Preservation of peeled potato. I.–use of sulphite and its effect on the thiamine content

Dipping potato chips in a solution of metabisulphite of concentration 0.5–1.0% (w/v) at pH 5.3–6.0 was the most effective treatment for retarding enzymic browning. Temperature had a direct influence on storage life: at 5° chips could be stored for 7 days and at 1° for 14 days. Dipping potatoes in metabisulphite solutions caused no immediate loss of thiamine, but there was a loss of 24% of the vitamin in 3 days during storage at 5°. Losses up to 30% may be experienced when sulphited raw potatoes are boiled immediately, compared with about 15% for untreated tubers. Frying potato chips normally results in a loss of about 10% of thiamine, and if dipped in sulphite solution a loss of 35–45% occurs which increases to 75% after 30 min. on a hot plate.