Acrylamide bioaccessibility in potato and veggie chips. Impact of in vitro colonic fermentation on the non-bioaccessible fraction.

Potato-based products contribute largely to the daily intake of acrylamide. In addition to potato crisps, the European Commission has included veggie crisps in the list of foods that should be monitored for their acrylamide content. In the present study, acrylamide content in potato and veggie chips (sweet potato, beetroot and carrot) and their bioaccessibility after in vitro digestion was assessed. The non-bioaccessible fraction was also submitted to in vitro fermentation under colonic conditions. Faecal samples from volunteers of three age groups (children, adolescents and adults) were used to evaluate the microbiota effect on the acrylamide availability. Sweet potato chips exhibited the highest acrylamide content (2342 µg/kg), followed by carrot (1279 µg/kg), beetroot (947 µg/kg) and potato chips (524 µg/kg). After in vitro digestion, acrylamide bioaccessibility was significantly lower in veggie chips (59.7-60.4 %) than in potato chips (71.7 %). Potato and sweet potato chips showed the significantly lowest acrylamide content in the non-bioaccessible fraction (22.8 and 24.1 %, respectively) as compared with beetroot chips (28.4 %). After the fermentation step, acrylamide percentage in the soluble fraction of veggie chips ranged from 43.03 to 71.89 %, the highest values being observed in sweet potato chips fermented with microbiota from children. This fact would involve that the acrylamide was released from the non-bioaccessible fractions by the microbiota. These findings point out that the levels of potentially absorbable acrylamide after the complete gastrointestinal process could be modulated by both the food matrix composition and the microbiota. These factors should be further considered for a more precise risk assessment of dietary acrylamide in humans.

Relationship of quality parameters, antioxidant capacity and total phenolic content of EVOO with ripening state and olive variety.

The aim of this work was to study the evolution of quality parameters, fatty acid composition, antioxidant capacity and total phenolic content of olive oil obtained from two olive varieties (Manzanilla and Picual) with different maturation. Antioxidant capacity and total phenolic content were measured after submitting the olive oil to in vitro digestion and fermentation to mimic physiological conditions. Quality parameters were always within the legal limits to be called "Extra Virgin Olive Oil". Antioxidant capacity, total phenolic content, saturated fatty acids and monounsaturated fatty acids (MUFA) decreased along maturation, whereas polyunsaturated fatty acids (PUFA) increased in both varieties. Manzanilla showed higher PUFA content, whereas Picual had higher MUFA concentration, antioxidant capacity and total phenolic content. The fermented fraction of olive oil displayed a higher antioxidant capacity. Finally, the statistical approach demonstrated that the type of variety is more important than collection date regarding fatty acid composition and antioxidant capacity.