Erikssonmeyer1094

This work reports a kind of novel antioxidant Pickering high internal phase emulsions (HIPEs; with an oil fraction, ϕ > 0.74) stabilized by soy β-conglycinin (β-CG) and polyphenol complex nanoparticles, as outstanding protective containers for lipophilic nutraceuticals. The nanoparticles with a representative polyphenol ((-)-epigallocatechin-3-gallate; EGCG) encapsulated were fabricated through an ethanol-mediated dissociation and re-assembly process of β-CG, with greater particle size and higher surface hydrophilicity observed at higher initial EGCG concentrations. Using these co-assembled nanoparticles as sole stabilizers, a kind of HIPE gels with similar gel stiffness and microstructure, could be easily fabricated at ϕ = 0.8 and a protein concentration in the aqueous phase of 1.0 wt% using polyunsatuated fatty acid-rich flaxseed oil as the dispersed phase. These HIPE gels were extraordinarily stable against heating or long-term storage, but susceptible to freeze-thawing. The as-fabricated HIPEs showed an excellent protection to β-carotene (encapsulated in oil phase) against heating, as well as an inhibition of lipid oxidation. The oxidation protection was in an EGCG concentration dependent manner. The results would be of interest for providing a novel strategy to fabricate functionalized Pickering HIPEs as potential containers or delivery systems for lipophilic nutraceuticals.The relationship between biofilm formation and RpoS status was assessed in nine field isolates of C. sakazakii. click here Their ability to form biofilms was studied in BHI and minimum media with different pH values and supplemented or not with the amino acids arginine, lysine and glutamic acid. Biofilm formation, both on polystyrene and stainless steel, was measured by spectrometric determination of the fixed crystal violet and the biofilms were visualized by confocal laser scanning microscopy and scanning electron microscopy. Despite the existing heterogeneity among the different strains, biofilm formation was generally higher in buffered minimum media (pH 7.0) supplemented with lysine than in other culture media and on stainless steel plates than on polystyrene. The results showed a lower ability to form biofilms for a strain with a loss-of-function mutation in the rpoS gene, the general stress response regulator of Gram-negative bacteria, when compared to the rest of the strains, which harboured a functional rpoS. The complementation of this strain with a functional rpoS gene resulted in an increase in its biofilm formation ability up to levels comparable to those observed for strains with a functional rpoS. However, the differences were markedly reduced when the incubation time was increased from 24 to 48 h, indicating that the loss of RpoS caused a delay in the development of mature biofilms, rather than a complete inhibition of biofilm production in C. sakazakii.Herein we investigated the effects of heat shock treatment on the resistance of Lactobacillus acidophilus ATCC4356 to freeze-drying and the underlying mechanisms. We assessed the survival rate, cell morphology, enzyme activities, and metabolites in glycometabolism and energy metabolism. Heat shock treated at 45 °C for 30 min has increased the survival rate from 39.1% to 56.3% and had a certain protective effect on the integrity of the cell wall and membrane after freeze-drying. Activities of key enzymes, namely glucose-6-phosphate isomerase and lactate dehydrogenase in the glycolytic pathway; phosphoglucomutase, UDP-glucose pyrophosphorylase, and glycosyltransferases in the glycogen biosynthetic pathway; and Na+ -K+ -ATPase in energy metabolism were significantly altered. Further, the utilization rate of extracellular glucose in the broth decreased 7.59% but the conversion rate of intracellular glucose increased 24.04%, which led to the production of lactic acid and energy. Meanwhile, the production of polysaccharides with potential protectant function was increased by 47.6% and the proportion of glucose in the monosaccharide fraction decreased from 21% to 17%. However, the production of galactose increased from 17% to 26%, consequently enhancing the activities and survival rate of bacterial cells in a freeze-drying environment. This is the first study to determine the potential mechanisms and metabolic changes induced by heat shock treatment that make LAB tolerant to freeze-drying, and providing a new insight on the anti-adversity for LAB during the process.This study evaluated the effects of High-Temperature Short Time (HTST), Ultra High Temperature (UHT), and the non-thermal processes High Power Ultrasound (US), UV-pulsed-light and Low Pressure Plasma (LPP) on the composition, stability, and bioactive compounds bioaccessibility of açai juice. 1H NMR based approach, coupled to chemometrics, was applied to evaluate the changes in the juice composition. All the non-thermal processes increased the sugars content (glucose and fructose), and the amino acid betaine, except the combined processing of ultrasound followed by low-pressure plasma (US.LPP). HTST and UHT increased the fatty acids and phenolic compounds content in the açai juice. The bioaccessibility of phenolic compounds decreased due to the processing. After thermal sterilization (UHT), the anthocyanin bioaccessibility was 2-fold higher. The combined non-thermal treatment reduced the biocompounds bioaccessibility to 40% of the non-processed juice. However, the combined US.LPP improved the bioaccessibility of vitamin C by 8%. UHT increased the anthocyanin's bioaccessibility but sharply decreased vitamin C bioaccessibility. Higher impact of thermal processing on vitamin C, anthocyanins, total phenolics, PPO, POD, DPPH, ABTS, and FRAP was verified after 45 and 60 days of storage compared to the non-thermally processed samples.Agro-industrial by-products containing considerable amounts of protein (10-50%) such as soybean meal, rice bran and coconut pulp are promising bioactive peptide sources with annual disposal rate of 800 million tons in the world. More recently, plant by-products rich in protein content have been studied under various prisms that include recovery techniques, peptide production methods, determination of technological benefits and functional properties, and their applications in foods. The researches in bioactive peptides provide evidence over the techno-functional properties and the health benefits are highly dependent upon their amino acid sequences, molecular weights, conformations and surface properties. Research findings compared bioactive properties of the obtained peptides with respect to their amino acid sequences and also reported that hydrophobic/hydrophilic properties have direct effect on both functional and health effects. In addition, the resultant properties of the peptides could be affected by the conducted extraction method (alkaline, enzymatic, ultrasound assisted, microwave assisted, etc.