High Pressure Processing (HPP) in Beverages

Objective:

High pressure processing is a new method of beverage pasteurization that has many advantages over traditional methods and produces a safe and nutritious beverage. Due to these reasons beverages industries use high pressure processing techniques to make beverages.

HPP:

HPP is a non-thermal technique that use cold water and high pressure (87000 psi) to inactive microbes’ form juices and some other beverages without other any effect on beverages.

Factors that affect HPP effectiveness:

• ·       The amount of pressure that applied
• ·       Time of holding the vessel
• ·       Type of product
• ·       Targeted microbes
• ·       More effective with high water activity products

Benefits of HPP for beverages:

• ·       Increase the shelf life
• ·       Reduction of food waste
• ·       Maintain Color
• ·       Maintain Flavor and taste
• ·       Maintain nutritional value
• ·       To kill microbes
• ·       Safe the food according to consumer demand
• ·       More Efficient
• ·       More productivity

HPP applications in beverages:

• ·       Fresh Juices
• ·       Some functional beverages
• ·       Cold coffee
• ·       Non-carbonated beverages

Why HPP is preferred:

HPP is preferred for some beverages because it is beneficial preservation method for these products. This technique removes bacteria and other threats without disturbing the nutritional profile, color, and flavor.

Why not thermal pasteurization of juice:

·       Because nutritional profile will disturb by destroying vitamins, minerals and antioxidants

·       Interactions between polymers

·       Color and flavor also disturb

Why HPP is not used for carbonated beverages:

In carbonated beverages, there is high pressure present inside the packaging because of CO2 that kills the microbes. If we provide pressure to carbonated beverages, the pressure will increase that cause bursting (htt1).

Mechanism of HPP:

·       First of all, load the packages that are hermetically sealed into carrier baskets

·       Then these baskets are penetrated into vessel that are sealed by plugs.

·       Creating pressure on packaging by pump the water into vessel

·       This pressure will remain continue for six minutes and time will also vary

·       The pressure is provided through the packed food to kill the microbes and disturb the autolytic enzymes without disturbing the nutritional profile, color and flavor

·       This mechanism helps to preserve the freshness of beverage and extend the shelf life

Popularity of HPP:

·       HPP technique is more popular for cold pressed juice because its name tells that it’s all things are done without heat.

·       The shelf life of cold pressed juice is from week to days without opening.

Opportunity of HPP:

·       HPP technique is commercially available for more than 15 years

·       More than 200 industries have HPP machine services for their products in US

·       HPP is a fresh preservation method alternative to other preservative and pasteurization techniques

·       Using of HPP technique is increased every year and many industries are familiar with it and used it in their industries for their products (htt2).

Conditions of HPP:

·       600MPa for 3 min

·       550MPa for 1 min

·       For acidified juices and beverages which pH have less than 4.5 to kill the microbes

Bacteria in acidified juices and beverages:

·       Escherichia coli

·       Salmonella enterica

·       Listeria monocytogenes (Usaga & Acosta, 2020).

Recognition:

·                FDA Juice HACCP Rule in 2004, HPP was recognized as a non-thermal pasteurization process

Inactivation of microorganisms:

How HPP inactivate the bacteria:

·                At low pressure, the cellular functions of bacteria such as replication of DNA, transcription and translation are disturbed that retard bacterial growth

·                At high pressure, microbes are injured due to rupture of cell membrane and loss of protein functionality

·                Mold, yeast and parasites are more sensitive to pressure

Type of packaging used for HPP:

Packaging that are used for HPP are elastic because when pressure is applied the volume is reduced and this elasticity prevents from rupture of packaging

·       Plastic bottles

·       PET, PE, PP trays

·       Pouches

·       Cups

·       They all have good barrier properties and flexibility

How shelf life is affected by HPP:

·       Extension of shelf life by HPP is depends on Product parameters and process

·       Longer the holding time and high pressure inactivate the microbes and reduce the activity of enzyme (htt3).

Comparison of shelf life: