Influence of the farming system on the xanthophyll content of soft and hard wheat.

The organic market is growing rapidly. This is because customers expect organic food to be authentic and healthy. For plant products the awareness of pesticide residues is one main point in customers' decisions for organic food, but in terms of secondary plant compounds, antioxidants are also expected benefits of organically produced foods. For wheat the xanthophylls are one group of those secondary plant compounds. There are no recent studies about the influence of cultivation practices on the xanthophyll content. This study examined the influence of the farming system on the content of lutein and zeaxanthin. To evaluate this, samples of a long-term field trial were examined by comparing conventional (nonorganic) and organic produce grown under controlled conditions. Additionally, samples were examined from farm pairs located in Germany. Each of the pairs consisted of one organically and one conventionally producing farm, located in local neighborhood and cultivating the same wheat variety. To summarize, the influence of the farming system is very small. The differences are mainly caused by different kernel sizes (thousand-kernel weight), which are found to be correlated to the lutein content.