High-pressure Homogenization Pressure Research Articles

Exploring the emulsifying properties of biopolymers from Ulva lactuca in stabilizing high internal phase emulsions

Seaweed is a promising raw material for food emulsion stabilizers due to its abundance, low cost, and rich content of various natural biological macromolecules. This study explores the potential of using Ulva lactuca (UL) to stabilize emulsions by employing high-pressure homogenization (HPH) to release its interfacial active components. The results demonstrate that UL extract (ULE) with emulsifying activity was gradually extracted as the HPH pressure increased from 100 to 800 MPa. Concentrating the macromolecular components, specifically polysaccharides and proteins, in the ULE via membrane filtration resulted in a concentrated fraction, referred to as ULER, which exhibited enhanced emulsification performance. By optimizing the oil volume fraction (φ) and pH, it was found that high internal phase emulsions (φ = 0.7–0.8) showed superior viscoelasticity and stability at pH 3–7. In terms of stability, it was observed that the emulsions stabilized by ULER maintained their structure over extended periods without significant phase separation. The strong interaction between exogenous Ca2⁺ and ULER increased the apparent viscosity and viscoelasticity of the emulsion. However, the addition of Ca2⁺ did not significantly enhance the stability of the ULER-stabilized emulsions and, in some cases, even led to a decrease in emulsion stability. This effect may be probably due to the specific interactions between the Ca2⁺ ions and the polysaccharides and proteins in the ULER, which can affect the network structure of the emulsion. Overall, this study highlights the potential of HPH treatment in processing UL to transform it into an effective emulsion stabilizer for applications in the food industry.

Development and characterization of pH-sensing films based on red pitaya (Hylocereus polyrhizus) peel treated by high-pressure homogenization for monitoring fish freshness

High pressure homogenization (HPH) was used to physically modify red pitaya (Hylocereus polyrhizus) peel (RPP) dispersions to develop pH-sensing films for monitoring fish freshness. Effects of HPH treatment at various pressures of 0 (control), 10, 20, 30, 40, 60 and 80 MPa on microstructure and properties of RPP film-forming dispersions (FFDs) and their resultant films were systematically investigated. Results showed that due to the structure destructing effect of HPH, the mean particle size of RPP dispersion treated at 80 MPa decreased significantly from 129.17 to 37.41 μm and its total soluble solids content increased from 7.64 to 8.62 °Bx. Rheological analysis manifested that all FFDs exhibited a shear thinning behavior with higher apparent viscosities as well as storage modulus and loss modulus with increasing HPH pressure. Besides, the HPH treated FFDs had a higher total betacyanins content and showed an obvious color response to pH variation. Consequently, the resultant films had not only smoother surfaces and more transparent appearance, but also better water vapor barrier and mechanical properties than the control. Particularly, film obtained from RPP treated at 60 MPa showed a highest tensile strength of 21.87 MPa and elongation at break of 22.09%, together with a lowest water vapor permeability of 11.41 g⋅mm⋅m−2⋅d−1⋅kPa−1. Notably, this film also exhibited high sensitivity to volatile ammonia and showed a remarkable color variation when applied for monitoring fish spoilage at 25 °C. Thus, the pH-sensing films developed from HPH treated RPP had desirable properties to be potentially used in intelligent food packaging.

Physicochemical and rheological properties of soybean oil body fermented milk: Impacts of high pressure homogenization

In the present research, the impacts of high-pressure homogenization (HPH) (20, 60, 90, 120 and 150 MPa) on the physicochemical, rheological and sensory properties of soybean oil body (SOB) fermented milks were explored. Experimental results showed that with the increase of HPH pressure, acidity and water-holding capacity (WHC) of SOB fermented milk significantly increased, while its pH, peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) significantly decreased. The SOB fermented milk was found to be pseudoplastic fluids and the SOB fermented milk at 150 MPa had the highest apparent viscosity. Meanwhile, the SOB fermented milk of 150 MPa possessed the highest sensory score. Finally, principal component analysis (PCA) and heatmap showed that SOB fermented milk had the best characteristics after HPH treatment at 150 MPa. Therefore, HPH pressure could observably improve sensory, textural and rheological properties of SOB fermented milk. These results provide theoretical reference for HPH treatment to develop high-quality fermented dairy products.

Investigating the synergistic effects of high-pressure homogenization and pH shifting on the formation of tryptophan-rich nanoparticles

A combined treatment of high-pressure homogenization (HPH) and pH-shifting on the mixture of α-lactalbumin (α-LA) and tryptophan (Trp) was used to fabricate nanoparticles (α-LA-Trp-NP). The optimal α-LA/Trp ratio (5:1), HPH pressure (206.8 MPa), and recirculation time (40 min) was found to produce small α-LA-Trp-NP (243.0 ± 7.2 nm) with a narrow particle size distribution. Comparing the size and morphology of α-LA-NPs with α-LA-Trp-NPs indicated that the presence of Trp significantly affected the size and morphology of the NPs in the dry form. The stability of the α-LA-Trp-NPs was improved by using the combination of HPH and pH-shifting. The α-LA-Trp-NPs showed better freeze–thaw stability and retained the particle characteristics with heat treatment at 63 °C, 30 min after the freeze–thaw cycle. α-LA-Trp-NPs were also observed to have remarkable stability against pH changes and thermal treatments at 63 °C, 30 min, and 90 °C, 2 min.

Structural and Physical Properties of Alginate Pretreated by High-Pressure Homogenization.

To develop a high-efficient extraction method, we investigated the use of high-pressure homogenization (HPH) as a novel pretreatment technology for the extraction of sodium alginate (SA) from Laminaria japonica. After the single-factor experiment, the results demonstrated that under the conditions of 100 MPa HPH pressure, 4 cycles, pH 6.0, and 0.5% EDTA for 3.0 h, the optimized extraction yield of HPH reached 34%. To further clarify the effect on the structural properties of HPH-extracted SA, we conducted comprehensive analysis using SEM, FTIR, MRS, NMR, XRD, TGA, and a T-AOC assay. Our findings revealed that HPH pretreatment significantly disrupted the structure of L. japonica cells and reduced their crystallinity to 76.27%. Furthermore, the antioxidant activity of HPH-extracted SA reached 0.02942 mgVceq∙mg-1. Therefore, the HPH pretreatment method is a potential strategy for the extraction of alginate.

Evaporative concentration and high-pressure homogenization for improving the quality attributes and functionality of goat milk yogurt

Goat milk yogurt is gaining scientific attention worldwide due to its nutritional quality and potential health benefits to consumers. Understanding the impact of evaporative concentration and high-pressure homogenization (HPH) on goat milk yogurt quality is of high importance for dairy industry. This study aimed to investigate the influences of vacuum-assisted evaporative concentration combined with HPH (20–150 MPa) on the physicochemical, sensory characteristics and in vitro digestion of fermented goat milk (FGM). Concentrated FGM (CFGM) exhibited longer fermentation times, smaller particle size, increased viscosity, firmness and cohesiveness compared with pristine FGM, whereas HPH treatments induced shorter acidification processes. Meanwhile, the CFGM produced by HPH treatment at 150 MPa showed enhanced stability by decreasing the average particle size, and exhibited the highest overall acceptability among all FGM and CFGM samples assessed. Furthermore, CFGM treated with higher HPH pressure showed an improved degree of hydrolysis, protein digestibility and antioxidant activity during digestion compared with CFGM treated at HPH pressure of 20 MPa. Therefore, the results demonstrated the feasibility of the combination of evaporative concentration and HPH in the development of goat milk yogurt with enhanced quality attributes and functionality. These results are crucial to enhance the processing and handling of the goat milk.

High-pressure induced structural modification of porcine myofibrillar protein and its relation to rheological and emulsifying properties

Here, we investigated the effects of high-pressure homogenization (HPH) on the physicochemical, rheological, and emulsifying properties of myofibrillar proteins (MFPs). The mean particle size of MFPs treated by HPH with different pressures (0–150 MPa) decreased from 886.0 ± 120.2 nm to 172.6 ± 13.7 nm with increasing HPH pressure. In addition, more uniform and homogeneous protein particles were obtained as the HPH pressure was increased. In SDS-PAGE, the band intensities of high molecular weight proteins (200 kDa) decreased and the intensities of some of the smaller molecular fractions (70–120 kDa) increased when the MFPs were subjected to HPH treatment at more than 60 MPa owing to the fragmentation of high molecular weight proteins, such as myosin heavy chains. The surface hydrophobicity of MFPs increased with increasing HPH pressure owing to the exposure of buried hydrophobic groups by protein unfolding. In the rheological study, the MFP dispersions exhibited shear thinning fluid behavior, but the MFP dispersion homogenized at high pressure (120–150 MPa) presented close to Newtonian fluid behavior with low viscosity. The emulsifying activity (EA) and emulsion stability index (ESI) of MFPs improved with increasing HPH pressures. The MFPs treated with HPH at different pressures were used for o/w emulsion preparation, and their dispersion stabilities were investigated during storage. The emulsion systems stabilized with MFPs pressurized at more than 60 MPa showed comparatively less cream formation in the top layer, indicating high dispersion stability.

Highly Efficient Water-Based Extraction of Biliprotein R-Phycoerythrin From Marine the Red-Macroalga Sarcopeltis skottsbergii by Ultrasound and High-Pressure Homogenization Methods

Sarcopeltis skottsbergii is an endemic species of the southern region of South America, with R-phycoerythrin (R-PE) as an accessory photosynthetic pigment. The production of S. skottsbergii is around twenty thousand tons of dry alga per year. The evaluation of (R-PE) in a biorefinery model is still incipient in the algal biotechnology area and will be used in the food, pharmaceutical, cosmeceutical, and nutraceutical industries. This work evaluated the cell disruption and separation processes by using two green technologies, ultrasound-assisted extraction (UAE) and high-pressure homogenization (HPH), to obtain an R-phycoerythrin enriched extract from S. skottsbergii. Two-levels three-factor central composite design (CCD) and response surface methodology (RSM) were carried out to optimize the extraction conditions, including the factors for UAE (time, amplitude, and solvent) and HPH (Pressure, number of passes, and solvent). Additionally, a second-order polynomial fit was performed to fit the experimental data by the green method. HPH method was the most efficient extraction method under the conditions obtained of 100-400 MPa pressure power, 2-3 number of passes, and distilled water as solvent. Furthermore, the experimental extraction yields ranged from 4.4-5.7 mg of PE g-1 of dry biomass under the optimal extraction conditions (400 MPa; 2 passes), which agreed with the predictive yield of 4.6-5.5 mg g-1 DW. The ultrafiltration membrane used for the separation process for both methods exhibited a rejection of R-phycoerythrin concentrated at 30 KDa. Furthermore, R-phycoerythrin showed a positive correlation between the antioxidant capacity (ORAC) in the best-selected extractions. After the extraction, the same pattern was observed in Chlorophyll a and total carotenoids with DPPH. Thus, it was an attractive non-aggressive extraction alternative with biological activity of interest for formulating biotechnological products for the food industry is suggested.

Impact of High-Pressure Homogenization on the Cell Integrity of Tetradesmus obliquus and Seed Germination.

Microalgae have almost unlimited applications due to their versatility and robustness to grow in different environmental conditions, their biodiversity and variety of valuable bioactive compounds. Wastewater can be used as a low-cost and readily available medium for microalgae, while the latter removes the pollutants to produce clean water. Nevertheless, since the most valuable metabolites are mainly located inside the microalga cell, their release implies rupturing the cell wall. In this study, Tetradesmus obliquus grown in 5% piggery effluent was disrupted using high-pressure homogenization (HPH). Effects of HPH pressure (100, 300, and 600 bar) and cycles (1, 2 and 3) were tested on the membrane integrity and evaluated using flow cytometry and microscopy. In addition, wheat seed germination trials were carried out using the biomass at different conditions. Increased HPH pressure or number of cycles led to more cell disruption (75% at 600 bar and 3 cycles). However, the highest increase in wheat germination and growth (40–45%) was observed at the lowest pressure (100 bar), where only 46% of the microalga cells were permeabilised, but not disrupted. Non-treated T. obliquus cultures also revealed an enhancing effect on root and shoot length (up to 40%). The filtrate of the initial culture also promoted shoot development compared to water (21%), reinforcing the full use of all the process fractions. Thus, piggery wastewater can be used to produce microalgae biomass, and mild HPH conditions can promote cell permeabilization to release sufficient amounts of bioactive compounds with the ability to enhance plant germination and growth, converting an economic and environmental concern into environmentally sustainable applications.

Comparison of high pressure homogenization, selective thermal denaturation and glycosylation on textural properties of green soybean (Glycine max)tofu by TOPSIS analysis

Impacts of high pressure homogenization (HPH), selective thermal denaturation (STD) and glycosylation (GLY) on textural properties, water holding capacity (WHC) and yield of green soybean tofu were compared and optimal treatment was obtained by TOPSIS analysis. Firstly, the increase in HPH pressure and cycle numbers enhanced the quality of green soybean tofu. Hardness, WHC and yield of HPH-treated tofu (60 MPa, four cycles) were increased by 48.3%, 17.0%, 6.7%, respectively, compared with those untreated. Moreover, STD condition (85 °C, 10min) made hardness, WHC and yield of green soybean tofu increased by 109%, 15.4%, 21.6%, respectively. Accordingly, hardness and WHC of green soybean tofu increased and afterward declined (P < 0.05) with glucose from 0 to 2.5%, whereas it significantly increased with GLY temperature from 80 to 100 °C. Finally, through TOPSIS multi-index evaluation, STD treatment (85 °C, 10 min) was selected as the most effective way to improve textural characteristics, WHC and yield of green soybean tofu. Therefore, our research provides the optimum processing guidance for producing high-quality edible tofu, expanding the soybean products market.

Physicochemical properties and rheological behavior of chrysanthemum powder made by superfine grinding and high pressure homogenization

AbstractThe effects of superfine grinding on the properties of chrysanthemum powder (CP) and high pressure homogenization (HPH) on the rheological properties of CP suspensions were investigated. Superfine grinding reduced particle size to a D50 of 28.45 μm. Instantaneous flow function and wall friction tests demonstrated that superfine ground CP had poor flowability and was more cohesive than more coarsely ground samples. Superfine grinding increased thermal stability and reduced the crystallinity of CP. After HPH treatment, the apparent viscosity and consistency coefficient (k, from 0.027 ± 0.005 to 1.847 ± 0.472) of CP suspension was significantly improved (p &lt;.05), indicating that HPH treatment increased the consistency and reduced the fluidity of CP suspensions. As the HPH pressure increased from 40 to 120 MPa, the storage modulus (G') and loss modulus (G") of the CP suspensions increased, which fitted well with the Power Law model (R2 &gt;.961). The CP suspension is a non‐Newtonian fluid with shear thinning behavior. Flow and rheological characteristics are measured under different consolidation pressures and HPH pressures, respectively. These findings reveal the potential application of superfine grinding and high pressure homogenization in the development of CP.Practical applicationThe use of superfine grinding and high pressure homogenization to process CP has broad application prospects, such as the preparation of micronized Chinese medicinal powders in the pharmaceutical industry and functional foods and beverages in the food industry.

Effect of high pressure homogenization on sugar beet pulp: Physicochemical, thermal and structural properties

The effect of high pressure homogenization (HPH) on the physicochemical, thermal and structural properties of sugar beet pulp (SBP) was investigated in this study. The SBP suspensions (2 g/100 g) were homogenized under different HPH pressure from 0 to 100 MPa. The results indicated that the mean particle size of SBP suspensions increased after HPH treatment at 5 MPa and decreased as the HPH pressure increased from 5 to 100 MPa. The soluble dietary fiber content increased and insoluble dietary fiber decreased as the HPH pressure increased from 5 to 25 MPa. The HPH treatments under 50 and 100 MPa decreased the total dietary fiber and soluble dietary fiber contents. The water and oil holding capacities increased with the increment of HPH pressure ranged from 0 to 100 MPa. The HPH treatment increased the transition temperature and decreased the melting peak temperature. Fourier transform infrared spectra indicated that HPH had little effect on main components of SBP but decreased the intensity of characteristic bands in absorbance. The X-ray diffraction patterns showed similar tendency and HPH treatment decreased the crystallinity index. In addition, microscopic pictures revealed that homogenized samples gradually stretched and showed flake-like structures after HPH treatment.

High-pressure homogenization thinned starch paste and its application in improving the stickiness of cooked non-glutinous rice

Improving the stickiness of non-glutinous rice is an important strategy in scaling out the applications of rice foods, e.g. Sushi, Zongzi etc. In this study, the effect of HPH treatments on the transparency and molecular structure of starch and the stickiness of cooked non-glutinous rice were investigated by cooking rice with high-pressure homogenization (HPH) thinned starch paste. HPH treatments significantly increased the light transmittance of starch paste from 7.6% to 81.3% (p < 0.05). The average molecular size of corn starch is reduced with HPH pressure increasing while HPH treatment significantly decreases the content of starch chains with degree of polymerization (DP) 37–100 and DP 2000–20000 (p < 0.05). By cooking rice with the HPH treated starch paste solutions, the stickiness of non-glutinous rice is significantly increased (p < 0.05) and the HPH treatment with 60 MPa and 3% starch concentration is the optimal condition in increasing rice stickiness. This study paves a way in improving the stickiness of non-glutinous and a great potential in amplifying the applications of rice products by modifying rice stickiness attribute.

Effect of high pressure homogenization on sugar beet pulp: Rheological and microstructural properties

The effect of high pressure homogenization (HPH) on the rheological and microstructural properties of sugar beet pulp (SBP) suspensions was investigated. The results showed that the mean particle size of SBP suspensions increased from 43.07 to 70.77 μm at the pressure of 5 MPa and then decreased from 72.09 to 38.28 μm as the pressure increased from 15 to 100 MPa. The steady state behavior of homogenized SBP suspensions could be well fitted by the Power Law model (R2 ˃ 0.998) and consistency coefficient (K) increased with the increased HPH pressure. The HPH treatment enhanced both storage modulus (G′) and loss modulus (G″) of SBP suspensions. Untreated SBP suspension (0 MPa) could be classified as type Ⅰ (strain shinning) and transformed to type Ⅲ (weak strain overshoot) after HPH treatment. Large amplitude oscillatory shear analysis revealed that as the pressure increased to 50 and 100 MPa, the trend of I3/1 and I5/1 with strain showed a transition from a “soft gel” to “hard gel”. Confocal laser scanning micrographs showed that the red-stained areas of pectin substances increased as the pressure increased from 0 to 50 MPa, which further confirmed the cell wall breaking effect of HPH on SBP particles.

Effect of high-pressure homogenization on gelling and rheological properties of soybean protein isolate emulsion gel

The effect of high-pressure homogenization (HPH) on the functional properties of soy protein isolate (SPI) emulsion gel was studied in this paper. The results show that, with the increase of HPH pressure, the strength of SPI emulsion gel raised from G’ = 291 Pa (5 MPa) to G’ = 528 Pa (80 MPa). The higher HPH pressure also reduced the frequency dependence of the SPI emulsion gel (n’ descended from 0.105 to 0.065). However, there is no monotonous relationship between the recovery rate and the HPH pressure. Water holding capacity of the emulsion gel increased from 87.7% to 91.4% (when the pressure rose from 5 to 20 MPa), and then remain stable (when the pressure rose from 20 to 80 MPa). The microscopic fractal dimension of SPI emulsion gel ranges from 2.96 to 2.99. Generally speaking, at a higher HPH pressure, the emulsion tends to form a more stable isotropic network gel structure.

Effects of high-pressure homogenization on physical and thermal properties of citrus fiber

In this study, the adsorption and morphology properties of the dehydrated citrus fiber dispersion produced by high-pressure homogenization (90 MPa and 160 MPa) were investigated, and the microstructure and thermal properties were further analyzed for their alteration of physical properties. The fiber dispersions were homogenized at two pressure levels (90 MPa and 160 MPa). The average particle size of citrus fiber reduced significantly after the high-pressure homogenization (HPH) process. Meanwhile, the HPH process significantly increased the adsorption properties both for water and oil. Citrus fiber particles changed from spherical to multi-branched flake-like structure after HPH. On the molecular level, it is shown that the main components of citrus fiber were transformed and the crystal structure was changed after the HPH. In addition, the glass transition temperature (Tg) of the citrus fiber reduced with the increase of HPH pressure, with the lowest Tg of samples dropped from 71.14 ± 1.21 to 51.08 ± 1.33 °C after HPH.

Effect of high-pressure homogenization on the extraction of sulforaphane from broccoli (Brassica oleracea) seeds

High-pressure homogenization (HPH) has the potential to improve the exaction yield of bioactive compound from food and food waste. This study investigated the use of HPH or microfluidization as an alternative assisted method for sulforaphane extraction from raw broccoli seeds. The mean particle size, morphological characteristics, and extraction yields of all samples processed at different HPH pressure levels (3000-23,000 psi) and passes (1–5) were examined. After HPH, the particle size of broccoli seeds was reduced 2–10 times and the particle size distribution pattern also changed from bimodal to unimodal with increasing pressures and number of passes. The highest sulforaphane content obtained with HPH at 5000 psi and 5 passes was 2199 μg sulforaphane/g broccoli seeds, which is 3 times more than the control one. Particular interest was given to the relationship between sulforaphane yield and particle size. Generally, the extraction yield increased with decreasing particle size; however, excessive size reduction did not necessarily result in significant increase in sulforaphane content. In addition, the pressure is not the higher the better (<8000 psi, 55 MPa). Scanning electron morphology (SEM) also confirmed that cell rupture and cell walls breakage occurred during the HPH process.

Systematic Development and Optimization of an in-situ Gelling System for Moxifloxacin Ocular Nanosuspension using High-pressure Homogenization with an Improved Encapsulation Efficiency.

The objective of this study was to apply Quality by Design (QbD) principles on process parameter optimization for the development of hybrid delivery system (combination of (SLNs) and In-situ gelling system) for hydrophilic drug Moxifloxacin Hydrochloride (MOX) to achieve its controlled delivery, which otherwise may not be possible through single type of technology. Risk assessment studies were carried out to identify probable risks influencing CQAs on the product. In design of experiments (DoE), the process parameters (independent variables) i.e., chiller temperature X1, High Pressure Homogenization (HPH) pressure X2, and HPH cycles X3 were optimized using a three-factor two level face-centered central composite design to streamline the influence on three responses, namely encapsulation efficiency Y1, particle size Y2 and outlet temperature Y3. Independent and dependent variables were analyzed to establish a full-model second-order polynomial equation. F value is used to confirm the omission of insignificant parameters/interactions to derive a reduced-model polynomial equation to predict the Y1, Y2 and Y3 for optimized moxifloxacin in situ gelled nanosuspension. Desirability plots showed the effects of X1, X2, and X3 on Y1, Y2 and Y3, respectively. The design space is generated to obtain optimized process parameters viz. chiller temperature (-5°C), HPH pressure 800 - 900 bar and 8 cycles that resulted in nanosuspension with ≈ 500 nm size, encapsulation efficiency >65% and final formulation temperature <23°C that were necessary to maintain the formulation in a liquid state. Quality by Design (QbD) approach is recently been encouraged by regulatory bodies to improve the quality of the finished product. This approach proved to be a useful tool in the development of robust nanosuspension of highly hydrophilic drugs with improved efficiency. Results indicate that such hybrid gel systems can be used to control the release of SLNs from application site and prolong their action in a sustained manner.

Influence of High Pressure Homogenization on Free Fatty Acid Formation in Nannochloropsis sp.

Although Nannochloropsis lipids have many potential applications in biofuels and high value products, their extraction is limited by the tough cell wall of this species. High pressure homogenization (HPH) can be used to improve the extraction efficiency. However, this can possibly induce free fatty acid (FFA) formation, which has a negative impact on oil quality. In this study, the HPH pressure and number of passes are varied in a full factorial design to study the impact of these factors on FFA formation, lipid extraction efficiency, and fatty acid profile. It is found that substantial amounts of FFA are formed during HPH treatments when compared to the non‐disrupted biomass. The FFA formation is mostly influenced by the number of passes applied, which can explained by a combined effect of the longer time residing as a wet paste and the temperature increase during the treatment. The large amount of FFA formed during the least intensive HPH treatment is in contrast with only a slight increase of the lipid extraction efficiency, which indicates that minor damage to the cell is sufficient to induce lipolytic reactions. The relative fatty acid profile after HI extraction is not influenced by the HPH treatment.Practical Applications: These results have important implications for the application of HPH treatments on microalgae with the aim to improve the extraction efficiency. It is demonstrated that more intensive HPH treatments with several passes are necessary to improve the extraction efficiency of Nannochloropsis lipids. However, the least intensive HPH treatments (1 pass at 400 bar) already induced the formation of substantial amounts of FFA. Consequently, to produce a biomass with a low FFA content and a high lipid extraction efficiency, a compromise should thus be made.High pressure homogenization (HPH) can efficiently be used to improve the extraction effiency of interesting compounds from Nannochloropsis cells. However, this treatment also induces the formation of free fatty acids (FFA), which have a negative influence on oil quality.

Disruption and molecule degradation of waxy maize starch granules during high pressure homogenization process

The mechanism underlying the fragmentation of waxy maize starch (WMS) granules during high-pressure homogenization (HPH) was studied and the results were interpreted in terms of granular and molecular aspects. The diameter of disrupted starch granules decreased exponentially with increasing HPH pressure, but decreased linearly with increasing of HPH cycles. Scanning electron microscopy revealed a cone-like inside-out disruption pattern through the channels that resulted in separation of blocklets fragments or starch fragments. The Mw of amylopectin was reduced by ∼half following treatment at 150MPa with two cycles, or at 100MPa for eight cycles, and the decrease was in accordance with the disruption of starch granules. This indicated that amylopectin was “protected” by blocklets, and the disruption of WMS granules mainly occurred close to the linkage among blocklets. Increasing the HPH pressure appeared to be more effective for breaking starch granules than increasing the number of HPH cycles.