Changes in Components during Storage of Ginkgo Nuts

Abstract

The qualities of ginkgo nuts stored at room temperature in general deteriorate gradually and consequently the cookability of the nuts is losted in a year. There has not been reported about the mechanism underlying the loss of cookability depending on storage time and conditions. In this work, changes in components of ginkgo nuts during storage under different conditions were studied and storage conditions essential for the preservation of the good qualities were determined.
Ginkgo nuts were stored for 6 months under five different conditions of temperature, relative humidity and air oxidation state. Moisture, total lipid, crude fiber, ash, crude protein and SH group were determined after 2, 4 and 6 months of storage.
After 6 months, the qualities of almost all nuts under two conditions of low temperature were preserved on the satisfactory state, however more than 80% of the nuts stored under three conditions of high temperature deteriorated.
The remarkable decrease of SH groups and moisture and a so ewhat decrease of total lipids in the deteriorated nuts show that the deterioration is due to the cross-linking on proteins, the oxidation of lipids and the dehydration.
The chemical changes under different storage conditions show that the storage temperature is the most critical parameter, but the relative humidity and the air oxidation are not so significant for the deterioration.
Consequently low temperature is essential for the preservation of the good qualities of ginkgo nuts.