High Pressure Processing Treatment Research Articles

Microscopical Evaluation of the Effects of High-Pressure Processing on Milk Casein Micelles.

The effect of different high-pressure processing (HPP) treatments on casein micelles was analyzed through scanning electron microscopy (SEM) and a particle size distribution analysis. Raw whole and skim milk samples were subjected to HPP treatments at 400, 500 and 600 MPa for Come-Up Times (CUT) up to 15 min at ambient temperature. Three different phenomena were observed in the casein micelles: fragmentation, alterations to shape and agglomeration. The particle size distribution analysis determined that, as pressure and time treatment increased, the three phenomena intensified. First, the size of the casein micelles began to decrease as their fragmentation occurred. Subsequently, the casein micelles lost roundness, and their shape deformed. Finally, in the most intense treatments (higher pressures and/or longer times), the micelles fragments began to agglomerate, which resulted in an increase in their average diameter. Homogenization and defatting had no significant effect on the casein micelles; however, the presence of fat in whole milk samples was bioprotective, as the effects of the three phenomena appeared faster in treated skim milk samples. Through this study, it was concluded that the size and structure of casein micelles are greatly altered during high-pressure treatment. These results provide information that broadens the understanding of the changes induced on casein micelles by high-pressure treatments at room temperature.

Production of Marinated Chinese Lotus Root Slices Using High-Pressure Processing as an Alternative to Traditional Thermal-and-Soaking Procedure.

Marinated vegetables are traditional cold dishes with a long history and special flavor in the Chinese deli market. However, the traditional thermal-and-soaking (TS) procedure often results in unreproducible flavor quality properties of marinated vegetables and waste of brine and time in production. A novel green and sustainable technique, high-pressure processing (HPP), has caught the attention of the food industry. In this study, the effects of HPP and TS treatment on the visual, flavor, textural, and microbiological qualities of Chinese marinated lotus root slices were investigated. Compared to the TS products, lighter color, more varieties of volatile compounds, and crunchier texture were detected in the HPP products. Throughout the 4 °C, 25 °C, and 45 °C shelf life challenges, the HPP products retained their original color and crunchiness better than the TS ones, whereas no significant differences were found in total viable counts (TVCs) in the first half of the shelf lives. The Arrhenius model under the first-order reaction of TVC deterioration showed a good fit to the shelf life of the HPP marinated lotus root slices. This study demonstrates that HPP may assist in making the best use of brine in a more time-efficient manner to improve the visual, flavor, and textural quality of traditional Chinese marinated lotus root slices.

Pressure, shear, thermal, and interaction effects on quality attributes of pea–dairy protein colloidal dispersions

This study evaluated the feasibility of producing stable protein colloidal dispersion by blending dairy and pea proteins using ultra shear technology (UST). The influence of different UST process parameters (shear, temperature, pressure, and interactions) on the quality attributes of milk and pea protein suspensions of different protein proportions viz., milk:pea 1:0.5, 1:1, and 1:3 protein ratios was evaluated. UST treatment was performed at 400 MPa pressure and process temperatures of 40 and 70 °C. High pressure processing (HPP) at 400 MPa at 25 ± 2 °C and thermal treatment at 72 °C were conducted to study pressure-only and temperature-only effects. UST treatment reduced particle size at lower protein concentrations, however, aggregation of particles was observed above certain concentrations. For example, for the UST treatment at 40 °C, the mean particle size of milk:pea 1:0.5 and 1:3 protein suspensions were 2.48 and 23.06 μm, respectively. HPP and thermal treatments did not alter the particle size of the samples. UST treatment produced stable colloidal dispersions, with no sedimentation up to 15 days storage at 4 °C. UST treatment created homogenous stable dairy–pea protein blends, emulsions, or gel structures depending on treatment intensity and protein concentration. • Ultra-shear technology produced stable milk-pea protein blends without preservatives. • UST treatment increased viscosity of liquid foods as function of protein content. • UST modified the particle size characteristic and prevented sedimentation in blends.

229 Effects of High-Pressure Processing on Cooked Color and Sensory Attributes of Dark-Cutting Beef

Abstract Consumers often use meat color to determine doneness. A greater than normal pH of dark-cutting (DC) beef leads to less myoglobin denaturation, resulting in a persistent pink color that negatively impacts the perception of consumers of the cooked beef degree of doneness. High-Pressure Processing (HPP) is a non-thermal pasteurization technology to extend shelf-life. High pressure leads to denaturation of proteins and structural changes. There has been limited research and application utilizing HPP on fresh meat due to the pale color caused by HPP. The objective of the study was to evaluate different HPP levels on cooked steak color and sensory attributes of dark-cutting beef. Eight USDA Choice (mean pH = 5.5) and twelve DC (mean pH = 6.3) strip loins were obtained from a commercial packing plant within 1 d of harvest. Loins were cut into equal sections, vacuum packaged, and assigned HPP levels of 0 (no HPP), 300, 450, and 600 MPa with a holding time of 90 s. Following 48 hours of dark storage, loin sections were cut into 1.9 cm thick steaks, vacuum packaged, and randomly assigned to external cooked color, Warner-Braztler shear force (WBSF), and trained sensory panel. Steaks were cooked and then tempered to 71ºC. A trained sensory panel (n = 6) evaluated initial juiciness, sustained juiciness, tenderness, beef flavor intensity, and overall acceptability. The data were analyzed using the Glimmix Procedure of SAS. HPP treatment did not (P > 0.05) affect initial juiciness, sustained juiciness, beef flavor intensity, or overall acceptability. However, 600 MPa made DC steaks tougher and lighter in appearance (P < 0.05) than all other treatments. HPP treatments did not affect the a* and chroma of the external cooked color. In conclusion, low (300 MPa) and moderate (450 MPa) pressure levels did not have a negative impact on cooked steaks.

High pressure treatment and green tea extract synergistically control enteric virus contamination in beverages

Consumers are driving food production toward the use of natural preservatives and minimal processing technologies. Green tea extract (GTE) at low concentration could be combined with high pressure processing (HPP) for reduced treatment times and quality impact on foods in a hurdle concept for synergistic effects on foodborne viral pathogens, specifically human norovirus and hepatitis A virus (HAV). Viral inactivation by HPP (at 300, 400, and 500 MPa for 5 min) combined with 3.3 mg/mL aged-GTE was initially evaluated in buffer (PBS) against murine norovirus (MNV), a culturable human norovirus surrogate, and HAV. Furthermore, human norovirus inactivation was evaluated by the novel human intestinal enteroid system (HIE) and a capsid integrity binding assay (ISC-RT-qPCR). HPP treatment completely inhibits human norovirus GII.4 infectivity when applied at 500 MPa alone and at 400 MPa combined with aged-GTE. Additional experiments investigated the reduction of MNV and HAV infectivity in apple and horchata juices exposed to combined aged-GTE and HPP treatments. Results demonstrated that the addition of aged-GTE to the juices exposed to HPP significantly inactivated MNV and HAV at reduced holding pressure time. This synergistic effect of aged-GTE combined with HPP treatments represents a hurdle technology that could be exploited as a control measure to improve the food safety of beverages.

Evaluating the Quality of Cheese Slices Packaged with Na-Alginate Edible Films Supplemented with Functional Lactic Acid Bacteria Cultures after High-Pressure Processing.

The aim of the current study was to assess the efficacy of Na-alginate edible films as vehicles for delivering lactic acid bacteria (LAB) with functional properties to sliced cheeses, with or without high-pressure processing (HPP). A three-strain LAB cocktail (Lactococcus lactis Τ4, Leuconostoc mesenteroides Τ25 and Lacticaseibacillus paracasei Τ26) was incorporated into Na-alginate solution in a final population of 9 log CFU/mL. The cheese slices (without or with HPP treatment at 500 MPa for 2 min) were packaged in contact with the LAB edible films (LEFs), and subsequently vacuum packed and stored at 4 °C. Cheese slices without the addition of films, with or without HPP treatment, were used as controls. In all cases, microbiological, pH and sensory analyses were performed, while the presence and the relative abundance of each strain during storage was evaluated using Random Amplified Polymorphic DNA-PCR (RAPD-PCR). In addition, organic acid determination and peptide analysis were performed using high-performance liquid chromatography. The results showed that in cheeses without HPP treatment, the microbiota consisted mostly of mesophilic LAB and lactococci (>7.0 log CFU/g), while HPP caused a reduction in the indigenous microbiota population of approximately 1–1.5 log CFU/g. In the LEF samples, the populations of mesophilic LAB and lactococci were maintained at levels of >6.35 log CFU/g during storage, regardless of the HPP treatment. Sensory evaluation revealed that the LEF samples without HPP had a slightly more acidic taste compared to the control, whereas the HPP-LEF samples exhibited the best organoleptic characteristics. RAPD-PCR confirmed that the recovered strains were attributed to the three strains that had been entrapped in the films, while the strain distribution during storage was random. Overall, the results of the study are promising since the functional LAB strains were successfully delivered to the products by the edible films until the end of storage.

Effect of high-pressure processing in improving the quality of phosphate-reduced Irish breakfast sausages formulated with ultrasound-treated phosphate alternatives

This work examined the effects of High-pressure processing (HPP) treatment on pork meat subsequently used to generate three phosphate-reduced sausage formulations (1–3) containing ultrasound (US) treated apple pomace (AP) and coffee silverskin (CSS) ingredients as phosphate replacers and compared against control (traditional) sausage formulations. Results showed that HPP and formulations produced significant interactive (P < 0.05) positive changes in the water holding capacity (WHC), cook loss, emulsion stability values. Texture, colour, TBARS, and emulsion stability values for sausage formulations showed no significant interactive impacts. Overall comparison of treatment sausage formulations against control formulations with non-HPP treated meat showed that HPP improved overall sausage quality attributes, where sausage formulation 2 employing HPP-treated meat and US-treated AP and CSS was regarded as the optimal sausage formulation. In conclusion, there is potential to manufacture sausages with reduced-phosphate concentration using combined novel processing technologies and clean label ingredients such as AP and CSS.

Effects of high‐pressure processing on aquatic products with an emphasis on sensory evaluation

SummaryPrevious intensive research has described the molecular impacts of high‐pressure processing (HPP) on fish meat chemical composition, such as myofibril structural proteins, enzymes, myoglobin and lipids. This work aims to collect articles on sensory evaluation of pressure‐treated aquatic products to determine the practical effects of HPP on aquatic products, especially sensory properties, by comparing the differences between instrumental tests and sensory evaluation, between trained sensory assessors and consumers to guide and improve the processing of aquatic products. The findings indicate that laboratory devices such as spectrophotometers, texture analysers and electronic noses, and trained sensory assessors can detect pressure‐induced changes in appearance, texture, off‐odour, and flavour, such as discoloration, whitening, increased hardness and initiation of lipids oxidation. However, consumers did not perceive the pressure‐induced changes in odour and colour. Besides, consumers' attitudes towards pressure‐treated aquatic products are ambiguous in the range of 300 to 600 MPa, and professional testing and assessment fail to replace hedonic tests. In complex matrices of aquatic products, particular attention is needed to be paid to changes in sensory qualities dominated by microorganisms, endogenous enzymes and bioactive compounds after HPP treatment and throughout commercial storage.

Impacts of Thermal Processing, High Pressure, and CO2-Assisted High Pressure on Quality Characteristics and Shelf Life of Durian Fruit Puree.

Durian fruit puree (DFP) is a nutrient-dense food, but it has a short shelf life. Presently, little research has been undertaken on extending the shelf life of DFP. Hence, it is necessary to develop treatment methods that can prolong the shelf life of DFP. In the present study, thermal processing (TP), high-pressure processing (HPP), and CO2-assisted HPP (CO2 + HPP) treatments are used for DFP, and their influences on quality properties of DFP during storage (35 days, 4 °C) are investigated. Compared to other treatments, the CO2 + HPP treatment had a lower pressure and a shorter time to achieve the same effect of inactivating the microorganisms of DFP. During storage, CO2 + HPP treated DFP showed higher retention rates of sugars, total soluble solids, color, bioactive components, and antioxidant capacity in comparison with other treated DFPs. Moreover, after 35 days of storage, the microbial count of (CO2 + HPP)-treated DFP (3.80 × 103 CFU/g) was much lower than those of TP (4.77 × 105 CFU/g) and HPP (8.53 × 103 CFU/g)-treated DFPs. The results of this study reveal that CO2 + HPP treatment could not only better preserve the quality of DFP, but also effectively extend the shelf life of DFP, providing an effective method for the processing of DFP.

Study of Inducing Factors on Resveratrol and Antioxidant Content in Germinated Peanuts.

When peanuts germinate, bioactive compounds such as resveratrol (RES), γ-aminobutyric acid (GABA), isoflavones, and polyphenol compounds are generated. Peanut kernels were germinated in the dark for two days, and stimuli including soaking liquid, rice koji, high-pressure processing (HPP), and ultrasonic treatment were tested for their ability to activate the defense mechanisms of peanut kernels, thus increasing their bioactive compound content. The results of this study indicate that no RES was detected in ungerminated peanuts, and only 5.58 μg/g of GABA was present, while unstimulated germinated peanuts contained 4.03 µg/g of RES and 258.83 μg/g of GABA. The RES content of the germinated peanuts increased to 13.64 μg/g after soaking in 0.2% phenylalanine solution, whereas a higher GABA content of 651.51 μg/g was observed after the peanuts were soaked in 0.2% glutamate. Soaking peanuts in 5% rice koji produced the highest RES and GABA contents (28.83 µg/g and 506.34 μg/g, respectively). Meanwhile, the RES and GABA contents of HPP-treated germinated peanuts (i.e., treated with HPP at 100 MPa for 10 min) increased to 7.66 μg/g and 497.09 μg/g, respectively, whereas those of ultrasonic-treated germinated peanuts (for 20 min) increased to 13.02 μg/g and 318.71 μg/g, respectively. After soaking peanuts in 0.5% rice koji, followed by HPP treatment at 100 MPa for 10 min, the RES and GABA contents of the germinated peanuts increased to 37.78 μg/g and 1196.98 μg/g, while the RES and GABA contents of the germinated peanuts treated with rice koji followed by ultrasonic treatment for 20 min increased to 46.53 μg/g and 974.52 μg/g, respectively. The flavonoid and polyphenol contents of the germinated peanuts also increased after exposure to various external stimuli, improving their DPPH free radical-scavenging ability and showing the good potential of germinated peanuts as functional products.

Comparative effects of high hydrostatic pressure, pasteurization and nisin processing treatments on the quality of pickled radish

The quality of pickled vegetables is essentially safeguarded through various processing techniques. In this study the effects of high hydrostatic pressure processing (HPP), pasteurization (Pt), nisin, HPP + nisin and Pt + nisin on fermented radishes (Raphanus sativus L.) were compared. The effects of the different treatments on firmness were not immediately apparent, however, the HPP-treated pickles maintained their hardness best during storage. Compared with Pt, the non-thermal treatments were found to have moderate effects on the colors, both immediately after treatment and during storage. Both HPP and Pt reduced microbes, while HPP + nisin completely inactivated bacteria. The activities of polyphenol oxidase (PPO), peroxidase (POD) and pectin methylesterase (PME) were most inactivated via Pt, followed the action of HPP and then by that of the nisin. The sensory evaluation suggested that non-thermal pickled radish might be better accepted by consumers. Moreover, Pt had the strongest ability to reduce oxalic acid and sulfur-containing compounds, while the effects of HPP were relatively moderate, and HPP not only effectively reduced sulfur-containing compounds, but also helped to retain the favorable factors in the pickles. The findings of this study, thus, indicate that HPP could be a promising alternative to traditional pasteurization in the processing and storage of fermented vegetables.

Effects of High Pressure Processing and Thermal Treatment on the Interaction between α-Lactalbumin and Pelargonium-3-Glucoside.

In this study, high pressure processing (HPP) and thermal treatment were comparatively evaluated by examining their impacts on the binding behavior and interaction between α-lactalbumin (α-La) and pelargonium-3-glucoside (P3G) under pH values of 6.0, 7.4, and 8.0. The methods of circular dichroism spectroscopy, fluorescence quenching, dynamic light scattering, and molecular simulation were used to characterize the effects of processing-induced changes in protein structure, size distribution, binding site conformation, and residue charges on their binding characteristics between them. The results indicated that the thermal treatments significantly increased the quenching constants of the complex at pH 7.4/8.0 and 60/80 °C, as well as the accessible fraction of protein at pH 8.0/80 °C. Both HPP and thermal treatments increased the random coil content and showed limited effects on the α-helix and β-sheet contents of α-La and caused the aggregation of the complex to varying degrees. Molecular dynamic simulation and docking analyses revealed that the binding site of the complex did not change under different processing conditions, but the solvent-accessible surface area varied under different conditions.

Comparison of high‐pressure processing, ultrasound and heat treatments on the qualities of a gallic acid copigmented blueberry–grape–pineapple–cantaloupe juice blend

SummaryA blueberry–grape–pineapple–cantaloupe juice blend was copigmented with gallic acid (GA) firstly and treated by high‐pressure processing (HPP) at 550 MPa, 25 °C for 5 min, ultrasound (US) at 520 W, 40 °C for 10 min, or heat treatment (HT) at 90 °C for 3 min to determine their influence on its physicochemical qualities. The shelf lives of HPP‐, US‐ and HT‐juice blends were 72, 48 and 88 days, respectively. The total anthocyanins (ACs), ascorbic acid and total phenols content in juice blends treated by HPP, US and HT did not change immediately after treatment or during the first 16 days' storage. However, after the three treatments, the total ACs, ascorbic acid and total phenols content in juice blends decreased in the following order after 16 days: US &gt; HPP &gt; HT. The HPP‐ and US‐treated juices were superior to the HT‐treated juices regarding flavour, and in the preservation of more types and relative content of esters and aldehydes. In conclusion, GA improved the total ACs and ascorbic acid stability in the juice, while the flavour of the HPP‐ and US‐treated juices surpasses that of HT‐treated juice. Therefore, the HPP treatment was deemed to be more advantageous and had greater market potential for short‐term storage.

Impact of High-Pressure Processing (HPP) on Selected Quality and Nutritional Parameters of Cauliflower (Brassica oleracea var. Botrytis)

In recent years, innovative food processing methods, such as high-pressure processing (HPP) treatment, have been shown to improve food quality. The purpose of this work was to determine the effects of high-pressure processing (HPP; 400 and 600 MPa for 2 or 5 min, 20 °C) of cauliflower. Microbial shelf-life (total aerobic count and spores), texture, color, drip loss, dry matter, antioxidative capacity, total phenolic content, and ascorbic acid were analyzed before and after processing, as well as during storage (4 °C) for up to 42 days. Among the different treatments, HPP at 600 MPa exhibited low microbial counts between days 14 and 28 of storage, while at 400 MPa already had high bacterial counts between days 7 and 14. HPP at both 400 and 600 MPa was the best method to maintain the color during storage. The texture of the cauliflower did not differ from the control during storage for HPP. For all samples, the dry matter content remained stable during storage, with few differences between treatments. The nutritional quality of high-pressure-processed cauliflower at 600 MPa for 2 min remained high until day 28. The overall results of this study demonstrate that HPP has the potential to preserve the quality of cauliflower.

Effect of high pressure processing on structural and functional properties of canned aquafaba.

Aquafaba is chickpea cooking water. It has great functional properties since it consists of starch and protein. High pressure processing (HPP) is proven to modify the functionality of starch by keeping its integrity. The objective of this study was to check if HPP can improve structural and functional properties of canned aquafaba. HPP treatments were given at pressure levels: 200, 259, 400, 542, and 600MPa with holding time between 5 and 30min. After HPP, part of the samples was freeze dried for crystallinity and particle size analysis and the fresh part used for rheological, functional properties, and colour. HPP enhanced functional properties, mostly foaming stability which increased from 50.5 to 67min. Rheological properties were enhanced mainly for consistency coefficient from 0.6 to 1.4Pa.s. Crystallinity dropped slightly compared to control sample, while the colour got brighter, from 27.5 to 49.6. Processing time and pressure intensity did not contribute in increasing particle size. The combination of high intensity and long pressurization time resulted the smallest particle size (90µm).

High-pressure processing treatment of beef burgers: Effect on Escherichia coli O157 inactivation evaluated by plate count and PMA-qPCR.

Propidium monoazide coupled to real time PCR (PMA-qPCR) is a novel methodology proposed for the quantification of viable bacteria in food after microbial inactivation treatments. The aim of this work was to assess the effectiveness of different pressure levels on the lethality of a pool of Escherichia coli O157 strains in beef burgers by plate count and PMA-qPCR using uidA as target gene. Also, the effect on native microbiota counts, E. coli O157 counts, and physiochemical parameters of beef burgers during storage in refrigeration and frozen conditions were assessed. The treatment at 600MPa for 5min was the most lethal and was selected for the evaluation of bacteria behavior under storage conditions. Native microbiota and E. coli O157 were not recovered during refrigerated and frozen storage (4°C for 7 days and -18°C for 35 days). Cooking weight loss, pH, chromatic parameters, and texture were affected by HPP. PRACTICAL APPLICATION: Practical Application: PMA-qPCR can be used as an alternative to assess microbial inactivation by different high pressure processing (HPP) conditions (pressure level, holding time and temperature) more rapidly than conventional plate counts. In addition, it has the benefit of being able to quantify viable but nonculturable bacteria from contaminated beef burgers after HPP. Moreover, this novel technique generates less pathogenic residues, which minimizes workers' exposure to human biohazards.

High pressure processing improves the texture quality of fermented minced pepper by maintaining pectin characteristics during storage.

Texture quality affects the sensory and market acceptance of fermentation minced pepper (FMP), but it will deteriorate during storage. Thus, high pressure processing (HPP) and thermal pasteurization (TP) were used to improve the texture quality of FMP during storage. The results showed that variations in texture quality and pectin characteristics under HPP and TP treatments were similar during storage. The hardness, cell wall material (CWM) and sodium carbonate-soluble pectin (SSP) content, water-soluble pectin (WSP) molecular weight (Mw ) decreased, while WSP content and sodium chelate-soluble pectin (CSP) Mw increased after storage. HPP-treated FMP showed higher hardness (66.64-85.95 N) than that in TP-treated one (57.23-62.72 N) during storage. Rhamnose (Rha), arabinose, mannose, and glucose were the crucial compositions in three pectins, and their total molar ratios, respectively, reached 89.19% and 87.97% after HPP and TP treatment. However, the molar ratio of most monosaccharide in three pectins decreased after storage. Atomic force microscope images indicated the short chains and branch structures increased but aggregates decreased in most pectin components during storage. Pearson correlation analysis demonstrated FMP hardness was extremely (p<0.01) positively correlated with CWM and SSP content, and extremely (p<0.01) negatively correlated with WSP content. Compared to TP treatment, HPP presented higher hardness, SSP content and Mw , Rha content, CSP Mw , and lower WSP content during storage. Hence, HPP was an effective method to improve the texture quality of FMP by maintaining pectin characteristics during storage. PRACTICAL APPLICATION: Softening is one of the main factors affecting market value and consumer preferences for FMP, and it is closely related to the modification and depolymerization of pectin. Changes of texture quality and pectin properties in HPP- and TP-treated FMP during storage were assessed, including hardness, the content, monosaccharide compositions, Mw distribution, and nanostructure of WSP, SSP, and CSP. Compared to TP treatment, HPP could effectively improve the texture quality of FMP by inhibiting pectin degradation during storage. All the findings presented in this study would help to provide new insights into regulating the texture quality of FMP.

Inhibitory Effects of High-Hydrostatic-Pressure Processing on Growth and Histamine Formation of Histamine-Forming Bacteria in Yellowfin Tuna Meat during Storage.

Simple SummaryHigh-hydrostatic-pressure treatment effectively inhibited the growth and histamine formation of histamine-forming bacteria species in tuna meat during storage at low temperatures. Our findings can be used to enhance food safety and decrease the risk of histamine poisoning associated with consumption of tuna meat products.In the research, we evaluated the effects of high-pressure processing (HPP) on the growth and histamine formation of histamine-forming bacteria (HFB) in yellowfin tuna meat during storage. Tuna meat samples inoculated with the individual HFB species Morganella morganii and Photobacterium phosphoreum were subjected to HPP treatment at 250, 350, 450, and 550 MPa for 5 min, and the changes in bacterial count, total volatile basic nitrogen (TVBN) content, pH, and histamine content during storage at 4 and 15 °C were analyzed. The results indicate that the bacterial counts of the HFB species decreased significantly with increasing pressure, and HFB became undetectable in the samples treated at 450 and 550 MPa. At a storage temperature of 15 °C, the bacterial counts of both HFB species in the control group and samples subjected to HPP treatment at 250 and 350 MPa increased significantly with storage time. The bacterial counts of M. morganii in the samples stored at 4 °C decreased, whereas those of P. phosphoreum increased gradually owing to its psychrophilic nature. HPP treatment (>250 MPa) inhibited the increases in pH and TVBN content of the samples stored at 15 °C and delayed histamine formation in the samples during storage; these effects were more significant as the pressure during HPP treatment was increased.

Effects of ultrafiltration combined with high‐pressure processing, ultrasound and heat treatments on the quality of a blueberry–grape–pineapple–cantaloupe juice blend

SummaryThis study investigated the effect of ultrafiltration (UF) combined with high‐pressure processing (HPP) at 550 MPa, 25 °C for 5 min, ultrasound (US) at 520 W, 40 °C for 10 min and heat treatment (HT) at 90 °C for 3 min on the microbial, physicochemical and sensory properties of a blueberry–grape–pineapple–cantaloupe juice blend during 104 days of storage at 4 °C. After UF, the shelf life of the HPP‐ and US‐treated clear juice blends were 104 and 72 days during the storage at 4 °C respectively. HPP, US and HT treatment minimally affected the anthocyanin and total phenol contents, while HPP better maintained the ascorbic acid levels and sensory properties in the clear juice blend during the storage. Therefore, HPP combined with UF was identified as a prospective processing technique in the fruit juice industry.

Application of iTRAQ Technology to Identify Differentially Expressed Proteins of Sauce Lamb Tripe with Different Secondary Pasteurization Treatments.

Vacuum-packed sauce lamb tripe was subjected to secondary pasteurization by high-pressure processing (HPP) and heat treatment (HT), and iTRAQ technology was applied to investigate the differentially expressed proteins (DEPs). The analysis revealed 484 and 398 DEPs in the HPP and HT samples, respectively, compared with no treatment. These DEPs were sorted by texture results, and it was revealed that these DEPs acted in different biological processes with many structural proteins and protein subunits related to lamb tripe texture. The results verified by Western blot were consistent with the protein expression changes observed by proteomics. The bioinformatics analysis showed that the hardness and gumminess of the sauce lamb tripe after HT might be related to changes in the expression of CNN1 and FN1. The changes in the expression of TMP, FN1, YWHAG, TTN, collagen isoforms, and ARPC3 might be related to the improved springiness and chewiness of lamb tripe after HPP.