Plant derived polyphenolic compounds are well known for their bioactivities such as antioxidant and anti-inflammatory action in the human system, which would have important implications in health maintenance and chronic disease risk reduction. The health outcome of the polyphenolic compounds are related to the amounts, the specific chemical structures present in the plants, and bioavailability/bioactivity in human system.
Fruits, especially berries, are rich sources of polyphenolic compounds. Consumers are already familiar with targeted evidence-based research emphasizing the health benefits of polyphenolic compounds which may help more people to meet daily serving recommendations of fruits. However, seasonal availability, delicate tissue, and high moisture content present in polyphenolic rich fruits are an issue for perishability, which limits the availability of those fruits throughout the year.
Processing technologies and strategies could offer consumers another source of fruit (i.e. beverage) that is convenient and flexible with different lifestyles. Conventional food processing methods involve higher temperatures (thermal pasteurization) which alter the levels of polyphenolic compounds and other essential nutrients, resulting in reduced bioavailability/bioactivity. Therefore, methods for preserving the “fresh-like” attributes of polyphenolic rich fruits, including flavor and nutritional value, have several advantages. Recent research has investigated alternative techniques to thermal pasteurization in order to facilitate the preservation of unstable bioactive compounds and other essential nutrients in food products such as fruit beverages.
High-pressure processing (HPP) is considered as one of the advanced emerging technologies for delivering high nutritional value and high organoleptic attributes in foods while achieving food safety requirements. HPP is a non-thermal process employing pressures in the range of 200 to 1000 MPa with only small increases in processing temperature. The ultra-high pressures inactivate microorganisms by disrupting membrane systems, retaining the biological activity of polyphenolic compounds, sensory, and other nutrients which extend the shelf-life of foods. HPP has varying effects on bioactive compounds in different food matrices. Available data clearly indicates that high pressure treatment at low/moderate temperatures can retain polyphenolic compounds and other food quality attributes of flavor, color, and essential nutritional properties. Additionally, it has been observed that HPP significantly increased the extractability of polyphenols from the food compared to untreated samples.
However, pressure treatments at elevated temperatures have been shown to induce certain biochemical reactions in the food systems that could reduce the polyphenolic compounds and other nutritional value of food products. Therefore, it is important that polyphenolic compounds should be quantitatively and qualitatively analyzed in food after applying different pressures/temperatures/time to identify the optimum parameters that meet food safety objectives as well as high levels of polyphenolic compounds. Successful research to validate and standardize HPP on fruit derived food and beverages is demanded to obtain high quality food/beverage with increase shelf-life while maintaining its physicochemical and nutritional characteristics, as well as polyphenolic bioactive compounds to satisfy both consumer and scientific requirements.