High-pressure processing (HPP) is a “non-thermal” technology that has been developed to get microbiologically safe food products whereas avoiding undesirable changes within the sensory, physicochemical, and nutritional properties of foods. The high-Pressure process is also known as the cold pasteurization technique in which food is sealed in versatile and waterproof packaging, and then subjected to a high level of hydraulic pressure of 600 MPa / 87,000 psi for a couple of seconds to minutes.
Although the Non-Thermal sterilization impact of high pressure on foods has been legendary since the nineteenth century, it had been not till the 1990´s that the primary HPP product was developed. There has been rapid commercialization since 2000, high pressure processing has been successfully implemented in every food industry worldwide.
High-Pressure Processing is considered to be a natural, environmentally friendly methodology that respects the ingredient and helps maintain the food characteristics like flavor and nutrients. It is totally different from ancient thermal and chemical treatments.
Thus, HPP has become one amongst the innovative food process technologies most accepted by customers worldwide. In this process, both liquid and solid products are processed, but these must be pre-packed in pouches that have a high barrier, flexibility, or plastic container.
High-Pressure Processing equipment is of two types – Horizontal model and Vertical Model. In the Food industry Horizontal model is preferable because of Horizontal design for traceability and easy installation. The stainless-steel body of equipment enables cleaning in place. The equipment allows Automatic loading/unloading system. Working pressure is up to 600 MP (6000 bar).
- BASIC HPP PRINCIPLES:
High-Pressure Processing is based on two principles:
- Le Chatelier’s principle: Any phenomenon (phase changes, modification in molecular configuration, chemical reaction) in a midst of a decrease in volume is increased by pressure. Accordingly, the pressure shifts the system there to of lowest volume.
- Isostatic principle: Pressure is transmitted instantly and uniformly throughout a sample, and pressure is gradients do not exist so that the dimensions and geometry of the product are inapplicable.
A typical HPP system consists of four key components:
1. Pressure vessel
2. Pressurization fluid
• The packages are loaded into the high-pressure chamber by using a perforated basket. • The vessel is sealed and filled with a fluid which will transmit fluid (normally water).
• Pressurized using a high-pressure pump, which injects additional quantities to fluid obtain targeted pressure.
• The product is controlled at the required pressure for about 3 to 10 minutes.
• Once holding the product for the required time at the given targeted pressure, the vessel is decompressed by releasing the pressure transmission fluid.
• Now the product will be ready for unloading.
- PHYSICO-CHEMICAL CHANGES:
Effects on Food Color & Flavor:
• Fresh or marinated meat: Iron within the hemoprotein (myoglobin) changes from ferrous to ferric and simple protein is denatured-the red color is lost.
• Cooked meat color meat is largely unaffected.
• Flavors are mostly unaffected.
Effects on Food Texture:
• Slight softening in foods which consist of cell membrane structures. Effects on Fats and Lipids:
• Reversible crystallization
Effects on Proteins and Enzymes:
• Proteins are partly denaturized in the products wherever proteins have not been previously changed by an alternative method like heating, drying, and fermentation, etc.
• Retains food quality, maintains natural freshness, and extends the microbiological time.
• Results in foods with higher style taste, appearance, texture, and nutrition.
• Food is preserved equally throughout.
• Environment friendly.
• No waste generation.
• Independent of size and form of food.
• High capital cost of equipment.
• Food enzyme and bacterial spores require high pressure for inactivation.
• Enhance Enzymatic and oxidative degradation.
• Fragile food requires special attention.
What food trends will HPP follow in upcoming years?
• Ready-to-eat meals (RTE) ready-to-drinks beverages (RTD):
The 2020 consumer desires meals that give comfort however with extras of flavor, quality, and selection, compatible with a healthy and varied diet, with high added worth.
• Single bite snacks:
Growing demand for healthy snacks to “kill a craving” between meals.
• Plant-based products:
Foods of vegetable origin with organoleptic characteristics, like meat products are numerous and the achievements exciting.
• Food for more than just a pet:
The concern for the health associate degree of pets is an upward trend that has climbed in high hydraulic pressures.
• Preservation for colostrum:
HPP is the best choice to preserve and respect the practicality of thermosensitive bioactive elements present in colostrum like immunoglobulins, lactoferrin, and growth factors.
HPP will help reduce the use of chemical additives since the shelf life extension by HPP treatment is based on physical processing. The development of vessels of upper volumes, with the incorporation of automatized solutions, can end in higher processes outputs and possibly within the reduction of price per metric weight unit. HPP play an outstanding role in the pasteurization and structure modification of pumpable foods in a continuous operation processing soon. The annual growth rate of HPP food production is estimated to be around 8.4% through 2022. HPP will help in the reduction in the environmental footprint, which could be of greater importance soon.