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With the aim of exploring a natural antilisterial peptide from food-derived origin, an antibacterial peptide named as Alpep7 was purified from the bromelain hydrolysate of rice bran protein (RBP) in this study. The resulting amino acid consequence was identified as KVDHFPL (Lys-Val-Asp-His-Phe-Pro-Leu) by ultraperformance liquid chromatography tandem matrix-assisted laser desorption/ionisation quadrupole time-of-flight mass spectrometry (MALDI Q-TOF MS). In addition, to assess the probability of the targeted delivery of liposome encapsulation of the peptide to Listeria biofilm, Alpep7-loaded liposomes were further prepared from a mixture of dipalmitoylphosphatidylcholine, stearylamine and cholesterol in a molar ratio of 10 : 3 : 2 and characterised by the analysis of particle size, zeta potential, microtopography and storage stability. The results showed that the liposomes exhibited a well-defined spherical shape, with an average diameter below 200 nm. The liposomes maintained favourable stability after storage at 4 °C for 4 weeks. Comparisons between the activities of free and liposomal Alpep7 via microbroth dilution, regrowth analysis and confocal scanning laser microscopy suggested that liposomal delivery was more effective during the initial exposure of the liposomes to the biofilms. The thermodynamic analysis indicated that the adsorption of liposomal Alpep7 to the listerial biofilm was a spontaneous, exothermic process. The results may provide a natural means for the treatment of listerial contamination and guide the potential application of liposomes for the targeted delivery of antimicrobials to pathogenic biofilms in the food industry.

Liposomes constructed from Escherichia coli membrane lipids were used as a pseudo-stationary phase in capillary electrophoresis and immobilised liposome chromatography to evaluate the interaction between antibacterial peptide (ABP) Apep10 and bacterial membrane lipids. The peptide mobility decreased as the concentration of liposomes increased, providing evidence for the existence of this interaction. The binding constant between Apep10 and the Escherichia coli membranes lipid liposome was higher than that of Apep10 with a mixed phospholipids liposome at the same temperature. The capillary electrophoresis results indicate that the binding ability of Apep10 with a liposome was dependent on the liposome's lipid compositions. Thermodynamic analysis by immobilised liposome chromatography indicated that hydrophobic and electrostatic effects contributed to the partitioning of Apep10 in the membrane lipids. The liposomes constructed from bacterial membrane lipid were more suitable as the model membranes used to study dynamic ABP/membrane interactions than those constructed from specific ratios of particular phospholipids, with its more biomimetic phospholipid composition and contents. This study provides an appropriate model for the evaluation of ABP-membrane interactions., Competing Interests: The authors have declared that no competing interests exist.

Anchovy (Engraulis japonicus) cooking wastewater (ACWW) is a by-product resulted from the production of boiled-dried anchovies in the seafood processing industry. In this study, the protein hydrolysate of ACWW (ACWWPH) was found to have antimicrobial activity after enzymatic hydrolysis with Protamex. For the targeted screening of antibacterial peptides, liposomes constructed from Staphylococcus aureus membrane lipids were used in an equilibrium dialysis system. The hydrolysate was further purified by liposome equilibrium dialysis combined with high performance liquid chromatography. The purified antimicrobial peptide (ACWWP1) was determined to be GLSRLFTALK, with a molecular weight of 1104.6622Da. The peptide exhibited no haemolytic activity up to a concentration of 512μg/ml. It displayed a dose-dependent bactericidal effect in reconstituted milk. The change in cell surface hydrophobicity and membrane-permeable action of the purified ACWWP1 may have contributed to the antibacterial effect. This study suggests that liposome equilibrium dialysis can be used for the targeted screening of antimicrobial peptides., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Squid belongs to the cephalopod class of mollusks, with short survival time, fast reproduction speed, comprehensive nutrition, high protein content, low-fat content, and low-calorie content. Squid skin accounts for 8% - 13% of squid processing waste, and full utilization of squid skin can prevent resource waste. This article reviewed the nutritional components, peeling methods, extraction methods of collagen and gelatin from squid skin, as well as the preparation methods of squid skin collagen peptides with antioxidant activity, antihypertension, anti-skin aging, anti-tumor activity, and anti-freezing activity. The application of squid skin collagen products in industries such as food, medicine, cosmetics, and cosmeceuticals was also introduced. This article provided a systematic introduction to the research progress in the processing and utilization of squid skin, aiming to provide a theoretical basis for the deep processing of squid skin and promote the sustainable and healthy development of China's aquatic product processing industry. In the future, the research should focus on optimizing the extraction process of squid skin collagen, improving the targeting of its target peptide screening, and conducting active clinical validation studies, to provide reference for the development and high-value utilization of squid skin. [ABSTRACT FROM AUTHOR]

To design a delivery system with effective protective attribute for lutein and explore the effect of the peptides conjugated with different phenolics on the carrier performance, zein peptide was covalently bonded to three phenolic acids, i.e. vanillic acid, protocatechuic acid, and gallic acid, to form the corresponding phenolic acid-zein peptide conjugates as stabilizers for preparing emulsion gels with sodium alginate and Ca2+. The emulsifying activity of the peptide was significantly increased by 49%–76% after the conjugation. The presence of the hydrophobic methoxy group on the benzene ring of vanillic acid contributed to the highest surface hydrophobicity of the corresponding conjugate, while the more hydrophilic phenolic hydroxyl groups of protocatechuic acid and gallic acid resulted in lower surface hydrophobicity for their conjugates. Among all the emulsion gels, the gel fabricated by vanillic acid-zein peptide conjugate exhibited the tightest network structure, the most favorable thixotropy with the recovery rate of 82%, the highest storage stability and UV protective effect for lutein. The in vitro digestion demonstrated that the gel with a more tight structure achieved the lower free fatty acids release rate and bioaccessibility. These findings suggest that the hydrophobicity of phenolic acids inflences the controllable release and protective effect for hydrophobic bioactives of the emulsion gels based on their covalent conjugates with zein peptides. • Three phenolic acids, VA, PA and GA were covalently conjugated with zein peptide. • Hydrophobicity of phenolic acids affected the interface performance of the conjugates. • Emulsion gels prepared by the conjugates provided effective protection for lutein. • FFA release rate was positively correlated with lutein bioavailability. • Lutein bioavailability was negatively correlated with storage modulus of emulsion gel. [ABSTRACT FROM AUTHOR]

[Display omitted] • HAP was used as a carrier for walnut peptides loaded proliposomes. • HAP improved the encapsulation efficiency of walnut peptides in proliposomes. • Hydrogen bonds formed between HAP and phospholipids in the proliposomes. • HAP improved thermal and environmental stability of the liposomes. • HAP facilitated a slow-release effect in simulated digestion for the proliposomes. To explore the feasibility of hydroxyapatite (HAP) as the carrier for proliposomes and improve the stability of walnut peptides (WPs), WPs-loaded proliposomes (WPs-PROLIPs) with hydroxyapatite (HAP) as the carrier were fabricated, and the physicochemical properties, environmental stability as well as in vitro simulated digestion release performance of the proliposomes were investigated. The proliposomes with HAP possessed smaller particle sizes and higher encapsulation efficiencies than those without HAP. FTIR analysis revealed that hydrogen bonds formed between HAP and phospholipids in the proliposomes. The inclusion of HAP in WPs-PROLIPs led to the improvement of the thermal degradation stability and environmental stabilities of the system. HAP also induced the conversion of free water into bound water in the proliposomes, as evaluated by LF NMR. In addition, proliposomal encapsulation did not affect the antioxidant activity of WPs-PROLIPs and the lateral order of the liposome membrane. Finally, in vitro digestion showed that the addition of HAP endowed the proliposomes with a retarded free fatty acid release effect, which was dependent on the weight ratio of phospholipids to HAP. These results offer opportunities for the use of HAP as a feasible carrier and lyoprotectant for proliposomes encapsulating biopeptides. [ABSTRACT FROM AUTHOR]