High-pressure Homogenization Treatment Research Articles

Slowly digestible properties of lotus seed starch-glycerine monostearin complexes formed by high pressure homogenization

Starch-lipid complexes were prepared using lotus seed starch (LS) and glycerin monostearate (GMS) via a high-pressure homogenization process, and the effect of high pressure homogenization (HPH) on the slow digestion properties of LS-GMS was investigated. The digestion profiles showed HPH treatment reduced the digestive rate of LS-GMS, and the extent of this change was dependent on homogenized pressure. Scanning electron microscopy displayed HPH treatment change the morphology of LS-GMS, with high pressure producing more compact block-shape structure to resist enzyme digestion. The results of Gel-permeation chromatography and Small-angle X-ray scattering revealed high homogenization pressure impacted molecular weight distribution and semi-crystalline region of complexes, resulting in the formation of new semi-crystalline with repeat unit distance of 16–18 nm and molecular weight distribution of 2.50–2.80 × 105 Da, which displayed strong enzymatic resistance. Differential scanning calorimeter results revealed new semi-crystalline lamellar may originate from type-II complexes that exhibited a high transition temperature.

Effect of high pressure homogenization on the structure and the interfacial and emulsifying properties of β-lactoglobulin

The effect of high pressure homogenization (HPH) on the structure of β-lactoglobulin (β-lg) was studied by combining spectroscopic, chromatographic, and electrophoretic methods. The consequences of the resulting structure modifications on oil/water (O/W) interfacial properties were also assessed. Moderated HPH treatment (100 MPa/4 cycles) showed no significant modification of protein structure and interfacial properties. However, a harsher HPH treatment (300 MPa/5 cycles) induced structural transformation, mainly from β-sheets to random coils, wide loss in lipocalin core, and protein aggregation via intermolecular disulfide bridges. HPH-modified β-lg displayed higher surface hydrophobicity leading to a faster adsorption rate at the interface and an earlier formation of an elastic interfacial film at Cβ-lg = 0.1 wt%. However, no modification of the interfacial properties was observed at Cβ-lg = 1 wt%. At this protein concentration, the prior denaturation of β-lg by HPH did not modify the droplet size of nanoemulsions prepared with these β-lg solutions as the aqueous phases. A slightly increased creaming rate was however observed. The effects of HPH and heat denaturations appeared qualitatively similar, but with differences in their extent.

Paste structure and rheological properties of lotus seed starch–glycerin monostearate complexes formed by high-pressure homogenization

Starch–lipid complexes were prepared using lotus seed starch (LS) and glycerin monostearate (GMS) via a high-pressure homogenization (HPH) process, and the effect of HPH on the paste structure and rheological properties of LS–GMS was investigated. Rapid Visco Analyser (RVA) profiles showed that HPH treatment inhibited the formation of the second viscosity peak of the LS–GMS paste, and the extent of this change was dependent on the level of homogenized pressure. Analysis of the size-exclusion chromatography, light microscopy, and low-field 1H nuclear magnetic resonance results revealed that high homogenized pressure (70–100MPa) decreased molecular weight and size by degrading the branch structure of amylopectin; however, intact LS–GMS granules can optimize the network structure by filler–matrix interaction, which causes free water to transition into immobile water in the starch paste. The steady-shear results showed that the LS–GMS pastes presented non-Newtonian shear-thinning behavior, with higher homogenized pressure producing a smaller hysteresis loop area. During the oscillation process, the LS–GMS pastes prepared at 100MPa exhibited the lowest loss tangent values in all the complexes, indicating a stronger resistance to vibration.

Extending protein functionality: Microfluidization of heat denatured whey protein fibrils

The functional attributes of globular proteins can be extended by controlling the nature of the aggregates they form. In this study, the effect of thermal treatment (85°C/20 min) and high pressure microfluidization (20,000 psi, 1 pass) on the physical properties of whey protein isolate solutions (5–9%; pH 2) was investigated. Heating solutions of native whey protein isolate (8 wt%) under these acidic conditions led to the formation of highly viscous solutions (η = 306 mPa s) with low turbidity (τ = 0.04 cm−1), which was attributed to the formation of protein fibrils (effective d = 310 nm). Microfluidization of these protein fibrils decreased their length (effective d = 97 nm) leading to a substantial reduction in solution viscosity (η = 3.8 mPa s), and a slight reduction in turbidity (τ < 0.03 cm−1). The impact of solution pH (2–7) on the appearance and rheology of native, heated, and heated-microfluidized whey protein isolate solutions was then examined. For all systems, highly turbid solutions (τ > 1 cm−1) were formed at pH values close to the isoelectric point of the whey proteins (pH 4.5) due to protein self-association caused by reduction of the electrostatic repulsion between the protein molecules. Highly viscous or gelled solutions were formed for the heated and heated-microfluidized proteins across a wide pH range, which was attributed to the presence of fibrils. The study showed that the functional attributes of whey proteins can be modulated by thermal and high-pressure homogenization treatment.

Fabrication of stable glycine/palygorskite nanohybrid via high-pressure homogenization as high-efficient adsorbent for Cs(I) and methyl violet

Abstract A series of stable glycine/palygorskite (GLY/PAL) nanohybrid absorbents were prepared by incorporating GLY molecules into PAL via a simple high-pressure homogenization. The structural characterization demonstrated that 3.15% of GLY molecules were incorporated into the GLY/PAL hybrid adsorbent and formed H-bonding interactions with siloxane and inner channels of PAL, which caused slight distortion of the crystalline framework. Compared with conventional surface modification, high-pressure homogenization and heat treatment enabled GLY to insert into PAL channels well to form hybrid nanostructure. Among all hybrid absorbents, the 60GLY/PAL showed the highest adsorption capacities of 147 mg/g for methyl violet (MV) and 80 mg/g for Cs(I) as well as the removal ratios of 98% for MV and 80% for Cs(I) from 150 mg/L of MV and 100 mg/L of Cs(I) solutions, respectively. In contrast, raw PAL (without modification) could adsorb only 112 mg/g of MV and 45 mg/g of Cs(I). This work has demonstrated that utilizing a simple high-pressure homogenization process improved stability of GLY/PAL nanohybrid absorbents by increasing the incorporation of guest (GLY) molecules into the tunnels/channels of hosts (PAL), leading to a novel enhanced adsorbent for Cs(I) and MV. This finding has provided a new way to fabricate nanohybrid adsorbents.

Combined process of high-pressure homogenization and hydrothermal extraction for the extraction of fucoidan with good antioxidant properties from Nemacystus decipients

Sulfated polysaccharides (fucoidan) were recovered from Nemacystus decipients using a combination of high pressure homogenization (HPH) and hydrothermal extraction process through employing different homogenization pressure (40–100MPa) and cycle times (1–3). HPH treatment could result in a high fucoidan yield with preserving sulfate content and the optimal yield was 16.67±0.36%, obtained from 70MPa for 2 cycles’ extraction. Chemical composition analysis, HPAEC, IR and HPSEC analysis were applied for characterization of extracted polysaccharides. The molecular weight of extracted fucoidan decreased with increasing extraction pressure. All fucoidan exhibited antioxidant activities as determined by DPPH radical scavenging, hydroxyl radical scavenging, and ferrous ion chelating ability as well as reducing power, among which fucoidan extracted at 70MPa (HN2) possessed excellent antioxidant ability. This study shows that HPH can be used as an efficient means to assist extraction of fucoidan from seaweed and N. decipients could potentially be a raw resource for natural antioxidant.

Characterization of intrinsic material properties of a model lipoproteic emulsion gel by oscillatory and creep compliance rheometry.

This research evaluates the effects of formulation and processing factors on the properties of a protein/fat-based food system. These properties may be related to sodium mobility and salty taste perception. This research provides information on strategies that can be used to control factors influencing the physical properties of protein/fat-based food systems targeting sodium reduction.

Integrity of the microalgal cell plays a major role in the lipolytic stability during wet storage

Microalgae are promising sources of lipids for applications in food, fuel, pharmaceutics and cosmetics. However, these lipids are also subject to lipolysis reactions during processing and storage. Especially during wet biomass storage, substantial amounts of free fatty acids (FFA) are formed, which has negative effects on flavor and nutritional value and can cause downstream processing problems in biodiesel production. This study contributes to a better understanding of the underlying processes leading to lipolysis by focusing on cell wall differences between species. Therefore, in a first phase, a comparison was made between the lipolytic stability of Nannochloropsis oculata and T-Isochrysis lutea, two species reported to have substantial differences in cell wall structure and strength. Nannochloropsis appeared to be stable during the first days of wet storage, while in T-Isochrysis, lipolysis started immediately after harvest. In a second experiment, the influence of cell disruption by high pressure homogenization (HPH) on lipolytic stability during wet storage of Nannochloropsis was investigated. It was observed that the HPH treatment induced lipolysis, as the FFA content was rapidly increasing immediately after the treatment, in contrast to the control sample, in which the FFA content was constant during the first days of storage. The integrity of the microalgal cell was thus found to play a crucial role in lipid stability during short-term post-harvest wet storage.

Modification of dietary fibers from purple-fleshed potatoes ( Heimeiren ) with high hydrostatic pressure and high pressure homogenization processing: A comparative study

Abstract In this study, we evaluated the effects of high hydrostatic pressure (HHP) and high pressure homogenization (HPH) treatments on the physicochemical, functional, and structural properties of dietary fibers (DFs) obtained from purple-fleshed potatoes. DFs subjected to HHP and HPH exhibited increased content of soluble dietary fiber. HHP and HPH treatments did not improve water holding capacity, but increased oil holding and swelling capacities, and emulsion activity and stability. DFs treated with HPH showed the increased antioxidant activities (DPPH 0.89, ABTS 2.65, FRAP 3.39 mg Trolox/g DF), content of total phenol, and α-glucosidase inhibition (98.3%). HHP and HPH treatments changed monosaccharide compositions and structural characteristics of DFs. Therefore, DFs from purple-fleshed potatoes could be used as a fiber-rich ingredient in functional foods, and HPH was more useful in the modification of dietary fiber than HHP at the same treatment conditions. Industrial relevance : This article deals with the modification of dietary fibers from purple-fleshed potatoes ( Heimeiren ) with HHP and HPH treatments. Results suggest that HPH treated dietary fiber showed a higher ratio of soluble fraction, increased physicochemical and functional properties than HHP at 200 MPa. There outcomes could help the food industry identify the optimal high pressure processing type to improve physicochemical and functional properties of dietary fiber.

Characterization of Sodium Mobility and Binding by 23 Na NMR Spectroscopy in a Model Lipoproteic Emulsion Gel for Sodium Reduction.

The effects of formulation and processing parameters on sodium availability in a model lipid/protein-based emulsion gel were studied for purposes of sodium reduction. Heat-set model gels were prepared with varying levels of protein, lipid, and NaCl contents and high pressure homogenization treatments. Single quantum and double quantum-filtered 23 Na NMR spectroscopy experiments were used to characterize sodium mobility, structural order around "bound" (restricted mobility) sodium, and sodium binding, which have been correlated to saltiness perception in food systems previously. Total sodium mobility was lower in gels with higher protein or fat content, and was not affected by changes in homogenization pressure. The gels with increased protein, fat, or homogenization pressure had increased structure surrounding "bound" sodium and more relative "bound" sodium due to increased interfacial protein interactions. The data obtained in this study provide information on factors affecting sodium availability, which can be applied towards sodium reduction in lipid/protein-based foods.

Effect of high pressure homogenization (HPH) on microstructure and rheological properties of hazelnut milk

Abstract The effect of high pressure homogenization (HPH) on microstructure and rheological properties of hazelnut milks was investigated. Hazelnut milk samples were produced from cold pressed hazelnut cake and homogenized up to 150 MPa pressure. Microstructural and rheological properties of products, except temperature sweep, were greatly affected by HPH treatments. Homogenized samples showed significant reduction in particle size, which turned from bimodal and poly-disperse to monodisperse distributions. HPH decreased the consistency of products from 91.82 to 0.51 Pa.sn and increased flow behavior index from 0.15 to 0.36. All samples showed higher values G′ than G″, which indicates that samples could be classified as soft-gel network, and hazelnut milk samples did not obey the Cox-Merz rule without multiplying angular frequency with shift factor. In conclusion, HPH can be used to reduce the consistency of samples and the friction loss, thus minimizing the amount of energy required to flow during processing and distribution. Industrial relevance. Vegetable based beverages are available at any supermarket as an alternative to dairy products with an increasing consumer acceptance. Between these beverages hazelnut milk samples are the most noteworthy products due to important role in human nutrition and health, and moreover due to well accepted and widely consumed product. Due to its composition, hazelnut milks have very high consistency, and therefore, the energy consumption for processing and handling is too high. In this research, the high pressure homogenization (HPH) technology was successfully proposed to be used for improving microstructural properties, and hence reducing its consistency. The energy consumption during processing and distribution can be minimized by reducing the consistency and friction losses of product.

Effect of high pressure homogenization and high power ultrasound on some physical properties of tomato juices with different concentration levels

The effect of high pressure homogenization (HPH) and ultrasound (US) on rheological properties, color, precipitate weight ratio, pectin esterification degree and cell integrity of tomato juices with different soluble solids content (5.0, 7.5, 10.0 °Brix) was studied. Samples were subjected to HPH up to 150 MPa or US up to 30 min. The energy efficiency associated to the processes was also evaluated. Results showed that stress type and product concentration influenced the changes of tomato juice physical properties. In particular, HPH and US treatments were responsible for higher G′ and consistency of processed tomato juices than untreated samples. Increases in sample rheological properties were comparable for the 5.0 and 7.5 °Brix treated HPH and US samples, whereas HPH was more effective than US in the case of 10.0 °Brix sample. These changes were in agreement with other indexes, i.e. precipitate weight ratio increase and cell integrity decrease, and were attributed to stronger of inter-particle interactions. The process energy efficiency showed that lower energy was involved in HPH in comparison to US.

Impact of Thermal and Pressure-Based Technologies on Carotenoid Retention and Quality Attributes in Tomato Juice

The aim of this study was to investigate the impact of thermal processing (TP) (90 °C, 90 s), high-pressure processing (HPP) (600 MPa, 46 °C, 5 min), and high-pressure homogenization (HPH) (246 MPa, 99 °C, <1 s) on product quality parameters, specifically carotenoid content, and physicochemical attributes of particle size, color, viscosity, total soluble solids, and pH in tomato juice. Unprocessed tomato juice was used as control. The four major species of carotenoids (lycopene, β-carotene, phytoene, and phytofluene) in tomato juice were analyzed by HPLC. The content of total lycopene, all-trans-lycopene, cis-lycopene isomers, phytoene, and phytofluene, in TP-, HPP-, and HPH-treated tomato juice did not significantly differ from that in unprocessed (control) juice. Significant reduction in β-carotene content was observed after TP treatment but not after HPP and HPH treatments. HPH significantly reduced tomato juice particle volume mean diameter from ∼330 μm in control, HPP-, and TP-treated tomato juices to ∼17 μm. A concomitant increase in apparent viscosity was observed in HPH-treated juice versus control. HPH-treated juice had increased redness (a*) and yellowness (b*) than that in control and HPP-treated tomato juices. These results indicate that high-pressure-based technologies (HPP and HPH) can preserve carotenoids as well as improve physicochemical properties.

Intensification of protein extraction from soybean processing materials using hydrodynamic cavitation

High pressure homogenisation (HPH) has been investigated for its potential to aid the aqueous extraction of protein and other components from soybeans. HPH treatments (50–125 MPa) were applied to soy slurry and okara, the diluted waste stream from soybase production. Extraction yields of oil, protein and solids were calculated, and the feasibility of the technology was assessed. The most productive HPH treatment investigated improved extraction yields of protein up to 82% with a single pass of soy slurry at 100 MPa. In comparison, a maximal protein extraction yield of 70% has been achieved previously using ultrasound at lab-scale for 15 min (20 kHz, 65 W according to manual, 13 mm probe tip) (Preece et al., in press). Results showed a particle size reduction upon HPH and disruption of intact cells, confirmed via confocal laser scanning microscopy. Multiple HPH passes of soy slurry caused an increase in dynamic viscosity and a small increase in particle size probably due to cell wall swelling, resulting in decreased separation efficiency and consequently a reduced extraction yield. HPH offers extraction assistance, with more promising results reported in comparison to ultrasound-assisted extraction of soybean processing materials. Improvement of current soybean processing is desirable on an industrial level to better use available raw materials and reduce waste production. This study shows the effects of a technology already widely employed in industry for other benefits, such as fine emulsion production and microbial cell disruption. High pressure homogenisation was carried out on a lab-scale on soybean processing materials which were prepared in a pilot plant, with similar feed compositions to those produced at an industrial scale.

Influence of Moderate High-Pressure Homogenization on Quality of Bioactive Compounds of Functional Food Supplements

Current interest in health has led to an increase in demand for functional food supplements as well as in industry concern for maintaining the bioactive compounds of such foods via the application of new technologies. In this study, we evaluated the effect of moderate high-pressure homogenization (HPH) treatments (80 and 120 MPa) versus thermal treatment (80°C, atmospheric pressure) on the functional bioactive compounds from four different functional supplements stored under accelerated conditions (40°C ± 2°C and 75% ± 5% relative humidity) for 6 months. HPH proved to be a better alternative than thermal treatment for functional supplements containing heat-sensitive compounds such as vitamin C, vitamin A, and unsaturated fatty acids (10-hydroxy-2-decenoic acid). The proanthocyanidin, cynarin, chlorogenic, and iron contents, however, were not initially affected by HPH treatments. The storage time caused important reductions in the majority of the compounds studied (mainly in vitamins C, B12, and A), although the lowest decrease was found in the HPH samples. The food matrix had an important effect on the final functional composition and required the optimization of HPH treatments for each functional food supplement. HPH is a recommended alternative to thermal treatment for functional food supplements, in particular when they are rich in thermolabile bioactive compounds.

Engineering Process Characterization of High-Pressure Homogenization—from Laboratory to Industrial Scale

Fluid foods are a rapidly growing segment serving the needs of consumers’ healthy life style. Though high-pressure pasteurized beverages have been recently commercialized, the batch nature of the technology has been a hurdle for wider adaptation of the technology for high-throughput commodity-oriented beverage products. Further development of continuous flow through high-pressure processing methods is desired. High-pressure homogenization (HPH) consists of forcing a pressurized fluid to flow through a minute gap, which not only homogenizes the fluid but also increases the fluid’s temperature. HPH offers the possibility of combining homogenization and preservation into a single unit operation. By manipulating initial temperature and applied pressure, HPH treatment can be used to pasteurize or sterilize the product. This work critically examines the efforts in understanding fundamental process engineering aspects of HPH, including pressure-thermal process characterization, valve design (gap size and pressure relation), flow pattern, temperature history, and residence time distribution. This review will also highlight the HPH impact on food quality and bioactive compound retention. Quality aspects examined include particle size distribution and microbial and enzyme inactivation. The insight gained by this review will assist readers to gain a better appreciation of the HPH process design and system scale-up.

Biorefinery of microalgal soluble proteins by sequential processing and membrane filtration

A mild biorefinery process was investigated on the microalga Nannochloropsis gaditana, to obtain an enriched fraction of water soluble proteins free from chlorophyll. After harvesting, a 100g.L−1 solution of cells was first subjected to cell disruption by either high-pressure homogenization (HPH) or enzymatic treatment (ENZ). HPH resulted in a larger release of proteins (49%) in the aqueous phase compared to the Alcalase incubation (35%). In both cases, an ultrafiltration/diafiltration (UF/DF) was then performed on the supernatant obtained from cell disruption by testing different membrane cut-off (1000kDa, 500kDa and 300kDa). After optimising the process conditions, the combination of ENZ→UF/DF ended in a larger overall yield of water soluble proteins (24.8%) in the permeate compared to the combination of HPH→UF/DF (17.4%). A gel polarization model was implemented to assess the maximum achievable concentration factor during ultrafiltration and the mass transfer coefficient related to the theoretical permeation flux rate.

Effective of different homogeneous methods on physicochemical, textural and sensory characteristics of soybean (Glycine max L.) yogurt

ABSTRACTThe effect of ultrasonication (US), shear mixing (SM) and high pressure homogenization (HPH) on soybean (Glycine max L.) milk-produced set-type soybean yogurt was evaluated. The US treated with 280 W sample had the lowest water holding capacity value and highest syneresis value. Rheological constants were predicted by means of fitting the rheological model of non-Newton model. The soybean yogurt samples were found as a pseudoplastic fluid nature and the SM treated with 20,000 r/min sample had the highest apparent viscosity value and the US treated with 280 W had the lowest value. The HPH treatment caused a general decrease of hardness and adhesiveness in comparison to other samples. The overall acceptability scores of all the samples were above 6 on a scale of 1–10 indicating acceptability yogurts and the lower score in beany flavor for the yogurt might be partly due to the objectionable beany flavor still present in the samples.

Effect of alkaline and high-pressure homogenization on the extraction of phenolic acids from potato peels

Abstract Phenolic acids were extracted from potato peels with NaOH treatment and a high-pressure homogenization (HPH) process. Total phenolic content, total flavonoid content, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity and extraction yield were determined with different treatment conditions. Significant improvement was observed after the alkaline and HPH treatments. HPLC analysis shows that the phenolic compounds contained gallic acid, sinapic acid, vanillic acid, syringic acid, protocatechuic acid, p-coumaric acid, chlorogenic acid, caffeic acid and ferulic acid. The yields of these specific phenolic acids varied with different treatments. Scanning electron microscope, nuclear magnetic resonance and particle size measurements suggest that changes in cellular structure may be the mechanisms for the improvement in extraction rendered by the HPH and NaOH treatments. In conclusion, the combined treatment of NaOH and HPH increased the extraction yield and functionality of the phenolic acids from the potato peel residues. Industry relevance High-pressure homogenization as a process method has been applied widely in food industry. It can help with emulsification and sterilization significantly. But the potential of High-pressure homogenization as an assist method to improve the yield of extraction from food and food waste has not been developed. The positive effect of phenolic and flavonoids has been proved and found in potato peels. However, the release of these bioactive components is a difficulty with traditional method. The High-pressure homogenization can reduce the particle size apparently and release the bioactive compound. For potato peels, the production can be added into bread, meat, beverage, etc. to increase the fiber and nutrition. For other sorts of similar material, the high-pressure homogenization can be a novel to improve the extraction process of bioactive component bound in cell wall instead of inside the cell. In this article, we developed a new method with high-pressure homogenization and alkaline treatment to improve the extraction process dramatically. Meanwhile, the process can be scale up to industry with minor modification and adjustment.

Effect of high-pressure homogenization on different matrices of food supplements.

There is a growing demand for food supplements containing high amounts of vitamins, phenolic compounds and mineral content that provide health benefits. Those functional compounds have different solubility properties, and the maintenance of their compounds and the guarantee of their homogenic properties need the application of novel technologies. The quality of different drinkable functional foods after thermal processing (0.1 MPa) or high-pressure homogenization under two different conditions (80 MPa, 33 ℃ and 120 MPa, 43 ℃) was studied. Physicochemical characteristics and sensory qualities were evaluated throughout the six months of accelerated storage at 40 ℃ and 75% relative humidity (RH). Aroma and color were better maintained in high-pressure homogenization-treated samples than the thermally treated ones, which contributed significantly to extending their shelf life. The small particle size obtained after high-pressure homogenization treatments caused differences in turbidity and viscosity with respect to heat-treated samples. The use of high-pressure homogenization, more specifically, 120 MPa, provided active ingredient homogeneity to ensure uniform content in functional food supplements. Although the effect of high-pressure homogenization can be affected by the food matrix, high-pressure homogenization can be implemented as an alternative to conventional heat treatments in a commercial setting within the functional food supplement or pharmaceutical industry.