Antibrowning agents inhibit polyphenol oxidase.
Scientists at The Ohio State University found that antibrowning agents can inhibit polyphenol oxidase, extending, in this case, the shelf life and consumer acceptability of processed raw potato products by preserving their color. Their efforts revealed that malic acid, citric acid and a combination of sodium acid sulfate, citric acid and sodium erythorbate are better acidulants for inhibiting color change as well as the growth of spoilage bacteria, yeast and mold than is sodium acid pyrophosphate, the industry standard.
In tests, Burbank and Norkotah potato slices were dipped into 3% sodium acid sulfate, citric acid, sodium erythorbate, malic acid, sodium acid pyrophosphate, or a combination of sodium acid, sulfate citric acid and sodium erythorbate. The scientists measured the extent of browning caused by polyphenol oxidase (PPO) obtained from potato extract, to which were added 0.04 to 0.016 grams per mL of antibrowning solutions at pH 2.0 to 6.9.
Using a calorimeter, the researchers measured, on a daily basis, the color of slices dipped in antibrowning solutions at pH 2 to 7 and stored at 4 C for 15 days. Headspace analysis of volatiles in raw and cooked potato samples was performed using a selected ion flow tube mass spectrometer and statistical techniques that analyzed the calculated odor activity values. Microbial growth was measured at 15 days.
At unadjusted pH (1.1 to 7.1), the PPO browning of the control and samples with sodium acid pyrophosphate was not significantly different. Sodium acid sulfate, citric acid and malic acid inhibited some browning, while sodium erythorbate and the combination of sodium acid sulfate, citric acid and sodium erythorbate prevented browning.
At pH 5 to 7, only sodium erythorbate and sodium acid sulfate, citric acid and sodium erythorbate were effective browning inhibitors. Cooking increased volatile levels in the treated potatoes and decreased differences between volatile profiles. Sodium acid sulfate, citric acid and the combination of sodium acid sulfate, citric acid and sodium erythorbate inhibited microbial growth. Sodium acid pyrophosphate, sodium erythorbate and the control did not, most likely due to pH levels.
Further information. Sheryl A. Barringer, Department of Food Science and Technology, The Ohio State University, 2015 Fyffe Rd., Columbus, OH 43210; phone: (614) 688-3642; email: email@example.com.
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|Publication:||Emerging Food R&D Report|
|Date:||Jul 1, 2013|
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