Abstract:
The preservability of two walnut cultivars (Hartley and Sorrento) was studied under 4 different storage conditions: a) at room temperature and humidity (following the seasonal variations); b) at room temperature in desiccator; c) at 5° C and 70–90% relative humidity; d) at 5° C in desiccator.
Nuts from commercial lots were analyzed at the beginning of the storage period for moisture content, total lipids and fatty acid composition, kernel colour, acidity and peroxide value (PV). Acidity, PV, moisture and kernel colour were determined periodically for one year.
At the beginning of storage the lipid content (as dry weight) was 70.9% in 'Sorrento' and 71.8% in 'Hartley'. Kernel colour was lighter in 'Hartley'. 'Sorrento' nuts had a higher PV. During winter and spring no significant differences among the methods of storage could be detected from PV and acidity.
In summer PV increased in samples stored at environment temperature, while acidity had higher values in the non-controlled R.H. conditions.
A gradual reduction of the kernel moisture was observed during storage, especially in the nuts kept in desiccator.
Increasing darkening of kernel was evident during storage, but 'Hartley' always maintained a lighter colour than 'Sorrento'.
High temperature and relative humidity proved to be the main negative factors affecting preservability.
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