การกักเก็บสารสกัดบีตา-แคโรทีนจากสาหร่ายเกลียวทองเพื่อประยุกต์ใช้ในผลิตภัณฑ์ธัญพืชอัดแท่ง

Abstract

The objectives of this research were to study the appropriate method for extracting carotenoid from Spirulina (Arthrospira platensis). The effect of encapsulation factors on encapsulated carotenoid by spray drying and application in cereal bar products were investigated. Spirulina composed of ß-carotene 8.48 ± 0.35 mg /g dry sample, carotenoids 20.75 ± 0.09 mg / g dry sample and antioxidant activity by DPPH and ABTS of 40.70 ± 0.62 and 154.04 ± 10.32 mg TE / g samples, respectively. The carotenoid content of extract obtained by sunflower oil was significantly higher that canola oil using conventional extraction (p<0.05). Sunflower oil was used for further extraction studies by microwave and ultrasonic assisted extraction. The application of microwave assisted extraction (MAE) at 400 watts for 5 minutes should ß-carotene content as 22.4 ± 2.1 µg /g extract and the carotenoid content of 8.06 ± 0.52 mg /g extract. A antioxidant activities by DPPH and ABTS were 38.36 ± 0.82 and 96.22 ± 9.94 mg TE / g extract, respectively. On the other hand, the extraction by ultrasonic at 40% amplitude for 5 minutes presented ß-carotene content of 22.6 ± 1.4 µg / g extract and the carotenoid content of 4.43 ± 0.46 mg / g extract and antioxidant activity by DPPH and ABTS of 43.67 ± 7.03 and 82.39 ± 11.53 mg TE / g extract, respectively. ß-carotene extract by MAE was used to encapsulation by spray dry. Two independent variables including inlet temperature (140 and 180 °C) and the wall material ratio of maltodextrin and gum arabic (ratio of 2.0:0.0, 1.5:0.5 and 1.0:1.0) on carotenoid encapsulation. It was found that the temperature of 180 °C and the ratio of maltodextrin : gum arabic (1.0:1.0), resulting the highest encapsulation efficiency of 47.34 ± 2.96% with 22.07 ± 0.50% yield. The physicochemical properties of encapsulated powder were ß-carotene of 6.97 ± 0.52 µg /g powder, carotenoid content of 2.50 ± 0.16 mg / g powder, moisture content of 1.03 ± 0.21, water activity of 0.068 ± 0.008 and color values of L *, a * and b * as 86.95 ± 0.30, 3.66 ± 0.09 and 16.05 ± 0.40, respectively. The stability of encapsulated beta-carotene extract was carried out at temperatures of 40, 60, 80 and 100 °C. It was found that the total carotenoid content of the encapsulated extract decreased with increasing temperature. Consumer survey was conducted by 350 general consumers involved priority of ingredients that consumer requirements in cereal bar. The prototype of cereal bar were developed and sensory testing using the 9-point hedonic scale method. The preference score of appearance, color, grains flavor and overall taste at moderate like (7.0-7.7), while overall flavor, sweet taste, hardness and firmness were slightly liked (6.1-6.9). An encapsulated beta-carotene extract applied in cereal bar products found that 83% of the target consumers accepted the developed product.