Value addition of wheat and maize based cookies with the addition of milk thistle (Silybum marianum)

Abstract

This study was conducted with the aim to produce wheat flour based cookies with supplementation of maize flour (MF) and milk thistle seed powder (MTSP). For this purpose the study was divided in to four phases. In first phase whole wheat flour (WWF), MF and their various blends were characterized for cookies preparation. During analysis protein, fat, fiber and ash content 13.10-10.93%, 5.96-4.70%, 2.15-1.01%, 1.65-1.03% decreased, while moisture content and nitrogen free extract (NFE) increased from 9.66 to 9.74% and 67.45 to 72.59%, respectively. The addition of MF to WWF in different ratios had significantly decreased calcium and magnesium contents from 45.80 to 26.59 mg/100 g and 169.20 to 82.51 mg/100 g. While increase was found in iron (9.90 to 80.80 mg/100 g), manganese (4.05 to 6.69 mg/100 g), copper (4.50 to 8.99 mg/100 g) and zinc (6.11 to 25.08mg/100 g). Functional properties i.e bulk density, swelling power and foaming capacity showed a slight decrease (0.66 to 0.57 g/cm3), (10.18 to 10.06%), (11.20 to 10.85%) respectively, while water and oil absorption capacities increased from 87.90 to 94.02% and 1.29 to 1.50%. Gluten content was decreased both on wet (28.10-0%) and dry (8-0%) basis. Image obtain through scanning electron microscopy (SEM) revealed that both WWF and MF had small and large particles with irregular shape and mostly tied in cluster form. In the second phase of the study cookies were prepared from WWF, MF and their various blends and were studied for selected physical, physico-chemical and sensory attributes. The diameter of the cookies decreased slowly with the addition of MF (47.7-44.3 mm), while thickness increased (12.61-13.8 mm), spread ratio decreased (3.80-3.20) and hardness of the cookies also decreased (2.123-1.246 kg). The overall mean score of cookies for color was 7.22 (WM2) to 6.88 (WM0), for taste 7.04 (WM2) to 6.04 (WM6) and for texture 7.08 (WM2) to 6.15 (WM6). The maximum overall acceptability was recorded in treatment WM2 (7.32), whereas the minimum overall acceptability was recorded in treatment WM6 (6.37). Increase was observed in moisture content (3.24 to 3.29%) and NFE (57.86 to 58.60%). While protein, fat, fiber and ash contents decreased from 8.20 to 7.68%, 24.23 to 23.94%, 6.47 to 6.38%, and 0.80 to 0.73% respectively. On overall quality basis cookies prepared from treatment WM2 gave the best result and was selected for further study. Best combination of WWF and MF i.e. 80:20 was selected from studied in which MTSP was added at the ratio of 2, 4, 6, 8 and 10%. The prepared flour samples were examined for physico-chemical analysis, minerals contents, gluten content (wet and dry basis) and SEM. Moisture content and NFE decreased from 9.66 to 9.45% and 68.65 to 65.45% respectively, Whereas protein, fat, fiber and ash increased from 12.40 to 14.47%, 5.83 to 6.44%, 1.98 to 2.32% and 1.55-1.87% respectively. The calcium, magnesium and copper increased from 39.09 to 48.07 mg/100 g, 145.20 to170.39 mg/100 g and 5.89 to 8.31 mg/100 g respectively after the addition of MTSP to wheat and maize composite flour. While iron, manganese and zinc decreased from 16.20 to 10.11 mg/100 g, 4.99 to 4.01 mg/100 g, 11.11 to 9.07 mg/100 g. Gluten contents decreased after the addition of MTSP on wet (24.50 to 15.02%) and dry (6.75 to 4.00%) basis. In final phase of the study cookies were prepared from blend of WWF:MF (80:20) and MT seeds powder (2, 4, 6, 8, 10%) and were studied for selected physical, physicochemical and sensory attributes. The diameter and spread ratio of the cookies decreased slowly from 46.50-44.8 mm and 3.55-3.23 in treatment WM2 to WMT12 thickness increased from 13.10-13.87 mm. The maximum hardness of the cookies was observed in treatment WM2 (2.120kg), while minimum hardness was observed in treatment WMT10 (1.229kg). The sensory evaluation score of the cookies for color was 6.91 (WMT12) to 7.27 (WMT10), for taste 7.04 (WM2) to 6.55(WMT12) and for texture 7.08 (WM2) to 6.58 (WMT12) respectively. The maximum overall acceptability was recorded in treatment WMT10 (7.24) followed by WMT9 (7.16), while the minimum overall acceptability was recorded in treatment WMT12 (6.87) followed by WM2 (7.11). Mean values of NFE decreased (57.93 to 56.98%), while moisture, ash, fat, protein and fiber increased from 3.26 to 3.31%, 0.76 to 0.84%, 24.18 to 24.48%, 8.19 to 8.65% and 6.44 to 6.58% respectively. Addition of 6% MTSP is recommended to produce cookies with 80:20 blend of WWF and MF