Abstract 053
Haze-active protein and polyphenols in apple juice assessed by turbidimetry
J. Food Sci. 62: 79-84, 1997
K. J. Siebert and P.Y. Lynn
The amount of haze-active protein in apple juice was determined by adding tannic acid to induce haze followed by turbidimetry. Turbidity was essentially linear with protein concentration. PVPP treatment prior to tannic acid addition appeared to remove endogenous polyphenols and resulted in slightly weaker response. Adding gelatin to apple juices or clarified ciders induced hazes in response to their content of haze-active polyphenols. At an appropriate gelatin concentration the turbidity was nearly linear with polyphenol concentration. Treatment with bentonite prior to gelatin addition appeared to remove endogenous protein. Temperature control during the induction period was critical to reproducibility.
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