The objective of this study is to investigate the stability of total phenolic content (TPC) and antioxidant activity after high temperature and short time (HTST) extrusion cooking of a wheat and rice-based crispbreads with addition of apple, carrot and pumpkin by-products obtained after juice extraction and dried. Raw materials for crispbread production were wheat flour, rice flour, wheat bran (72%, 24% and 4% respectively) with addition of microwave–vacuum dried by-product powder in different amount (5%, 10%, 15%, 20%). Extrusion process was performed by using a laboratory singlescrew extruder GÖTTFERT 1 screw Extrusiometer L series (Germany). Total phenolic content (TPC) was determined using the Folin Ciocalteu method. Antioxidant activity was evaluated by free radical 2, 2-diphenyl-1-picrylhydrazyl (DPPH) antioxidant scavenging activity using a modified colorimetric method. Comparing different raw formulations, it was observed that the TPC of the apple by-product flour was significantly higher (p is less than 0.05) than in carrot and pumpkin flour. TPC in cereal-based crispbread was 36.06±1.15 before extrusion and 13.90±1.01 mg GAEgE-1 DW (milligram Gallic acid equivalent per 100 g of dry weight (mg GAE 100 gE−1 DW) after extrusion. Addition of apple BPF increased TPC in crispbreads to 106.25±2.08, carrot BPF 84.73±3.45 and pumpkin BPF to 108.82±1.04 mg GAEgE−1 DW. Antioxidant activity of control sample was 1.07±0.01mg TE (Trolox equivalents) gE−1 DW but in samples with addition of 20% apple by-products, it reached 3.77±0.02 TE gE−1 DW for samples with 20% carrot by-products reached 2.52±0.03TE gE−1 DW and for samples with 20% pumpkin by-products reached 3.77±0.02 TE gE−1 DW.

Faba beans (Vicia faba L.) are an excellent protein source and should be more present in human diet, but due to their long cooking time, they are rarely used. So, in order to increase the accessibility of faba beans (Vicia faba L.), experiments were carried out to obtain new food products. Extrusion-cooking was chosen as the potential thermal cooking process and two different products were obtained. One was made exclusively from faba bean (Vicia faba L.) flour, while the second one was produced with a 50% addition of wheat flour to bean flour. Protein content, size, volume mass, pH and starch content for obtained products were analysed in order to characterise the products, as well as to see the differences from non-extruded faba beans (Vicia faba L.) and obtained samples. The experiments were carried out using faba beans (Vicia faba L.) obtained at Ltd. “Pure Horticultural Research Centre”. They were milled at Ltd. “Grauda spēks” and extruded with a twin screw extruder at Ltd. “Milzu”. The experiments showed that the extrusion process had decreased the protein content by 9%, but the starch content had risen by 13% with the addition of wheat flour. But, for sample, without added wheat flour differences were not significant. No significant size differences were observed in the obtained samples and pH values had no significant differences between extruded samples.