Abstract
In a two-year field trial, the effect of nitrogen (N) and sulfur (S) fertilization was investigated on grain yield, grain quality parameters, formation of acrylamide (AA), and the precursor free asparagine (Asn) in organically and conventionally produced winter wheat cultivars. In both production systems, different types, amounts, and temporal distributions of N were tested. The the effect of S fertilizer types and amounts on free Asn was only tested in the conventional farming system. Within both cropping systems, grain yield and baking quality were significantly influenced by N treatment while the effect on free Asn was only minor. Especially within the organic farming system, increasing N fertilization levels did not increase free Asn significantly. A slight trend of increasing free Asn levels with an intensified N supply was observed, especially in the presence of crude protein contents of 14% or higher. However, only N amounts of 180 kg N ha−1 or higher increased the probability of high free Asn contents considerably, while N supply below that amount led to free Asn values similar to the unfertilized controls. The results indicated that good baking quality can be achieved without significantly increasing free Asn levels. In addition, cultivars affected the levels of free Asn significantly. Compared to cv. Bussard and Naturastar, cv. Capo exhibited the lowest AA formation potential at an N supply of 180 kg N ha−1 while simultaneously reaching a crude protein content > 15% (conventional) and > 12% (organic). Thus, it seems that cultivars differ in their ability to store and incorporate free Asn into proteins. Over all trials, a relation of free Asn and AA was shown by R2 = 0.77, while a relation of free Asn and protein was only R2 = 0.36. Thus, lowering free Asn by adjusting N treatments should not necessarily affect baking quality. S fertilization within conventional farming did not change the free Asn amount or crude protein significantly, probably due to the fact that soil was not sulfate-deficient. In summary, it was evident that free Asn amounts in wheat varied widely both within cultivars and between cropping systems. In order to clearly unravel genotypic differences and their interaction with environmental factors and especially N fertilization, further research is needed.
Highlights
Food industry and gastronomy are facing a big challenge because current regulation of the European Commission [1] was announced that limits the level of acrylamide (AA) in cereal food products and requires that minimization strategies are applied.Agronomy 2018, 8, 284; doi:10.3390/agronomy8120284 www.mdpi.com/journal/agronomyAA—a probable carcinogen to humans—is formed in carbohydrate-rich food thermally by means of the Maillard-reaction, where free Asn and reducing sugars react [2,3,4].Its discovery in 2002 by a Swedish research group [5] gained immediate attention by health authorities worldwide
Studies have successfully shown that the limiting factors for AA formation in potato products are the concentrations of reducing sugars, while for cereal products, the content of free Asn is the limiting factor [6,7,8,9]
Grain yield and sedimentation value of conventionally produced cultivar Bussard were significantly influenced by the main effects treatment and year, but the interaction was not significant
Summary
Food industry and gastronomy are facing a big challenge because current regulation of the European Commission [1] was announced that limits the level of acrylamide (AA) in cereal food products and requires that minimization strategies are applied.Agronomy 2018, 8, 284; doi:10.3390/agronomy8120284 www.mdpi.com/journal/agronomyAA—a probable carcinogen to humans—is formed in carbohydrate-rich food (e.g., cereals and potatoes) thermally by means of the Maillard-reaction, where free Asn and reducing sugars react [2,3,4].Its discovery in 2002 by a Swedish research group [5] gained immediate attention by health authorities worldwide. AA—a probable carcinogen to humans—is formed in carbohydrate-rich food (e.g., cereals and potatoes) thermally by means of the Maillard-reaction, where free Asn and reducing sugars react [2,3,4]. Studies have successfully shown that the limiting factors for AA formation in potato products are the concentrations of reducing sugars, while for cereal products, the content of free Asn is the limiting factor [6,7,8,9]. Strongly heated potato products can contain much more AA than cereal-based bakery products, bread and bread rolls contribute to about 25% to 45% of the dietary AA intake in Germany, due to the high daily per capita consumption of almost 240 g [10,11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
