The Relationship Between Varieties and Acrylamide Formation in Roasted Barley

Document Type : Original Article


1 Crops Technology Research Department, Food Technology Research Institute (FTRI), Agricultural Research Centre, Al Giza, 12619, Egypt

2 Barley Research Department, Field Crops Research Institute, Agricultural Research Center, Al Giza, 12619, Egypt


Attempts being made to increase the awareness for addressing the acrylamide issues among barley breeders and food technologists. Selection from existing hulled barley varieties and genotypes for low free asparagine accumulation and specifying the optimal roasting conditions in coffee-substitutes based on roasted barley offer suitable mitigation interventions and strategies at the agronomic and the industrial scales to avoid excessive acrylamide formation and to generate safe barley products for dietary use. To these interventions, this study aims to compare the acrylamide forming potential of three hulled barley varieties with different genotypic origins grown under normal agronomic conditions during two growing seasons of 2018/2019 and 2019/2020, then used for roasted coffee-substitutes manufacture, and correlate this to different roasting temperatures and acrylamide concentrations. Mean squares of genotypes were highly significant (P ≤ 0.05) for all agronomic characteristics and free asparagine accumulation (12.96**, 12.65**) in both seasons. Acrylamide concentrations in coffee substitutes showed strong negative or weak correlations with glucose, sucrose, fructose, and maltose and strong positive correlations (r =‎0.8029& 0.8025) with free asparagine contents (318.2-682.3& ‎322.3‎-681.5 ‎mg Kg-1) in the grains in both seasons. Indicating free asparagine is the main determinant of acrylamide-forming potential in different barley genotypes. The acrylamide concentrations in the ground (<10-242.8µg kg-1) and brewed (0.26-1.70‎ µg 70 mL-1) coffee substitutes significantly increased as roasting temperatures increased at 180, 200& 220C, except for variety Giza133 decreased shortly at 220C. These levels did not exceed the recommended limit (500 µg kg-1) by the European Commission; however, overconsumption should be of concern. Roasting temperatures significantly (P ≤ 0.05) influenced the physical properties of the roasted barley grains and the physicochemical properties of coffee substitutes with strong correlations with acrylamide concentrations. This study exhibits an indicator to help risk managers and decision-makers to set priorities for further action for addressing the acrylamide problem.


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