Electrolysed water (EW) is an activated liquid with a high oxidation-reduction potential. EW causes oxidative damage to pathogenic microorganisms and as a result, may have utility in the food industry. The molecular mechanism of EW's action is not understood. In this study, we exposed Escherichia coli ATCC 25922 to a sub-lethal concentration of EW and examined structural and metabolic changes. Atomic force microscopy revealed that EW caused damage to E. coli membranes. To understand the metabolic responses to EW perturbations in of E. coli, multivariate data analysis of NMR spectroscopy demonstrated that EW significantly influenced the metabolic state. This included reducing nucleotide and amino acid biosynthesis, suppressing energy-associated metabolism, altering osmotic adjustment, and promoting fatty acid metabolism. The results enrich our understanding of E. coli metabolic changes caused by EW perturbation and support the effectiveness of the NMR metabolomics as a valuable tool to analyse and evaluate such a complex biological system.

Effects of chitosan, calcium chloride, and their combination on preventing quality and safety deterioration of postharvest fresh-cut honeydew melon at 7 C were investigated. Treatments of all these three delayed weight loss, improved firmness, delayed colour changes and moderately inhibited microbial growth. Interestingly, combined treatment of chitosan and calcium chloride was the most effective, leading to 40% less weight loss, 45% (3.70 N) increase in firmness, less overall colour difference, and more than 0.5 log CFU/g inhibition on mesophilic and psychrotropic growths on day 13 of storage as compared to control group. In addition, these treatments also inhibited degradation of pectin chains. Nanostructural analysis of fruit pectin via atomic force microscopy (AFM) indicated that firmness was closely related to the nanostructure of sodium carbonate-soluble pectin (SSP). Short and narrow SSP chains were observed more in samples with less firmness. We conclude that edible coating of chitosan combined with calcium chloride treatment synergistically extends the shelf-life of fresh-cut honeydew melon by maintaining the integrity of SSP via interactions between SSP and calcium ions or protonated chitosan groups.

Coating of gelatin and chitosan can improve fish fillet’s quality, but the mechanism is not clear. Chitosan/gelatin coatings significantly prevented deterioration of golden pomfret fillet at 4 C. Chitosan with 7.2% gelatin group showed the best effect on preserving the length of myofibril, which remained greater than 15 lm at day 17 of storage, while for control, chitosan and chitosan combined with 3.6% gelatin group, it was 5.03, 10.04 and 9.02 lm, respectively. The MALDI-TOF MS result revealed that the coatings slowed down the protein deterioration of fillet. On days 13 and 17, the myosin light chain and myoglobin in control group degraded, while the two proteins still existed in chitosan/gelatin coated groups. Overall,the chitosan with 7.2% gelatin coating had the best effect on preserving fillet’s quality during storage.The coating may exert its protective effect via inhibiting myofibril degradation within fillet.

A detection method using polystyrene-coated magnetic nanoparticles based extraction technique coupled to HPLC was developed for trace amount of pyrethroids residue detection in vegetable matrixes.The recoveries for five kinds of commonly used pyrethroids were in the range of 91.6%–116.2%. The sensitivity and precision of the method were satisfactory with the limits of detection and limits of quantification in the range of 0.0200–0.0392 ng g1 and 0.072–0.128 ng g1, respectively. The intra-day and inter-day relative standard deviations for the recoveries of the analytes were lower than 6.8% and 10.7%, respectively. The nanoparticles can be washed and recycled after use. The results indicate that the developed method was efficient, fast, economical and environmentally friendly. The method was successfully applied to detect the pyrethroids residue in ten pairs of commonly consumed organic and conventional fresh vegetables in Singapore. Pyrethroids residue was detected in four kinds of conventional vegetables and one kind of organic vegetable.

The effects of rice bran wax coating on the physicochemical properties such as firmness, weight loss, titratable acidity (TA) and soluble solid content (SSC) of cherry tomatoes were studied during cold storage. The chemical and nanostructure properties of chelate-soluble pectin (CSP) were also investigated by high-performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM). The results indicated that there was no significant difference of firmness between control (2.48 N) and waxed (2.87 N) fruits at the end of storage (20 days), while the weight loss of waxed fruits (13.54%) was lower than that of control fruits (16.02%). And the degree of esterification (DE) of both fruits decreased after cold storage by FTIR. The structural analysis by atomic force microscopy (AFM) indicated that rice bran wax coating inhibited the degradation of CSP. The CSP molecular widths ranged from 15 to 250 nm, and the vertical heights varied from 0.2 to 2.0 nm. Greater frequency (Fq) of large width and length CSP was found in waxed fruits than in control fruits. The results suggest that rice bran wax coating was an effective way to preserve fresh fruits.

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The aim of this study was to develop and evaluate the characteristics and performance of a portable electrolytic sanitising unit. Free available chlorine (FAC), oxidation-reduction potential, and pH of electrolysed water were measured. Response surface methodology coupled with a Box-Behnken design was used to describe the input-output relationship and optimise FAC production. A partial catholyte solution was reintroduced to electrolysis for generating neutral electrolysed water. The result found that RuO2- IrO2/TiO2 electrode was very effective. A FAC concentration of 4 mg/L achieved >2 log CFU/mL reduction, while a FAC concentration of 40 mg/L achieved >6 log CFU/mL reduction in Escherichia coli O157:H7 and Listeria monocytogenes BAA-839. The developed sanitiser had a pH of 7.08 ± 0.08, and the commercial sanitiser had a pH of 3.77 ± 0.18. The developed sanitiser had similar bactericidal effects as the commercial sanitiser. The results revealed that the developed sanitising unit is promising for the control of foodborne pathogens.

本文评估了低浓度电解水（LcEW)）（4 mg/L 游离有效氯 ）温热处理清洗消毒技术，对有机西兰花安全和质量的影响。发现LcEW在50 oC温热处理情况下，对微生物及病原菌的杀灭能力最强。处理后的西兰花，抗氧化物含量、总酚水平以及铁离子还原力都维持不变，但是和未经过消毒处理的样品对比，氧自由基吸收能力升高。此外，温热处理提升了西兰花坚实度，这与果胶结构的改变相关。结果显示，温热处理引发了果胶链的拟定向和自发聚合。本研究显示，LcEW的温热处理能够在保证新鲜有机西兰花质量不打折扣的前提下，有效的减少微生物总数。

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Cakes are important confectionery and are enjoyed socially within groups. Eggs are important components of cakes, providing emulsification, flavour, colour, and many other properties. However, because of various health concerns and religious beliefs, some consumers cannot enjoy traditional cakes made with eggs. In the current study, isolated pea protein (PPI), xanthan gum (XN), and emulsifier mixtures were investigated to prepare eggless cakes and their roles were determined. The physicochemical properties of the batter and final cake products, the microstructure of the final cakes, and structural properties of starches and glutens at the meso-scale were characterised. The eggless cake recipe containing PPI, 0.1% XN and 1% soy lecithin (SL) was found to be close to the control traditional cakes in terms of specific gravity (1.01 vs. 1.03), crumb colour (a* at 0.09 vs. 0.04), and crumb pore properties (average pore area both 0.20 mm2). Cakes with formulation R4 were most similar to the control cakes with respect to the 1047/1022 relative intensity of the IR spectra of starches (both 0.55) and the nanostructures of glutenins. Therefore, formulation PPIþ0.1% XNþ 1% SL was considered as a potential candidate recipe for substituting eggs in cakes.

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Carvacrol is an effective antimicrobial agent originated from essential oils, this natural antimicrobial agent has higher consumer acceptance compared to chemical agents. Due to the low solubility of carvacrol in water, carvacrol was delivered as a nanoemulsion. A carvacrol nanoemulsion contained 3.5% (w/w) oil phase (1% carvacrol and 2.5% corn oil, w/w) and 3.5% (w/w) Tween 80 was produced by ultrasonification at 10 min using 100% amplitude; the median particle size was 309 ± 19 nm. The nanoemulsion was shelf-life stable for 1 month without any significant changes in particle size. When applied against Escherichia coli ATCC 25922 and Pichia pastoris GS115 growth in nutrient broth, carvacrol nanoemulsion (0.5% w/w carvacrol) achieved 3 log reductions of microorganisms. When microorganisms were fixed and dried on stainless steel coupon surface, the carvacrol nanoemulsion treatment was more effective on E. coli than P. pastoris with about 5 and 0.3 log reduction of viable count, respectively. The native microflora on shredded cabbages was challenged by combining carvacrol nanoemulsion and acidic electrolysed water (AEW) that contained 4 mg/L free available chlorine (FAC). The treatment reduced about 0.5 log of aerobic mesophilic and psychrotropic bacteria counts and the antimicrobial activity of carvacrol nanoemulsion and AEW lasted up to 2 days. The results indicated that carvacrol nanoemulsion is promising in controlling the safety of fresh-cut vegetables.

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To evaluate the feasibility of substituting eggs in yellow cake by a mixture of soybean proteins, plant polysaccharides, and emulsifiers, the batter properties, including specific gravity and viscosity; cake properties, including specific volume, texture, colour, moisture, microstructures, and structural properties of starch and glutens of the replaced cake and traditional cake containing egg, were evaluated. Replacing eggs with a soy protein isolate and 1% mono-, di-glycerides yielded a similar specific volume, specific gravity, firmness and moisture content (1.92 vs. 2.08 cm3/g, 0.95 vs. 1.03, 319.8 vs. 376.1 g, and 28.03% vs. 29.01%, respectively) compared with the traditional cakes baked with eggs. Structurally, this formulation comprised dominant gliadin aggregates in the size range of 100–200 nm and glutenin networking structures containing fewer but larger porosities. The results suggest that a mixture of soybean proteins and emulsifier is a promising substitute for eggs in cakes.

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