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Quality retention of calcium and ascorbic acid fortified muscadine grape juice [electronic resource] /

by Pires, Danielle M.

Abstract (Summary)
ABSTRACT: Muscadine grapes (Vitis rotundifolia) have developmental potential to become an important economic crop for growers in the southeastern US, and grape juice is an important commodity by which muscadine grapes can be introduced to the remainder of US market. However, important quality changes during processing and storage may affect advancement of future markets. Paramount is color degradation that occurs under normal storage conditions. Presumably the result of oxidation of anthocyanins, the major grape pigments, juice color turns from a deep red or purple to a red-brown color that is visually unappealing. Off color development may also result from oxidation of non-anthocyanin polyphenolics that together could hinder sales of muscadine grape juice. Therefore, it is hypothesized that fortification of muscadine grape juice with various compounds may serve to extend shelf life, color, and antioxidant properties. Various fortificants were evaluated including ascorbic acid, calcium, and various metal chelated forms of ascorbic acid in attempt to control oxidation and stabilize anthocyanins during processing and storage. Fortified juices were evaluated over time for anthocyanin and color stability, composition and concentration of phenolic acids, and antioxidant capacity compared to non-fortified controls. Results show 70% loss of anthocyanin concentration in samples containing 100 mg/L ascorbic acid alone and 100
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School:University of Florida

School Location:USA - Florida

Source Type:Master's Thesis

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