This study investigated the influence of homogenization valve design and formulation parameters on the stability of oil-in-water emulsions produced with chia and sunflower oils (1:1) and buttermilk (BM) as the emulsifier. Three high-pressure homogenization techniques-microfluidization (MF), ultra-high-pressure homogenization (UHPH), and conventional homogenization (CH)-were compared at 100 MPa using buttermilk (5 and 7 %, w/v) and oil concentrations (10 and 20 % v/v). MF produced the most stable and uniform emulsions, characterized by the smallest droplet size and narrowest distribution, attributed to the effective control of droplet breakup in the homogenization chamber. UHPH produced fine but larger, less uniform droplets, reducing stability and increasing lipid oxidative susceptibility in the emulsions. This effect was attributed to intense shear forces and temperature rise at the UHPH valve outlet, which disrupted interfacial protein, causing partial denaturation and emulsion instability. CH emulsions, despite their larger droplet size, showed long-term physical stability due to droplet packing and surface charge density, which increased electrostatic repulsion but were the least oxidatively stable. Emulsion composition (BM and oil concentration) also played a critical role. In MF emulsions, higher BM concentration enhanced stability under low shear, whereas in UHPH systems, excess BM promoted protein aggregation under high shear. Increasing oil concentration (20 %) generally enhanced oxidative stability, attributed to viscosity effects and closer droplet packing that limited oxygen diffusion. Overall, the results highlight that both the homogenization technique and formulation composition must be optimized to balance physical and oxidative stability in chia/sunflower-BM emulsions, underscoring its potential for emulsion-based product development.

This study investigated the characteristics of yogurts produced by substituting dairy fat with polyunsaturated fatty acids (PUFA)-rich oils encapsulated with buttermilk (BM) in spray-dried emulsions (SDE). Two homogenization methods, conventional (CH) and ultra-high-pressure homogenization (UHPH), were compared to obtain the emulsions for spray drying. Recombined milks (RMs) were formulated using two different concentrations (4 g/100 g and 6 g/100 g) of SDE, followed by fermentation. Yogurt characteristics were evaluated during cold storage using various parameters, including coagulation properties, texture and rheology, microstructure, physicochemical characteristics (color, pH, total acidity, and water holding capacity), oxidative stability, main fatty acid profile, microbial assessment, and sensory evaluation. During cold storage, several parameters significantly influenced the yogurt characteristics. The CH yogurts exhibited higher textural parameters (firmness and consistency) and viscoelastic parameters (G ' and G") compared to the UHPH yogurts at the same SDE concentration. However, UHPH yogurts generally showed better water holding capacity (WHC) values. UHPH yogurts also demonstrated superior stability to oxidation and higher PUFA content. The observed differences between the CH and UHPH treatments can be attributed to the structuring of fat-protein-BM into colloidal particles based on the homogenization system employed in this study. Neither of the homogenization systems nor the SDE content impacted yogurt flavor.

Integrating functional ingredients, such as buttermilk and omega-3 rich oils, in spray-dried emulsions (SDE) is a suitable way to incorporate these ingredients in dairy products to substitute dairy fat and increase their added value. Ultra-high-pressure homogenization (UHPH) processing of liquid emulsions considerably improves stability compared to the conventional homogenization (CH) process. With this premise, SDE were produced while comparing CH (30 MPa) and UHPH (100 or 200 MPa) processing of feeding emulsions. Emulsions were formulated with (50:50 chia:sunflower) oil, whole commercial buttermilk (BM), and maltodextrin (MD) as wall materials. Further spray drying of emulsions was then conducted. Obtained SDE were characterized in terms of water content, Aw (water activity), flowing properties, water solubility, encapsulation efficiency (EE), color, and microstructure. Oxidation stability of SDE was analyzed in accelerated oxidation conditions at 50 C for one month for primary and secondary oxidation analysis evolution on days 1, 7, 14, and 31 of storage. Results showed better ability of BM as encapsulating agent in UHPH-processed emulsions with 7% of BM. This improvement was especially observed in the flowing properties and encapsulating efficiency. Seven percent BM UHPH-treated SDE showed the best primary oxidation stability during storage, while the 4% BM-UHPH-treated SDE exhibited better secondary oxidative stability.

Functional foods are highly demanded by consumers. Omega-3 rich oil and commercial buttermilk (BM), as functional components, used in combination to produce emulsions for further drying may facilitate the incorporation to foods. Ultra-high-pressure homogenization (UHPH) has a great potential for technological and nutritional aspects in emulsions production. The present study aimed to examine the potential improvement of UHPH technology in producing buttermilk-stabilized omega-3 rich emulsions (BME) for further drying, compared with conventional homogenization. Oil-in-water emulsions formulated with 10% chia: sunflower oil (50:50); 30% maltodextrin and 4 to 7% buttermilk were obtained by using conventional homogenization at 30 MPa and UHPH at 100 and 200 MPa. Particle size analysis, rheological evaluation, colloidal stability, zeta-potential measurement, and microstructure observations were performed in the BME. Subsequent spray drying of emulsions were made. As preliminary approximation for evaluating differences in the homogenization technology applied, encapsulation efficiency and morphological characteristics of on spray-dried emulsions (SDE) containing 21.3 to 22.7% oil content (dry basis) were selected. This study addresses the improvement in stability of BME treated by UHPH when compared to conventional homogenization and the beneficial consequences in encapsulation efficiency and morphology of SDE.

Ultrahigh-pressure homogenization (UHPH) is a promising technology that is gaining importance over time as a potential technology to replace or complement the traditional heat processing of liquid foods. UHPH consists of forcing a pressurized fluid to flow through a small gap, offering the possibility of combining homogenization and preservation into a single-unit operation. This technology has been tested on different liquid food products of vegetal and animal origins enabling pasteurized or sterilized products with good sensorial, nutritional, functional, and technological properties. The aims of this chapter are to present the potential application of UHPH with respect to conventional homogenization and heat treatments applied to milk and dairy products, and to discuss their effects on the microbiology, main structures, and components of milk, and on their techno-functional properties of dairy products.

In the present study, oil-in-water emulsions were formulated using 5.0% (w/v) of sodium caseinate (SC) and different oil concentrations (10-30%, v/v) by conventional homogenization (CH) and ultra-high pressure homogenization (UHPH, 200-300 MPa). The effect of oil concentration and pressure of treatment on emulsions characteristics and stability was studied. Emulsions were characterized assessing their microstructure, droplet size distribution, rheological properties, emulsifying activity index (EAI), creaming stability by Turbiscan (R), and photo-oxidation. UHPH emulsions, especially those treated at 200 MPa, showed smaller droplet size and greater physical stability than CH emulsions. In addition, emulsions containing higher oil volume fractions (20 and 30%) exhibited greater physical and oxidative stability. UHPH emulsions treated at 200 MPa and containing 20% oil content were the most stable emulsions against physical separation and photo-oxidation. These results show that UHPH is a potential technology to enhance the physical and oxidative stability of emulsions containing sodium caseinate as emulsifier for several applications.

The present study aimed to evaluate the effect of UHPH treatments (at 200 and 300MPa and 40°C of inlet temperature) on the physico-chemical characteristics of tiger nuts' milk beverages, in comparison with the raw beverage and the product treated by a conventional homogenization-pasteurization (18+4MPa, 80°C, 15s) without stabilizers (H-P1) or with them (H-P2). The long term evaluation of samples showed that UHPH-treated beverages presented the highest colloidal stability, principally against creaming, due to the reduction in particle size and the new particle interactions, even if comparing with H-P2 beverage. Peroxidase activity showed the highest reduction after applying 300MPa treatment, and regarding fat oxidation reactions, 200MPa-treated beverage appeared to be the most stable. In this sense, the UHPH is presented as an emerging technology for obtaining tiger nuts' milk beverages free of additives with improved physico-chemical characteristics.

The need for enhancing microbial food safety, shelf-life, and quality, without negatively altering the sensory, functional, technological, and nutritional characteristics of foods, has led to increased interest in innovative low-temperature technologies for food preservation. Among these technologies, high-pressure homogenization has been identified as a particularly promising technology for processing liquid foods. The aim of this chapter is to present the potential application of ultrahigh-pressure homogenization with respect to classical homogenization and heat treatments applied to animal and vegetable milks, dairy products (cheese and yogurt), and fruit juices, and to discuss their effects on the main structures and components of these products and on their technological properties.

Current knowledge of the main changes induced in milk (including goat, ewe, and buffalo milks) and milk products when treated by high hydrostatic pressure (HHP) is presented. The effects of HHP on casein micelles, whey proteins, lipids, indigenous enzymes, mineral equilibrium, and microorganisms are described. The significance of these effects on the technological properties of milk, particularly in cheese-and yogurt-making applications, and functional properties is also discussed.

The effects of ultra-high-pressure homogenization (UHPH) at 200 MPa, in combination with different inlet temperatures (55 or 75 °C) during storage at 4 °C were studied and compared with pasteurized (90 °C, 90 s) almond beverage. Microbiological analysis of the physical (particle sedimentation and color) and volatile profile of the most relevant compound in almond beverages was performed at days 1, 7, 14, and 21 of cold storage. UHPH treatment 200 at 75 °C led to higher microbiological reduction after treatment and higher stability during cold storage in almond beverages than pasteurization or UHPH 200 at 55 °C. Physical characteristics of UHPH-treated samples exhibited a high stability during storage with a stable color. Volatile compounds extracted by solid-phase microextraction were identified by gas chromatography coupled with mass spectrometry. The effect of UHPH treatment significantly (p < 0.05) affected the volatile profile compared with pasteurized beverages, although UHPH conditions applied produced similar effects in almond beverages. Benzaldehyde was the most abundant compound detected in all treatments. Hexanal was more abundant in UHPH-treated samples, indicating a higher lipid oxidation compared to pasteurized almond beverages.

Optimization of a headspace–solid phase microextraction (HS-SPME) technique for analyzing the volatile profile of almond beverages was performed. An ultra-high temperature (UHT)-treated almond beverage prepared at the pilot plant was used as a model for this kind of vegetable beverage. For the analysis a 2-mL almond beverage, aliquot was used in the presence of salt (NaCl) at saturation levels. Heating of sample was carried out at 60 °C for 60 min with a stirring rate of 700 rpm using a divinylbenzene (DVB)/Carboxen™ (CAR)/polydimethylsiloxane (PDMS) fibre. The most abundant volatile compounds found were benzaldehyde and hexanal. Most volatiles belong to the aldehyde, ketone and alcohol functional groups. Volatiles derived from thermal treatments such as furans and pyrazines were detected in lesser extent. This technique may be useful to characterize and detect changes in the volatile profile of almond beverages arising from the technological treatments applied in their production.

Donkey milk has functional properties of great interest to human nutrition. The effects of ultra-high pressure homogenization (UHPH) at 100 MPa, 200 MPa and 300 MPa in comparison with different pasteurization treatments of 70 °C for 1 min and 85 °C for 1 min on the physicochemical quality and shelf-life of treated and raw (untreated) donkey milk were studied. Gross composition and pH, total mesophilic counts, lysozyme activity and physical stability were studied during storage at 4 °C for 28 days. The compositional profile showed resemblance to that of human milk characterized by high lactose, low fat and low protein content and was least affected by the treatments. UHPH treatments at 200 MPa, 300 MPa and 85 °C were able to maintain steady pH during storage whereas the low intensity treatments showed a significant decrease. The observed lysozyme activity in the samples was generally high and appeared to have been enhanced by the applied UHPH and pasteurization treatments with no significant change during storage. Although the raw milk showed good initial microbial quality, extensive growth of mesophilic microorganisms occurred after 7 days of storage, unlike the treated samples which were able to maintain significantly low counts throughout the storage period. The physical stability of milk was negatively influenced by the higher UHPH treatments of 200 MPa and 300 MPa which exhibited sedimentation phenomenon, while creaming was insignificant.

BACKGROUNDA relatively new technology based on a continuous system of ultra-high-pressure homogenization (UHPH) was used for producing high-quality soy and almond beverages as an alternative to conventional heat treatments (pasteurization and UHT). The aim of this study was to compare those treatments by analyzing the most relevant quality parameters with a broad vision from the production to the potential toxicological changes, passing through the main nutritional characteristics.RESULTSUHPH treatment at 200 MPa, 55 degrees C T-in produced a higher reduction of microorganisms than pasteurization. UHPH treatment at 300 MPa, 75 degrees C T-in led to complete inactivation of microorganisms, similar to UHT treatment. A much better colloidal stability was observed in both UHPH-treated almond and soy beverages compared with those processed by conventional heat treatments. UHPH treatments led to the same increase in digestibility as heat treatments and did not produce a reduction in the availability of lysine. In addition, UHPH samples of soy beverage seem to be less allergenic based on their lower gut immune response in comparison with heat-treated samples.CONCLUSIONUHPH treatments could be used to produce high-quality commercial vegetable beverages with different quality standards (fresh or long-life storage) according to consumer preference. (c) 2014 Society of Chemical Industry

Ultra high pressure homogenization (UHPH) was applied on soymilk to produce an aseptically packaged beverage. UHPH-treated soymilk (300 MPa, 80 degrees C inlet temperature and 144 degrees C/0.7 s at the homogenization valve) was compared with samples treated by ultra high temperature (UHT) at 142 degrees C for 6 s. After treatment, soymilk samples were aseptically packaged in coated paperboard cartons of 200 mL Tetra Brik containers. Tetra Brik containers were stored for 6 months at room temperature and analyzed at different days. Microbiological (total mesophilic aerobic bacteria, aerobic spores, Bacillus cereus, and enterobacteria counts), physical (dispersion stability and particle size distribution), chemical (hydroperoxide index and volatile profile evolution) and sensory analyses were performed on soymilks. Both UHPH and UHT soymilks did not present microbiological growth during storage. UFIPH soymilk presented high colloidal stability and relevant decrease in hydroperoxide index during storage. On the other hand, almost all of the compounds associated to off-flavors were detected in the volatile profile of soymilk. Sensory results indicated that UHPH treatment did not produce changes in soymilk which could affect the panel perception for different UHT and UHPH soymilks and for selecting their preference.Industrial relevance: Soymilk constitutes one of the food industry sectors with the highest worldwide growth and its consumption has experienced a noticeable increase in the last years. The growing consumer demand for safe products, environmentally friendly processes and high quality nutritional foods has challenged the food industry to adapt the technological processes. This tendency impacts directly on traditional technologies, like heat treatments. In this sense, UHPH technology has been applied as an alternative to those thermal treatments. This research paper presents a comparative study between soymilk treated by UHPH and by UHT to produce a product stored at room temperature for 6 months. Results showed stable levels of oxidation, high physical stability, no microbial growth and a positive trend of sensory response during the period analyzed for UHPH soymilk. Moreover, the UHPH system was designed to work at continuous flow, allowing its application in several industrial food processes. (C) 2014 Elsevier Ltd. All rights reserved.

The effect of ultra high pressure homogenization (UHPH) at 200 MPa combined with 55 and 75 degrees C of inlet temperature on soymilk was studied. UHPH-treated soymilks were compared with the base product (untreated sample) and pasteurized (90 degrees C, 30 s) soymilk. Microbiological (total mesophilic aerobic bacteria, aerobic spores and enterobacterial counts), colloidal and color stability, volatile profile evolution and sensory analysis were performed on soymilks. Samples were analyzed at 1, 7, 14 and 28 days while stored at 4 degrees C. UHPH-treated soymilk presented higher microbiological reduction and higher colloidal stability than pasteurized soymilk during the storage. In this sense, both UHPH treatments showed high color stability and most of the compounds identified were related to off-flavors of soymilk according to published studies. Sensory results indicated that soymilk treated at 200 MPa and 55 degrees C of inlet temperature achieved better sensory acceptance than pasteurized soymilk.Industrial relevance: The consumption of soymilk in western countries have experimented a noticeable increase in the last decade. Consumer opinion is a key element for the development and modernization of the industrial process. In the case of soymilk, heat treatments may compromise the nutritional and sensorial qualities of the product. UHPH is a technology which uses the combined effect, high pressure and temperature to improve quality aspects of soymilk. This research paper presents a comparative study between soymilk treated by UHPH and by pasteurization to produce a product stored under refrigeration conditions during 28 days. During this period, UHPH soymilks presented a greater microbiological reduction, a higher colloidal and color stability than pasteurized soymilk. These results were confirmed by sensory analysis which, in addition, indicated better sensory acceptance for UHPH soymilk than pasteurized samples. Moreover, UHPH system was designed to work at continuous flow, allowing its application in several industrial food processes. (C) 2013 Elsevier Ltd. All rights reserved.

The effect of ultra high pressure homogenisation (UHPH) on the volatile profile of soymilk was studied and compared with conventional treatments. Soymilk was treated at 200 MPa combined with two inlet temperatures (55 or 75 °C) and treated at 300 MPa at 80 °C inlet temperature. UHPH-treated soymilks were compared with base product (untreated sample), pasteurised soymilk (90 °C, 30s) and ultra high temperature (UHT; 142 °C, 6s) treated samples. Volatile compounds were extracted by solid-phase microextraction and were identified by gas chromatography coupled with mass spectrometry. Pasteurisation and UHPH treatments at 200 MPa produced few changes in the volatile composition, reaching similar values to untreated soymilk. UHT treatment produced the most important effects on volatile profile compared to UHPH at 300MPa and 80 °C. Hexanal was the most abundant compound detected in all treatments. The effect of UHPH technology on volatile profile induced modifications depending on the combinations of processing parameters.