The titration of vitamin C in citrus juices

Auto‐oxidatios, of Filtered Citrus Juices

“…Williams and Corran (1930) found that both potassium metabisulfite and sodium benzoate had a destructive effect on the vitamin. Bennett and Tarbert (1933) reported that sulfur dioxide and benzoic acid both had a destructive effect on vitamin C. Morgan, Field, and Nichols (1931) found, however, that there was less loss of vitamin C in dried fruit that had been sulfured than in unsulfured i'ruit.…”

“…The possible interference of SO, in this titration has not been studied heretofore. Bennett and Tarbert (1933) determined ascorbic acid in sulfited orange and lemon juice by first distilling off the SO, in a current of CO,. This procedure does not include dehydroascorbic acid.…”

The health of nine Royal Naval Arctic crews, 1848 to 1854: implications for the lost Franklin Expedition

“…If 'strengthened' was a synonym for the 'fortified' juice supplied to Collinson, it implies the addition of 10% brandy which would have reduced by 10% the vitamin C content by volume, and by a further unknown amount due to the interaction with alcohol (Bennett and Tarbert 1933). It is not recorded whether all or part of the juice was also boiled although, as noted, it was common practice to do so.…”

“…Other 'raw' juice was 'drawn off' (ADM 114/18, 10 March 1852), presumably from store, and 'fortified' by adding 10% brandy which had the benefit of reducing the freezing point of the mixture (Drummond and Lewis 1938: 814) but also the inevitable adverse consequence of reducing by 10% the vitamin C content by volume. Furthermore, the alcohol itself may have significantly reduced the vitamin C content because, in an early study, Bennett and Tarbert (1933) demonstrated a 41% reduction in the ascorbic acid content of fresh lemon juice only eight days after the addition of 10% alcohol as a preservative. Regrettably, this important study does not appear to have been replicated using modern assays.…”