Juicy joy: Tetra Pak perfects new pasteurization process

After trials with Finnish dairy giant Valio – using one of its orange juice brands – the Swiss-headquartered multinational insists there is no impact upon product quality and that the process will also allow high acid juice producers to cut carbon emissions by 20%.

So how do you pasteurize juice? After juice has been squeezed a first pasteurization deactivates enzymes and kills microorganisms to achieve acceptable commercial sterility.

However, for not from concentrate (NFC) juice there is a risk of microorganisms entering juice during transport or bulk storage, while juices or nectars from concentrate may be subject to recontamination during storage and transport or during reconstitution with water.

‘No impact on quality of juice’​

Therefore, a second pasteurization prior to filling, usually 95C for 15 seconds, is employed to kill microorganisms that have grown during this interim period.

But Tetra Pak insists a temperature of 80C for 15s is effective for products with a pH of 4.2 or below.

Micael Simonsson, manager of Tetra Pak’s Center of Expertise, said the development helped customers improve their bottom line in an ever more competitive market.

“At the same time, extensive tests show that the new process has no impact on the quality of the juice produced, be it in terms of taste, nutrition, storage stability or visual appearance,”​ he said.

Tetra Pak aims to cover its new process via two international patents – PCT/EP2013/074496 and PCT/EP2013/074473 – and a recent white paper outlines the science behind the move.

2013 tests with Valio Oy​

Tests with Tetra Pak customer Valio Oy at its juice plant in Helsinki in June 2013 used beverages packed in Tetra Prisma Aseptic (250ml) packages, and found the drinks were commercially sterile after three weeks following pasteurization at 80C for 15 seconds.

Taste tests after six weeks of storage, using the orange juice treated at 80C and 95C, both for 15s, showed no significant differences, and the result was the same after six months.

Vitamin C degradation during storage (due to normal oxygen ingress) was consistent across  both samples and no visual differences between the two were detected.

Calculating cost benefits based on a 22,000 liter/hour Tetra Therm Aseptic Drink line (pictured left) Tetra Pak predicted lower heating and cooling loads and an energy cost of €80,000, a 19% cut.

The line’s carbon footprint would also fall 20% to 6.7kg CO2/1000 liters of product, Tetra Pak added.