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The surfactant rhamnolipid (RL) was used to modify the liposomes. β‐carotene (βC) and rutinoside (Rts) were utilized to generate co‐encapsulated liposomes through an ethanol injection method that used both hydrophilic and hydrophobic cavities to fabricate a novel cholesterol‐free composite delivery system. The RL complex‐liposomes loaded with βC and Rts (RL–βC–Rts) showed higher loading efficiency and good physicochemical properties (size = 167.48 nm, zeta‐potential = −5.71 mV, and polydispersity index = 0.23). Compared with other samples, the RL–βC–Rts showed better antioxidant activities and antibacterial ability. Moreover, dependable stability was uncovered in RL–βC–Rts with still 85.2% of βC storage from nanoliposome after 30 days at 4°C. Furthermore, in simulated gastrointestinal digestion, βC exhibited good release kinetic properties. The present study demonstrated that liposomes constructed from RLs offer a promising avenue for the design of multicomponent nutrient delivery systems using both hydrophilic. [ABSTRACT FROM AUTHOR]

BACKGROUND Presently, identifying natural compounds as emulsifiers is a popular topic in the food industry. Rapeseed protein isolate (RPI) is a natural plant protein with excellent emulsifying properties, but it has not been systematically developed and utilized. RESULTS: This study investigated the surface hydrophobicity, wettability, and protein solubility of RPI to further explain its emulsifying behavior in emulsion systems. Nanoemulsions stabilized by RPI at varying protein concentration, pH, and ionic strength were prepared. The size distribution, zeta potential, flocculation index, creaming index, microstructure, rheology, and protein secondary structure of emulsions were measured. The emulsion stabilized by 20 g L−1 RPI at pH 10.0, 200 mmol L−1 ionic strength revealed an appropriate droplet size of 555 nm and the most internal gel strength without creaming phenomenon. Circular dichroism spectroscopy showed a positive correlation between emulsion stability and α‐helix ratio, indicating the environment factors affected emulsion stability by acting on its hydrogen bonds. CONCLUSIONS: This study demonstrates that RPI is a practical emulsifier for stabilizing nanoemulsions. About 20 g L−1 RPI can stabilize 100 mL L−1 oil in water; stable emulsions can be formed at most pH conditions (except 7.0); ion addition will aggravate the emulsion flocculation, but also increase the internal gel strength. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The Octapeptide ELHQEEPL, which was identified from the rapeseed protein napin showed prominent Dipeptidyl peptidase‐IV (DPP‐IV) inhibitory activity. The objective of this study was to investigate the DPP‐IV inhibitory activity and transepithelial transport of ELHQEEPL in an approaching intestinal condition using Caco‐2 cell monolayers. ELHQEEPL and its degraded fragments EL, HQEEP, and methylated ELHQEEPL were transported across Caco‐2 cell monolayers through different pathways. Compared with the nonbiological enzyme inhibition test, the in vitro experiment on Caco‐2 cell monolayers showed that the IC50 value of DPP‐IV inhibition increased by 43.11% for ELHQEEPL. There was no significant change in DPP‐IV gene expression in the Caco‐2 cell monolayers upon treatment with ELHQEEPL. Furthermore, molecular docking predicted that the weaker binding between inhibitory peptide and enzyme for the degradation products from ELHQEEPL during transepithelial transport greatly limited its role in inhibiting DPP‐IV. Practical applications: The DPP‐IV inhibitory activity of ELHQEEPL was confirmed using Caco‐2 cell monolayers as a novel assessment tool, although its potency was reduced by metabolic degradation. In general, this study reported the use of Caco‐2 cell monolayers as a tool for comprehensively studying peptides as sources of DPP‐IV inhibitors. A Caco‐2 cell‐based approach with molecular docking can be adapted for the investigation of intestinal absorption and activity attenuation of food peptides being considered for enzymatic action. Moreover, since the Caco‐2 cells express a wide range of enzymes, this method can be used for screening for other active food peptides such as for the inhibitors of ACE and a‐glucosidase. [ABSTRACT FROM AUTHOR]

Single natural vegetable oils may have some drawbacks in terms of structure and function. Enzymatic interesterification can greatly improve the quality of natural vegetable oils. In this study, soybean oil (SO) and coconut oil (CO) are combined to synthesize structured lipids (SLs) using Lipozyme RM IM as a catalyst to modify the structure of coconut oil, which can make coconut oil have better physicochemical properties. A total of 55.73% structured lipids of total triacylglycerols are synthesized under the optimum reaction conditions. The main fatty acids of SL‐SOCO are linoleic (C18:2, 37.11%), oleic (C18:1, 21.73%), and lauric (C12:0, 14.05%). The most abundant TAG species in SL‐SOCO are (14:0‐18:1‐18:3), (12:0‐14:0‐18:3), and (14:0‐14:0‐18:3) with the relative content of 10.56%, 7.13%, and 5.52%, respectively. Compared to the crystallization curves of SOCO, SL‐SOCO showed a delayed crystallization and a decreased enthalpy. Moreover, the curcumin nanocarrier prepared by SL‐SOCO as the oil phase has good stability, encapsulation efficiency (91.12%), and improved bioavailability (54.02%). To conclude, SL‐SOCO with monounsaturated fatty acid, polyunsaturated fatty acids, and medium‐chain fatty acids has good structural composition and SL‐SOCO nanoparticles have excellent applications in drug delivery system. Practical Applications: The prepared SLs can be used as one kind of functional lipids, which has the potential to improve lipid metabolism. In addition, it can be used as an oil phase to prepare carriers for encapsulating active substances, which have good stability, improved encapsulation efficiency, and bioavailability. [ABSTRACT FROM AUTHOR]

BACKGROUND Although rapeseed protein isolate (RPI) possessed some good functional properties, the use of RPI as an ingredient in the food industry is restricted mainly due to its inferior gelation. The purpose of this study was to improve the heat‐induced gel properties of RPI using double processes of acylation and additional transglutaminase catalysis. RESULTS: Scanning electron microscopy showed that the gel formed by native RPI exhibited randomly aggregated particulate network structures whereas transglutaminase (TG)‐assisted RPI gels significantly improved gelation properties. More importantly, the combined modifications of RPI using TG‐assisted acylation can form a gel with unique percolating and small porous structure. Furthermore, TG‐catalyzed 5% acylated RPI gel (100 U g‐1, protein basis) exhibited excellent gel properties in terms of gel strength, thermal stability, surface roughness and apparent viscosity compared to non‐treated or single modification of RPI gel as determined by texture analyzer, atomic force microscopy and rheometer. Mechanistically, Fourier‐transform infrared spectra and gel dissociation test revealed that TG‐catalyzed acylation extensively unfolded the hydrophobic and sulfhydryl residues of RPI, in turn, reinforced re‐assembly of protein molecules via hydrophobic interactions and disulfide bonds during gel formation. CONCLUSION: Combined processes of acylation and additional TG catalysis improved the thermal gelation properties by altering inter‐ and intra‐protein structures. Such sequential processes will provide a promising approach to improve the protein gelation that could be potentially applied in the food industry. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND Rice bran is a nutrient‐dense and resource‐rich byproduct produced from the rice milling. The limitation of rice bran utilization is mainly caused by oxidative deterioration. Improvement of stability to prolong rice bran shelf‐life has thus become an urgent requirement. RESULTS: The present study aimed to determine the characteristics of infrared radiation heat treatment of rice bran (IRRB) and raw rice bran stored under different temperatures. The effects of heating and storage time on physicochemical, microbial, storage stability and structural properties were investigated. Additionally, the prediction model for the shelf‐life of rice bran was established based on free fatty acids and the peroxide value by fitting the curve of bran lipid oxidation. The results obtained demonstrated that infrared radiation heating at 300 °C for 210 s resulted in decreased lipase activity and peroxidase activity of 73.05% and 81.50%, respectively. The free fatty acids and peroxide value of IRRB stored at 4 and 25 °C for 8 weeks were only reached at 2.35% and 3.17% and 2.53 and 3.64 meq kg−1, respectively. The shelf‐life prediction model showed the the shelf‐life of infrared radiation‐treated samples increased to 71.6 and 25.8 weeks under storage at 4 and 25 °C, respectively. CONCLUSION: The stabilizing process could effectively suppress microbial growth and had no prominent effect on the physicochemical and microstructure properties of rice bran and, simultaneously, storage life was greatly extended. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND: Fermented rapeseed meal has been used as an alternative protein source for animal feed, but the volatile compounds and how their contents change during fermentation have not been reported. To clarify the effect of static‐state fermentation on its aroma, the volatile compounds of rapeseed meal during different stages of fermentation were analyzed using an electronic nose system and headspace solid‐phase microextraction‐gas chromatography–mass spectrometry. RESULTS: The results suggested that the volatile compounds in the raw rapeseed meal, mostly hydrocarbons and some aldehydes, were lost. The levels of the volatile compounds resulting from microbial metabolism, especially pyrazines, greatly increased during fermentation. Nonanal was the dominant volatile measured in the headspace of raw rapeseed meal. However, the volatile compounds found at high concentrations in rapeseed meal after 5 days of fermentation were tetramethylpyrazine, followed by butanoic acid, benzenepropanenitrile, 2‐methylbutanoic acid, trimethylamine, 2,3,5‐trimethyl‐6‐ethylpyrazine, and 2,3,5‐trimethylpyrazine. CONCLUSION: The fermentation process could significantly change the composition and content of volatile compounds in rapeseed meal. The results may provide reference data for studies on the choice of fermentation period and formation mechanism of flavor substances in fermented rapeseed meal. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Target cell recognition is an important issue in the realization of bacteriocin's activity. In this report, we provide genetic and biochemical evidence of durancin GL, a new bacteriocin produced by Enterococcus durans 41D, and use ⅡC subunit in the mannose phosphotransferase system (Man‐PTS) of Listeria monocytogenes as target/receptor. First, the L. monocytogenes mutants with Man‐PTS IIC or IID deletion were constructed with the vector pHoss1. Then, the utilization of glucose and mannose and the sensitivity to durancin GL of the mutant strains were investigated. Afterward, the interactions between durancin GL and the subunits of IIC or IID in Man‐PTS of L. monocytogenes were characterized by yeast two‐hybrid system. The results showed that the L. monocytogenes mutants with either IIC or IID deletion were not only resistant to durancin GL, but also their absorption and utilization of glucose and mannose were not disturbed by the presence of durancin GL. Finally, in situ detection of the interaction between durancin GL and Man‐PTS subunits of IIC or IID by yeast two‐hybrid system revealed that there was a strong interaction between durancin GL and Man‐PTS subunit IIC. However, the interaction between durancin GL and Man‐PTS subunit IID was not present or weak. Based on the experimental evidence above, the Man‐PTS subunit IIC is responsible for the sensitivity of L. monocytogenes to bacteriocin durancin GL. [ABSTRACT FROM AUTHOR]

This study described the manufacture and characterization of different levels of succinic anhydride (0–15%, w/w) on rapeseed protein isolate (RPI) films. Mechanical, barrier, optical, surface, microstructure, and thermal properties were investigated. Results showed that 5% succinylated rapeseed protein isolate (SRPI) film revealed the overall optimal properties. The mechanical and barrier properties of 5% SRPI film were enhanced significantly compared to the RPI film. The water vapor permeability values of RPI and 5% SRPI films were 0.77 and 0.32 g mm/[hour m2 kPa], respectively. Succinylation improved the color of RPI. The contact angle of 5% SRPI film was 108.68° and was the most hydrophobic combination. Moreover, scanning electron microscopy images revealed that 5% SRPI showed a dense, homogenous, and smooth microstructure. Thermogravimetric analysis results verified a low level of succinylation strengthened the thermal resistance of SRPI films. The content of β‐sheet was almost half of all secondary structures after succinylation, which was supported by analyses of Fourier transform infrared spectroscopy. Results demonstrated that succinylation could be employed to improve the properties of rapeseed protein and SRPI films have great potential to be used as edible films. [ABSTRACT FROM AUTHOR]

In this paper, an indirect competitive enzyme‐linked immunosorbent assay (IC‐ELISA) has been developed and optimized to detect Hg(II) in tap water and lake water based on a monoclonal antibody (mAb‐A24). Some stabilizing additives (Gelatin, bovine serum albumin [BSA], polyvinyl alcohol [PVA], and polyvinyl pyrrolidone [PVP]) and surfactant (Tween‐20) have been investigated thoroughly in the optimization process. Under the optimal condition, the 50% half maximal inhibitory concentration (IC50) and limit of detection (LOD) were 1.68 and 0.079 ng/ml, respectively. These anti‐Hg mAbs also have some affinity with methyl mercury (CH3Hg) and with no cross‐reactivity with other thirteen metal ions. The developed method has shown satisfactory recovery of Hg(II), ranged between 91% and 116%, from tap water and lake water. Therefore, this immunoassay can be used to detect trace Hg(II) in environment water. [ABSTRACT FROM AUTHOR]

Information on the physicochemical variability in rapeseed oil from different varieties during each refining process is lacking. Our purpose was to investigate the physicochemical properties, micronutrients and oxidative stability of the oil extracted from the five varieties of rapeseeds during their different stages of refining process. Increase in the acid value, peroxide value and p-anisidine value were detected in the refining, while content of tocopherols, sterols, β-carotene and phenols, which are regarded as important nutritional compounds diminished. Moreover, the loss rate of total phytosterols of all oils during neutralization (9.23–7.3%) and deodorization (9.97–8.27%) were higher than that of degumming (3.01–0.87%) and bleaching (2.75–1.18%). Deodorization affected total tocopherols contents the most, followed by bleaching, neutralization and degumming. There was a remarkable reduction in total content of phenol, β-carotene and oxygen radical absorbance of all oils during refining. The accumulated information can be used in looking for the optimum condition to meet the basic requirements for oil and minimize micronutrients losses so as to increase their market value. [ABSTRACT FROM AUTHOR]

Paper-based lateral flow immunoassays (LFIAs) are an interesting on site technique for detecting heavy metals. Pb(II) is one of the toxic heavy metals in polluted environmental water. This paper reports the synthesis and characterization of three Fe3O4-based nanoadsorbents that show different performance to Pb(II), Cu(II), Cd(II), Hg(II), As(V), Zn(II), Fe(III), Ca(II), Mg(II), Mn(II), and Al(III) when a GO or an amino group is introduced. Compared with Fe3O4, Fe3O4-GO showed higher adsorption percentage to many heavy metal ions under slightly acid condition. The negative surface on Fe3O4@NH2 had favourable interactions for four main divalent metal ion adsorption, which followed the order: Pb(II) > Cu(II) > Hg(II) > Cd(II). Combined with antibody-functionalized AuNPs showed high affinity and specificity toward Pb(II), an Fe3O4@NH2-based LFIA with five times greater sensitivity for detecting Pb(II) in lake water was developed. The cut-off value of this Fe3O4@NH2-combined LFIA method for detection Pb(II) in lake water was 20 ng/mL and the detection result for 10 ng/mL Pb(II) was obviously observable by the naked eye or a strip reader machine. This detection strategy could be readily adapted for other small molecules or biomolecules as an ultrasensitive screening tool. [ABSTRACT FROM AUTHOR]

The microbiological and chemical changes in Taihu white prawn (Exopalaemon modestus) during ice storage were evaluated. For the microbiological changes, total viable counts were obtained. PCR coupled with denatured gradient gel electrophoresis was then performed to investigate the changes in microflora. For the chemical changes, total volatile basic nitrogen was determined and biogenic amines were detected. The initial total viable count was 6.2 log CFU/g, which increased to 7.1 log CFU/g after storage at 0°C for 10 days. Pseudomonas sp., Shewanella, Flavobacterium, and Staphylococcus were the dominant bacteria in fresh white prawn, whereas lactic acid bacteria, Pseudomonas sp., Shewanella, and Flavobacterium were dominant in the spoiled products. The initial total volatile basic nitrogen was 7.2 mg/100 g, a value that significantly increased to 30.5 mg/100 g at the end of storage. Putrescine was the dominant biogenic amine, and its content reached 95.5 mg/kg at the end of storage. PCR coupled with denatured gradient gel electrophoresis showed that Chryseobacterium sp., Acidovorax sp., Pelomonas sp., Kinneretia asaccharophila, and uncultured Curvibacter sp. were the dominant strains during storage, whereas Lactococcus garvieae became dominant at the end of storage. This study facilitated the development of preservation techniques that target these predominant spoilage bacteria. [ABSTRACT FROM AUTHOR]