Redox properties' changing in canned products as an effect of citric and ascorbic acids' addition

Presents the results of investigation for influence of citric and ascorbic acids added to puree from apple, plum, carrot and pumpkin on the reducing capacity index. The concentration of the minor component was varied from 0 to 0.8% for citric acid and from 0 to 120 mg in 100 g for ascorbic acid. Active acidity (pH) and the redox potential (Eh) were determined in the finished products. The reducing capacity index (RH) was calculated by the original method. The presence of a statistically significant effect for the mass fraction of citric acid added to vegetables puree on the reducing capacity index was established. However, the effects for the carrot and pumpkin puree were the opposite. Positive effect was observed for pumpkin puree only, where the target dynamic was occurred until the mass fraction of the minor components in the product become up to 0.1%. The expediency of ascorbic acid addition to pumpkin and fruit puree for positive correction of the reducing capacity index with concentration up to 70-80 mg per 100 g of product was obtained. Further increase in concentration showed a tendency to transfer plateau area in relationship "concentration - RH». For the same reason the maximum effective from the viewpoint of influence on reducing properties of carrot puree mass fraction of ascorbic acid was 15-20 mg per 100 g product.