The use of high pressure homogenization (HPH) to reduce consistency of concentrated orange juice (COJ)

Ultra-high pressure treatment improve the content of characteristic aromatic components of melon juice from the view of physical changes

Introduction

The effectiveness of ultra-high pressure (UHP) technology in retaining the flavor of fresh fruit and vegetable juices has been acknowledged in recent years. Along with previously hypothesized conclusions, the improvement in melon juice flavor may be linked to the reduction of its surface tension through UHP.

Methods

In this paper, the particle size, free-water percentage, and related thermodynamic parameters of melon juice were evaluated in a physical point for a deeper insight.

Results

The results showed that the UHP treatment of P2-2 (200 MPa for 20 min) raised the free water percentage by 7,000 times than the other treatments and both the melting enthalpy, binding constant and Gibbs free energy of P2-2 were minimized. This significantly increased the volatility of characteristic aromatic compounds in melon juice, resulting in a 1.2-5 times increase in the content of aromatic compounds in the gas phase of the P2-2 group compared to fresh melon juice.

Effects of Ultrasonic Treatment on Physical Stability of Lily Juice: Rheological Behavior, Particle Size, and Microstructure

The aim of this study was to investigate the rheological properties, particle size distribution, color change, and stability of lily juice under different ultrasonic treatment conditions (152 W, 304 W, 456 W, 608 W, and 760 W). The results showed that the lily juice exhibited non-Newtonian shear thinning behavior, and the viscosity decreased with the increase in ultrasonic power. Under ultrasonic treatment conditions, there was no significant change in the pH value and zeta potential value of the samples. The content of cloudy value and total soluble solids (TSS) increased gradually. However, both the sedimentation components and centrifugal sedimentation rate showed a downward trend and an asymptotic behavior. In addition, high-power ultrasound changed the color index (L* value decreased, a* value increased), tissue structure, and particle distribution of the sample, and small particles increased significantly. To sum up, ultrasonic treatment has great potential in improving the physical properties and suspension stability of lily juice.

Effect of microfluidization on quality characteristics of sapodilla (Manilkara achras L.) juice

Various oxidative enzymes account for the quality degradation of sapodilla (Manilkara achras L.) juice and need to be inactivated through emerging and continuous green pressure processing technology. In this study, pressurization of sapodilla juice was attempted via microfluidization (MF) at pressure range of 10,000-30,000 pound per square inch (psi) with 1-3 passes or cycles. The impact of microfluidization on the activity of polyphenol oxidase (PPO), peroxidase (POD), color, total soluble solid (TSS), viscosity, serum cloudiness along with particle size, and microbial load of sapodilla juice was assessed. Results showed that microfluidization (MF) decreased the residual PPO activity from 100 to 80.78 % and POD activity from 100 to 40.57%. However, TSS (18.81-19.01 %), viscosity (2.64-2.06 cP), serum cloudiness (2.19-1.22 %) and total color change (3.19-18.54) was also significantly affected. Most of these changes were observed due to particle size (PS) reduction that varied from 65.19 to 8.13 μm. Microfluidized juice revealed color improvement at particular MF pressure and pass due to enzyme inactivation. Moreover, lowest microbial load (2.89 Log CFU/ mL) was found at 30,000 psi/3 pass of MF as compared to control sample (unprocessed juice) (7.57 Log CFU/ mL). Consequently, MF can be potential candidate in processing of juices against spoilage.

Conformational Changes in Proteins Caused by High-Pressure Homogenization Promote Nanoparticle Formation in Natural Bone Aqueous Suspension

As a natural calcium resource, animal bone needs to be miniaturized to the nanoscale to improve palatability and absorption capacity. To explore the mechanism of high-pressure homogenization (HPH) in preparing natural bone aqueous nanosuspensions, the relationships between the changes in protein conformation, solubility and quality characteristics of rabbit bone aqueous suspensions (RBAS) prepared by different HPH cycles were studied. The results showed that the improvements in particle size, stability and calcium solubility of RBASs could be mainly attributed to the improvement of protein solubility induced by the changes in protein conformation. HPH treatment led to the denaturation and degradation of protein in rabbit bone, generating soluble peptides and improving the stability of the suspensions by enhancing the surface charge of the particles. When collagen as the main protein was partially degraded, the hydroxyapatite in the bone was crushed into tiny particles. The increase in the particle-specific surface area led to the release of calcium ions, which chelated with the peptides to produce peptide calcium. However, excessive HPH treatment caused the production of protein macromolecular aggregates and affected the quality of RBASs. This study is helpful to promote the application of HPH technology in animal bone nanoprocessing.

The Emulsion Properties of Chicken Liver Protein Recovered through Isoelectric Solubilization/Precipitation Processes

This study investigated the feasibility to improve the emulsifying capacity of chicken liver (CL) protein using different isoelectric solubilization/precipitation (ISP) processes. The CL proteins were first solubilized at alkaline pH 10.5, 11.0, 11.5, and 12.0, followed by precipitation at pH 5.0, 5.5, and 6.0, respectively. Fresh CL paste was set as the control (raw). With the increase in solubilization pH, the protein recovery yield increased under the same precipitation pH, and the pH 12.0, 5.5 treatment obtained the highest recovery yield of 82% (p < 0.05), followed by the pH 5.0 precipitation treatments and the pH 12.0, 6.0 treatment. The particle size distribution of D3,2 and D4,3 was smaller for the pH 10.5 (except for the D4,3 of pH 10.5, 5.0) and pH 11.0 solubilization treatments than those of the other treatments (p < 0.05), regardless of precipitation pH. Compared with that of the raw control, the emulsions of the pH 10.5 and pH 11.0 solubilization treatments, and pH 12.0, 6.0 treatment showed good stability. The pH 10.5, 6.0 treatment showed the best emulsification activity, followed by the pH 10.5, 5.5, pH 11.0, 6.0, pH 12.0, 6.0, pH 10.5, 5.0, pH 11.0, 5.5, and pH 11.0, 5.0 treatments, which were uniformly distributed and were stable without the stratification of emulsions. It was concluded that CL protein recovered through suitable ISP showed potential as an emulsifier, and thus expanded the application of CL protein for human consumption.

Thermosonication effect on bioactive compounds, enzymes activity, particle size, microbial load, and sensory properties of almond (Prunus dulcis) milk

The object of this research was to appraise the physicochemical characteristics of almond milk and consumer acceptability after the thermosonication (TS) processing. The almond milk was subjected to TS processing (frequency: 40 kHz; power: 600 W; Temperature: 30, 45, and 60 °C; Time: 10, 20, 30, and 40 min) and pasteurization (for 60 s at 90 °C). After treatments, all samples were analyzed for bioactive compounds, antioxidant activities, microbial, enzymatic, and sensory attributes. The results showed a non-significant difference in total soluble solids and pH while TS processing at 45 and 60 °C significantly increased the cloudiness, viscosity, browning index, and color properties. TS processing increased the bioavailability of total phenolic, flavonols, flavonoids, condensed tannin contents, and antioxidant activity as compared to untreated and pasteurized samples. TS processing also significantly reduced the particle size distribution through acoustic cavitation. Microbial inactivation with TS at 60 °C resulted in ≥ 5 log reduction oftotal plate count and ≥ 4 log reduction ofyeast & moldwas achieved. The highest inhibition of lipoxygenase (LOX) and peroxidase (POD) were observed at 60 °C for 30 min. Moreover, the best sensorial properties were observed after TS processing at 60 °C. Thus; TS processing can increase the almond milk quality and safety as a viable substitute for thermal processing.

Effect of high pressure homogenization on water-soluble pectin characteristics and bioaccessibility of carotenoids in mixed juice

The effect of high pressure homogenization (HPH) compared with simple blending and milling on mixed juice properties, including water-soluble pectin (WSP) characteristics and total carotenoid bioaccessibility (TCB) was investigated. Overall, HPH treatments, which comprised of varied pressures, passes and inlet temperature (IT) affected WSP characteristics. Increased pressure showed decreased molecular weight (M_w), galacturonic acid (GalA) content and branching, and enhanced degree of methylesterification (DM) and chain linearity, suggesting degradation of RG-I fragments. Two passes at 140 MPa enhanced GalA content, nevertheless it reduced DM, implying rearrangement of depolymerized fractions. Besides, elevated IT combined with high pressure increased GalA content and DM signifying thermo-solubilization of certain HG-rich pectin. Notably, the TCB was enhanced by higher pressure and elevated temperature, which had positive relationship with DM and chain linearity of WSP and negative correlations with GalA content and M_w. Results highlighted the potential of HPH to improve WSP characteristics to enhance TCB.

High pressure homogenization with a cooling circulating system: The effect on physiochemical and rheological properties, enzymes, and carotenoid profile of carrot juice

The influence of high pressure homogenization (HPH) at 100-150 MPa performed by multiple passes below 35 °C on carrot juice quality and stability was studied. The highest reduction in microorganisms (by 2.47 log) was noted at 150 MPa with 5 passes of the juice through the homogenizer. The PPO and POD's residual activity increased after HPH; PG was at the same level, while PME activity increased or decreased depending on the process parameters used. HPH treatment resulted in a decrease in the apparent dynamic viscosity, turbidity and colour parameters. Five passes at 150 MPa caused an increase in the carotenoid content, especially 9-Z-β-carotene (by 154%) while the TPC did not change significantly. Carrot juice treatment at 150 MPa with 5 passes may extend its shelf-life by 3 days when stored at 4 °C.

An overview of different homogenizers, their working mechanisms and impact on processing of fruits and vegetables

Fruits and vegetables (F&V) are the second highest recommended foods, rich in antioxidants, vitamins and minerals, vital for building immunity against chronic diseases. F&V processing involves particle size reduction, for which different types of homogenizers, categorized as mechanical homogenizers, pressure homogenizers and ultrasonic homogenizers are used. The review discusses different types of homogenizers, their working mechanism, and application in F&V processing. Among mechanical homogenizers, knife mills are used for primary size reduction, ball mills for the micronization of dried F&V and rotor-stator homogenizers for emulsification. Use of the ultrasonic homogenizer is limited to extraction of bioactive compounds or as a pre-treatment for dehydration of F&V. High-pressure homogenizers are most widely used and reported due to the synergistic effect of homogenization and temperature increase, resulting in longer shelf-life and better physicochemical properties of the product. Additionally, the review also explains the effect of homogenization on the physicochemical, sensory and nutraceutical properties of the product.

Effects of High-Pressure Homogenization on Pectin Structure and Cloud Stability of Not-From-Concentrate Orange Juice

Not-from-concentrate (NFC) juice is popular with consumers due to its similarity to fresh fruit juice in taste, flavor, and beneficial nutrients. As a commonly used technology in fruit juice production, high-pressure homogenization (HPH) can enhance the commercial value of juice by improving the color, flavor, taste, and nutrient contents. In this study, the effects of HPH on the pectin structural properties and stability of NFC orange juice were investigated. The correlations between HPH-induced changes in the structure of pectin and the stability of orange juice were revealed. Compared with non-homogenized orange juice, HPH increased the galacturonic acid (GalA) content and the linearity of pectin, while decreasing the molecular weight (Mw), pectin branching, and rhamnogalacturonan (RG) contribution, and cracks and pores of different sizes formed on the surface of pectin, implying depolymerization. Meanwhile, with increasing pressure and number homogenization of passes, HPH effectively improved the stability of NFC orange juice. HPH can effectively prevent the stratification of orange juice, thereby promoting consumer acceptance and endowing a higher commercial value. The improvement of the stability of NFC orange juice by HPH was related to the structural properties of pectin. Turbidity was significantly (P < 0.01) positively correlated with GalA and pectin linearity, but was significantly (P < 0.01) negatively correlated with Mw, RG contribution, and pectin branching. Modification of pectin structure can improve the stability of NFC orange juice. In this work, the relationship between the pectin structure and stability of NFC orange juice is elucidated, providing a path toward improving consumer acceptance and enhancing the palatability and nutritional and functional qualities of orange juice. Manufacturers can use this relationship to modify pectin directionally and produce high-quality NFC orange juice beverages.

Potential Use of Vacuum Impregnation and High-Pressure Homogenization to Obtain Functional Products from Lulo Fruit (Solanum quitoense Lam.)

Lulo (Solanum quitoense Lam.) is a Colombian fruit that is mostly used in the preparation of homemade juice as well as natural remedy for hypertension. The aim of this study was to determine physicochemical and antioxidant properties (antioxidant capacity, total phenols, flavonoids and spermidine content, and polyphenolic compounds profile by liquid chromatography-mass spectrometry (LC-MS)) of the lulo fruit and its juice. Additionally, vacuum impregnation (VI) properties of the fruit and the effect of high homogenization pressure (50, 100, and 150 MPa) on the juice properties were studied. The results revealed a good availability and impregnation capacity of the pores in fruits with similar maturity index. The main differences observed between the juice and fruit derive from removing solids and bioactive components in the filtering operation. However, the effect of high-pressure homogenization (HPH) on particle size and bioactive compounds increases the antiradical capacity of the juice and the diversity in polyphenolics when increasing the homogenization pressure.

Continuous High-pressure Cooling-Assisted Homogenization Process for Stabilization of Apple Juice

The effect of high-pressure homogenization (HPH) at 100–200 MPa (with up to 5 passes) on the quality and storage stability of apple juice was investigated. The microbiological quality, polyphenol oxidase (PPO), peroxidase (POD), polygalacturonase (PG) and pectinmethylesterase (PME) activity, particle size distribution (PSD), apparent viscosity, turbidity, concentration of vitamin C, individual polyphenols and their total content (TPC), antioxidant activity, and colour of fresh, HPH-treated apple juice were all evaluated. The highest reduction in microorganisms (1.4 log) and oxidoreductase activity (~20%) was observed at 200 MPa, while hydrolases did not change significantly. HPH led to significant disintegration of the tissue and a decrease in viscosity. Vitamin C decreased by 62%, while TPC increased by 20% after HPH. Significant correlations were observed between antioxidant activity, TPC, and individual polyphenols. Chlorogenic, ferulic, and gallic acid were most stable at 200 MPa. The optimal shelf-life of the juice was estimated as 7 days.

Influence of high pressure homogenization and pasteurization on the in vitro bioaccessibility of carotenoids and flavonoids in orange juice

Production of high-quality healthy foods through sustainable methodologies is an urgent necessity. High pressure homogenization (HPH) is an interesting alternative to obtain premium citrus juices, but its effects on bioactive compounds are unclear. There was studied the influence of HPH (150 MPa) and pasteurization (92 °C for 30 s and 85 °C for 15 s) processing on physicochemical properties and in vitro bioaccessibility of carotenoids and flavonoids in orange juices. Regarding fresh juice, physicochemical properties of samples remained unchanged although cloudiness was improved by homogenization. Pasteurization did not affect total carotenoids content and retinol activity equivalents (RAE) of juices whereas homogenization yielded a significant reduction (1.37 and 1.35-fold, respectively). Interestingly, particle size reduction from homogenization drastically enhanced (about 5-fold) bioaccessibility of carotenoids including hardly bioaccessible epoxycarotenoids, finding unaltered rates in pasteurized samples. Bioaccessibility of flavonoids was constant in all cases. Results can promote HPH as an efficient option to obtain health-enhanced foods.

Effect of high pressure homogenization on mixed juice stability, rheology, physicochemical properties and microorganism reduction

Cloud instability and loss of fresh-like appearance are important quality defects of cloudy mixed juices determining consumer acceptability. Therefore, the aim of this study was to investigate the feasibility of high pressure homogenization (HPH) for improving cloud stability, flow behavior and physicochemical characteristics as well as reducing spoilage microorganisms in a cloudy mixed juice, consisting of carrot, apple and peaches. HPH treatments included pressure of 25 MPa, 100 MPa, 140 MPa and 180 MPa, pass of 1 and 2 and inlet temperature of 25 °C and 40 °C, respectively. Results indicated that increasing pressure and pass improved cloud stability, while increasing temperature had negative effect. Herschel Bulkey model could be well fitted to viscosity related data. Compared with control (non-homogenized, NH) sample, HPH at 140 MPa and 25 °C for 1 pass resulted in three times higher flow behavior index. Increasing inlet temperature also resulted in enhancing flow behavior. Besides, total soluble solids content was not affected by HPH, even though pH and color showed slight changes. Compared with NH sample, HPH at 140 MPa resulted in 4 log₁₀ and 3 log₁₀ reductions in total plate count and yeasts and molds count respectively. Thus, HPH at 140 MPa could effectively be used for enhancing cloud stability, improving flow behavior and reducing microorganisms in cloudy mixed juices.

Effects of High-Pressure Homogenization on the Structural, Physical, and Rheological Properties of Lily Pulp

The effects of high-pressure homogenization (HPH) on the structural, physical, and rheological properties of lily pulp (15%, w/w) were investigated. Different pressures ranging from 0 MPa to 100 MPa were used. The focus was on evaluating the changes in the particle size distribution (PSD), structure, pulp sedimentation behavior, serum cloudiness (SC), total soluble solids (TSS), color, and rheological behavior of the pulps. PSD analysis showed that the diameter of suspended lily particles significantly decreased with an increasing homogenization pressure. The suspended particles observed through optical microscopy became small after homogenization, highlighting the effect of HPH on disrupting the suspended particles. Compared with the untreated pulp, the SC and sedimentation velocity of the homogenized pulps decreased due to the disruption of the suspended particles. The effects of HPH on the sedimentation index and SC exhibited an asymptotic behavior similar to that of the changes in the particle size of lily pulp. Moreover, HPH processing reduced the viscosity of lily pulp and increased the TSS and lightness of the homogenized pulps. HPH significantly modified the structural, physical, and rheological properties of lily pulp. The pulp homogenized above 60 MPa had good suspension stability. This finding indicates that HPH technology can be used to improve the stability of lily pulp.

Comparison of the effects of dynamic high-pressure microfluidization and conventional homogenization on the quality of peach juice

BACKGROUND

Dynamic high-pressure microfluidization (DHPM) is an emerging and promising technique for continuous production of fluid foods. This study aimed to investigate the influence of DHPM and conventional homogenization (CH) on the quality of peach juice. Processing was performed by passing peach juice through CH at 20 MPa and DHPM at 20-160 MPa for one or three passes. The effect of DHPM pressure and passing number were also assessed.

RESULTS

The results indicate that DHPM could maintain the antioxidant activity of peach juice much better than CH processing. Total phenolic compounds were decreased by 11.7% and 7.9%-15.8% through CH and DHPM processing in different conditions. Moreover, particle size, non-enzymatic browning index and turbidity decreased significantly under DHPM and CH processing, and decreased more and more with the increasing of DHPM pressure and treatment times. However, vitamin C content and zeta-potential did not reveal remarkable variation before and after these two types of processing.

CONCLUSION

Taken together, DHPM is able to maintain the quality and stability of peach juice, which can be a reliable technological alternative to CH to produce fresh-like peach juices. © 2019 Society of Chemical Industry.

Application of time–intensity analysis in model system submitted to homogenization

The use of the high pressure homogenizer has been studied in fruit juices, but researches in model system for application in fruit nectar are scarce. Therefore, it is necessary to evaluate the application of these technologies and how the homogenization pressure (PH) can interfere in the sensorial profile of the samples. To prepare the solutions we used guar gum (0.1%), organic acids (0.3%), and sucrose (10%), which were later homogenized (0—control, 25 and 50 MPa) at 25 ℃. The rheological behavior and the temporal profile of the samples were evaluated. The model systems presented pseudoplastic behavior without residual tension and were fitted to the Ostwald–de Waele model. The consistency index reduced and the flow behavior index increased with processing. Apparent viscosity also decreased due to homogenization. In the time–intensity sensorial analysis, it was observed that the samples differed among the evaluated parameters, demonstrating that the samples with tartaric acid presented higher intensity for the sour taste. However, for sweetness, no change was observed. In the viscosity attribute, the model systems presented similar temporal profiles. Therefore, it was noted that the homogenization process favored a greater temporal profile of sour taste, making sensory perception more lasting in a model system for fruit nectar.

Influence of thermosonication (TS) process on the quality parameters of high pressure homogenized hazelnut milk from hazelnut oil by-products

Hazelnut, an important source of nutrition, is reasonably expensive for hazelnut milk production. Hazelnut cake, a by-product from hazelnut oil production by cold press extraction technique, does not contain any chemical residue and can be used for hazelnut beverage production. This study investigates the effects of thermosonication process on the quality parameters of hazelnut milks and also compares the observed results with the conventional thermal process. Different thermosonication conditions at different amplitude levels (40 and 60% amplitudes for 5, 10, 15, 20 and 25 min and 80% amplitude for 3, 5, 10 and 15 min) were studied for physicochemical and rheological properties, as well as microbial inactivation and bioactive compounds of hazelnut milk produced from the cold pressed hazelnut cake as byproduct of oil production. In general, sonication process significantly improved the total phenolic compounds, antioxidant activity, appearance and structural properties like syneresis, sedimentation, viscosity and consistency of samples. The application of thermosonication at 60% amplitude for 25 min and 80% amplitude for 15 min achieved complete inactivation of microorganisms (total aerobic mesophilic bacteria and yeast-mould). Complete inactivation of microorganisms was also achieved by conventional pasteurization at 85 °C, but this treatment caused some undesirable changes such as loses of bioactive compounds and deterioration of structural properties. The findings of the present study indicate that thermosonication can be successfully utilized for commercial processing of hazelnut milk with improved quality. This technique allows the production of hazelnut milks in safety and quality standards with highly nutritious then the conventional product.

(Ultra) High Pressure Homogenization Potential on the Shelf-Life and Functionality of Kiwifruit Juice

The increasing competition within the food industry sector makes the requisite of innovation in processes and products essential, leading to focus the interest on the application of new processing technologies including high pressure homogenization (HPH) and ultra high pressure homogenization (UHPH). In this context, the present research aimed at evaluating the effects of two UHPH treatments performed at 200 MPa for 2 and 3 cycles on quality and functionality of organic kiwifruit juice stored at three different temperatures, i.e., 5, 15, and 25°C. The results showed that only the treatment performed at 200 MPa for 3 cycles was able to significantly increase the shelf-life of organic kiwifruit juices when stored at refrigeration temperature, avoiding also phase separation that occurred in the sample treated at 0.1 MPa (control) after 20 days of refrigerated storage. The obtained data showed also that the highest applied pressure was able to increase some quality parameters of the juice such as viscosity and luminosity (L^∗) and increased the availability of total phenol content consequently enhancing the juice total antioxidant activity. The application of a treatment at 200 MPa for 3 cycles allowed to obtain a stable kiwifruit juice for more than 40 days under refrigerated storage. A challenge to implement this technology in food process as full alternative to thermal treatment could be represented by the adoption of pressure level up to 400 MPa followed by the packaging in aseptic conditions.

Application of multi pass high pressure homogenization to improve stability, physical and bioactive properties of rosehip (Rosa canina L.) nectar

The effect of high pressure homogenization (HPH) on physical and bioactive properties of rosehip nectar was investigated. Rosehip nectar has a sedimentation problem while waiting on the market shelf during the sale, for solving this problem, nectars were passed 1, 2 and 3 times through 75, 100 and 125 MPa pressures. Mean particle size decreased as pressure and pass number increased (p < 0.05), whereas zeta potential did not change (p > 0.05). Microstructural images revealed that HPH treatment disrupted the cells and caused to release of cell materials to serum. HPH treatment increased the ΔE values (from 2.48 to 6.03). HPH treated samples showed no sedimentation during storage for 15 days. All samples showed shear thinning behavior and were characterized as weak gel network (G' > G″). Total phenolic content and ascorbic acid results were decreased by HPH treatments due to increasing outlet temperatures of product, however, antioxidant capacity of nectars increased after treatment due to increasing total carotenoid content. This study indicated that HPH treatment could solve the sedimentation problem during shelf life with minimally affecting bioactive and physical properties of rosehip nectar.