top of page

The latest news, trends, analysis, interviews and podcasts from the global food and beverage industry

FoodBev Media Logo
Access more as a FoodBev subscriber

Sign up to FoodBev and unlock more insights from the international food and beverage industry. Subscribers have access to webinars, newsletters, publications and more...

German scientists develop process to enhance polyphenol content in apple juice
Siân Yates

Siân Yates

26 February 2024

German scientists develop process to enhance polyphenol content in apple juice

Researchers at Hochschule Geisenheim University in Germany have made a breakthrough in apple juice processing, with a new "super" apple juice that could enhance heart health by boosting blood flow. The study, published in Food Research International, reveals a novel squeezing method called a spiral filter press, which maximises polyphenols in apple juice. This technique actively removes oxygen through vacuum-driven pressing, thereby reducing nutrient deterioration throughout the processing stages.

Polyphenols – natural plant compounds abundant in fruits like apples, as well as red wine and cocoa – have been extensively studied for their benefits on heart and brain health. The researchers found that this new method increased polyphenol content in apple juice by four times compared to conventional methods. Lead author of the paper, Ralf Schweiggert, said: “Apple juice is already a source of polyphenol compounds, but you would need to drink several glasses to reach the levels recommended by scientists for heart health effects. The new juicing method that we’ve investigated takes the polyphenol content to a new level by minimising the nutrient losses we typically see during juicing.” A single 280ml serving of the enhanced apple juice could fulfil 100% of the ideal intake for a key group of polyphenols known as flavan-3-ols, essential for promoting healthy blood flow. This achievement aligns with recommendations proposed by an international consortium of scientists in 2022, advocating for a daily intake of 400mg–600mg of flavan-3-ols for cardiovascular health. Co-researcher Stefan Dussling added: “Nutrient losses are commonly due to the presence of oxygen which quickly degrades some of the nutrients in apple juice like flavan-3-ols or vitamin C. This would happen when we juice apples at home or buy a ready-made product. We hope that the new juicing method will be used more widely in the future to help people get more of these beneficial natural compounds simply by drinking one glass of juice.” The research paper concluded: "Spiral filter press dejuicing effectively mitigated enzymatic oxidation, resulting in particularly high levels of flavan-3-ols. The reached flavan-3-ol levels in spiral filter-pressed juices made without pectinase mash treatment (713.1mg/l) suggested that an approximate daily consumption of 280ml would meet the recommended daily flavan-3-ol dosage (200mg) associated with cardiovascular health benefits of an EU-authorised health claim regarding cocoa flavan-3-ols."

bottom of page