Chemistry Reference
In-Depth Information
6000
5000
4000
3000
2000
1000
0
0
210
1050
2100
4200
ASNU/kg DS
Fig. 4.14
Acrylamide in fabricated potato chips using increasing levels of enzyme in the dough. Dosages
were 210-4200 ASNU kg
−1
dry matter. Dough resting time was 45 min at room temperature.
(up to 95%) and a very clear dosage response was seen (Fig. 4.14). When chips were made at
a lower water content of 33%, the maximum reduction achieved was 48% and this response
was constant across dosages from 1000 to 5000 ASNU kg
−
1
flour (data not shown). Similar
results identifying water content as a very critical parameter were seen in ginger nut biscuits
(Fig. 4.7).
Potato-based snack pellets are an intermediate dried, extruded product made from dough
using either potato flakes and/or granules. The snack pellets are fried, seasoned and packed
at the final producer. Testing in snack pellets was done on industrial pilot scale without any
process changes. Asparaginase was added with the water to the dry ingredients during mixing
before the dough was extruded cold and dried. The snack pellets were then fried, and the
final product analyzed for acrylamide. Results are shown in Fig. 4.15. Acrylamide reduction
reached 95% at the highest enzyme dosage. These results show that the asparaginase worked
very efficiently in a dough containing 35% water, which illustrates that enzyme performance
depends very much on the specific recipe and probably on water activity more than water
content.
In a study by Vass
et al
.,
45
addition of asparaginase (from
E. coli
) to a potato cracker dough
resulted in 70% reduction in acrylamide in the final product, confirming the potential for such
a treatment. Reduction in a similar wheat cracker product was higher (85%), presumably
related to the much lower initial asparagine content in wheat compared to potato. Also
A. niger
asparaginase has been tested for acrylamide reduction in potato-based fabricated
chips, showing up to 90% reduction.
47
4.4.2.8
Conclusion - asparaginase in potato-based products
In summary, the results reviewed here show that it is clearly possible to significantly reduce
final acrylamide levels in fried potato-based products by manipulating the asparagine level
