 and 77 metabolites were identified with high confidence using GC-Q-TOF and UPLC-Q/Orbitrap mass spectrometry, respectively. Further screening via chemometrics revealed that 38 metabolites could potentially serve as potential biomarkers. Hierarchical cluster analysis showed that the screened metabolite biomarkers successfully distinguished the three tested tuna species. Furthermore, a total of 27 metabolic pathways were identified through enrichment analysis based on the Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathways.

A review: Interactions between protein from blue foods and functional components in delivery systems: Function exertion and transmembrane transport by in vitro digestion/cells model.

Functional compounds (FCs) had some functions, which are affected easily by digestion and transmembrane transport leading to low absorption rates, such as lutein, quercetin, xylo-oligosaccharide. Protein from blue foods is a potential bioactive compound, which had higher bioavailability, especially for bioactive peptides (BBPs). The BBPs has great limitations, especially the variability under pepsin digestion. However, the limitation of single FCs and BBPs in bioavailability might can be complemented by mixture of different bioactive compounds. Therefore, this review provides an in-depth study on the function and mechanism of different FCs/BBPs and their mixtures. Specifically, digestion effect of mixtures on function and transmembrane transport mechanisms of different bioactive compounds were exhibited to elaborate interactions between BBPs and FCs in delivery systems (function and bioavailability). Combination of FCs/BBPs could enhance bioactive compounds function by mutual complement of function mechanisms, as well as improving the function after digestion by regulating digestion process. Moreover, transmembrane absorption and transport of FCs/BBPs also could be facilitated by mixtures due to complement of transmembrane mechanism (endocytosis, protein channels, cell bypass way). This manuscript lays a foundation for the development of active ingredient bioavailability in functional food processing.

Discrimination of three commercial tuna species through species-specific peptides: From high-resolution mass spectrometry discovery to MRM validation.

The risk of tuna adulteration is high driven by economic benefits. The authenticity of tuna is required to protect both consumers and tuna stocks. Given this, the study is designed to identify species-specific peptides for distinguishing three commercial tropical tuna species. The peptides derived from trypsin digestion were separated and detected using ultrahigh-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-TOF/MS) in data-dependent acquisition (DDA) mode. Venn analysis showed that there were differences in peptide composition among the three tested tuna species. The biological specificity screening through the National Center for Biotechnology Information's Basic Local Alignment Search Tool (NCBI BLAST) revealed that 93 peptides could serve as potential species-specific peptides. Finally, the detection specificity of species-specific peptides of raw meats and processed products was carried out by multiple reaction monitoring (MRM) mode based on a Q-Trap mass spectrometer. The results showed that three, one and two peptides of Katsuwonus pelamis, Thunnus obesus and Thunnus albacores, respectively could serve as species-specific peptides.