Abstracto
Roasted nigella sativa seed as a functional ingredient in foods and beverageâ exploratory studies
Boshra Varastegani
Nigella sativa L., also known as black cumin or black seed, is extensively used for culinary purposes in many parts of the world. Upon roasting and grinding the seed appears dark brown with aroma and taste similar to roasted coffee bean. Since the roasted seed is rich in caffeine and bioactive compounds, the potential for utilizing it as a powdered coffee-like beverage product can be tremendous. In addition, the seed extracts could be developed into a nutraceutical product or used as a functional additive in food. The caffeine content, solubility and antioxidant activities; expressed as free radical-scavenging (DPPH) and ferric reducing antioxidant power (FRAP) of (Nigella sativa seed) roasted–NSS used in the study was 3.8 %, 72.5 %, 45 mmol/mg and 27.4% respectively. Following spray drying, the caffeine content of (Nigella sativa powder-gum arabic) NSP-AG and (Nigella sativa powder-maltodextrin) NSP-MD dropped significantly (P<0.05) to 1.6 and 1.9 % respectively, whilst the antioxidant activities (FRAP) dropped significantly (P<0.05) to 32 and 31 mmol/mg in NSP-AG and NSP-MD respectively. Solubility of NSP-MD and NSP-AG were 92.6 and 91.9 % respectively, that were significantly higher (P<0.05) than that of roasted-NSS (72.5 %). The oxidative stability of beef burgers incorporating Nigella sativa Super critical CO2 extraction (SC-NSX), Roasted Nigella sativa Super critical CO2 extraction (SC-roasted NSX) was compared with that of commercial-grade green tea extract (GTE) as positive control separately adding 200 and 500 mg/kg before kept at -18 0C for a period up to three months. The chemical composition, TBARS, protein oxidation, proximate, cooking yield, pH, colour, and textural properties and sensory attributes were assessed while held in storage at -18 0C at 3 months. The incorporation of natural antioxidants however resulted in a significant (?<0.05) decrease in TBARS (58%–62%) and protein oxidation (31–45%) as compared to control. Regarding the sensory characteristics, Furthermore, a vast improvement (P<0.05) in cooking yield and textural properties was observed and noted. Although, incorporating NSX and GTE into the beef patties did not have a major influence (P>0.05) on sensory acceptability, proximate composition, pH and colour of the patties.