Articles
The influence of the harvest time and duration of drying on the quality of walnuts
Article number
1420_15
Pages
111 – 118
Language
English
Abstract
Mature walnuts contain 30 to 40% moisture, and even up to 50% in rainy years, which makes them extremely susceptible to various molds and spoilage processes if not processed properly.
In a two-year study, we investigated the impact of harvest date and drying time on the external and internal quality of nuts of cultivars ‘Sava’’, ‘Franquette’ and ‘Lara’. At the stage of technological maturity, we divided the fall nuts into three groups.
The nuts of the first group were harvested immediately (T0). After six days we collected the nuts of the second group (T6) and after 13 days those of the third group (T13). The nuts of the cultivars ‘Sava’ and ‘Lara’, which were dried for only one day (S1), had the most moldy shells regardless of the harvest time, while a drying period of two days was sufficient to completely remove at least 96% of the mold from the shells.
In the ‘Franquette’ cultivar, shells were most moldy in walnuts harvested and dried 13 days after maturity.
Between 4 and 16% of the kernels were black. 4-8% had more than half the mold area.
Bright kernels were obtained when harvested immediately and dried for three days.
Cultivars differed in kernel total phenolic content (TPC), with cultivar ‘Lara’ having the lowest value, while treatments had no effect on TPC. A correlation between darker color of the kernels and a higher TPC was determined.
Harvest and postharvest treatments affected the fatty acid content of the kernels (FA), with the ‘Franquette’ and ‘Lara’ T13S1 combination containing more saturated FA. The unsaturated FA content was highest in kernels harvested after six days for ‘Franquette’ and ‘Sava’’, and in kernels harvested after 13 days for ‘Lara’.
In a two-year study, we investigated the impact of harvest date and drying time on the external and internal quality of nuts of cultivars ‘Sava’’, ‘Franquette’ and ‘Lara’. At the stage of technological maturity, we divided the fall nuts into three groups.
The nuts of the first group were harvested immediately (T0). After six days we collected the nuts of the second group (T6) and after 13 days those of the third group (T13). The nuts of the cultivars ‘Sava’ and ‘Lara’, which were dried for only one day (S1), had the most moldy shells regardless of the harvest time, while a drying period of two days was sufficient to completely remove at least 96% of the mold from the shells.
In the ‘Franquette’ cultivar, shells were most moldy in walnuts harvested and dried 13 days after maturity.
Between 4 and 16% of the kernels were black. 4-8% had more than half the mold area.
Bright kernels were obtained when harvested immediately and dried for three days.
Cultivars differed in kernel total phenolic content (TPC), with cultivar ‘Lara’ having the lowest value, while treatments had no effect on TPC. A correlation between darker color of the kernels and a higher TPC was determined.
Harvest and postharvest treatments affected the fatty acid content of the kernels (FA), with the ‘Franquette’ and ‘Lara’ T13S1 combination containing more saturated FA. The unsaturated FA content was highest in kernels harvested after six days for ‘Franquette’ and ‘Sava’’, and in kernels harvested after 13 days for ‘Lara’.
Publication
Authors
A. Solar, R. Vidrih, A. Medic, R. Veberic, M. Hudina
Keywords
common walnut, Juglans regia L., harvest and postharvest treatments, nut quality
Groups involved
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