Some effects of reducing, during storage, the water content of dehydrated strip potato

Abstract

The effect of various levels of moisture content of dehydrated potato on the relationship of ‘total’ and ‘free’ sulphur dioxide contents has been studied and the influence of these relationships on the development of non‐enzymic browning has been noted. The use of ‘in‐package’ desiccants to reduce moisture contents reduces the rate of loss during storage of the total sulphite previously added to the potato. Free sulphur dioxide is also found to decrease during storage until the moisture content reaches a critical low value. At or below this moisture level, loss of ‘free’ sulphur dioxide is prevented, and in fact at moderate temperatures of storage it may actually increase. It is suggested that for potatoes of the variety and condition tested, the onset of non‐enzymic browning would be delayed beyond 52 weeks by ensuring that ‘free’ sulphur dioxide levels were maintained at not less than 250 p.p.m.

The Maillard Reaction and its Inhibition by Sulfite

“…This observation is in conflict with data recorded in the present work (in which the inhibition period is considerably longer than that reported by Song et al, 1867b, for a similar system) and in previous publications by other workers (Stadtman et al, 1945;Hearne et al, 1956).…”

“…Without comment, at this stage, on the first of these conclusions we draw attention to the (fact that the second of these findings is based primarily upon the experimental observation that 64-73% of the bisulfite added originally is still present when inhibition has been completed (Song et al, 1967b). This observation is in conflict with data recorded in the pres-ent work (in which the inhibition period is considerably longer than that reported by Song et al, 1867b, for a similar system) and in previous publications by other workers (Stadtman et al, 1945;Hearne et al, 1956).…”

Chemistry of sulphur dioxide in vegetable dehydration

“…In this context, it is interesting to note that if dehydrated S(1V)-treated potato strips (water content 7.7%, total S(1V) content 200 mg SO,/kg, free S(1V) content 100 mg SOJkg) are placed over a desiccant, there is a significant time-dependent increase in the measurable amount of free S(1V). During this period the action of the desiccant causes the water content to fall to 2.2% (Hearne & Tapsfield, 1956). A control experiment maintained at the original water content shows a time-dependent loss of free S(1V) under the same conditions.…”

Physical loss and chemical reactions of SO2 in strawberry jam production

“…It is therefore not surprising that after its incorporation into a food the amount of measurable SOZ decreases progressively. (Stadtman et al, 1946;Joslyn & Braverman, 1954;Hearne & Tapsfield, 1956).…”