Effect of chlorine dioxide on ascorbic acid and total polyphenols in model systems and fruit and fruit juices
Abstract
Chlorine dioxide (ClO2) has potential as an effective sanitizer for the food industry because of its strong oxidizing power. However, its capacity as an oxidant means it may also react with beneficial food components and alter nutritional quality. The purpose of this work was to understand the reaction of ClO2 with nutritionally important food compounds, specifically ascorbic acid (AA) and fruit polyphenols. The reaction of ClO2 with AA was first studied in a model system. At concentrations of 0.3-3.2 mg/L ClO2, corresponding to ratios of 5:1 to 50:1 ascorbic acid to ClO2, there was a dose-dependent rapid reduction in AA concentration followed by a slower period of first-order degradation. Reaction of AA with chlorite, a by-product of ClO2 reduction, followed a similar first-order degradation rate without the initial rapid decrease in concentration. Thus chlorite is likely responsible in part for AA degradation after the initial reaction with ClO2. More complex model systems containing AA with glucose and/or polyphenols, catechin and hesperidin, showed variation in AA degradation after reaction with ClO2. Glucose and catechin demonstrated a slight protective effect while hesperidin seemed to enhance AA degradation. HPLC-MS analysis indicated that dehydroascorbic acid (DHAA) was a primary degradation product of the reaction between AA and ClO2. In commercial orange and apple juices, no significant differences (p<0.05) were observed after 6 weeks between AA and total polyphenol (TP) content in controls versus juices treated with 1 mg/L aqueous ClO2. Furthermore, 5 mg/L gaseous and 115 mg/L aqueous ClO2 treatments performed on whole apples did not result in significant degradation of AA in apple peels. However, a significant decrease in TP compared to controls occurred in apple flesh after 30 minutes of treatment with 115 mg/L aqueous ClO2. This work has shown that although ClO2 will readily oxidize AA in a model system, responsible industrial use of ClO2 in low concentrations will not likely affect the nutritional quality of fruits and fruit juices.
Degree
M.S.
Advisors
Ferruzzi, Purdue University.
Subject Area
Food Science|Agronomy
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