High Hydrostatic Pressure Treatment Research Articles

The impact of high hydrostatic pressure treatment time on the structure, gelatinization and thermal properties and in vitro digestibility of oat starch

As a non-thermal processing technology, high hydrostatic pressure (HHP) can be used for starch modification without affecting the quality and flavour constituents. The effect of HHP on starch is closely related to the treatment time of HHP. In this paper, we investigated the impacts of HHP treatment time (0, 5, 10, 15, 20, 25, 30 min) on the microstructure, gelatinization and thermal properties as well as in vitro digestibility of oat starch by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, 13 C NMR and differential scanning calorimeter. Results showed that 5-min HHP treatment led to deformation and decreases in short-range ordered and double-helix structures of oat starch granules, and further extending the treatment time to 15 min or above caused the formation of a gelatinous connection zone, increase of particle size, disintegration of short-range ordered and double-helix structures, and crystal structure change from A type to V type, indicating gelatinization occurred. Longer treatment time also resulted in the reduction in both the viscosity and the stability of oat starch. These indicated that HHP treatment time greatly influenced the microstructure of oat starch, and the oat starch experienced crystalline destruction (5 min), crystalline disintegration (15 min) and gelatinization (> 15 min) during HHP treatment. Results of in vitro digestibility showed that the rapidly digestible starch (RDS) content declined first after treatment for 5 to 10 min then rose with the time extending from 15 to 30 min, indicating that longer pressure treatment time was unfavourable to the health benefits of oat starch for humans with diabetes and cardiovascular disease. Therefore, the 500-MPa treatment time for oat starch is recommended not more than 15 min. This study provides theoretical guidance for the application of HHP technology in starch modification and development of health foods. This paper investigated the impacts of HHP treatment time (0, 5, 10, 15, 20, 25, 30 min) on the microstructure, gelatinization and thermal properties as well as in vitro digestibility of oat starch by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, 13 C NMR and differential scanning calorimeter. The results provided theoretical guidance for the application of HHP technology in starch modification and development of health foods.

Influence of high-pressure processing and varying concentrations of curing salts on the color, heme pigments and oxidation of lipids and proteins of Iberian dry-cured loins during refrigerated storage

The effect of high hydrostatic pressure (HHP) on reduced ingoing amounts of both nitrate and nitrite (150, 75, 37.5, and 0 mg/kg of each curing salt) dry-cured loins during the refrigerated storage was studied. Changes in instrumental color, nitrosylmyoglobin (NOMb) and Zinc protoporphyrin (ZnPP) contents, and lipid and protein oxidation were analyzed. The reduction of ingoing amounts of nitrate/nitrite in loins decreased the redness (CIE a*) and NOMb content in the dry-cured products while increased the ZnPP content and the lipid oxidation measured as TBA-RS. In contrast, the diminution of ingoing curing agents up to 37.5 mg/kg NO3−/NO2− did not significantly affect color, lipid, and protein oxidation over refrigerated storage. In comparison to control samples, HHP increased lightness (CIE L*) and the extent of lipid oxidation, meanwhile reduced protein carbonyl and thiol contents over storage. Neither NOMb nor ZnPP contents were affected by HHP treatment over storage time. Therefore, the reduction of ingoing amounts up to 37.5 ppm NOx together with a pressurization treatment at 600 MPa 7 min controlled lipid and protein oxidation.

Effects of high hydrostatic pressure on the structure and retrogradation inhibition of oat starch

SummaryAs a non‐thermal processing technology, high hydrostatic pressure (HHP) can be used for starch modification without affecting the quality and flavour constituents. The effect of HHP on starch is closely related to the treatment pressure of HHP. In this paper, we investigated the impacts of HHP treatment pressure (0, 100, 200, 300, 400, 500, 600 MPa) on the microstructure and retrogradation characteristics of oat starch, established the retrogradation kinetic model and elaborated the mechanism of HHP treatment inhibiting the retrogradation of oat starch. Results show that HHP treatment caused the microstructure of oat starch experienced crystallisation perfection (100–300 MPa), crystallisation destruction (400 MPa), crystallisation disintegration and gelatinisation (500–600 MPa). Results of oat starch retrogradation showed that, after treated at 500 MPa for 15 min, the recrystallisation rate of oat starch was reduced, the formation of nuclei at the early stage of oat starch retrogradation suppressed and its nucleation mode was changed from instantaneous to spontaneous, otherwise, the mobility of water in oat starch gel system reduced. Therefore, 500 MPa treated for 15 min can inhibits the retrogradation of oat starch. This study provides theoretical guidance for the application of HHP technology in starch modification and food processing.

The characteristics of soybean protein isolate obtained by synergistic modification of high hydrostatic pressure and phospholipids as a promising replacement of milk in ice cream

In this study, soybean protein isolate (SPI) was modified by high hydrostatic pressure (HHP) treatment and compounded phospholipids, and used to replace milk to produce a low-fat vegetable ice cream. We compared changes in the structure and functional properties of HHP- or phospholipid-modified SPI (HSPI, SPI-PLW), phospholipid-modified HSPI (HSPI-PLW), HHP-modified SPI-PLW (H(SPI-PLW)), and SPI, and their secondary structure, ζ point, average particle size, and scanning electron microscopy (SEM) images were recorded. The results showed that the secondary structure of the protein was significantly changed following HHP treatment. The addition of phospholipids increased the surface charge of SPI-PLW, HSPI-PLW, and H(SPI-PLW), and the average particle size increased regardless of the modification method. HSPI-PLW presented the best functional characteristics. Compared with SPI, the nitrogen soluble index was increased by 163.40%, emulsifying activity and emulsion stability were increased by 74.98 and 25.30%, respectively, and foaming and bubble stability were increased by 233.33 and 95.02%, respectively. In addition, the expansion and melting rates of both H (SPI-PLW) and HSPI-PLW ice creams were significantly improved. Sensory evaluation revealed good acceptability, and the overall quality was close to that of milk ice cream.

High hydrostatic pressure treatment induced microstructure changes and isothiocyanates biosynthesis in kale

Effects of high-pressure processing (HPP) on the myrosinase activity, glucosinolate (GLS) content, isothiocyanate (ITC) conversion rate, color, and bacterial count of kale leaves were investigated. Thermal process at 100 °C were used as negative control groups. The sample processed at 600 MPa exhibited the highest myrosinase activity and ITC conversion rate of 70.4%, while the GLS content was significantly lower than those in the raw and the thermally processed samples. However, processing of the samples at elevated temperatures results in gradual loss of myrosinase activity. SEM images showed that HPP induces irregular crushing damage to the veins, edges, and surfaces of the leaves, thereby promoting the conversion process in the myrosinase–GLS–ITC system. Additionally, HPP caused less significant color change of the kale leaves than thermal treatment. HPP achieved the same level of pasteurization as thermal treatment in terms of bacterial count.

Effect of high hydrostatic pressure treatment on the formation and in vitro digestion of Tartary buckwheat starch/flavonoid complexes

Tartary buckwheat is rich in flavonoids and starch, and the interaction between these two components affects the structural and digestive properties of the food product. In this study, we analyze the effects of thermal gelatinization (GT), ultrasonic treatment (UT), and high hydrostatic pressure treatment (HHP) on the compounding degree of starch and flavonoids in Tartary buckwheat and on the properties of the starch/flavonoid complex system (HBS-BF). Based on scanning electron microscope (SEM) and X-ray diffraction (XRD) analyses, the surface of HBS-BF becomes rough after GT or UT, and many small cavities appear. Comparatively, HHP treatment is less damaging to HBS-BF. Moreover, HHP maintains the original A-type crystal morphology of buckwheat starch in HBS-BF, whereas GT and UT change to V-type. Repeated HHP further improves the crystallinity and digestion resistance of HBS-BF. According to the recorded Fourier transform infrared (FT-IR) spectra, HBS-BF by different methods does not exhibit new covalent bonds.Practical application: The results reported herein promote the application of Tartary buckwheat starch and flavonoids in the food industry by providing a theoretical basis for the development of starch anti-digestion mechanisms and the preparation of resistant starch.

Effect of high hydrostatic pressure on chlorophyll/soybean protein isolate interaction and the mixtures properties

Chlorophyll (Chl) is highly susceptible to degradation due to food processing (especially thermal processing), resulting in color changes in food. This study was designed to examine the interaction between Chl and soybean protein isolate (SPI) after high hydrostatic pressure (HHP) treatment from fluorescence spectroscopy, SPI structure changes, and physical stability of mixtures as well as thermal stability perspectives. Based on fluorescence quenching analysis, binding constants (Ka) and number of binding sites (n) were calculated. At 100 MPa, the Ka (13.7670 × 105 L/mol) of SPI was the largest, forming a strong interaction, but the results at 300 MPa were completely different. The surface hydrophobicity (H0) of SPI significantly decreased due to the incorporation of Chl at 100 MPa, changing the tertiary and quaternary structures of SPI. Molecular docking showed that phytyls of Chl penetrated into the hydrophobic area of SPI and interacted with it, and porphyrin rings were mainly bound to regions with strong polarity in SPI. The particle size and polydispersity index (PDI) of mixtures were the smallest at 100 MPa, presenting a more compact and stable structure. The samples after HHP treatment were then treated at 80 °C. Chl showed a good color stability (higher retention and -a* values) at 100 MPa and 200 MPa with smaller changes in particle size and PDI value after thermal treatment. Altogether, the Chl-SPI interaction at high pressures appeared to have a positive effect on the stability of Chl and Chl-SPI mixtures.

High hydrostatic pressure treatment reduces the potential antigenicity of β-conglycinin by changing the protein structure during in vitro digestion.

High hydrostatic pressure (HHP) treatment has been used to alleviate the allergenicity of soybeans, but there are little data about the potential antigenicity of β-conglycinin after HHP treatment. We examined the effects of HHP treatment on the antigenicity and structure of β-conglycinin. When the pressure was 300 and 400 MPa, HHP treatment reduced the immunoglobulin (Ig)G binding capacity of β-conglycinin, while its IgE binding capacity did not change significantly. After in vitro digestion, both the IgE and IgG binding of β-conglycinin was obviously inhibited after HHP treatment at 400 MPa and 60 °C, although its binding capacity with linear epitope antibodies increased. Moreover, HHP treatment changed the secondary structure of β-conglycinin, the content of α-helix and random coils increased, while the β-sheet and β-turn decreased. After HHP treatment, the conformational structure was unfolded so that a large number of hydrophobic regions were exposed. HHP treatment alleviated the potential antigenicity of β-conglycinin by modifying its structure, which facilitated in vitro digestion and destroyed epitopes. This research provides a new insight into the mechanism of HHP treatment that affects the sensitization of soy protein allergens. © 2022 Society of Chemical Industry.

Effect of high hydrostatic pressure on activity, thermal stability and structure of horseradish peroxidase

The mechanism of the high hydrostatic pressure (HHP) effect on horseradish peroxidase (HRP) is still unclear. The activity, thermal stability and structural changes of HRP after HHP treatments were studied in this work. Compared with the untreated sample, the enzyme activity reduces by 36% after 800 MPa processing. The results indicated that the conformation of the enzyme active center changes under pressure. Furthermore, HHP also changes the conformation of disulfide bonds and some secondary structures in HRP. These structural and conformational changes induce decreased activity. In addition, differential thermal scanning (DSC) results showed that the thermal denaturation temperature decreased from 103.74 °C to 85.78 °C after pressure treatment, suggesting HRP molecules formed large aggregates after pressure treatment. In this study, the interaction mechanism between pressure and enzyme was studied as well, and the results can provide some guidance for the application of HHP technology in fruit and vegetable products processing.

Effects of high hydrostatic pressure and thermal treatment on texture properties of pickled kohlrabi

The effects of high hydrostatic pressure (HHP, 400 MPa for 20 and 30 min) and thermal treatment (90 °C for 15 and 30 min) on the texture of pickled kohlrabi and their mechanisms were evaluated by in situ method, including low-field nuclear magnetic resonance, immunofluorescence, transmission electron microscopy, etc. Results showed that HHP could better maintain pickled kohlrabi texture than thermal treatment, with the samples showing higher hardness, springiness, moisture content, lower moisture freedom, and more uniform moisture distribution. Moreover, HHP significantly decreased the degree of esterification of pickled kohlrabi pectin, indicating the potential effectivity for Ca2+-based texture keeping additive. HHP caused no further damage on kohlrabi microstructure or pectin chain. However, damage of microstructure and loss of moisture significantly contributed to the texture loss of thermal-treated pickled kohlrabi, which revealed the necessity for microstructure protection and water holding during thermal processing to maintain pickled kohlrabi texture. These researches could provide guidance for better maintaining the texture of pickled vegetables during HHP and thermal processing.

Effect of high hydrostatic pressure treatment with room-temperature ionic liquid 1-ethyl-3-methylimidazolium acetate - dimethyl sulfoxide mixture on lipid extraction from Chlorella vulgaris

ABSTRACT In this study, Chlorella vulgaris (C. vulgaris) was immersed in a mixture of 1-ethyl-3-methylimidazolium acetate and dimethyl sulfoxide, and treated hydrostatically at 0.1-250 MPa. For the first time, the relationship between the amount of lipids and fatty acids and high hydrostatic pressure was investigated, as well as the relationship between the amount of fatty acids and the morphology of C. vulgaris cells after treatment. We found that the amount of lipids was maximized and the amount of fatty acids extracted was significantly higher following treatment at 50 MPa than at ambient pressure. The purity of the extracted fatty acids (the amount of fatty acids contained in the extracted lipids) was high following treatment at 200 and 250 MPa, and was about double that of the amount of fatty acids obtained using the Bligh & Dyer and Soxhlet extraction methods, which are typically used for lipid extraction.

Evaluation of Non-Thermal Decontamination Processes to Have the Equivalence of Thermal Process in Raw Ground Chicken.

The present study was aimed at examining the antibacterial effects of non-thermal decontamination processes, which are equivalent to thermal treatment, to ensure microbiological safety of raw ground chicken. Escherichia coli or Salmonella were inoculated into 25 g of raw ground chicken samples. The raw ground chicken samples were non-treated or treated with high hydrostatic pressure (HHP) at 500 MPa (1–7 min), light-emitting diode (LED) irradiation at 405 nm wavelength (30–120 min), and heat at 70°C, 90°C (1–60 min), and 121°C (1–15 min). E. coli and Salmonella cell counts were enumerated after treatments. Moreover, the color parameters of treated raw ground chicken were analyzed. HHP treatment reduced E. coli and Salmonella cell counts by more than 5 Log CFU/g and more than 6 Log CFU/g after 7 min and 1 min, respectively; these effects were equivalent to those of thermal treatment. However, LED irradiation reduced Salmonella cell counts by only 0.9 Log CFU/g after 90 min of treatment, and it did not reduce E. coli cell counts for 90 min. Compared with those of the non-treated samples, the ΔE (total color difference) values of the samples treated with HHP were high, whereas the ΔE values of the samples treated with LED irradiation were low (1.93–2.98). These results indicate that despite color change by HHP treatment, HHP treatment at 500 MPa could be used as a non-thermal decontamination process equivalent to thermal treatment.

A comparative study of the cloudy apple juice sterilized by high-temperature short-time or high hydrostatic pressure processing: shelf-life, phytochemical and microbial view

Cloudy apple juice (CAJ) is popular due to its potential health benefits and pleasant flavor. However, the common used sterilization methods of CAJ by High hydrostatic pressure (HHP) or high-temperature short time (HTST) still showed many inadequacies. The present work studied the impact of HHP (400MPa/10 °C/10 min) and HTST (98 °C/50s) on CAJs made from a new cultivar Changfu 2 planted in Loess plateau area. We comparatively evaluated the microbes inactivation, enzymatic activity, phytochemical parameters, and sensory quality after the HHP and HTST treatment and during the cold storage (4 °C). Results showed that during the cold storage, both HHP and HTST treated CAJ showed a declining trend in sensory attributes like aroma, taste and overall acceptability. HTST showed a higher killing rate of bacteria, and the CAJ was detected a higher diversity of microorganisms (expressed as OTU) during the cold storage. At the end of shelf-life, Rickettsia, oxyphotobacteria, and pseudomonas were detected as the dominant genera in both HHP and HTST treated CAJs. Spearman bivariate correlate analysis determined the relationship between the bacterial profiles and enzymatic activity, phytochemical parameters, and sensory quality after the HHP and HTST treatment.

Anti-inflammatory and intestinal microbiota modulation properties of high hydrostatic pressure treated cyanidin-3-glucoside and blueberry pectin complexes on dextran sodium sulfate-induced ulcerative colitis mice.

This study investigated the anti-inflammatory effects of cyanidin-3-glucoside (C3G) and blueberry pectin (BP) complexes on mice with dextran sodium sulfate (DSS)-induced colitis before and after high hydrostatic pressure (HHP) treatment. Real-time polymerase chain reaction (RT-PCR), western blotting, and 16S rDNA sequencing were used to study the expression of inflammation-related factors, activation of signal pathway-related proteins, and changes in the intestinal flora in ulcerative colitis (UC) mice. The results showed that HHP-treated C3G-BP complexes significantly relieved diarrhea and blood loss in the stool of UC mice and alleviated colon shortening. The potential mechanism of action involved reduction in intestinal oxidative stress mRNA expression of pro-inflammatory factors, improvement in anti-inflammatory factor levels, inhibition of the NF-κB signaling pathway, increased protein levels of Bcl-2/Bax and caspase-3/cleaved caspase-3 genes, and improved gut microbiota composition. Compared with other experimental groups, the HHP-treated C3G-BP complexes group exhibited the best anti-inflammatory effect on DSS-induced UC mice. The results may provide new ideas for using C3G-BP complexes for treating UC and help develop better processing methods.

Effect of High Hydrostatic Pressure Treatment Combined with Alkaline Electrolyzed Water on the Injury and Growth Characteristics of Bacterial Spores.

The characteristics of growth and injury of Bacillus subtilis spores whose heat resistance was reduced by the treatment of high hydrostatic pressure processing (HPP) combined with/without alkaline electrolyzed water (AlEW) were investigated. The delay in the lag phase of growth curve observed when used in combination with AlEW, especially at 50 MPa or less, and was prolonged by about 4 to 6 hours. However, the effects of temperature and time during treatment on the lag phase were not significantly different between solo-HPP and in combination with AlEW. The injury characteristics of the treated bacterial spores were evaluated by using antibiotics (penicillin G, rifampicin and chloramphenicol) supplemented trypticase soy broth. In the chloramphenicol supplemented TSB, although the lag phase of bacterial spores treated by HPP with AlEW was not prolonged as compared with the normal-TSB, the decrease in growth rate during logarithmic phase and increase in maximum growth amount were observed. This result could suggest due to a damage by combined treatment of HPP with AlEW such as the inhibition of protein synthesis. Furthermore, the combined treatment with AlEW increased the catalase activity by 1.45, 1.63 and 4.25 times at 30, 80 and 100 MPa, respectively, as compared with solo-HPP, therefore the combined treatment could cause high oxidative stress on bacterial spores.

Effect of High Hydrostatic Pressure Treatment on Urease Activity and Inhibition of Fishy Smell in Mackerel (Scomber japonicus) during Storage.

In this study, the physicochemical changes related to fishy smell were determined by storing high hydrostatic pressure (HHP)-treated mackerel (Scomber japonicus) meat in a refrigerator for 20 days. The inhibition of crude urease activity from Vibrio parahaemolyticus using HHP treatment was also investigated. The mackerel meat storage experiment demonstrated that production of trimethylamine (TMA) and volatile basic nitrogen (VBN), the main components of fishy smell, was significantly reduced on the 20th day of storage after the HHP treatment compared to the untreated mackerels. The results demonstrated that the increased ammonia nitrogen rates in the 2000, 3000, and 4000 bar, HHP-treated groups decreased by 23.8%, 23.8%, and 31.0%, respectively, compared to the untreated groups. The enzyme activity of crude urease was significantly reduced in the HHP-treated group compared to that in the untreated group. Measurement of the volatile organic compounds (VOCs) in mackerel meat during storage indicated that the content of ethanol, 2-butanone, 3-methylbutanal, and trans-2-pentenal, which are known to cause off-flavor due to spoilage, were significantly reduced by HHP treatment. Collectively, our results suggested that HHP treatment would be useful for inhibiting the activity of urease, thereby reducing the fishy smells from fish and shellfish.

Synergetic Inactivation Mechanism of Protocatechuic Acid and High Hydrostatic Pressure against Escherichia coli O157:H7.

With the wide application of high hydrostatic pressure (HHP) technology in the food industry, safety issues regarding food products, resulting in potential food safety hazards, have arisen. To address such problems, this study explored the synergetic bactericidal effects and mechanisms of protocatechuic acid (PCA) and HHP against Escherichia coli O157:H7. At greater than 200 MPa, PCA (1.25 mg/mL for 60 min) plus HHP treatments had significant synergetic bactericidal effects that positively correlated with pressure. After a combined treatment at 500 MPa for 5 min, an approximate 9.0 log CFU/mL colony decline occurred, whereas the individual HHP and PCA treatments caused 4.48 and 1.06 log CFU/mL colony decreases, respectively. Mechanistically, membrane integrity and morphology were damaged, and the permeability increased when E. coli O157: H7 was exposed to the synergetic stress of PCA plus HHP. Inside cells, the synergetic treatment additionally targeted the activities of enzymes such as superoxide dismutase, catalase and ATPase, which were inhibited significantly (p ≤ 0.05) when exposed to high pressure. Moreover, an analysis of circular dichroism spectra indicated that the synergetic treatment caused a change in DNA structure, which was expressed as the redshift of the characteristic absorption peak. Thus, the synergetic treatment of PCA plus HHP may be used as a decontamination method owing to the good bactericidal effects on multiple targets.

Efficient Decellularization by Application of Moderate High Hydrostatic Pressure with Supercooling Pretreatment.

Decellularized tissues are considered superior scaffolds for cell cultures, preserving the microstructure of native tissues and delivering many kinds of cytokines. High hydrostatic pressure (HHP) treatment could remove cells physically from biological tissues rather than chemical methods. However, there are some risks of inducing destruction or denaturation of extracellular matrices (ECMs) at an ultrahigh level of HHP. Therefore, efficient decellularization using moderate HHP is required to remove almost all cells simultaneously to suppress tissue damage. In this study, we proposed a novel decellularization method using a moderate HHP with supercooling pretreatment. To validate the decellularization method, a supercooling device was developed to incubate human dermal fibroblasts or collagen gels in a supercooled state. The cell suspension and collagen gels were subjected to 100, 150, and 200 MPa of HHP after supercooling pretreatment, respectively. After applying HHP, the viability and morphology of the cells and the collagen network structure of the gels were evaluated. The viability of cells decreased dramatically after HHP application with supercooling pretreatment, whereas the microstructures of collagen gels were preserved and cell adhesivity was retained after HHP application. In conclusion, it was revealed that supercooling pretreatment promoted the denaturation of the cell membrane to improve the efficacy of decellularization using static application of moderate HHP. Furthermore, it was demonstrated that the HHP with supercooling pretreatment did not degenerate and damage the microstructure in collagen gels.

High hydrostatic pressure processing of human milk preserves milk oligosaccharides and avoids formation of Maillard reaction products

High hydrostatic pressure (HHP) processing is a non-thermal method proposed as an alternative to Holder pasteurization (HoP) for the treatment of human milk. HHP preserves numerous milk bioactive components that are degraded by HoP, but no data are available for milk oligosaccharides (HMOs) or the formation of Maillard reaction products, which may be deleterious for preterm newborns. We evaluated the impact of HHP processing of human milk on 22 HMOs measured by liquid chromatography with fluorescence detection and on furosine, lactuloselysine, carboxymethyllysine (CML) and carboxyethyllysine (CEL) measured by liquid chromatography with tandem mass spectrometric detection (LC-MS/MS), four established indicators of the Maillard reaction. Human raw milk was sterilized by HoP (62.5°C for 30min) or processed by HHP (350MPa at 38°C). Neither HHP nor HoP processing affected the concentration of HMOs, but HoP significantly increased furosine, lactuloselysine, CML and CEL levels in milk. Our findings demonstrate that HPP treatment preserves HMOs and avoids formation of Maillard reaction products. Our study confirms and extends previous findings that HHP treatment of human milk provides safe milk, with fewer detrimental effects on the biochemically active milk components than HoP.

Structural and Emulsifying Properties of Soybean Protein Isolate-Sodium Alginate Conjugates under High Hydrostatic Pressure.

Soybean protein isolate (SPI) is a kind of plant derived protein with high nutritional value, but it is underutilized due to its structural limitations and poor functionalities. This study aimed to investigate the effects of high hydrostatic pressure (HHP) treatment on SPI and sodium alginate (SA) conjugates prepared through the Maillard reaction. The physicochemical properties of the conjugate synthesized under 200 MPa at 60 °C for 24 h (SPI–SA–200) were compared with those of the conjugate synthesized under atmospheric pressure (SPI–SA–0.1), SPI-SA mixture, and SPI. The HHP (200 MPa) significantly hindered the Maillard reaction. This effect was confirmed by performing SDS-PAGE. The alterations in the secondary structures, such as α-helices, were analyzed using circular dichroism spectroscopy and the fluorescence intensity was determined. Emulsifying activity and stability indices of SPI-SA-200 increased by 33.56% and 31.96% respectively in comparison with the SPI–SA–0.1 conjugate. Furthermore, reduced particle sizes (356.18 nm), enhanced zeta potential (‒40.95 mV), and homogeneous droplet sizes were observed for the SPI-SA-200 emulsion. The present study details a practical method to prepare desirable emulsifiers for food processing by controlling the Maillard reaction and improving the functionality of SPI.