Microencapsulated Nigella sativa L. oil as functional ingredient for non-dairy creamer
The main objective of this research was to produce Nigella sativa oil (NSO) based non-dairy creamer (NDC) via microencapsulation and agglomeration process. Two extraction methods namely, supercritical fluid extraction (SFE) and cold press (CP) were used to extract the oil from Nigella sativa s...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
2018
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/68858/1/FSTM%202018%205%20IR.pdf |
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| Summary: | The main objective of this research was to produce Nigella sativa oil (NSO) based
non-dairy creamer (NDC) via microencapsulation and agglomeration process. Two
extraction methods namely, supercritical fluid extraction (SFE) and cold press (CP)
were used to extract the oil from Nigella sativa seed. The microencapsulation using
spray dryer was used and the effectiveness of three different independent variables
namely, oil concentration (10-30%), wall materials content (10-30%) and inlet air
temperature (150-190ºC) were optimized using response surface methodology (RSM).
The effects of accelerated storage time (24 days) at 65ºC on the stability of
microencapsulated Nigella sativa oil (MNSO) compared to the NSO without
encapsulation were evaluated. Total oil was recovered from the powder of MNSO and
evaluated in every 6 days along with the NSO. Optimization of the fluidized bed dryer
process conditions in terms of drying time (20-60 min), drying temperature (20-50ºC)
and feed flow rate (1-2.5 mL/min) were conducted using RSM to obtain the non-dairy
creamer (NDC) by agglomeration the microencapsulated oil. The NDC was
characterized based on antioxidant activity and physical properties. It was found that
the oil obtained by SFE showed high content of thymoquinone (TQ) and total phenolic
content (TPC) compared to the oil obtained by CP. In addition, antioxidant activity
measured by DPPH and ferric reducing antioxidant power (FRAP) activity showed
higher activity for SFE oil. The optimal conditions of microencapsulation were 30%
wall material, 10% concentration of oil, and 160°C drying inlet air temperature. The
properties of oil without encapsulation has undergone many changes with a reduction
in oxidative stability, bioactive compounds content, antioxidant activity, and fatty acid
composition alteration. Microencapsulated oil indicated a higher stability and
resistance under the same storage conditions. The optimum conditions of the fluidized
bed agglomeration were: inlet air temperature (50ºC), drying time (25 min), and feed
flow rate (1 mL/min). This process resulted in further improvement of the powder
properties with high solubility, particle size, and glass transition temperature (Tg), as well as lower moisture content, water activity (aw), wettability, hygroscopicity, and
bulk density compared to the spray dried powder with acceptable results of sensory
evaluation. In conclusion, the SFE represents suitable method for NSO. The
encapsulation extended the shelf life of the NSO and the agglomeration improved the
instant properties and palatable taste. The developed NSO-based NDC can be used as
an alternative to the saturated fat and/or hydrogenated oils based NDC. |
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