COMPARISON OF NEW ZEALAND (SOUTH ISLAND) AND AUSTRALIAN (TASMANIAN) WALNUT CULTIVARS

Seven different cultivars of walnuts (Juglans regina L.) grown in Tasmania, Australia in 2008 were compared with six cultivars grown in Canterbury in the South Island of New Zealand in the same year. A preliminary assessment of the physical attributes and taste of all the nuts was carried out by seven members of the scientific committee of the New Zealand Walnut Industry Group (NZWIG). The overall assessment scores (total possible score, 100) of the Tasmanian grown nuts was 73 compared to 65 for nuts grown in Canterbury, New Zealand. While most of the attributes between the two groups of nuts were similar the overall crackout score of the Tasmanian nuts received a perfect score of 20 while the New Zealand nuts scored a mean of 14 for all of the six cultivars. The two groups of nuts were then subjected to organoleptic assessment using 59 untrained tasters. The tasters recorded their impressions of the taste and after taste of all the nuts using a five point hedonic scale. In this test the tasters worked in pairs and were blindfolded during their tasting assessments. The overall taste and after taste scores for the Tasmanian and Canterbury nuts were very similar but individual cultivars ‘Earnscleugh’, ‘Vina’ and ‘Fernette’ achieved higher scores for taste when compared with all of the other cultivars evaluated while ‘Fernette’ grown in Australia was given the highest overall score for after taste. Overall the cultivar ‘Fernette’ grown in Tasmania had the best mean scores for both taste (3.5) and after taste (3.5) which were significantly greater than the scores for all of the other cultivars evaluated. From the consideration of taste alone it was recommended to NZWIG that this cultivar should be imported and grown in New Zealand to improve the range of high quality walnuts grown in Canterbury.