Spiral filter pressing and nutrient retention in apple juice

Research findings on polyphenol content

Researchers at Oxford Brookes University in the UK have introduced a new method for juicing apples that quadruples polyphenol content compared to ordinary apple juice.

Polyphenols, natural plant compounds found in fruits, red wine, and cocoa, are antioxidants that offer numerous health benefits for the heart and brain while helping to prevent diseases. Therefore, if widely adopted in the future, this new juicing technique could help people obtain more of these beneficial natural compounds.

How oxygen is eliminated during juicing

The new method, known as spiral filter pressing, actively removes oxygen by applying a vacuum during pressing. According to experts, oxygen is also eliminated from all subsequent processing steps, thereby minimizing nutrient degradation.

Previous research findings show that a group of polyphenols called flavan-3-ols can help improve blood pressure, cholesterol levels, and blood sugar control. Stefan Dussling, co-author of the study, stated: “Nutrient loss typically occurs because oxygen rapidly degrades certain nutrients in apple juice, such as flavan-3-ols or vitamin C. This happens whenever we juice apples at home or buy ready-made juice.”

Considerations regarding sugar and juice consumption

Dr. Ana Rodriguez-Mateos from King's College London, who was not involved in the study, noted that finding a way to retain more flavan-3-ols and vitamin C in apple juice during industrial processing is of great value. This enables consumers to choose a healthier option than standard commercial juices. However, Dr. Ana also cautioned that apple juice contains high amounts of sugar, though conventional apple juice processing produces juice with similar sugar levels but fewer phytochemicals. Therefore, if someone still wishes to drink apple juice, it is best to opt for juice richer in phytochemicals rather than regular juice.

The UK National Health Service (NHS) recommends that individuals consume no more than 150ml of fruit juice, vegetable juice, or smoothies per day.

According to Dr. Aisling Daly, co-author of the study, the new technique produces apple juice richer in flavanols than other juicing methods. Nevertheless, the research team emphasizes that people should consume whole fruits and their associated nutrients in whole fruit form.