Global food production sustainability and the demand for fresh and nutritious food necessitate the development of novel technologies to provide food with a long shelf life. Hurdle technologies ...combing several interventions can ensure microbial safety without inducing notable changes to food quality. Cold plasma, as a promising nonthermal technology, has increasingly attracted attention in food industry. Recently, cold plasma–based hurdles have been proposed as novel intervention strategies for microbial decontamination. This review summarizes currently existing cold plasma–based hurdle strategies, including thermal treatment and nonthermal techniques (e.g., organic acids, essential oils, ultrasound) that have been reported in the literature. In addition, we highlight some critical issues, including the microbial stress response, the processing parameters, and the effects on food quality, that need to be taken into account during the optimization and implementation of cold plasma–based hurdles. Cold plasma–based hurdles overcome certain limitations of individual cold plasma treatment to improve the inactivation efficacy and retain the maximum food quality attributes.
Cold plasma (CP) is a non-thermal preservation technology that has been successfully used to decontaminate and extend the shelf life of aquatic products. However, the preservation effect of CP ...treatment is determined by several factors, including voltage, time, and gas compositions. Therefore, this study aimed to investigate the effects of gas composition (GasA: 10% O
, 50% N
, 40% CO
; GasB: air; GasC: 30% O
, 30% N
, 40% CO
) on the lipid oxidation of tilapia fillets treated after CP treatment. Changes in the lipid oxidation values, the percentages of fatty acids, and sensory scores were studied during 8 d of refrigerator storage. The results showed that the CP treatment significantly increased all the primary and secondary lipid oxidation values measured in this study, as well as the percentages of saturated fatty acids, but decreased the percentages of unsaturated fatty acids, especially polyunsaturated fatty acids. The lipid oxidation values were significantly increased in the GasC-CP group. After 8 d, clearly increased percentages of saturated fatty acids, a low level of major polyunsaturated fatty acids (especially linoleic (C18:2n-6)), and a decrease in the percentages of eicosapentaenoic acid (C20:5n-3) and docosahexaenoic acid (C22:6n-3) were found in GasC-CP; that is, the serious oxidation of lipids was found in the high O
concentration group. In addition, the sensory score was also lower than that of the hypoxia CP group. Therefore, high O
concentrations can enhance lipid oxidation and the changes in the fatty acid concentration. Controlling the O
concentration is reasonable to limit the degree to which lipids are oxidized in tilapia after the in-package CP treatment.
•Extraction of pectin from grapefruit peel by ultrasound-assisted heating method.•Power intensity, temperature and sonication time were investigated.•Using response surface methodology to optimize ...factors and study combined effects.•The innovative method is efficient and economic for pectin extraction.•Structure and properties of pectin were affected by different extraction methods.
The extraction of pectin from grapefruit peel by ultrasound-assisted heating extraction (UAHE) was investigated using response surface methodology and compared with the conventional heating extraction (CHE). The optimized conditions were power intensity of 12.56W/cm2, extraction temperature of 66.71°C, and sonication time of 27.95min. The experimental optimized yield was 27.34%, which was well matched with the predicted value (27.46%). Compared with CHE, UAHE provided higher yield increased by 16.34% at the temperature lowered by 13.3°C and the time shortened by 37.78%. Image studies showed that pectin extracted by UAHE showed better color and more loosen microstructure compared to that extracted by CHE, although Fourier Transform Infrared Analysis indicated insignificant difference in their chemical structures. Furthermore, UAHE pectin possessed lower viscosity, molecular weight and degree of esterification, but higher degree of branching and purity than CHE pectin, indicating that the former was preliminarily modified during the extraction process.
In nature, 10-hydroxy-2-decenoic acid (10-HDA), an important unsaturated fatty acid, is only available in royal jelly. Natural 10-HDA exhibits several biological activities, including anticancer ...activity, and provides protection against acute radiation injury. In this study, we identified a method for extraction of 10-HDA from royal jelly. The antimicrobial effect of 10-HDA on beer-spoilage bacteria and yeast was investigated by flow cytometry and bacteriostatic circle (paper assay) experiments. We also determined the minimum inhibitory concentration of 10-HDA using the double-dilution method. Our results showed that 10-HDA could significantly inhibit common microorganisms, such as Lactobacillus brevis and Pediococcus damnosus, found in beer but had no inhibitory effect on yeast. A novel approach for preparing draft keg-conditioned wheat beer was developed using top-fermenting yeast strain 303 and bottom-fermenting yeast strain 308. The beer was then kegged for secondary fermentation. Because living yeasts were still in the beer, pasteurization could not be used, and it was difficult to keep everything clean and sanitary during brewing and kegging processes. In this study, 10-HDA was added to the green beer during kegging. We confirmed that 10-HDA, acting as an antimicrobial agent, increased the sanitary aspects of the kegged beer and improved the microbiological stability and shelf life of the beer.
Summary
Peanut protein concentrates (PPCs) were prepared by aqueous extraction processing (AEP), organic solvent extraction processing (SEP) and prepress‐organic solvent extraction processing (P‐SEP) ...and converted into powder by freeze and spray drying. The drying method showed an influence on the surface morphology and second structure of PPCs. Peanut protein concentrates of AEP were found to have lower protein contents, solubility and higher surface hydrophobicity, resulted in similar emulsion ability index (EAI) values and lower emulsion stability index (ESI) and water‐holding capacity (WHC) values compared to PPCs of SEP and P‐SEP. Foaming capacity was barely affected by oil extraction processing and drying methods, foaming stability was significantly influenced by oil extraction processing. Freeze‐dried PPCs had higher solubility, WHC and fat absorption capacity than spray‐dried PPCs, which was not the case for EAI and ESI. Hence, PPCs of AEP showed adequate functional properties, making AEP more appropriate for phytoprotein beverages.
Characterization of PPCs from aqueous extraction processing
Summary
A two‐stage microfiltration and ultrafiltration (MF/UF) for peanut protein recovery and water recycling from aqueous extraction processing (AEP) were investigated. Peanut protein aggregates ...and alkaline water were obtained using flat and wound MF/UF and alkaline water recycled in AEP. With this approach, most of the wastewater could be recycled to produce reusable water to solve wastewater problems in aqueous oil extraction processing from oilseeds. The result showed that a little oil and protein were lost (1.21% and 4.35%, respectively) during the recycling of permeate in AEP, which was still acceptable. Peanut protein aggregations (PPAs) were characterised by analysis with Fourier‐transform infrared spectroscopy (FTIR), sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS‐PAGE), high‐performance gel filtration chromatography (HPGFC) and binding force analysis. Solubility analysis suggested that PPA had molecular structures with more hydrophobic groups on the surface than in the peanut protein isolate (PPI). In vitro, PPA was digested by both pepsin and trypsin more than PPI. FTIR profiles demonstrated there were more β‐sheet and less α‐helix in PPA, which means much more aggregation. In addition, binding force analysis showed hydrophobic interaction was the major force that restricted dissolution of PPA and disulfide bonds were of second importance, which provided a possible physical treatment opportunity for improving the solubility of PPA.
Sequential microfiltration and ultrafiltration was used for recovery proteins from aqueous phase. Recycling of permeate obtained from UF processing in AEP was primarily explored. Solubility, in vitro digestion and binding forces peanut protein aggregates(PPA) was investigated. Hydrophobic interaction was the majority force restrict dissolving of PPA and disulfide bonds took the second place.
The interfacial properties of ultrahigh methoxylated pectin (UHMP) prepared via esterification of citrus pectin (CP) were investigated. The intrinsic viscosity (η) of pectin was significantly ...decreased from 1211.5 mL/g to 294.9 mL/g as the degree of methylation (DM) increased from 63.18 ± 0.08% to 91.52 ± 0.11%. Surface tension (γ) analysis indicated that UHMP had a critical micelle concentration (CMC) of 0.8 g/L, which was slightly smaller than that of sugar beet pectin (SBP) (1.0 g/L). The morphology of the UHMP aggregation presented a network structure and irregular clusters at 10 μg/mL and 1 μg/mL based on atomic force microscopy (AFM). Transmission electron microscopy (TEM) observations further confirmed the self-aggregation behaviours and rod-like micelles of UHMP. The surface excess (Γ) was 1.69 ± 0.17 μmol/m2 for UHMP, which was lower than the values of SBP (1.88 ± 0.21 μmol/m2) and CP (2.91 ± 0.57 μmol/m2). Correspondingly, UHMP possessed the highest molecular area (A) of 0.99 ± 0.10 nm2. Thus, UHMP was proposed to be more flexible and extendable at the interface. The interfacial shear rheology study suggested that UHMP was able to form an elastic-dominant interfacial film to stabilize the oil/water interface.
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