Dietary exposure to acrylamide: A critical appraisal on the conversion of disregarded intermediates into acrylamide and possible reactions during digestion.

The amount of acrylamide in asparagine rich thermally processed foods has been broadly monitored over the past two decades. Acrylamide exposure can be estimated by using the concentration of acrylamide found in foods and alternatively, biomarkers of exposure are correlated. A better estimation of dietary acrylamide exposure is crucial for a proper food safety assessment, regulations, and public health research. This review addresses the importance of the presence of neglected Maillard reaction intermediates found in foods, that may convert into acrylamide during digestion and the fate of acrylamide in the gastrointestinal tract as a reactive compound. Therefore, it is questioned in this review whether acrylamide concentration in ingested foods is directly correlated with the dietary exposure to acrylamide.

Investigations on the formation of α-dicarbonyl compounds and 5-hydroxymethylfurfural in fruit products during storage: New insights into the role of Maillard reaction.

The formation of α-dicarbonyl compounds and 5-hydroxymethylfurfural was investigated under different conditions and the amino acid adducts of them were confirmed using high-resolution mass spectrometry in fruit products during storage. Changes in the concentrations of sugars, amino acids, α-dicarbonyl compounds, and 5-hydroxymethylfurfural in fruit juice concentrates and dried fruits were monitored. Among the dicarbonyls, glucosone was the dominant one in 30 °Bx of fruit juice concentrates, whereas 3-deoxyglucosone was the major in 50 and 70 °Bx of those and in all dried fruits during storage. The highest level of 3-deoxyglucosone was found as 7251 ± 896.6 mg/kg in dried date at the end of the storage. During storage, the loss of free amino acids significantly increased (p < 0.05) in the higher initial reactant concentrations in fruit juice concentrates. The confirmation of amino acid adducts of dicarbonyls and 5-hydroxymethylfurfural generally with high mass accuracy proved the contribution of Maillard reaction to non-enzymatic reactions in fruit products.

Investigations on the formation of Maillard reaction products in sweet cookies made of different cereals.

In this study, the content of Maillard reaction products from its initial, intermediate and final stage (5-hydroxymethylfurfural, α-dicarbonyl compounds, furosine, N-ε-carboxymethyllysine and N-ε-carboxyethyllysine) was measured in sweet cookies made of wholegrain flour of eight genotypes of small-grain cereals (bread wheat, durum wheat, soft wheat, hard wheat, triticale, rye, hulless barley and hulless oat) and four corn genotypes (white-, yellow- and red-colored standard seeded corn and blue-colored popping corn). Furthermore, the effect of the initial content of sugars, total proteins, free and total lysine in flour on the formation of Maillard reaction products was investigated using the principle component analysis. 3-deoxyglucosone was the predominant α-dicarbonyl compound in all cereal cookies and the highest content was measured in those made from flour of different colored corn genotypes (on average, 98.35, 151.28 and 172.85 mg/kg after baking for 7, 10 and 13 min, respectively). Heating dough at 180 °C for 7, 10 and 13 min differently affected the content of 5-hydroxymethylfurfural and α-dicarbonyl compounds in the cereal cookies. The 5-hydroxymethylfurfural content gradually increased, while a reduction in 3-deoxyglucosone content was observed in the cookies baked for 13 min except for those made from soft wheat, hulless oat, red- and blue-colored corn. After 7 min of heating, the content of furosine measured in the cereal cookies reached its maximum (from 320.9 mg/kg in yellow-colored corn-based cookies to 585.7 mg/kg in hulless oat-based cookies), while N-ε-carboxymethyllysine and N-ε-carboxyethyllysine showed the opposite trend. The highest content of advanced glycation end products was detected in cookies also made from hulless oat flour rich in proteins (16.80%) and total lysine (10670.3 mg/kg). The interrelationship analysis showed that the initial content of sugars in flour of cereals affected 5-hydroxymethylfurfural and 3-deoxyglucosone formation in the cookies. In addition, a high correlation between protein-bound Maillard reaction products in the cookies and the total proteins and the total lysine content in the flours was found.

Acrylamide formation in biscuits made of different wholegrain flours depending on their free asparagine content and baking conditions.

Due to a high content of bioactive compounds with beneficial health effects, wholegrain flours of different cereals have been extensively used in the confectionery industry. However, according to our study, cereal species and their varieties have different potential for the formation of acrylamide in biscuits. In this study, wholegrain flours of eight genotypes of small grain cereals (bread wheat, durum wheat, soft wheat, hard wheat, triticale, rye, hulless barley and hulless oat) and four genotypes of maize (white-, yellow- and red-coloured standard seeded maize, and blue-coloured popping maize) were used to prepare biscuits. The biscuits were baked at 180 °C for 7, 10 and 13 min. At 180 °C, acrylamide was detected at all baking times, reaching a final concentration of 72.3 up to 861.7 µg/kg after 13 min of baking in refined bread wheat-based biscuits and hulless oat-based biscuits, respectively. Data indicated that acrylamide in biscuits could not exactly correspond to free asparagine in flour. However, hulless oat, durum wheat and rye flour with the highest content of free asparagine of 859.8, 603.2 and 530.3 mg/kg, respectively, generated most acrylamide in biscuits baked for 13 min. The lowest content of acrylamide was found in biscuits prepared from refined bread wheat flour and wholegrain red maize flour that also contained the lowest content of free asparagine. After baking for 7, 10 and 13 min, the content of acrylamide in these samples was 17.9 and 24.4 µg/kg, 51.9 and 28.7 µg/kg and 72.3 and 95.2 µg/kg, respectively. The results suggest that the use of cereal flours low in free asparagine can be an effective strategy for acrylamide mitigation in biscuits, together with the use of lower thermal load during baking.