Veeriah, Harivaindaran K.
(2024)
Utilisation Of Superheated Steam And
Torrefacto Roasting On Quality
Attributes Of Black Seed (Nigella
Sativa) For Beverage Application.
PhD thesis, Universiti Sains Malaysia.
Abstract
Nigella sativa, known as black seed, has many health benefits and is
typically roasted prior to consumption. This causes detrimental quality loss, thus,
an innovative method such as superheated steam (SHS) and torrefacto roasting
may be advantageous. This research aims to develop a beverage from SHS
torrefacto (TR) roasted black seeds. In the first phase, SHS was applied to black
seeds at 150℃, 200℃ and 250℃ for 10, 15, and 20 mins at each temperature
then compared to convection roasting at the same parameters for lipid oxidation,
proximate, antioxidants, and essential oils. Results indicated that SHS roasted
seeds yielded more oil (24.83 % vs only 23.23 % oil for convection) and had
better peroxide value (highest value for convection, 84.00 versus SHS, 48.00 meq
O2/kg of oil), p-anisidine value (highest value; for convection, 28.36 versus SHS,
23.73), FRAP values (SHS; 327 to 435 mM FeSO4/g sample, convection; 301 to
356 mM FeSO4/g sample), and DPPH scavenging capacity (SHS; 92.45 to 69.97 %
inhibition, convection; 92.08 to 65.81 % inhibition). Results also indicate unsuitable
extraction method and poor seed quality since oil oxidative analysis results were
all above standard acceptable levels. Convection roasting also caused loss of
thymoquinone, an important characteristic component of black seed essential oil.
In the second phase, black seeds were TR and SHS roasted at 220℃ for 10 min.
This roasting time and temperature was derived via response surface methodology
for maximum antioxidant capacity.
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