Chapter 17
Non-Enzymatic Browning in Orange Juice and Mango Puree 1
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Robert S. Greenberg , Catherine A. Culver , Nicholas S. Kretchman , and Jennifer DiCicco 1
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Pepsi-Cola Company, R&D Center, 100 Stevens Avenue, Valhalla, NY 10595 Sensory Consultant, Beavercreek, OH 45432 2
The quality of Not-From-Concentrate Orange Juice (NFC) and Totapuri mango puree deteriorates during storage because of changes caused by non-enzymatic browning. Juice and puree quality is typically determined by trained sensory panels. This study investigates the relationship between dissolved and headspace oxygen levels, ascorbic acid levels, juice color, and sensory scores for NFC orange juice stored under various conditions. The color and sensory scores for mango puree were evaluated as a function of storage time, temperature, and package type. These studies showed that juice quality can be rapidly evaluated by measuring the hue angle, an indicator of juice browning. The role of tin packaging in preserving mango puree color remains unclear.
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© 2008 American Chemical Society
213 The quality of fruit juices depends on the preservation of juice color, flavor, and aroma during processing and distribution. Quality losses are typically due to browning and the development of off-flavors (/). Juice browning develops from carbonyl-amine reactions between amino acids, sugars, and ascorbic acid breakdown products (2, 3). Browning degradation products isolated from citrus model systems include aroma active organic acids, furans, furanones, pyranones, and pyrroles (7). The kinetics of juice browning and ascorbic acid degradation have been reported as either zero order or first order (3, 4). These kinetics may actually describe multiple reactions, depending on temperature and oxygen levels. The initial rapid loss of ascorbic acid may reflect oxidation by dissolved and headspace oxygen, followed by slower thermal degradation. For aseptically packaged orange juice stored six months at ambient temperature, approximately one third of ascorbic acid loss is attributed to oxidative and two thirds to nonoxidative pathways (5). The oxidative reaction proceeds approximately 10-1000 times more rapidly than non-oxidative processes (2). Browning in juices other than citrus, apple, and pear has received relatively little attention. Processors have long known that non-enzymatic browning of pineapple and mango products can be greatly reduced by use of tin-lined steel cans (
