Kernel oil content and oil composition in walnut (Juglans regia L.) accessions from north-eastern Italy

BACKGROUND:Walnut oil use is currently limited by its poor oxidative stability due to the high percentage of polyunsaturated fatty acids. Modifying the oil composition may be a goal in walnut breeding to increase interest in this crop. Exploring natural variability and identifying the main environmental factors affecting oil quality are necessary in crop selection. Therefore 190 wild accessions were collected and evaluated during 2013 and 2014 for oil content and its fatty acid profile and compared with five commercial cultivars as references. RESULTS: High variation inkerneloil content andfatty acid compositionwas foundin thenativewalnut.Kerneloil content ranged from 54.2 to 72.2% (w/w). The major fatty acids were linoleic (range 46.9–68.6%), oleic (10.0–25.1%), linolenic (6.9–17.6%), palmitic (3.9–11.4%) and stearic (1.1–5.2%) acids. Some accessions had oil with a fatty acid ratio very different from the reference commercial cultivars, especially the oleic acid/polyunsaturated fatty acid (PUFA) ratio. A significant linear relationship and positive correlation between the daily minimum temperature and oleic acid content was observed in the wild walnuts. CONCLUSION: The wide variation in fatty acid content and composition allows superior accessions to be selected for diffusion among growers. A suitable strategy would be to make a selection against PUFA content rather than just for high oleic acid. In addition, the selected high oleic accessions, before being utilized per se or as donor parents in breeding programs, have to demonstrate they are not adversely affected by the environment

Protein and the demand for hard wheats *

Wheat protein is one of the most important specifications used in domestic and import purchase contracts and is used partly as a proxy for functional quality. The purpose of this article is to analyse the demand for wheat delineated by protein class. A choice-based econometric model is specified and estimated using a novel dataset of pooled wheat shipments to individual importing countries. Buyers are importing countries that make purchase decisions among different protein levels. The model frames the choice in terms of attributes of the choice and of the importing countries. Results indicate that there have been shifts over time, and purchase probabilities are highly price elastic and vary across importing regions. Functional characteristics including wet gluten content and extraction rates have significant impacts on purchase probabilities. These results have implications for breeders as it clearly illustrates the role of protein and functional characteristics on demand. The results also have implications for analysts modelling wheat trade in that there are many factors impacting market segments that would not be captured in conventional demand specifications. Copyright 2009 The Authors. Journal compilation 2009 Australian Agricultural and Resource Economics Society Inc. and Blackwell Publishing Asia Pty Ltd.