We report that the degradation chemistry of hexafluoropropylene oxide dimer acid (HFPO-DA), a per- and polyfluoroalkyl substance (PFAS), can be altered by enabling uncoupled parallel reductive and oxidative processes (PROP) by simultaneous radical generation via ultrasonication and UV irradiation. PROP significantly suppresses trifluoroacetic acid (TFA), a dominant end product in the degradation of perfluorocarboxylic acids (PFCAs), which are of emerging health concern, and promotes much deeper fragmentation of long-chain transformation products.

Traditional chemical hair dyes are associated with potential health risks, while botanical alternatives are often hampered by poor stability and limited color longevity. In this study, discarded squid ink was used to prepare bionic hair colorants of high performance. By synergizing ultrasound disruption with enzymatic hydrolysis, the crude ink aggregates were transformed into highly uniform squid ink melanin nanoparticles (SIMNPs) with size and zeta potential of ~174 nm and −37.5 mV, respectively. This effectively improved the solubility but reduced the steric limitation of natural melanin. To overcome the weak affinity between melanin and human hair, a biomimetic interface where Fe(III) ions act as supramolecular bridges was further engineered to stably bind the SIMNPs to hair keratin. Under optimized conditions (pH 8.0, 45 °C, and 80 min), the dyed hair achieved a natural deep black with a total color difference (ΔE*) of 68.79 ± 0.29, which was maintained at 63.19 ± 0.27 even after 13 consecutive water washing cycles. Unlike destructive oxidative dyes, this SIMNP dyeing system assisted by coordination-driven assembly preserved the native α-helical architecture and disulfide bond networks of hair keratin. Furthermore, the deposited SIMNP layer effectively protected hair fibers from ultraviolet (UV) damage due to its powerful UV-shielding capacity. Crucially, in vitro and in vivo evaluations confirmed the exceptional biosafety of this formulation, demonstrating robust cellular tolerance and absence of murine skin irritation. The work demonstrates a green, low-damage paradigm for the development of bio-based hair colorants of high performance and presents a promising pathway for the high-value utilization of marine by-products.

Temperature significantly affects the function and application of collagen. In this study, bighead carp skin collagen (SC) with a triple helix structure was prepared. Circular dichroism experiments revealed that at a thermal denaturation temperature (Td = 31.1 °C), the positive peak of SC disappeared, with a triple helix fraction of 24.11 %. Secondary structure results showed that the random coils (36.43 ± 2.93 %) became the dominant conformation at Td. Emulsifying property results showed that as the temperature increased, the emulsifying activity index improved. At 30 °C, the EAI value of the SC solution peaked at 161.83 ± 2.87 m2/g. Steady shear test results showed that the pseudoplasticity of SC solutions weakened as temperature increased. Dynamic frequency sweep results revealed that when the temperature was below Td, temperature increase mainly weakened the G' of the solution. This study provides valuable information for the processing and further application of collagen.

Fish-derived collagen can reduce the risk of disease transmission and has no religious or cultural restrictions. However, it has limited applications due to its poor thermal stability. In this study, black carp swim bladder collagen (BBC), classified as a type I collagen, was extracted. Amino acid composition analysis revealed that BBC had a higher proline hydroxylation rate of 39.57%. Fourier transform infrared spectroscopy revealed that BBC exhibited a complete triple-helix structure. The fractional viscosity curve and differential scanning calorimetry curves revealed that the thermal denaturation temperature (Td) and the melting temperature (Tm) were 30.85 °C and 107.19 °C, respectively. The dynamic rheological analysis showed that as the concentration increased from 5 mg/mL to 20 mg/mL at 0.01 Hz, the storage modulus increased from 0.979 Pa to 84.2 Pa. When the temperature exceeded the Td, the BBC solution exhibited viscous behaviour as the frequency increased. The steady-shear analysis showed that the BBC was a shear-thinning fluid. Functional properties analysis revealed that BBC exhibited better emulsification properties, foaming properties, water absorption capacity and oil absorption capacity than land-derived collagen, making it suitable for emulsifiers, bubbling beverages, and frozen meat preservation. Additionally, BBC promoted the growth of MT3C3-E1 cells and maintained the normal morphology of the cells. These results showed that BBC is a promising substitute for terrestrial collagen in functional foods, cosmetics, and biofunctional materials.

In response to growing concerns over PFAS exposure from cosmetics, this study developed a level-5a (Suspect Screening Exact Mass Match) PFAS suspect screening protocol using liquid chromatography and time-of-flight high-resolution mass spectrometry to identify PFAS in 35 U.S.-market cosmetic products. A screening workflow developed by a Native PFAS Precision and Recovery Standards Solution, containing 30 typical PFAS, enabled maximum-likelihood suspect identification against a PFAS list of 3,882 compounds from National Institute of Standards and Technology with least false-negatives and false-positives. PFAS suspects were identified in 34 of 35 samples, with 13 samples containing over 10 unique PFAS suspects. Powder-based cosmetics exhibited more PFAS suspects than cream-based products. Targeted analysis with 30 PFAS standards via Triple Quadrupole LC-MS/MS confirmed 26 of the 218 identified suspects. These results underscore the feasibility of the total PFAS suspects in cosmetics and highlight the need for stricter regulation of fluorinated ingredients and further research on dermal PFAS exposure.

This study compared collagens from cold-water and warm-water fish for their structural, rheological, and functional properties, and explored their potential applications, aiming to realize the high-value utilization of marine biological resources. To this end, chum salmon skin collagen (CSSC) and Nile tilapia skin collagen (NTSC) were both successfully extracted. Collagens from the two species had different primary and secondary structures, with NTSC having a higher molecular weight, imino acid content, and α-helices and β-turns content. The denaturation temperatures were 12.01 °C for CSSC and 31.31 °C for NTSC. CSSC was dominated by viscous behavior and its structure varied with temperature, while NTSC was dominated by elastic behavior and its structure remained stable with temperature. Both collagens had good oil holding capacity, foaming capacity, and emulsifying activity, but NTSC had better water holding capacity and foaming and emulsifying stability. Their different properties make CSSC more suitable for the preservation of frozen and chilled foods and the production of sparkling beverages, and give NTSC greater potential in biofunctional materials and solid food processing.

Collagen is an important biopolymer widely used in food, cosmetics and biomedical applications. Understanding the effect of pH on the structure and properties of collagen is beneficial for its further processing and exploitation. In this study, greenfin horse-faced filefish skin collagen (GHSC) was prepared and identified as a type I collagen. We systematically investigated the effect of pH on the structural, functional and rheological properties of GHSC. Scanning electron microscopy showed that the collagen morphology changed from an ordered stacked sheet structure to a rough silk-like structure as pH increased. Gaussian-fitted Fourier infrared spectroscopy results of the collagen revealed that it unfolded with increasing pH. Moreover, the ordered structure was reduced, and random coils became the dominant conformation. Its β-sheet and random coil contents increased from 18.43 ± 0.08 and 33.62 ± 0.17 to 19.72 ± 0.02 and 39.53 ± 1.03%, respectively, with increasing pH. α-helices and β-turns decreased from 35.00 ± 0.26 and 12.95 ± 0.01 to 29.39 ± 0.92 and 11.36 ± 0.10%, respectively. The increase in β-sheets and random coils allowed the pI-treated collagen to exhibit maximum water contact angle. The emulsification and foaming properties decreased and then increased with increasing pH in a V-shape. The increased net surface charge and β-sheets in collagen benefited its emulsification and foaming properties. The rheological results showed that the protoprotein exhibited shear-thinning properties in all pH ranges. The collagen solutions showed liquid-like behaviour in low-pH (2, 4) solutions and solid-like behaviour in high-pH (6, 7.83 and 10) solutions. Moreover, the frequency-dependent properties of the storage modulus (G′) and loss modulus (G″) of the collagen solutions weakened with increasing pH. Collagen has considerable frequency-dependent properties of G′ and G″ at low pH (2, 4). Thus, the importance of collagen raw material preparation for subsequent processing was emphasised, which may provide new insights into applying collagen-based materials in food, biomaterials and tissue engineering.

Collagen electrospun fibers are promising materials for food packaging and tissue engineering. The conventional electrospinning of collagen, however, is usually carried out by dissolving it in organic reagents, which are toxic. In this study, collagen/pullulan (COL/PUL) ultra-thin fibers were prepared by electrospinning using acetic acid as a solvent. Compared to the conventional preparation method, the proposed method is safe and does not produce toxic solvent residues. The introduction of PUL increased the degree of molecular entanglement in the solution, so the viscosity of the COL/PUL electrospun solution increased from 0.50 ± 0.01 Pa∙s to 4.40 ± 0.08 Pa∙s, and the electrical conductivity decreased from 1954.00 ± 1.00 mS/cm to 1372.33 ± 0.58 mS/cm. Scanning electron microscopy analysis confirmed that PUL improved the spinnability of COL, and smooth, defect-free COL/PUL ultra-thin fibers with diameters of 215.32 ± 40.56 nm and 240.97 ± 53.93 nm were successfully prepared at a viscosity of greater than 1.18 Pa∙s. As the proportion of PUL increased, intramolecular hydrogen bonds became the dominant interaction between COL and PUL. The intermolecular hydrogen bonding content decreased from 52.05 % to 36.45 %, and the intramolecular hydrogen bonding content increased from 46.11 % to 62.95 %. The COL was gradually unfolded, the content of α-helices decreased from 33.57 % to 25.91 % and the random coils increased from 34.22 % to 40.09 %. More than 36 % of the triple helix fraction of COL was retained by the COL/PUL ultra-thin fibers, whereas only 16 % of the triple helix fraction of COL was retained by the COL nanofibers prepared with 2.2.2-trifluoroethanol. These results could serve as a reference for the development of green food COL-based fibers.

该研究以三文鱼(Salmo salar)加工副产物鱼皮为原料开发了一种海洋源胶原.利用酸法提取,盐析透析纯化制备胶原,通过SDS-PAGE和光谱鉴定其结构,在此基础上分析其理化性质、流变特性、功能特性以及细胞相容性.结果表明,三文鱼鱼皮胶原为典型Ⅰ型胶原,且保留了完整的三螺旋结构.鱼皮胶原热变性温度为22.3℃;鱼皮胶原乳化性为65.91～755.97 m2/g,高于牛皮胶原(28.4～56.2 m2/g)和鲵肌浆蛋白(0.6～3.38 m2/g);乳化稳定性为3.50 min,高于蒙古牛骨胶原(0.8 min)和军曹鱼鱼皮胶原(0.2 min),可作为乳化剂用于面包生产;起泡性为16.56％ ～77.79％,高于酪蛋白(3.95％ ～10.15％)和米糠浓缩蛋白(5.2％ ～10.03％);泡沫稳定性(13％)高于大鲵肌浆蛋白(5％)和牛皮胶原(10％),可用于啤酒、乳制品生产.MC3T3-E1细胞在0.4 mg/mL的胶原溶液中相对增殖率为111.6％,优于罗非鱼鱼皮胶原.研究表明,三文鱼鱼皮胶原具有替代市场主流胶原产品的开发潜力.

Collagen has been ubiquitously applied in the food, cosmetic, biomedical, and pharmaceutical industries. However, the existing collagen in the market cannot meet the demand of consumers. In this study, double-spotted pufferfish collagen (DPC) was extracted from the skin of the pufferfish and characterized as type I collagen, which maintains a native triple helical structure. Liquid chromatography-tandem mass spectrometry analysis revealed that α1 and α2 subunits of DPC comprised 378 and 372 uninterrupted Gly-X-Y triplets, respectively, which were 78.3 % and 78.4 % of the total amino acid content. Secondary structure analysis revealed that DPC consisted of 50.23 % α-helices, 26.51 % β-sheets, 23.26 % β-turns, and 0 % random coils. Using XRD, the distance between collagen molecular chains was found to be 11.45 Å. The yield of DPC was 49.83 % ± 1.85 % (dry weight basis), which was higher than that of pigskin collagen. Dynamic sweep and steady-state shear of DPC were significantly affected by temperature and concentration. DPC solutions exhibited shear-thinning rheological behavior. DPC exhibited water holding and oil absorption capacities superior to terrestrial collagen, such as that of chicken feet collagen. The foaming properties and emulsifying properties of DPC were superior to commercial collagen, such as that of black ruff collagen. DPC was nontoxic to MC3T3-E1 cells and had good cytocompatibility. These results suggest that DPC is a new alternative for collagen with potential for further applications in food, cosmetic, and biomedical fields.

Whether a tire crumb rubber (TCR) playground would expose children to potentially harmful chemicals such as heavy metals is an open question. The released metals available for pickup on the surface of TCR tiles was studied by accelerated 2-year aging of the TCRs in the NIST-SPHERE (National Institute of Standards and Technology Simulated Photodegradation via High Energy Radiant Exposure). The dermal contact was mimicked by a method of composite surface wiping from US Environmental Protection Agency throughout the weathering process. The surface release of ten most concerned harmful metals (Be, Cr, Cu, As, Se, Cd, Sb, Ba, Tl, Pb) was monitored through the course of aging. The cumulative release of Cu, As, Tl, and Sb reached potentially harmful levels at various times within 3 years, although only Cr was found at a harmful level on the surface of the tiles. Taking the cleansing effect of precipitation or periodic cleansing with rain into account, TCR playgrounds may still be safe for use.

Collagen from tilapia skin was extracted and confirmed as type I collagen. Collagen was then hydrolyzed with alcalase for 4 h and the released peptides were identified. The structure-activity relationship of collagen-released peptides showed that proline at position C3 played a key role in improving ACE inhibitory activity, while proline at position C2 had a negative effect. Collagen peptide release kinetics showed that with the extension of time, the number of peptides increased dramatically at first, decreased, and then tended to be stable. This indicated that collagen peptides mainly originated from primary enzymolysis at the first stage and began to undergo secondary hydrolysis in the second stage. Afterwards, secondary enzymolysis was dominant at the third stage and finally remained stable at final two stages. Understanding the pattern of collagen peptide release kinetics might offer a powerful approach in the collagen-peptide food processing industry to better control food safety and quality.

The objective of this study was to develop an aquatic collagen with high thermal stability as a possible alternative to terrestrial sources. Swim bladder collagen (SBC) was extracted from grass carp with high yield of 39.2% (db), and characterized as type I collagen. X-ray diffraction indicated that SBC maintains a native triple helical collagen structure. Secondary structure analysis revealed that SBC consists of 41.93% alpha-helices, 45.31% beta-sheets, 12.76% beta-turns, and 0% random coils. Proteins from SBC exhibited foaming and emulsifying superiority to proteins from terrestrial sources, such as chicken feet collagen. The thermal denaturation temperature of SBC (34.3 degrees C) is similar to porcine skin collagen. Dynamic frequency sweep tests showed that elasticity plays a dominant role in the SBC solution system as the concentration increases. The SBC solution system shows viscous behavior when the temperature is below Td. In addition, the steady shear tests showed that all of the SBC solutions exhibited pseudoplasticity with shear-thinning behavior. SBC could provide a suitable environment for MC3T3-E1 cell growth and maintain normal cellular morphology. Overall, the results indicated that SBC might has potential for further applications in food, cosmetics and biomedical fields.

In this paper, the preparation process condition of chondroitin sulfate chelated zinc was optimized by orthogonal test. Chondroitin sulfate and zinc sulfate were selected as the raw materials, chelating rate of zinc as evaluation index, the effects of pH, reaction time, mass ratio of chondroitin sulfate to zinc sulfate heptahydrate, and reaction temperature on chelating rate of zinc were investigated by single factor test and orthogonal test. The structural characterization of chondroitin sulfate chelated zinc was analyzed by UV spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric and X-ray diffraction analysis. The bioavailability of zinc irons in chondroitin sulfate chelated zinc was determined by in vitro simulated gastrointestinal digestion and absorption. The results showed that optimal preparation conditions of chondroitin sulfate chelated zinc were as follows: pH4, reaction time was 1 h, mass ratio was 1:1, and reaction temperature was 30 ℃. Under these conditions, chelating rate of zinc was 80.6%±1.31%. UV spectrum combined with Fourier infrared spectrum analysis showed that chondroitin sulfate chelated zinc was formed by zinc ions combine with hydroxyl, carboxyl, sulfonic groups in chondroitin sulfate. Scanning electron microscopy and X-ray diffraction analysis showed that the micromorphology of chondroitin sulfate chelated zinc was microparticles with crystal structure. Thermogravimetric analysis proved that thermal stability of chondroitin sulfate chelated zinc was better than that of chondroitin sulfate. In vitro simulated gastrointestinal digestion and absorption analysis showed that the bioavailability of chondroitin sulfate chelated zinc was better than that of inorganic zinc salt. The research results would provide theoretical basis and technical support for the development of new zinc supplements.

Marine collagen is an ideal material for tissue engineering due to its excellent biological properties. However, the limited mechanical properties and poor stability of marine collagen limit its application in tissue engineering. Here, collagen was extracted from the skin of tilapia (Oreochromis nilotica). Collagen-thermoplastic polyurethane (Col-TPU) fibrous membranes were prepared using tilapia collagen as a foundational material, and their physicochemical and biocompatibility were investigated. Fourier transform infrared spectroscopy results showed that thermoplastic polyurethane was successfully combined with collagen, and the triple helix structure of collagen was retained. X-ray diffraction and differential scanning calorimetry results showed relatively good compatibility between collagen and TPU.SEM results showed that the average diameter of the composite nanofiber membrane decreased with increasing thermoplastic polyurethane proportion. The mechanical evaluation and thermogravimetric analysis showed that the thermal stability and tensile properties of Col-TPU fibrous membranes were significantly improved with increasing TPU. Cytotoxicity experiments confirmed that fibrous membranes with different ratios of thermoplastic polyurethane content showed no significant toxicity to fibroblasts; Col-TPU fibrous membranes were conducive to the migration and adhesion of cells. Thus, these Col-TPU composite nanofiber membranes might be used as a potential biomaterial in tissue regeneration.

Marine collagen is gaining vast interest because of its high biocompatibility and lack of religious and social restrictions compared with collagen from terrestrial sources. In this study, lizardfish (Synodus macrops) scales were used to isolate acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC). Both ASC and PSC were identified as type I collagen with intact triple-helix structures by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and spectroscopy. The ASC and PSC had high amino acids of 237 residues/1000 residues and 236 residues/1000 residues, respectively. Thus, the maximum transition temperature (Tmax) of ASC (43.2 °C) was higher than that of PSC (42.5 °C). Interestingly, the Tmax of both ASC and PSC was higher than that of rat tail collagen (39.4 °C) and calf skin collagen (35.0 °C), the terrestrial collagen. Solubility tests showed that both ASC and PSC exhibited high solubility in the acidic pH ranges. ASC was less susceptible to the "salting out" effect compared with PSC. Both collagen types were nontoxic to HaCaT and MC3T3-E1 cells, and ASC was associated with a higher cell viability than PSC. These results indicated that ASC from lizardfish scales could be an alternative to terrestrial sources of collagen, with potential for biomedical applications.

胶原是细胞外基质的主要结构蛋白,广泛存在于各类动物机体中.天然胶原存在纤维形态不一、机械性能差等不足,限制了其工业规模化应用.因此,如何有效地制备出性能优良的胶原材料成为热点问题.静电纺丝技术是一种新兴的纳米材料制造技术,利用该技术可获得具有不同结构和性能的胶原基纳米纤维材料,制成的纳米纤维材料展现出密度低、弹性高等优异特性,有望广泛应用于组织工程、医学、载体等领域.本文将从胶原的单独静电纺丝及其影响因素、胶原共混静电纺丝和影响因素以及应用等方面介绍胶原静电纺丝技术的研究进展,并针对存在的问题和发展方向进行了讨论和展望,为胶原的应用提供一定的理论指导和技术支撑.

The structure–activity relationship (SAR) and release behavior of angiotensin I-converting enzyme inhibitory (ACEi) peptides obtained from enzymolysis of collagen influence the large-scale production of ACEi peptides. However, researchers have paid insufficient attention to these areas. In this study, we extracted collagen from tilapia skin, and hydrolyzed it using three proteases. A total of 270 peptides were released from the collagen parent protein. The SAR of these larger collagen ACEi peptides indicated that the presence of proline at position C2 of three C-terminal sequences has a greater effect on increasing the ACEi activity of the peptide than at position C1. The release behavior of these collagen peptides showed that bromelain and alcalase preferentially cleave the N-terminal region of the collagen α1 subunit and then the C-terminal region. These enzymes evenly cleave regions of the collagen α2 subunit. Collagenase preferentially cleaves the C-terminal region of the collagen subunit, followed by the N-terminal region, and then the middle region. The pattern of peptide release from different proteases and the SAR of larger collagen peptides can help guide food production processes to ensure food safety, and to produce high-quality active peptide products.

本文以虾蟹漂烫汁酶解粉末为原料,以感官评价和褐变指数为指标,利用单因素和正交实验,优化美拉德反应工艺,并利用电子鼻和固相微萃取-气质联用技术分析反应前后挥发性物质的变化规律.实验结果表明,美拉德反应的最佳参数为:以虾蟹漂烫汁酶解液为基准,分别添加木糖4％,精氨酸3％,pH7.5,反应时间50 min,反应温度90℃,所得反应产物的感官评分为8.23分,褐变指数为0.7283.在此条件下,电子鼻分析结果表明,美拉德反应后,产品增加了烧烤味和海鲜风味;固相微萃取-气质联用技术分析结果表明,美拉德反应后,产品的胺类、烷烃类、醇类、醛类和酚类等挥发性风味成分明显减少,吡嗪类、有机酸类、酮类及硫化物等挥发性风味成分明显增加.本研究成果可为虾蟹漂烫汁的高价值开发和大规模生产提供理论依据和技术支持.