Abstract
The stability and type of vitamin C added to foods is important for enhancing product quality, label claims, and shelf-life. To improve understanding of stability, the effects of deliquescence, storage relative humidity (RH) formulation, and addition of ascorbyl palmitate and dehydroascorbic acid on degradation of vitamin C at 25°C were studied. Individual vitamin C forms (ascorbic acid, sodium, and calcium ascorbate) and mixtures were stored below, near, and above their deliquescence RH for up to 12 weeks. Vitamin C stability was significantly affected by RH and vitamin form (p < 0.0001). Formulation affected deliquescence and chemical stability: mixtures were significantly less stable above RH0mix than below (p < 0.0001). Ascorbyl palmitate-enhanced degradation rates of more soluble vitamin C forms, and the presence of dehydroascorbic acid reduced vitamin blend stability. It is important that vitamin C products be stored below the deliquescence RH to avoid enhanced vitamin losses.
ACKNOWLEDGMENTS
This research was supported in part by USDA-NRICGP Grant #07-35503-18405 and by a grant from the Lilly Endowment, Inc. to the School of Pharmacy and Pharmaceutical Sciences at Purdue University. Sarah Verkamp is also thanked for her contribution to this work.