Impact of asparagine content in flour on acrylamide formation in pizza during baking.
In wheat flour-based baked goods, the amount of free asparagine (fAsn) is a key factor in the formation of acrylamide (AA). In this context, the aim of a recent study carried out by a group of Italian researchers (Covino et al., 2024) was to evaluate the use of four different varieties of common wheat (Stromboli, Montecarlo, Sothys and Cosmic), selected for their different levels of fAsn, for the production of pizza with reduced AA content.
Therefore, wholemeal and refined flours were obtained from these varieties. The results show that fAsn levels vary from 0.25 to 3.30 mmol kg−1, with higher values for wholemeal flours, which also show a higher amount of ash, fibre and damaged starch than refined flours. A reduction in AA in the range of 47-68% was also observed for all selected varieties compared to a commercial variety, with significantly lower values recorded for refined samples.
After leavening, doughs made with refined flour also have reduced levels of fAsn and reducing sugars due to the fermentation activity of yeasts. Pizza prepared with wholemeal flour, on the other hand, showed lower values of rapidly digestible starch (RDS) and rapidly available glucose (RAG) than the other samples. In conclusion, the study confirms that a reduced asparagine content in wheat flour is an effective strategy for mitigating the formation of AA in pizza.
Reduction of acrylamide concentration in bread through the use of enzymes.
Acrylamide is a toxic substance that forms during high-temperature cooking (>120°C) as a product of the Maillard reaction. Reducing its presence in baked goods is one of the most complex challenges facing this industrial sector. In this context, the aim of a recent study carried out by a group of Italian researchers (Calabrese et al., 2024) was to evaluate the effectiveness of applying the enzyme asparaginase in mitigating the formation of acrylamide in bread.
This enzyme catalyses the hydrolytic cleavage of asparagine, a precursor of the toxin, into aspartic acid and ammonia, thus reducing its formation. In particular, samples were prepared with different doses of asparaginase (150 and 300 U/kg of flour) and baked under standard conditions (260°C for 40 min).
The results show that enzymatic treatments can reduce the acrylamide content by 61% and 78%, respectively, in bread treated at 150 and 300 U/kg, without affecting quality parameters such as product colour. However, further research is needed to fully assess the impact of this technology on the nutritional and organoleptic properties of the product, as well as to optimise treatment conditions, maximising the benefits of acrylamide reduction without compromising bread quality.
References: Covino et al., Journal of the Science of Food and Agriculture, 104, 2024, 4070-4082; Calabrese et al., LWT – Food Science and Technology, 209, 2024, 116770.
