REDUCING ASTRINGENCY, BITTERNESS, AND UNDESIRABLE FLAVORS OF POLYPHENOLIC-RICH FRUIT JUICES AND FUNCTIONAL BEVERAGES
Location: Food Processing and Sensory Quality Research
Project Number: 6435-44000-077-00
Start Date: Aug 10, 2010
End Date: Aug 09, 2015
Objective 1: Determine the correlative relationships between chemical composition and descriptive sensory scores to establish the levels of polyphenols (flavonoids, tannins, lignins, anthocyanins) relative to key flavor and taste compounds in model fruit juices that result in low to high ratings for astringency, bitterness, and other undesirable flavor attributes. Objective 2: Determine the effects of processing technologies on relative amounts of polyphenolic and key flavor compounds and resulting impact on the sensory profiles for juices, concentrates, and puree/fruit smoothie type products. Objective 3: Using the results of Objectives 1 and 2, develop means (e.g. complexation, masking, concentration, blending, buffering agents, encapsulating agents) to amplify positive flavor attributes and decrease astringency and bitter flavors in juices/beverages prepared from phytonutrient-rich fruits without adversely affecting phytonutrient content, solubility, stability, or phytonutrient bioavailability.
In Objective 1, baseline benchmarks will be established for high to low levels of sensory attributes in regards to total and selected monomeric and polymeric polyphenol content in single-strength blueberry and pomegranate juices prepared from commercial concentrates that have been diluted to Code of Federal Regulations (CFR) minimum and/or commercial °Brix standards. Flavor intensities will be related to the concentrations of polyphenol compounds, sugars, acids, and key flavor compounds. In Objective 2, changes in °Brix, acidity, color, total phenolic and key polyphenolic compound contents, antioxidant capacity, and sensory profiles of model, single-strength blueberry and pomegranate juices will be assessed at the juice processing stages (control points). Processing conditions will be altered at stages to improve the flavor profiles of juices, purées, and functional beverages without adversely affecting phytonutrient content, solubility, stability, or bioavailability. In Objective 3, further optimization of flavor and phytonutrient content/bioavailability will be achieved by incorporating into the processing scheme, novel physical and chemical means, and via varietal selection and blending.