Ultra-high Pressure Homogenization Processing Research Articles

UHPH processing of grape must to improve wine quality

Ultra High Pressure Homogenization (UHPH) consists of continuous pumping of must at pressures above 200 MPa, usually 300 MPa, and its subsequent instantaneous depressurization to atmospheric pressure after passing through a special valve. In the valve, the intense impact forces and shear stresses, together with the temperature, lead to the death of microbial cells and also to the inactivation of oxidative enzymes. Intense mechanical stresses also result in nanofragmentation of colloidal particles increasing the release of nutritional factors such as YAN and others, thus improving colloidal stability. Molecules with sensory impact such as terpenes are not affected by the UHPH process, thus preserving the varietal character, nor can thermal markers such as furfural be detected. UHPH-processed musts show and maintain higher antioxidant activity than control musts and show less browning effects during processing and even later throughout and after fermentation. This technique also affects the extraction and stability of anthocyanins and other phenolic compounds by increasing their release from cell structures and protecting them from oxidation. The antimicrobial effect and the inactivation of oxidative enzymes allow the production of wines without or with a very low level of sulfur dioxide. The ability to inactivate enzymes by affecting their tridimensional structure may also have some effect on colloidal proteins by preventing protein haze or facilitating the use of protease enzymes.

Characterization and oxidation stability of spray-dried emulsions with omega-3 oil and buttermilk processed by ultra-high-pressure homogenization (UHPH).

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.

Sea buckthorn pulp oil nanoemulsions fabricated by ultra-high pressure homogenization process: A promising carrier for nutraceutical

Food protein-stabilized with nanoemulsions were prepared by ultra-high pressure homogenization under appropriate homogenization condition, so as to improve the poor water solubility and instability of sea buckthorn pulp oil (SBPO). SBPO nanoemulsions stabilized by sodium caseinate (SC) and whey protein isolates (WPI) suggested good microstructures and rheological properties. SC-stabilized SBPO nanoemulsions system showed smaller mean particle size (<260 nm), lower Ke value (6.3–20.4%) and higher absolute value of zeta potential (55.70–67.20mV) over various pH (3–9), salinity (0–200 mM), temperature (20–80 °C). The SC-stabilized SBPO nanoemulsions showed no significantly increase in droplet size over 30 days at 4 °C and 25 °C, which proved it has good stability. The antioxidant activity of SC-stabilized SBPO nanoemulsions was evaluated by employing cellular antioxidant activity (CAA) model and the results showed good antioxidant activity. This study implied that protein-stabilized nanoemulsions are a promising carrier for extending the applications of SBPO as nutraceutical or functional dairy beverage.

Use of Ultra-High Pressure Homogenization processing in winemaking: Control of microbial populations in grape musts and effects in sensory quality

Abstract Ultra-High Pressure Homogenization (UHPH) is a fast and efficient technique that can sterilize fluid foods at low temperatures or even under cooling conditions. A white must (Vitis vinifera L.) was processed at 300 MPa (inlet temperature 20 °C, in-valve temperature 98 °C, outlet temperature 25 °C, and time in valve 0.02 s) and their performance was compared with two untreated controls, a must that underwent a spontaneous fermentation (without SO2 addition) and another must that was sulfited with 35 mg/L of total SO2 and inoculated with the same Saccharomyces cerevisiae yeast as the UHPH-treated must. UHPH treatment led to the total elimination of grape microorganisms considering an initial population of 1 × 106 CFU/mL in average of wild yeasts and fungi in must, and approximately 7 × 103 CFU/mL of background bacteria. In a parallel assay, UHPH-processed must without yeast inoculation showed absence of fermentation for eight days at 18 °C. The musts treated with UHPH showed a lighter appearance (10%) before fermentation compared to the control. The triangular test verified the existence of sensory differences between the wines obtained and the preference tests showed that the judges found the wine obtained from the UHPH-treated must more fruity (3.5/5 compared with 1.5–2 in controls) and with better aroma. Industrial relevance UHPH is an interesting way to process the must before fermentation allowing the reduction of sulfite addition while controlling wild and spoilage microorganisms.

Modeling the effect on skim milk during ultra-high pressure homogenization using front-face fluorescence

Abstract This study provides a rapid method to evaluate and control quality changes in skim milk, using front-face fluorescence during ultra-high pressure homogenization (UHPH), for potential inline usage. Tryptophan, dityrosine and Maillard compounds were selected as indicators for their intrinsic fluorescence. The homogenization pressure was from 100 to 300 MPa and inlet temperature was from 23 to 83 °C, both distributed on a central composite design. The selected fluorophores showed good fit to the models as functions of pressure and inlet temperature. However, there was little formation of dityrosine and Maillard compounds when inlet temperature was below 50 °C. Tryptophan and dityrosine fluorescence could provide information on milk protein changes, such as denaturation, reformation and aggregation, while generation of Maillard compounds indicated thermal effects between sugars and amino acids. This work shows a promising potential to monitor and predict structural and functional changes in milk during UHPH processing and decide on its appropriate usage for further dairy production.

Modeling of the changes in bovine milk caused by ultra-high pressure homogenization using front-face fluorescence spectroscopy

Ultra-high pressure homogenization (UHPH) has been considered as an effective method to modify/enhance liquid-food properties in many studies. This research provides an alternative approach to monitor, evaluate and control quality changes induced by UHPH processing of milk using front-face fluorescence spectroscopy for potential inline usage. The fluorescence intensity spectra provided structural, functional and nutritional information of milk compounds diversification. Homogenization pressure and inlet temperature were distributed on a central composite design which covered the range of commonly used UHPH treatment conditions for improving milk technological and sensory characteristics as well as microbiological safety. The indicators showed good fit to the response surfaces as functions of pressure and inlet temperature. Tryptophan and dityrosine fluorescence provided information on milk protein changes, such as denaturation and aggregation, and particle size changes also confirmed protein denaturation and aggregation information from the fluorescence results. Generation of Maillard compounds indicated the thermal effects between reducing sugar and amino acids on milk. The retinol concentration, as a nutrient, could be well predicted by principal components summarized from milk sample spectra, without sample preparation.

초고압균질 가공에 의해 제조된 초미세 비지 현탁액의 영양성분 및 항산화성

Biji is a tofu by-product made by squeezing the liquid out of the dregs left over from making tofu. The objectives of this research were to break the biji into sub-micron-scale particles and to prepare a biji sub-micron suspension having increased quality characteristics such as antioxidant capacity, polyphenol, dietary fiber, and soluble protein contents, in comparison with untreated biji. Disruption of biji by an ultra-high-pressure homogenization (UHPH) process was used to prepare the sub-micron suspension of biji. UHPH can be used to prepare emulsions or suspensions with extremely small particle sizes. The effect of the UHPH process on biji was studied at 1,000, 1,500, and 2,000 bar. The extraction yield increased up to 1.64 times by breaking the biji to form a sub-micron suspension. The soluble dietary fiber, protein, and free amino acid contents were increased by the UHPH process (p&lt;0.05), in comparison with those of untreated biji. Furthermore, the total sugar, free sugar, and total polyphenol contents of biji were augmented by the UHPH process. Antioxidant activity (ABTS) after exposure to UHPH (1,000-2,000 bar) was well retained (p&lt;0.05). The extraction efficiencies and nutritive components were enhanced by increasing the pressure in the UHPH process.

Special Issue on International Nonthermal Food Processing Workshop: FIESTA 2012

The first part of this Food Engineering Reviews Special Issue highlights outstanding review articles presented at the International Nonthermal Food Processing Workshop— FIESTA 2012, which was held in Melbourne, Australia, on October 16–17, 2012. Selected speakers were invited to submit manuscripts based on their presentations, which were then peer-reviewed in accordance with the standards of this journal. The workshop is an annual event organized by the Nonthermal Processing Division of the Institute of Food Technologists (IFT) and the European Federation of Food Science and Technology (EFFoST) in a number of countries around the world. In 2012, the workshop was hosted by the CSIRO, Australia’s National Research Organization, as part of the biennial Innovative Foods Conference Series, FIESTA, where the theme was ‘‘Innovative Processes for Sustainable, Safe and Healthy Foods.’’ The 2-day workshop program featured more than 20 internationally renowned speakers and 40 poster displays to further advance science and technology on fundamentals and applications of nonthermal and other advanced food processing technologies. To add value and enable the sustainable manufacture of healthier food products was the primary focus of this event. Other relevant topics featured in the workshop included consumers, markets and sustainability, which are all essential elements for successful adoption and commercialization of emerging technologies. The workshop was a major success attracting over 170 delegates from 18 countries and 86 organizations representing industry, academia and government. The workshop was also attended by several virtual delegates which followed presentations online and on Twitter. We are delighted to include five high-quality reviews on nonthermal food processing where the emphasis is on food engineering aspects. These articles cover atmospheric pressure plasma, ultra-high-pressure homogenization (UHPH), high-pressure processing (HPP), megasonic separation and ultrasound processing. In particular, this Special Issue reviews the latest research on plasma applications on solid and liquid foods, the effects and novel applications of the UHPH process, the application of HPP in fish muscles, design aspects of megasonic separation reactors and the latest research on the application of ultrasound to conventional dairy processes. We gratefully acknowledge the support of all workshop sponsors and thank all authors and reviewers for making possible this valuable, high-quality contribution to the body of knowledge on nonthermal processing of food.

Effect Of Ultra High-Pressure Homogenization on hydro- and liposoluble milk vitamins

The Ultra High-Pressure Homogenization (UHPH) process has proved to be an adequate technology to produce milk with similar microbial, sensory and physicochemical characteristics to the heat-treated milk. However, no information has been published regarding the effect of this technology on the vitamin content of milk. For this reason, the aim of this work was to evaluate the effect of the UHPH process on milk vitamins, comparing the results with those obtained by applying heat treatments. The UHPH conditions evaluated were those in which the microbial and physicochemical characteristics obtained in milk were similar to the characteristics of pasteurized (PA) and UHT milks, consisting these treatments in the application of 300MPa at different inlet temperatures (Ti) of 45, 55, 65, 75 and 85°C; the heat treatments applied were 90°C for 15s and 138°C for 4s in PA and UHT milks, respectively. The hydrosoluble vitamins analyzed were nicotinamide, thiamine, pyridoxal, pyridoxamine, folic acid, cyanocobalamin, riboflavin and vitamin C (total vitamin C), and retinol and α-tocopherol in the liposoluble vitamin group. The results showed an important reduction in the destruction of nicotinamide, thiamine, riboflavin and vitamin C in the UHPH-treated milks compared to those heat-treated. Further, the UHPH treatments tested were able to retain most of the vitamin content presented in raw milk. In this sense, the sample treated at 300MPa with Ti=45°C presented the closest vitamin content to that of raw fresh milk. In addition, the increase of the Ti in the UHPH treatments applied produced a significant increment (P<0.05) on the vitamin destruction, especially in nicotinamide, thiamine, riboflavin and vitamin C in milk, with a maximum of destruction of 19.97, 33.46, 13.46 and 22.56%, respectively at 300MPa with Ti=85°C. On the contrary, an important destruction of nicotinamide, thiamine, riboflavin and vitamin C (27.31, 33.46, 17.30 and 61.28%, respectively) was observed in the UHT milk. Additionally, the content of liposoluble vitamins in milk was almost not affected by both heat and UHPH treatments applied. These results show the possibility of employing the UHPH technology in milk to reduce the vitamin destruction, obtaining a milk with higher nutritional properties than a heat-treated milk.

Influence of ultra high pressure homogenization processing on bioactive compounds and antioxidant activity of orange juice

Abstract The purpose of this study was to evaluate the effect of ultra high pressure homogenization (UHPH) treatments on bioactive compounds and antioxidant activity of orange juice. Fresh squeezed orange juice was pre-warmed at two inlet temperatures (10 and 20 °C) and processed at 100, 200 and 300 MPa. The level of depletion of both l -ascorbic acid and carotenoids significantly depended (P l -ascorbic acid in the UHPH treated samples at any pressure was significantly higher (P Industrial relevance Nowadays, food researchers are testing alternative treatment technologies to heat pasteurization due to the increased interest in achieving high levels of food safety while producing high nutritive quality products. Ultra high pressure of homogenization (UHPH) is an emerging technology based on the dynamic application of high pressure allowing the processing of fluid foods continuously, which has been proposed as an alternative to thermal pasteurization for foods with heat-sensitive properties. The recent improvements in the UHPH equipments are design to apply semi-industrial treatments at pressures above 350 MPa, with a better temperature control. The successful application of UHPH treatments may provide with a new generation of minimally processed products, hopefully closer to the fresh ones in organoleptic and nutritive properties, but as safe and lasting as the pasteurized ones.

Aseptically packaged UHPH-treated apple juice: Safety and quality parameters during storage

Ultra-high pressure homogenization (UHPH) at 300MPa and 4°C inlet temperature were used to preserve apple juice, and shelf-life evaluation of aseptically packaged juice was investigated. After processing Tetra Brik containers were stored at temperatures of 4, 10, 20 and 30°C during 60days. In this article, the effect of processing on the spoilage inactivation was evaluated after processing and during the storage trial. Non-germinated and germinated spores were found in the UHPH-treated juice, being an inactive population during storage. Patulin content was also not modified by UHPH processing, but a significant decrease was observed during storage at 30°C (P<0.05). Polyphenoloxidase (PPO) and pectinmethylesterase (PME) activity was not found after UHPH-processing and during storage.A kinetic study of post-processing quality loss was conducted. Vitamin C, chlorogenic acid, total polyphenols and color change were measured during storage study and were used to model the UHPH-treated apple juice shelf-life. Loss of vitamin C was correlated with the hydroxymethylfurfural (HMF) accumulation (0.59, P<0.05). A limiting quality parameter was polyphenolic content. UHPH-treated apple juice stored at 4°C was found to show a shelf-life for about 21months by preserving the color characteristics of the juice with low HMF accumulation. From 15°C changes in quality parameters were more evident.

Inactivation of Salmonella enterica Serovar Senftenberg 775W in Liquid Whole Egg by Ultrahigh Pressure Homogenization

Two batches of samples of liquid whole egg were inoculated with a load of approximately 3 and 7 log CFU/ml, respectively, of Salmonella enterica serovar Senftenberg 775W and submitted to different ultrahigh pressure homogenization (UHPH) treatments at 150, 200, and 250 MPa. The inlet temperature of the samples was 6°C. Counts of viable and injured Salmonella cells were obtained 2 h after the UHPH treatments and after 5, 10, 15, and 20 days of storage at 4°C. The level of pressure applied influenced the lethality attained significantly (P < 0.05). In the samples with an initial load of approximately 7 log CFU/ml, the highest lethality value of 3.2 log CFU/ml was obtained at 250 MPa, and it is similar to those values reported in other surveys for thermal pasteurization with this same Salmonella strain. When the initial load was approximately 3 log CFU/ml, total inactivation was apparently obtained after the 250-MPa treatment (2.7 log CFU/ml). After 10 days of storage at 4°C, Salmonella counts decreased in UHPH-treated samples, and colonies were not observed in tryptone soy agar and yeast extract medium. Nevertheless, presence of viable Salmonella cells was detected with the VIDAS Salmonella immunoassay method during the entire storage period. These results encourage further investigation of UHPH processing of liquid whole egg, assaying the possibility of using higher pressures and fluid inlet temperatures.

Effects of Microfluidizer® Technology on Bacillus licheniformis Spores in Ice Cream Mix

We studied the effect of Microfluidizer® technology (sometimes referred to as “microfluidization”), a new ultra-high pressure homogenization process, on spores of Bacillus licheniformis in ice cream mix. Four batches of pasteurized ice cream mix were preheated to 33, 36, 44, or 50°C, and spores of B. licheniformis were added to yield an inoculum of 2.0×104 spores/ml of mix. Samples were treated at 50,000, 100,000, 150,000, and 200,000 kPa. Respective percentages of spore destruction ranged from 6 to 68%. As process pressure in the Microfluidizer® system increased, the temperature of the product also increased. At the Microfluidizer® system outlet, temperatures ranged from 46 to 88°C. Therefore, a combination of forces, including high pressure and temperature, likely had a multiplier effect on spore destruction during Microfluidizer® processing of ice cream mix. Data suggest that it might be possible to design a pasteurizer-Microfluidizer® system that would inactivate most bacterial spores in dairy foods without the extreme heat treatment currently required in commercial processing operations.