Ultra-high Pressure Homogenization Research Articles

Enhancing casein micelle dissociation in diluted skim milk systems using combined processing techniques

The present work aims to evaluate the dissociation of casein micelles in diluted skim milk (SM) systems after undergoing solvent- or emulsifying salt-based dissociation coupled with ultra-high-pressure homogenization (UHPH). Specifically, Part I evaluated dilute SM solutions combined with varying ethanol concentrations (0- 60%) at varying temperatures (5 - 65°C) in combination with UHPH (100-300 MPa), and Part II evaluated dilute SM solutions combined with varying concentrations (0-100 mM) of either sodium hexametaphosphate (SHMP) or sodium citrate (SC) in combination with UHPH (100-300 MPa). In Part I, high concentrations of ethanol (40-60% vol/vol) at elevated temperatures (45-65°C) achieved extensive dissociation of casein micelles, especially in combination with UHPH at ≥200 MPa, as shown by an ca. 6-fold reduction in sample absorbance and an ca. 3-fold reduction in casein particle size compared with the control (ca. dilute SM, 65°C) under optimum conditions (dilute SM, 60% ethanol, 65°C, ≥ 200 MPa). In Part II, the level of casein micelle dissociation using emulsifying salts (ES) was dependent on the ES type and concentration. Considerable casein micelle dissociation in dilute SM systems was achieved with SHMP concentrations ≥1 mM and SC concentrations ≥10 mM, resulting in decreased sample absorbance (>6-fold decrease in absorbance), bimodal casein size distributions, and increased hydrophobicity (ca. 2-fold increase in intrinsic fluorescence) compared with the control (dilute SM). This dissociation was further enhanced with UHPH (≥200 MPa). These results indicate that both solvent- and ES-based casein dissociation techniques can be optimized when used in combination with UHPH. Together, these processing techniques can be used to extensively dissociate casein micelles with the potential to use these altered systems for value-added applications such as functional ingredients or encapsulation agents.

Bacterial cellulose nanofibrils for the physical and oxidative stability of fish oil-loaded Pickering emulsions

Fish oil, a crucial unsaturated ω-3 unsaturated fatty acid supplement, is susceptible to oxidation. To improve the stability of fish oil, this study produced a fish oil Pickering emulsion via ultrahigh-pressure homogenization pressure (UHPH) using bacterial cellulose nanofibrils (BCNFs) as the water phase. The BCNFs exhibited a high aspect ratio fibril structure with an average diameter size of 12.64 nm. The results of particle size, zeta potential, emulsion properties, and oxidative stability showed that the emulsions with a 4:6 oil-water ratio and 0.15 % BCNFs exhibited excellent oxidative stability and good physical stability. The CLSM and rheological results suggested the BCNFs acted as a stabilizer and thickener, stabilizing the oil-water medium and enhancing the oxidation stability of fish oil Pickering emulsions. The Low-field nuclear magnetic analysis results indicated the emulsion had good physical stability, and water dispersed very well in the emulsion system. Moreover, the emulsions exhibited good stability at pH 6–12 and temperature 4–75 °C. This study provided a promising method for producing fish oil Pickering emulsions and improving the stability of fish oil.

Effect of processing Verdejo grape must by UHPH using non-Saccharomyces yeasts in the absence of SO2

Ultra-High Pressure Homogenization (UHPH) is an emerging non-thermal technology that can eliminate wild microorganisms from grape juice facilitating the use of non-competitive non-Saccharomyces yeast in fermentation to modulate the sensory profile.

Surface replication and characterization of ultrahigh-pressure homogenizer treated cellulose nanofiber-reinforced polyvinyl alcohol composites by thermal imprinting

Surface replication and characterization of ultrahigh-pressure homogenizer treated cellulose nanofiber-reinforced polyvinyl alcohol composites by thermal imprinting

Emerging biotechnologies and non-thermal technologies for winemaking in a context of global warming.

In the current situation, wine areas are affected by several problems in a context of global warming: asymmetric maturities, pH increasing, high alcohol degree and flat wines with low freshness and poor aroma profile. The use of emerging biotechnologies allows to control or manage such problems. Emerging non-Saccharomyces as Lachancea thermotolerans are very useful for controlling pH by the formation of stable lactic acid from sugars with a slight concomitant alcohol reduction. Lower pH improves freshness increasing simultaneously microbiological stability. The use of Hanseniaspora spp. (specially H. vineae and H. opuntiae) or Metschnikowia pulcherrima promotes a better aroma complexity and improves wine sensory profile by the expression of a more complex metabolic pattern and the release of extracellular enzymes. Some of them are also compatible or synergic with the acidification by L. thermotolerans, and M. pulcherrima is an interesting biotool for reductive winemaking and bioprotection. The use of bioprotection is a powerful tool in this context, allowing oxidation control by oxygen depletion, the inhibition of some wild microorganisms, improving the implantation of some starters and limiting SO2. This can be complemented with the use of reductive yeast derivatives with high contents of reducing peptides and relevant compounds such as glutathione that also are interesting to reduce SO2. Finally, the use of emerging non-thermal technologies as Ultra High-Pressure Homogenization (UHPH) and Pulsed Light (PL) increases wine stability by microbial control and inactivation of oxidative enzymes, improving the implantation of emerging non-Saccharomyces and lowering SO2 additions. GRAPHICAL ABSTRACT.

Effect of HHP and UHPH High-Pressure Techniques on the Extraction and Stability of Grape and Other Fruit Anthocyanins.

The use of high-pressure technologies is a hot topic in food science because of the potential for a gentle process in which spoilage and pathogenic microorganisms can be eliminated; these technologies also have effects on the extraction, preservation, and modification of some constituents. Whole grapes or bunches can be processed by High Hydrostatic Pressure (HHP), which causes poration of the skin cell walls and rapid diffusion of the anthocyanins into the pulp and seeds in a short treatment time (2-10 min), improving maceration. Grape juice with colloidal skin particles of less than 500 µm processed by Ultra-High Pressure Homogenization (UHPH) is nano-fragmented with high anthocyanin release. Anthocyanins can be rapidly extracted from skins using HHP and cell fragments using UHPH, releasing them and facilitating their diffusion into the liquid quickly. HHP and UHPH techniques are gentle and protective of sensitive molecules such as phenols, terpenes, and vitamins. Both techniques are non-thermal technologies with mild temperatures and residence times. Moreover, UHPH produces an intense inactivation of oxidative enzymes (PPOs), thus preserving the antioxidant activity of grape juices. Both technologies can be applied to juices or concentrates; in addition, HHP can be applied to grapes or bunches. This review provides detailed information on the main features of these novel techniques, their current status in anthocyanin extraction, and their effects on stability and process sustainability.

Encapsulating capacity of ultra-high-pressure homogenization (UHPH): Replacement of milk fat by vegetable oils using buttermilk as a functional ingredient in yogurt processing

This study investigated the characteristics of yogurts produced by substituting dairy fat with polyunsaturated fatty acids (PUFA)-rich oils encapsulated with buttermilk (BM) in spray-dried emulsions (SDE). Two homogenization methods, conventional (CH) and ultra-high-pressure homogenization (UHPH), were compared to obtain the emulsions for spray drying. Recombined milks (RMs) were formulated using two different concentrations (4 g/100 g and 6 g/100 g) of SDE, followed by fermentation. Yogurt characteristics were evaluated during cold storage using various parameters, including coagulation properties, texture and rheology, microstructure, physicochemical characteristics (color, pH, total acidity, and water holding capacity), oxidative stability, main fatty acid profile, microbial assessment, and sensory evaluation. During cold storage, several parameters significantly influenced the yogurt characteristics. The CH yogurts exhibited higher textural parameters (firmness and consistency) and viscoelastic parameters (G′ and G'') compared to the UHPH yogurts at the same SDE concentration. However, UHPH yogurts generally showed better water holding capacity (WHC) values. UHPH yogurts also demonstrated superior stability to oxidation and higher PUFA content. The observed differences between the CH and UHPH treatments can be attributed to the structuring of fat-protein-BM into colloidal particles based on the homogenization system employed in this study. Neither of the homogenization systems nor the SDE content impacted yogurt flavor.

Application of multiple ultra-high-pressure homogenization to the pasteurization process of Japanese rice wine, sake

Hiire is a pasteurization process in the production of Japanese rice wine (sake), which stabilizes the quality of product; however, it also generates the carcinogen ethyl carbamate (EC). In this study, we investigated the application of ultra-high-pressure homogenization (UHPH) as an alternative sterilization method for sake production. Microbiological analysis revealed that multiple UHPH treatments sterilized hiochi lactobacilli (Lactobacillus fructivorans, L. homohiochii, L. casei, and L. hilgardii) and Saccharomyces cerevisiae. Enzyme activity assays revealed that α-amylase, glucoamylase, and acid-carboxypeptidase activities were reduced to less than 1% of the levels in non-pasteurized sake after four-time UHPH treatment. These results show that UHPH treatment meets the two requirements of the sake sterilization process sterilization and enzyme inactivation. The UHPH-processed sake did not show any significant changes in general properties but had reduced organic acid and aromatic component contents, with ethyl caproate content showing the most significant reduction of approximately 20%. Interestingly, EC was detected in pasteurized sake but not in UHPH-processed sake. These findings indicate that the UHPH technology could be used to inactivate microorganisms and enzymes in sake without generating EC.

Effect of ultra-high-pressure homogenisation on sweet buttermilk

To improve buttermilk (BM) performance in dairy applications and extend the potential delivery of milk fat globule membrane (MFGM) biological activities, the effects of pH and ultra-high pressure homogenisation (UHPH) on the colloidal stability of MFGM and casein (CN) micelles in BM obtained from raw and pasteurised cream were investigated. Sharp decreases in particle size distribution and turbidity were observed as the UHPH pressure increased; this being more severe at alkaline pH. Separation of proteins and phospholipids between the pellet and serum phase by ultracentrifugation revealed more CNs present in the serum phase as loosely associated aggregates at higher pH. CN aggregate size decreased as the UHPH increased. UHPH reduced BM particle size due to the dissociation of the MFGM fragments into smaller phospholipid vesicles. These modifications could ameliorate BM's technological properties, especially gelling, improving its performance and delivery of MFGM health-promoting properties in yoghurt and cheese applications.

Effect of ultra-high pressure homogenization on structural and techno-functional properties of egg yolk granule proteins

The impact of ultra-high pressure homogenization (UHPH) (175 and 300 MPa, 1 and 4 passes) on the structure of egg yolk granule was evaluated to improve the techno-functional properties of the proteins. The UHPH treatment destabilized and modified the structure of egg yolk granule proteins, which was validated by protein profiles from gel electrophoresis. A decrease of free thiol and an increase of disulfide bond content was correlated with a decrease of the surface hydrophobicity, specifically at 300 MPa with 4 passes. The structural modifications induced by UHPH, mainly at 300 MPa (1 and 4 passes), improved the water and oil binding capacities of egg yolk granules with values ranging from 1.30 to 1.55 gwater/ggranule and 3.34 to 3.73 goil/ggranule, respectively as well as their stability index. However, egg yolk granule solubility was not impacted by the application of UHPH. These new insights are key to supporting the development of new egg yolk granule-based ingredients for the food industry.

Effect of Ultra-High Pressure Homogenization (UHPH) and Conventional Thermal Pasteurization on the Volatile Composition of Tiger Nut Beverage.

Tiger nut beverages are non-alcoholic products that are characterized by their pale color and soft flavor. Conventional heat treatments are widely used in the food industry, although heated products are often damaging to their overall quality. Ultra-high pressure homogenization UHPH) is an emerging technology that extends the shelf-life of foods while maintaining most of their fresh characteristics. The present work deals with the comparison of the effect of conventional thermal homogenization-pasteurization (H-P, 18 + 4 MPa at 65 °C, 80 °C for 15 s.) and UHPH (at 200 and 300 MPa, and inlet temperature of 40 °C), on the volatile composition of tiger nut beverage. Headspace-solid phase microextraction (HS-SPME) was used for detecting volatile compounds of beverages, which were then identified by gas chromatography-mass spectrometry (GC-MS). A total of 37 different volatile substances were identified in tiger nut beverages, which were primarily grouped into the aromatic hydrocarbons, alcohols, aldehydes and terpenes chemical families. Stabilizing treatments increased the total amount of volatile compounds (H-P > UHPH > R-P). H-P was the treatment that produced the most changes in the volatile composition of RP, while treatment at 200 MPa had a minor impact. At the end of their storage, these products were also characterized by the same chemical families. This study evidenced the UHPH technology as an alternative processing of tiger nut beverages production that minimally modifies their volatile composition.

Application of ultra-high pressure homogenization (UHPH) at different stages of wine production

Ultra-High Pressure Homogenization (UHPH) is an emerging, efficient and fast technology that can be applied at different stages in winemaking in order to reduce or avoid the use of sulphites or other antimicrobial and antioxidant treatments. During 2022 vintage, four batches of must of three different white cultivars (Vitis vinifera L.) were processed by UHPH at 300 MPa with an inlet temperature (Ti) of 4 ºC and their effectiveness was compared with control batches (without SO2 addition) and musts that were sulphited with 60 mg/L of total SO2. A complete inactivation of yeasts and bacteria was achieved when grape juices were processed by UHPH, reaching up to 7 log of reduction in yeasts, 4.6 log for acetic acid bacteria and 4.3 log for lactic acid bacteria. All UHPH musts remained stable from a microbiological point of view for more than 8 months stored at 4 ºC in aseptic containers. Results showed that when antioxidant activity, colour intensity and total phenol index were measured, UHPH can be considered a protective technique, with a similar action to that of adding SO2. Furthermore, PPO enzymatic activity was completely inactivated in UHPH and sulphited musts. When a red wine contaminated by Brettanomyces was treated by UHPH at 300 MPa and Ti = 17 ºC, a 6.6 log reduction was obtained for this spoilage microorganism and no increase of volatile phenols were detected after 2 months.

UHPH processing of grape must to improve wine quality

Ultra High Pressure Homogenization (UHPH) consists of continuous pumping of must at pressures above 200 MPa, usually 300 MPa, and its subsequent instantaneous depressurization to atmospheric pressure after passing through a special valve. In the valve, the intense impact forces and shear stresses, together with the temperature, lead to the death of microbial cells and also to the inactivation of oxidative enzymes. Intense mechanical stresses also result in nanofragmentation of colloidal particles increasing the release of nutritional factors such as YAN and others, thus improving colloidal stability. Molecules with sensory impact such as terpenes are not affected by the UHPH process, thus preserving the varietal character, nor can thermal markers such as furfural be detected. UHPH-processed musts show and maintain higher antioxidant activity than control musts and show less browning effects during processing and even later throughout and after fermentation. This technique also affects the extraction and stability of anthocyanins and other phenolic compounds by increasing their release from cell structures and protecting them from oxidation. The antimicrobial effect and the inactivation of oxidative enzymes allow the production of wines without or with a very low level of sulfur dioxide. The ability to inactivate enzymes by affecting their tridimensional structure may also have some effect on colloidal proteins by preventing protein haze or facilitating the use of protease enzymes.

Effect of reverse osmosis and ultra-high-pressure homogenization on the composition and microstructure of sweet buttermilk

Buttermilk (BM), the by-product of butter making, is similar to skim milk (SM) composition. However, it is currently undervalued in dairy processing because it is responsible for texture defects (e.g., crumbliness, decreased firmness) in cheese and yogurt. One possible way of improving the incorporation of BM into dairy products is by the use of technological pretreatments such as membrane filtration and homogenization. The study aimed at characterizing the effect of preconcentration by reverse osmosis (RO) and single-pass ultra-high-pressure homogenization (UHPH) on the composition and microstructure of sweet BM to modify its techno-functional properties (e.g., protein gel formation, syneresis, firmness). The BM and RO BM were treated at 0, 15, 150, and 300 MPa. Pressure-treated and control BM and RO BM were ultracentrifuged to fractionate them into the following 3 fractions: a supernatant soluble fraction (top layer), a colloidal fraction consisting of a cloudy layer (middle layer), and a high-density pellet (bottom layer). Compositional changes in the soluble fraction [lipid, phospholipid (PL), protein, and salt], as well as its protein profile by PAGE analysis, were determined. Modifications in particle size distribution upon UHPH were monitored by laser diffraction in the presence and absence of sodium citrate to dissociate the casein (CN) micelles. Microstructural changes in pressure-treated and non-pressure-treated BM and RO BM particles were monitored by confocal laser scanning microscopy. Particle size analysis showed that UHPH treatment significantly decreased the size of the milk fat globule membrane fragments in BM and RO BM. Also, pressure treatment at 300 MPa led to a significant increase in the recovery of total lipids, CN, calcium, and phosphate in the BM soluble fraction (top layer) following ultracentrifugation. However, PL were primarily concentrated in the pellet cloud (middle layer), located above the pellet in BM concentrated by RO. In contrast, PL were evenly distributed between soluble and colloidal phases of BM. This study provides insight into the modifications of sweet BM constituents induced by RO and UHPH from a compositional and structural perspective.

Preparation of Solid Lipid Nanoparticles of Cinnamaldehyde and Determination of Sustained Release Capacity.

Natural plant essential oils cannot be applied on a large scale due to their high volatility, easy deactivation, etc. This study provides a new method to prepare a long-lasting, slow-release essential oil product by taking advantage of solid lipid nanoparticles, which will provide a scientific guideline for the future essential oil industry. In this article, solid lipid cinnamaldehyde nanoparticles were prepared using an ultrahigh-pressure homogenization method. SLN-CA with a particle size of 74 ± 5 nm, PDI of 0.153 ± 0.032, and zeta potential of -44.36 ± 2.2 mV was screened using an additional amount of cinnamaldehyde, the ratio of oil phase components, and the homogenization pressure and number of times as factors. Differential thermal analysis and spectroscopy demonstrated that cinnamaldehyde was successfully encapsulated inside the nanoparticles. The change in particle size of nanoparticles under different conditions and times was used as an indicator of stability. The stability of the finished nanoparticles was evaluated. The retention and slow-release ability of cinnamaldehyde were investigated using the concentration of cinnamaldehyde in nanoparticles as an indicator. The results showed that after 15 days, SLN-CA retained 52.36% of the concentration from 15 days prior. The bacterial inhibition test shows that SLN-CA can inhibit bacteria.

Effect of Ultra-High-Pressure Homogenization Processing on the Microbiological, Physicochemical, and Sensory Characteristics of Fish Broth.

The effect of ultra-high-pressure homogenization (UHPH) treatments at 300 MPa at inlet temperatures (Ti) between 45 and 75 °C on the microbiological, physical, and sensorial characteristics of fish broth was evaluated. Before the application of UHPH treatments, different fish broth formulations were tested, selecting the formula with the best organoleptic and nutritional characteristics and the lowest cost, containing 45% monkfish heads and rock fish in the same proportion. The microbiological shelf-life of fish broth during cold storage at 4 and 8 °C was extended by a minimum of 20 days by applying UHPH treatments at inlet temperatures (Ti) between 45 and 65 °C. Fish broth UHPH-treated at Ti = 75 °C was microbiologically sterile during storage at 4 °C, 8 °C, and room temperature. Fish broth UHPH-treated was physically stable, significantly reducing the particle size. Color showed higher luminosity and lower yellowness as the inlet temperature increased. In fish broth UHPH-treated at Ti = 75 °C, selected for its microbiological stability, no differences were observed in the nutritional composition, antioxidant activity, and sensorial perception compared to untreated fish broth. Hence, UHPH treatments showed to be an alternative to preserving fish broth with an improved microbiological shelf-life and good sensorial characteristics.

Structural, rheological, and mechanical properties of polyvinyl alcohol composites reinforced with cellulose nanofiber treated by ultrahigh-pressure homogenizer

Cellulose nanofibers (CNF) were prepared by nanoisolation using a newly developed ultrahigh-pressure homogenizer (UHPH). The CNF was treated by UHPH with 0, 10, and 20 passes. The effect of UHPH on defibrillation of the CNF and its structure was investigated. The UHPH-treated CNF reinforced poly(vinyl alcohol) (PVA) composite was fabricated by solvent casting. The effect of CNF on morphology, high-order structure, rheological property, and mechanical performance of PVA/CNF composites was investigated. Structural analyses revealed that fiber diameters and fiber distributions of the CNF decreased, and the relative crystallinity increased with an increase in the UHPH passes. The mechanical treatment by UHPH promoted CNF fiber dissociation without interfering with the CNF crystal structure. High crystallinity and interaction of the hydrogen bonding of the defibrillated, treated CNF significantly enhanced the mechanical performance of the PVA/CNF composites. The UHPH treatment presented defibrillated CNF with high crystallinity, which was developed for the high-potential cellulose nanofiber in fiber-reinforced composite materials.

A Overview on Nanoemulsion

Nanoemulsions are colloidal emulsions made up of two immiscible liquids, one of which is scattered and the other continuous. Nanoemulsions are two types W/O and O/W. Nanoemulsion are size varies from 20 to 200nm. Nanoemulsions are thermodynamically stable. Emulsifiers are stabilised nanoemulsion. There are two types of emulsifiers: one is hydrophilic and the other is lipophilic. Nanoemulsion is widely used in food industry, beverages, agriculture, bio-pharmaceutical, dairy products. Nanoemulsion widely prepared by using high energy or brute force comprising ultra sonication and ultra high pressure homogenizer and low energy or persuasion method compressing both phase inversion composition (PIC) and the phase inversion temperature (PIT). Newly a developed method used as preparation of nanoemulsion bubble bursting, micro- fluidization and evaporative ripening. The aim of review a article focusing on to preparation method characterization application of nanoemulsion.

Effects of High-Pressure Treatments (Ultra-High Hydrostatic Pressure and High-Pressure Homogenization) on Bighead Carp (Aristichthys nobilis) Myofibrillar Protein Native State and Its Hydrolysate

The impacts of four treatments, ultra-high hydrostatic pressure (UHP), high-pressure homogenization (HPH), combined UHP + HPH (U-H), and HPH + UHP (H-U), on bighead carp (Aristichthys nobilis) myofibrillar protein (BMP) structure, functional hydrolysis property to pepsin, and antioxidant activity of hydrolysates were investigated. All treatments led to increase in low-molecular-weight BMP, the BMP stability, and hydrophobic group exposure, but decrease in total sulfhydryl content and BMP particle size, thus resulting in increased hydrolysis and antioxidant capacity of enzymatic hydrolysates. U-H treated BMP exhibited the highest surface hydrophobicity (924.5 ± 1.0), zeta potential absolute value (18.88 ± 0.11 mV), hydrolysis degree (54.5 ± 1.6%), and antioxidant activity, but the lowest α-helix (21.84 ± 2.61%), intrinsic fluorescence spectrum intensity, total sulfhydryl (7.24 ± 0.07 μmol/g), and mean particle size (182.57 ± 2.23 nm). Therefore, U-H might be a promising pretreatment to prepare bioactive peptide.

Development, characterization, and clinical investigation of Spinacia oleracea-based ultra-high pressure homogenized emulsion system for facial physiological parameters.

Spinacia oleracea (SO) exhibits radical scavenging and tyrosinase inhibition activity indicating potential as a depigmenting agent. To develop and characterize a stable emulsified system containing SO extract through ultra-high pressure homogenization, evaluate skin permeability, and enumerate in vivo performance in terms of melanin index, skin spots analysis, and related skin physiological parameters. Free radical scavenging and tyrosinase inhibition potential of SO extract was quantified through DPPH radical scavenging and mushroom tyrosinase inhibition assay, respectively. Six SO extract loaded ultra-high pressure emulsified systems (UHSO) were developed using ultra-high pressure homogenizer and assessed for size and polydispersity index (PDI). Among the prepared formulations, the optimized formulation (UHSO6) was subjected to 90days stability studies performed at 8°C, 25°C, 40°C, and 40°C+75% RH (relative humidity) for organoleptic features, pH, and rheology. Ex vivo skin permeability studies were performed on abdominal skin from male albino rat. Changes in skin physiological parameters were evaluated in healthy female volunteers (n=13) for 12weeks utilizing mexameter® , corneometer® , and sebumeter® . Skin spots were analyzed through computerized analysis of high-resolution images by visioFace® . SO extract exhibited promising antioxidant (88±0.0096%) and tyrosinase inhibition potential (90.6±0.0015mg of Kojic Acid Eq/g of extract). Optimized UHSO was found to be stable with respect to stability evaluation, globule size (1110nm), zeta potential (-27.6), and PDI (0.34). Ex vivo skin permeation of UHSO was significantly higher than SO loaded coarse emulsion. Moreover, the formulation showed a significant decrease in skin melanin, spot count, and spot % area, whereas skin hydration index was improved significantly. Stable SO extract loaded emulsion system was successfully developed by a novel, cost-effective technique of ultra-high pressure homogenization which showed improved performance in terms of skin permeation and other skin physiological parameters.