High-pressure Homogenization Treatment Research Articles

Effect of high pressure homogenization on aggregation, conformation, and interfacial properties of bighead carp myofibrillar protein.

Fish myofibrillar protein is underutilized due to the formation of insoluble aggregates in low salt media. High pressure homogenization (HPH) at 20, 40, and 60MPa for four passes was applied on bighead carp myofibrillar protein in order to modify its structure and interfacial properties. Changes in aggregation, conformation, solubility, emulsifying and foaming properties of myofibrillar protein were investigated. The aggregates of myofibrillar protein were obviously disrupted by HPH treatment. The size of myofibrillar protein aggregates became smaller and more uniform as the treating pressure increased, accompanied by notable decreases of cross-sectional height and Rq value in AFM image. Furthermore, the conformation of HPH-treated myofibrillar protein was unfolded into a flexible and open structure. α-helix and β-sheet were converted into β-turn and random coil. Surface hydrophobicity and zeta potential were strengthened, along with the exposure of sulfhydryl groups onto molecule surface. On the other hand, solubility, emulsifying activity index (EAI) and foaming capacity (FC) of HPH-treated myofibrillar protein were markedly enhanced with the increasing pressure. Especially after HPH treatment at 60MPa, myofibrillar protein was almost dissolved in low salt media (solubility 91.86%) with 4.92 fold for EAI and 3.52 fold for FC. But there was little variation in emulsifying and foaming stabilities. These results suggested that HPH treatment has interesting potential to induce the dissociation and unfolding of myofibrillar protein in low salt media, therefore improving its interfacial properties. PRACTICAL APPLICATION: Carp myofibrillar protein was treated by high pressure homogenization (HPH). Aggregates of myofibrillar protein were disrupted into smaller size form. Conformation of myofibrillar protein was unfolded into open and loose structure. Emulsifying and foaming capacities of myofibrillar protein were improved. HPH treatment modified the structure and interfacial properties of myofibrillar protein.

Microstructural and Texturizing Properties of Partially Pectin-Depleted Cell Wall Material: The Role of Botanical Origin and High-Pressure Homogenization.

In the current study, the texturizing properties of partially pectin-depleted cell wall material (CWM) of apple, carrot, onion and pumpkin, and the potential of functionalization by high-pressure homogenization (HPH) were addressed. This partially pectin-depleted CWM was obtained as the unextractable fraction after acid pectin extraction (AcUF) on the alcohol-insoluble residue. Chemical analysis was performed to gain insight into the polysaccharide composition of the AcUF. The microstructural and functional properties of the AcUF in suspension were studied before HPH and after HPH at 20 and 80 MPa. Before HPH, even after the pectin extraction, the particles showed a cell-like morphology and occurred separately in the apple, onion and pumpkin AcUF and in a clustered manner in the carrot AcUF. The extent of disruption by the HPH treatments at 20 and 80 MPa was dependent on the botanical origin. Only for the onion and pumpkin AcUF, the water binding capacity was increased by HPH. Before HPH, the texturizing potential of the AcUFs was greatly varying between the different matrices. Whereas HPH improved the texturizing potential of the pumpkin AcUF, no effect and even a decrease was observed for the onion AcUF and the apple and carrot AcUF, respectively.

Effects of high pressure homogenization on the solubility, foaming, and gel properties of soy 11S globulin

The effects of different homogenization pressure levels on the solubility, particle size, surface hydrophobicity, free sulfhydryl content, surface tension, water distribution and mobility, rheological, foaming and gel properties of soy 11S globulin were investigated in this study. High-pressure homogenization treatment (50–150 MPa) significantly increased the magnitude of protein zeta potential, solubility, while reduced the particle size, which increased surface hydrophobicity, and exposure to free sulfhydryl and disulfide bonds, as well as surface tension, foaming capacity and stability, elasticity index, macroviscosity index, initial apparent viscosity and shear stress. On the other hand, excessive pressure treatment at 150 MPa caused solubility, surface hydrophobicity, exposure to free sulfhydryl, the elasticity index, macroviscosity index, initial apparent viscosity and shear stress to decrease. The gel strength and water immobilization also increased, whereas the mobility of the water was low. Overall, our results show that high-pressure homogenization improves the physicochemical, foaming and gel properties of 11S globulin.

Effects of high pressure homogenization on the structural and emulsifying properties of a vegetable protein: Cyperus esculentus L.

In this study, we aimed to investigate the effects of high pressure homogenization (HPH) on the structural and emulsifying properties of Cyperus esculentus L. proteins. After HPH, the β-sheet content was decreased, and the α-helix and random coils were increased. Intrinsic fluorescence spectroscopy analysis showed that the maximum absorption wavelength was blue-shifted and the absorption intensity was increased after HPH. The untreated protein emulsion has a particle size of 12.29 μm, and then decreased as the homogenizing pressure increased and reached a minimum of 4.79 μm at 100 Mpa. The absolute value of Zeta potential gradually increased, reaching a maximum of 21.23 mV at 100 MPa, and the protein emulsion was most stable at a homogenization pressure of 100 MPa. The rheological properties showed that HPH treatment reduced the apparent viscosity and increased the fluidity of the emulsion. This work showed that HPH treatment has positive effects on structural and emulsifying properties of Cyperus esculentus L. protein for innovation technologies for the potential industrial applications.

Effect of high pressure homogenization on water-soluble pectin characteristics and bioaccessibility of carotenoids in mixed juice

The effect of high pressure homogenization (HPH) compared with simple blending and milling on mixed juice properties, including water-soluble pectin (WSP) characteristics and total carotenoid bioaccessibility (TCB) was investigated. Overall, HPH treatments, which comprised of varied pressures, passes and inlet temperature (IT) affected WSP characteristics. Increased pressure showed decreased molecular weight (Mw), galacturonic acid (GalA) content and branching, and enhanced degree of methylesterification (DM) and chain linearity, suggesting degradation of RG-I fragments. Two passes at 140 MPa enhanced GalA content, nevertheless it reduced DM, implying rearrangement of depolymerized fractions. Besides, elevated IT combined with high pressure increased GalA content and DM signifying thermo-solubilization of certain HG-rich pectin. Notably, the TCB was enhanced by higher pressure and elevated temperature, which had positive relationship with DM and chain linearity of WSP and negative correlations with GalA content and Mw. Results highlighted the potential of HPH to improve WSP characteristics to enhance TCB.

Efficient Production of Scleroglucan by Sclerotium rolfsii and Insights Into Molecular Weight Modification by High-Pressure Homogenization.

Scleroglucan is a non-ionic water-soluble polysaccharide, and has been widely used in the petroleum, food, medicine and cosmetics industries. Currently, scleroglucan is mainly produced by Sclerotium rolfsii. A higher level of scleroglucan (42.0 g/L) was previously obtained with S. rolfsii WSH-G01. However, the production of scleroglucan was reduced despite a higher glucose concentration remaining. Additionally, the molecular weight of scleroglucan was large, thus restricted its application. In this study, by adjusting the state of seeds inoculated, the degradation issue of scleroglucan during the fermentation process was solved. By comparing different fed-batch strategies, 66.6 g/L of scleroglucan was harvested by a two-dose fed-batch mode, with 53.3% glucose conversion ratio. To modify the molecular weight of scleroglucan, a combination method with HCl and high-pressure homogenization treatment was established. Finally, scleroglucan with molecular weight of 4.61 × 105 Da was obtained. The developed approaches provide references for the biosynthesis and molecular weight modification of polysaccharides.

Properties of starch nanoparticle obtained by ultrasonication and high pressure homogenization for developing carotenoids-enriched powder and Pickering nanoemulsion

The effect of ultrasound (US) and high pressure homogenization (HPH) on starch nanoparticles and their ability to stabilize Pickering nanoemulsion of carotenoids and bioactives-enriched olive oil was evaluated. The carotenoids used in nanoemulsion were extracted from the peel of passion fruit (Passiflora edulis). As the US treatment time increased, mean particle size decreased from microsize to 340 nm and subsequent HPH treatment of this suspension caused further decrease in particles size (<60 nm). US and HPH treatments increased swelling and solubility and also the gelatinization and melting temperatures of the starch nanoparticles. The Pickering nanoemulsion was rich in carotenoids and total phenolic content and exhibited high antioxidant activity, which had protective effect on its stability. The carotenoids-enriched nanoemulsion was found to be stable to heat and freeze-thaw treatments. The developed nanoemulsion showed better oxidative stability as well as physical stability during storage at 6 °C and 25 °C.

High pressure homogenization with a cooling circulating system: The effect on physiochemical and rheological properties, enzymes, and carotenoid profile of carrot juice

The influence of high pressure homogenization (HPH) at 100–150 MPa performed by multiple passes below 35 °C on carrot juice quality and stability was studied. The highest reduction in microorganisms (by 2.47 log) was noted at 150 MPa with 5 passes of the juice through the homogenizer. The PPO and POD’s residual activity increased after HPH; PG was at the same level, while PME activity increased or decreased depending on the process parameters used. HPH treatment resulted in a decrease in the apparent dynamic viscosity, turbidity and colour parameters. Five passes at 150 MPa caused an increase in the carotenoid content, especially 9-Z-β-carotene (by 154%) while the TPC did not change significantly. Carrot juice treatment at 150 MPa with 5 passes may extend its shelf-life by 3 days when stored at 4 °C.

High-pressure homogenisation of sheep milk ice cream mix: Physicochemical and microbiological characterisation

The effect of high-pressure homogenisation (HPH) treatment (0, 25, 50, 75, or 100 MPa) of mix on the physicochemical, textural, and microbiological characteristics of sheep milk ice cream was determined. Textural properties of the mix were not affected by HPH. However, HPH increased L*, a*, and b* values of the mix. In HPH-treated mix samples, the mean particle diameter was lower compared with the control. The hardness value of ice cream changed from 43.0 to 58.1 N, and HPH increased it depending on the increasing pressure. The highest overrun (58.3%) was determined in control, whereas the lowest overrun (35.8) was found in HPH-100. Melting time and first dripping time were increased depending on the increasing pressure of HPH, while HPH decreased the melting rate. HPH treatment of mix significantly reduced the microbial loads of ice cream samples. Consequently, HPH treatment can enhance the hardness, melting, and microbiological properties of ice cream from sheep milk.

High-pressure homogenization influences the functional properties of protein from oyster (Crassostrea gigas)

In this study, the effects of high-pressure homogenization (HPH) (20, 60, and 100 MPa) on the structure, microstructure, and functional properties of oyster (Crassostrea gigas) protein (CGP) were investigated. Circular dichroism examination showed that the secondary structure of oyster proteins became loose and that the α-helix transformed into a random coil structure. The fluorescence spectra had a redshift from 350 nm to 360 nm, exposing the chromophore and changing the tertiary structure of CGP. With the increase in homogeneous pressure, HPH significantly reduced particle sizes of CGP. Compared to other treatments, HPH at 100 MPa showed a higher surface hydrophobic index (86.84), solubility (84.7%), and water holding capacity (15.2 g/g). However, the emulsion activity index (137.5 m2/g) and foaming ability (113.3%) were best at a lower pressure (20 MPa). The scanning electron microscope showed that HPH treatment could improve emulsion stability. This work demonstrates that HPH treatment has a positive impact on the physicochemical and functional properties of CGP for potential industrial applications.

Double-Edged Metabolic Effects from Short-Term Feeding of Functionalized Wheat Bran to Mouse Revealed by Metabolomic Profiling

Health-promoting activities of wheat bran are limited by the high-degree crosslinking of its dietary fiber and the low bioavailability of its phenolics. In this study, functionalized wheat bran (FWB) was prepared through a combination of milling, alkaline hydrolysis, high-shear mixing, and high-pressure homogenization treatments. Feasibility and metabolic effects of feeding FWB were investigated by a short-term mouse feeding trial and liquid chromatography-mass spectrometry-based metabolomic analysis. The combinatorial processing dramatically enhanced the function-associated physicochemical properties of wheat bran, including viscosity, fiber compositions, free ferulic acid, and antioxidant capacity. FWB feeding led to diverse positive metabolic effects, including fecal sequestration of bile acids and cholesterol, reduced serum triacylglycerols and cholesterol, elevated fermentation for short-chain fatty acids, increased bioavailability of ferulic acid and its microbial metabolites, and improved redox balance. However, FWB feeding also negatively affected the nutritional status by decreasing the bioavailability of essential amino acids through the excessive loss of amino acids in feces and disrupting lipid homeostasis by reducing choline supply in the liver. These double-edged metabolic effects warrant further investigations on how to achieve the balance between the functionalization of wheat bran bioactives and the disruption of nutrient bioavailability.

Effects of Sub-Lethal High Pressure Homogenization Treatment on the Adhesion Mechanisms and Stress Response Genes in Lactobacillus acidophilus 08.

Cell surface hydrophobicity (CSH) and adhesion are very important phenotypical traits for probiotics that confer them a competitive advantage for the resilience in the human gastrointestinal tract. This study was aimed to understand the effects over time of a 50 MPa hyperbaric treatment on the surface properties of Lactobacillus acidophilus 08 including CSH, autoaggregation, and in vitro adhesion (mucin layer and Caco-2 cells). Moreover, a link between the hurdle applied and the expression of genes involved in the general stress response (groEL and clpP) and adhesion processes (efTu and slpA) was evaluated. High pressure homogenization (HPH) at 50 MPa significantly increased the CSH percentage (H%), autoaggregation and in vitro adhesion on mucin of L. acidophilus 08 cells compared with the untreated cells. Moreover, the hyperbaric hurdle induced an upregulation of the stress response genes groEL and ef-TU together with a down regulation of the clpP and S-layer slpA genes. Looking at the protein profile, HPH-treatment showed an increase in the number or intensity of protein bands at high and low molecular weights.

High pressure homogenization inactivation of Escherichia coli and Staphylococcus aureus in phosphate buffered saline, milk and apple juice.

High pressure homogenization (HPH) offers new opportunities for food pasteurization/sterilization. Escherichia coli and Staphylococcus aureus suspended in phosphate buffered saline (PBS) buffer, milk and apple juice at initial concentration of ~106 log10 CFU per ml were subjected to HPH treatments up to 200MPa with inlet temperatures at 4-40°C. After HPH at 200MPa with the inlet temperature at 40°C, the count of E. coli suspended in PBS, milk and apple juice reduced by 3·42, 3·67 and 3·19 log10 CFU per ml respectively while the count of S. aureus decreased by 2·21, 1·02 and 2·33 log10 CFU per ml respectively suggesting that S. aureus was more resistant. The inactivation data were well fitted by the polynomial equation. Milk could provide a protective effect for S. aureus against HPH. After HPH at 200MPa with the inlet temperature at 20°C, the cell structure of E. coli was destroyed, while no obvious damages were found for S. aureus.

Physical, chemical, and techno-functional properties of soy okara powders obtained by high pressure homogenization and alkaline-acid recovery

High pressure homogenization (HPH) at increasing intensity (50, 100, 150 MPa and 150 MPa for 5 passes) was combined with an alkaline-acid recovery method to prepare protein-enriched okara powders intended as ingredients with improved techno-functional properties. The treatment allowed obtaining from 4 to 8 g powder per 100 g fresh okara. The intensity of HPH treatment significantly affected amount, composition, particle size, protein structure and techno-functional properties. Treatments at intermediate pressures in the range 50−100 MPa resulted the most feasible from an industrial perspective allowing to obtain a good balance between protein content and the techno-functionalities (e.g. solubility, foaming, gelling and emulsifying properties) of the okara ingredient. Thus, HPH combined with simple pH-driven precipitation can be considered an efficacious and industrially feasible pre-treatment for okara valorisation into innovative ingredients.

Effect of high pressure homogenization on microstructural and rheological properties of A. platensis, Isochrysis, Nannochloropsis and Tetraselmis species

The rich nutritional profile of microalgae biomass has made it a promising clean label food ingredient that has the potential to fortify incorporated food with simultaneous modification of the structural properties. This work investigated the effect of high pressure homogenization (HPH) at 300, 600, and 900 bar on the microstructural and rheological properties of four microalgal suspensions, namely, Arthospira platensis, Isochrysis sp., Nannochloropsis sp., and Tetraselmis sp. HPH treatment resulted in the disintegration of microalgal cells, which altered the cell morphology, particle size, and rheological properties. A. platensis, Isochrysis sp., and Tetraselmis sp. showed a linear HPH intensity-dependent cell disintegration as evidenced by an increase in viscosity of the suspensions. While A. platensis exhibited the most pronounced effect of HPH treatment, Nannochloropsis sp. showed a minimal response that was attributable to its strong cell walls. The significant interspecies differences in the colloidal properties of the HPH-treated microagal suspensions coincided with the proportion of various nutrients where the fluctuation of lipids (between 8% and 17%) and proteins (between 10% and 57%) affected hydrophilic/hydrophobic interactions between the macromolecules. The findings demonstrate that HPH can be used to tailor microalgae biomass for specific food applications as potential structuring ingredients.

Effect of Cryoconcentration Assisted by Centrifugation-Filtration on Bioactive Compounds and Microbiological Quality of Aqueous Maqui (Aristotelia chilensis (Mol.) Stuntz) and Calafate (Berberis microphylla G. Forst) Extracts Pretreated with High-Pressure Homogenization

The objective of this study was to evaluate the effect of cryoconcentration assisted by centrifugation-filtration on the bioactive compounds and the microbiological quality of aqueous maqui (Aristotelia chilensis (Mol.) Stuntz) and calafate (Berberis microphylla G. Forst) extracts pretreated with high-pressure homogenization (HPH). Aqueous extracts were prepared from fresh fruits which were treated with HPH (predefined pressure and number of passes). The best pretreatment was determined by aerobic mesophilic, fungal, and yeast counts. Treated extracts were frozen at −30 °C in special tubes and centrifuged at 4000 rpm for 10 min to obtain the cryoconcentrated product. The optimal pretreatment conditions for HPH were 200 MPa and one pass in which the extracts exhibited no microorganism counts. Cryoconcentration by freezing and subsequent centrifugation-filtration in a single cycle showed high process efficiency (&gt;95%) in both soluble solids and bioactive compounds (total polyphenols and anthocyanins) and antioxidant capacity of the fresh fruits and extracts. The HPH treatment and subsequent cryoconcentration assisted by centrifugation-filtration is an efficient technology to obtain concentrates with good microbiological quality and a high content of bioactive compounds.

Production of bread from doughs composed of high-pressure homogenisation treated flour slurries: effects on physicochemical, crumb grain and textural characteristics

This study aimed to investigate the physicochemical and textural characteristics of bread produced from doughs composed of high-pressure homogenization (HPH) treated flour slurries. For this purpose, bread samples were produced from doughs composed of HPH treated flour slurries at 0 (control), 20, 30, 50, and 70 MPa. HPH treatment resulted in decreased particle size with more uniformity in flour slurries. A monomodal particle size distribution was determined in slurries. HPH obtained higher firmness, consistency, and cohesivity in slurries. In bread samples, HPH increased yellowness and lightness values. The bread samples prepared from HPH treatment had 1.09–1.25 times higher specific volumes than the control sample. HPH treatment provided decreased hardness and increased cohesiveness and springiness values. Image analysis results showed HPH treatment decreased total cell count, whereas increased mean cell area of bread samples. The findings revealed that HPH treatment results in higher quality bread compared to control.

Impact of High-Pressure Homogenization Parameters on Physicochemical Characteristics, Bioactive Compounds Content, and Antioxidant Capacity of Blackcurrant Juice.

High-pressure homogenization (HPH) is one of the food-processing methods being tested for use in food preservation as an alternative to pasteurization. The effects of the HPH process on food can vary depending on the process parameters used and product characteristics. The study aimed to investigate the effect of pressure, the number of passes, and the inlet temperature of HPH processing on the quality of cloudy blackcurrant juice as an example of food rich in bioactive compounds. For this purpose, the HPH treatment (pressure of 50, 150, and 220 MPa; one, three, and five passes; inlet temperature at 4 and 20 °C) and the pasteurization of the juice were performed. Titratable acidity, pH, turbidity, anthocyanin, vitamin C, and total phenolics content, as well as colour, and antioxidant activity were measured. Heat treatment significantly decreased the quality of the juice. For processing of the juice, the best were the combinations of the following: one pass, the inlet temperature of 4 °C, any of the used pressures (50, 150, and 220 MPa); and one pass, the inlet temperature of 20 °C, and the pressure of 150 MPa. Vitamin C and anthocyanin degradation have been reported during the HPH. The multiple passes of the juice through the machine were only beneficial in increasing the antioxidant capacity but negatively affected the colour stability.

Physicochemical and functional properties of a novel xanthan gum-lysozyme nanoparticle material prepared by high pressure homogenization

The electrostatic self-assembly between protein and polysaccharide is a widely used method to fabricate biopolymer nanoparticles (NPs). In the present study, a novel NPs material was prepared by the high pressure homogenization (HPH) electrostatic self-assembly complexes of xanthan gum and lysozyme using the same charge at pH 12. Dynamic light scattering studies showed that the HPH treatment (30 MPa, 5 min) resulted in a smaller particle size and larger surface charge. Cryo-scanning electron microscopy imaging results suggested that the HPH-NPs had a circular shape and the surface structure of HPH-NPs was compact. Circular dichroism spectrum and intrinsic fluorescence spectrum revealed that the secondary and tertiary structures of lysozyme changed due to the HPH treatment. By non-covalent binding with xanthan gum, the surface hydrophobicity of lysozyme increased. Fourier transform infrared spectroscopy results indicated that the hydrogen bonding and electrostatic interaction may be the major factors causing the formation of HPH-NPs. The HPH-NPs exhibited a good solubility, emulsification and antimicrobial activity. Therefore, our HPH-NPs material has a good potential use as the beverage ingredient for inhibiting the pathogen growth, and in turn benefiting the resultant products with a good safety.

Effect of particle size and microstructure on the physical properties of soybean insoluble dietary fiber in aqueous solution

The objective of this study was to investigate the effect of particle size and microstructure on the physical and functional properties of soybean insoluble dietary fiber (IDF) in aqueous solution. Different IDF suspensions were obtained by ball milling (BM) and high-pressure homogenization (HPH) treatments. The results showed that the BM treatment significantly reduced the particle size distribution of the IDF, and the additional HPH treatment (BM-HPH) caused the IDF to become more porous, resulting in the formation of a honeycomb structure. Samples with a honeycomb network structure had higher hydration capacity and solubility. The water holding capacity, swelling capacity and solubility of I8 reached 18 g/g, 72 mL/g and 35%, respectively. I8 had the highest emulsifying stability and suspension stability. These results of the present study suggested that the reduction in particle size of IDF cannot fully account for its functional properties, of which the honeycomb structure played a more significant role. From the results of this study, it was clear that the functional properties of IDF depend on its small particle size and honeycomb structure. The present study indicated that a combination of BM and HPH treatments provides a new perspective for modifying and utilizing dietary fiber.