Let's get one thing straight: You'll get the best juice if you make it yourself at home from fresh, organic vegetables, just like our cold-pressed juices . However, since these machines are very expensive (starting at $2,000) and cleaning after each pressing takes a lot of time, this isn't a real option for many of us (you can find out here why other machines besides cold pressing aren't an alternative).
Pascalization, bridgmanization, or High Pressure Processing (HPP) is a method for preserving food without heating. The product is placed under very high pressure within its packaging, which inactivates a large number of the microorganisms present. The process is named after Blaise Pascal, a French scientist who studied the effects of pressure on liquids as early as the 17th century. During the Pascalization process, pressure of up to 6,000 bar (≈ 87,000 psi) is applied to the packaged product, in our case, the juice. Using this high-tech method, we are able to provide you with the best, freshest, and most flavorful juice without sacrificing the convenience of extended shelf life – all without heat or chemicals, and therefore without any loss of quality.
We at HPP are the first company in Germany to use it for the gentle extension of the shelf life of our fresh juices. Here's why we're so convinced by HPP: To understand this, it's best to look at what happens to the juice from the very first second after pressing. As soon as the juice is pressed, the naturally occurring bacteria in the juice multiply. At the same time, air and light cause the content of vitamins, enzymes, and other nutrients to decrease immediately. And these multiplying bacteria need something to feed on – namely, the valuable nutrients you actually wanted to consume with your juice. So, the juice loses a significant amount of nutrients, vitamins, enzymes, and therefore quality, within the first few hours after pressing. In our opinion, unpasteurized, non-HPP-treated juice is no longer worth drinking after just a few hours, or at the latest, after a day. HPP stops this deterioration process without the use of heat or chemicals. During the HPP process, microorganisms such as bacteria are deactivated, meaning they die and can no longer multiply. Since the process takes place in the finished, sealed bottle, the juice itself never comes into contact with the machine or the pressure medium (water). Because the bottle is only opened again at the customer's premises after the process, there is no risk of recontamination with bacteria or vitamin oxidation. This is why HPP has been known as a premium process in the USA and Japan for several years and is used for many high-quality products. Customers there also appreciate the advantages of the process and are even willing to pay a premium for it. We firmly believe that if a juice is not consumed within the first 12 hours after production, HPP is the only way to maintain its high quality and food safety. We formed this opinion through extensive research of various scientific studies published in leading international journals. Below, you will find information about HPP from a scientific perspective.
The pressure chamber of a high-pressure calcification system. Inside, pressures of up to 6,000 bar are applied. At the deepest point of the Mariana Trench, eleven kilometers below the surface of the western Pacific Ocean, the pressure is just under 1,100 bar! Only with high-tech equipment can such high pressures be achieved. (Source: Multivac )
How does HPP work?
In HPP (High Pressure Processing), the juices in their final packaging are placed in a water bath under pressure (approx. 6000 bar/600 MPa). This pressure is insufficient to break covalent bonds or create new compounds through the degradation of molecules (Cheftel 1992). However, the pressure is capable of breaking weak bonds. Such weak bonds are found in microorganisms such as bacteria, but not in "simpler" compounds such as vitamins (Cheftel 1992). Therefore, HPP can inactivate bacteria WITHOUT noticeably attacking vitamins or significantly affecting enzyme activity.
Why do the juices have a longer shelf life when HPP is used?
The shelf life of the juices is extended by the inactivation of bacteria within the juice. A measure commonly used for food safety is the total aerobic microflora. Even after just 5 minutes under pressure, this number is reduced many times over in freshly squeezed orange and peach juice (Erkmen et al. 2004, Bull et al. 2004). This reduction logically extends throughout the juice's entire shelf life. Timmermans et al. (2011) demonstrate that the total aerobic microflora remained at a consistently low level even after 30 days. A comparable reduction has also been shown for the levels of E. coli and Salmonella in the juice (Teo et al., 2001). These contaminants naturally do not enter the juice in our IFS-certified production process, where we strictly adhere to all hygiene regulations and the HACCP concept. Since we, and no other manufacturer of cold-pressed juices, cannot rule out contamination of the raw materials with these bacteria, we consider the use of HPP to be an extremely important contribution to the safety of our juices and thus to your health.
What happens to the nutrients, especially the vitamins?
As mentioned previously, HPP has no significant impact on the vitamins and nutrients in the juice. Initially, a small portion of the vitamins is lost through the use of HPP. According to current studies, the vitamin content of juice after HPP treatment is still approximately 90% of that of freshly squeezed juice (Ferrari et al., 2010; Liu et al., 2010; Moreno et al., 2010). While this may sound like a relatively large loss at first, it is mitigated after a few hours. Fresh juice begins to lose important nutrients from the very first minute, so that after just a few hours following HPP treatment, the vitamin content is higher than in juice that has not been treated with HPP (Barbara et al., 2012). At the same time, the pressure applied during HPP increases the activity of various enzymes and secondary plant compounds in the juice, as studies have shown, for example, for an important antioxidant group of plant compounds (catechins) or polyphenols (Moreno et al., 2013). Overall, according to current scientific understanding, HPP does not harm the juice. Dr. Jennifer McEntire from the IFT Institute also summarizes a larger study on HPP with this conclusion: “For the enzymes and nutrients we're interested in, there definitely is, from my perspective, ample evidence to show that HPP is able to maintain the fresh, natural, raw characteristics of the product.” (Interview for well&good magazine). HPP is a gentle method to extend the shelf life of our fresh juice, offering you even more convenience and flexibility. Whether you want to keep a good portion of juice in the fridge, do a longer cleanse, or take your juices with you when you travel – thanks to HPP, the juice stays fresh longer without any loss of quality or nutritional content. Healthy. Convenient. Delicious.
Sources
- Barba, F.J. et al. Evaluation of quality changes of blueberry juice during refrigerated storage after high pressure and pulsed electric fields processing. Innovative food science and emerging technologies 14 (2012) 18-24
- Bull, MK et al. The effect of high pressure processing on the microbial, physical and chemical properties of Valencia and Navel orange juice. Innovative food science and emerging technologies 5, (2004) 135-149
- Cheftel, J.C. (1992). Effects of high hydrostatic pressure on food components: An overview. In C. Balny, R. Hayashi, KK. Heremans & P. Masson (Eds), High Pressure and Biotecnology, Colloque INSERM (Vol. 224) 195-209
- Erkmen O. & Dogan, OC. Effects of ultra-high hydrostatic pressure on Listeria monocytogenes and natural flora in broth, milk and fruit juices. International journal of food science and technology, 39, (2004) 91-97
- Ferrari et al. The application of high hydrostatic pressure for the stabilization of functional foods: Pomegranate juice. Journal of Food Engineering 100 (2010) 245-253
- Goh et al. Baroprotective effect of increased solute concentrations on yeast and molds during high pressure processing. Innovative food science and technologies, 8 (2007) 535-542
- Mandelová, L. and Totusek, J. Broccoli juice treated by high pressure: chemoprotective effects of sulforaphane and indole-3-carbinol. High Pressure Research 27(1), (2007), 151 – 156
- Liu et al. Effect of high hydrostatic pressure on overall quality parameters of watermelon juice. Food Science and Technology International, 19:3 (2013) 197 - 207
- Matser et al. How to compare novel and conventional processing methods in new product development: A case study on orange juice. New food magazine 5 (2012) 35-38
- Moreno et al. Altas presiones en la elaboración de zumo de uva tinta. Tecnifood, marzo/abril (2013) 121-123
- Oxen & Knorr. Baroprotective effects of high solute concentrations against inactivation of Rhodotorula rubra. Food Science & Technology, 26, (1993) 220-223
- Queiroz, C. et al. Effect of high hydrostatic pressure on phenolic compounds, ascorbic acid and antioxidant activity in cashew apple juice. High Pressure Research 30(4), (2010), 507-513
- Teo et al. Effect of low temperature, high pressure treatment on the survival of Escherichia coli O157:H7 and Salmonella in unpasteurized fruit juices. Journal of food protection vol 64-No 8 (2001), 112-1127
- Timmermans, RAH et al. Comparing equivalent thermal, high pressure and pulsed electric field processes for mild pasteurization of orange juice. Part I: Impact on overall quality attributes, Innovative Food Science & Emerging Technologies, 12 (3), (2011) 235-243
