BUKU ABSTRAK - Universiti Putra Malaysia

Characterisation and Stabilisation of Pytochemical-rich Hylocereus polyrhizus Seed
Oil by Microencapsulation
Assoc. Prof. Dr. Tan Chin Ping
Hong Kwong Lim and Jamilah Bakar
Faculty of Food Science and Technology, University Putra Malaysia,
43400 UPM Serdang, Selangor, Malaysia.
+603-8946 8418; tancp@putra.upm.edu.my
Hylocereus polyrhizus (red-skinned pitaya with red flesh) seed oil can serve as a potential new source of
natural antioxidants. The tiny black pitaya seeds (size < 1.0 mm) present in significant amounts as a waste of
pitaya juice processing, containing 18% of oil with a high degree of unsaturated fatty acid content. Linoleic, oleic
and palmitic acids were the major fatty acids in the pitaya seed oil (PSO). Both ?-tocopherol and ?-tocopherol
were detected and total tocopherol content in PSO was 43.50 mg/100 g. Abundance of ?-sitosterol was also found
in PSO. Most commonly found phenolic compounds such as p-hydroxybenzoic, vanillic and protocatechuic acids
were identified by liquid chromatographic analysis. In addition, spray-drying technique was used to encapsulate
PSO. Sodium caseinate/ maltodextrin DE10 as wall material was homogenized with PSO to form an O/W
emulsion and subsequently spray-dried into an encapsulated lipid powder. Shelf-life stability test: Oil Stability
Index by Rancimat and Schaal oven test were conducted. The result reveals that sodium caseinate/maltodextrin
DE10 can be used to protect PSO from oxidation and increase the shelf-life of PSO.
Keywords: Hylocereus polyrhizus, pitaya seed oil, tocophero, phytosterol, encapsulation
Preparation of Astaxanthin Nanodispersions using Multiple Emulsifier System via
Emulsification-evaporation Technique
Assoc. Prof. Dr. Tan Chin Ping
Navideh Anarjan, Hamed Mirhosseini and Badlishah Sham Baharin
Faculty of Food Science and Technology, University Putra Malaysia,
43400 UPM Serdang, Selangor, Malaysia.
+603-8946 8418; tancp@putra.upm.edu.my
A top-down approach based on an emulsification-evaporation technique was used to prepare nanodispersions
of astaxanthin. Astaxanthin can be used as supplement or colorant ingredient in food formulations and as a
“nutraceutical”. However, it cannot be readily absorbed by the human body because of its poor bioavailability.
The increase in bioavailability is due to the special characteristics of nanodispersions; it has been shown that
nanosized-dispersion increases the surface areas and dissolution velocities of poorly soluble compounds, thus
increasing their saturation solubility. Usually a blend of emulsifiers and stabilisers shows higher stabilisation
functionality in a lower total concentration in comparison of using them individually. In this study, simplex
centroid mixture design was used to study the interactions among pectin, sodium caseinate and sucrose oleate as
a multiple emulsifier system on the formation of astaxanthin nanodispersions through emulsification-evaporation
technique under optimised processing conditions. The multiple emulsifier system was considered as a mixture
of these three ingredients, in which the interactions between two ingredients were not isolated from the third
ingredient. The initial particle size and astaxanthin concentration, and changes of particle size and astaxanthin
concentration after one month of storage were characterized via laser diffraction particle size analyzer and HPLC,
respectively. For all studied responses, special cubic regression models with acceptable determination coefficient
(>77%) have been obtained. The multiple-response optimization predicted that an emulsifier mixture of 44%
sucrose oleate, 10% pectin and 46% sodium caseinate can be used to produce astaxanthin nanodispersions with
minimum particle size and maximum astaxanthin concentration and also maximum physicochemical stability.
Under these obtained proportions, no significant (p > 0.05) differences between the experimental and predicted
values were observed, confirming the suitability of the regression models relating the independent and response
variables studied.
Keywords: Astaxanthin nanodispersions, emulsification-evaporation, emulsifier mixture, mixture design
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Food