Turkish hazelnuts: Properties and effect of microbiological and chemical changes on quality

Turkey is the largest hazelnut producer in the world, and has a surplus of about 100,000 ton per year. Current knowledge about the properties of Turki sh hazelnut, microbiological and chemical changes during postharvest treatm ents and processing are reviewed. Microbial activities bring about signific ant quality loss due to inadequate harvest, drying, and storage methods and conditions. Storage, shelling, roasting, and packaging conditions and meth ods may contribute to lipid oxidation and subsequent rancidity that reduces shelf life of the hazelnut and its products. Roasting methods and conditio ns determine the color and aroma formed. Improvement of harvest, post-harve st, and processing conditions and methods should improve quality, but the b est quality can only be attained if the whole production and processing lin e is designed and operated properly.