Evaluating the role of microwave-baking and fennel (Foeniculum vulgare L.)/nigella (Nigella sativa L.) on acrylamide growth and antioxidants potential in biscuits

Abstract

This study aimed to investigate the impact of fennel seeds (FS) and black cumin seeds (BS) addition into the formulation of conventional and microwave-baked biscuits on the nutritional, physical, and sensory properties. Microwave biscuits were baked at 700 W for 90 s. Antioxidant activity DPPH·, ABTS·+, and total phenolic compounds (TPC) were evaluated by using a UNICO UV-2100 spectrophotometer, acrylamide content was evaluated using UPLC–ESI–MS/MS. The results indicated that microwave-baked biscuits have higher antioxidant activities DPPH·, ABTS·+, TPC, moisture, and breaking strength and lower acrylamide content compared to conventional-baked biscuits. However, the addition of BS gradually decreased the acrylamide content from 355.2 µg/kg in control samples to 138.6 µg/kg in conventional-baked biscuits and from 306.9 µg/kg in control samples to 97.8 µg/kg in microwave-baked ones. Meanwhile, with FS biscuits, acrylamide is decreased to the minimum limit of the quantitation in microwave-baked biscuits and 38%, 61%, and 78% in conventional-baked ones at 2%, 4%, 6% FS respectively. Correspondingly, FS samples had higher antioxidant activities in DPPH·, ABTS·+ and TPC. Acrylamide was correlated to ABTS·+, DPPH·, and colour values on high negative levels (r = − 0.914, − 0.943, − 0.947 and − 0.943) at P < 0.01. High antioxidants activity and low acrylamide content indicated the advantages of microwave-baking and addition of FS or BS to biscuit formulation and they could be used in food industries as a potential plant source antioxidant as well as enhancing the sensory properties of the biscuits.