OXIDATIVE STABILITY OF WALNUTS DURING LONG TERM IN SHELL STORAGE

Nine different cultivars of walnuts (Juglans regia L.) were harvested from the Rex Baker trial at Lincoln University in 1996, 1997, 1998 and 1999. The nuts evaluated were two US commercial cultivars (Tehama and Vina), two European commercial cultivars (Esterhazy and G120) and five New Zealand selections (Rex, Dublin’s Glory, Meyric, Stanley and New Zealand Purple). The kernels were evaluated fresh or after they had been stored in shell for 1, 2 or 3 years in a commercial storage facility. Peroxide values of the freshly extracted oil from the stored nuts were measured spectrophotometrically to give an indication of the stability of the oil during storage. The mean peroxide value (Meq O2/kg oil) for the nine cultivars was 0.29 ± 0.058 for fresh nuts, 1.66 ± 0.06 for nuts stored for one year, 3.58 ± 0.197 for nuts stored for two years and 2.06 ± 0.28 for nuts stored for three years. Cultivars Rex and Vina had the highest peroxide levels, while G120 and Stanley had the lowest levels after two years storage when compared to the mean value for all the nuts.

IV International Walnut Symposium

K. Österberg, G.P. Savage, D.L. McNeil

storage, peroxide value, stability, walnuts

https://doi.org/10.17660/ActaHortic.2001.544.82