Sains Malaysiana 39(5)(2010): 791–794

Physico-Chemical Properties and Quality of Palm-Based Vegetable Ghee

(Ciri-Ciri Fiziko-Kimia dan Kualiti Minyak Sapi Sayuran Berasaskan Minyak Sawit)

I. Nor Aini*, H. Hanirah & C.H. Maimon

Malaysian Palm Oil Board, No. 6, Persiaran Institusi, Bandar Baru Bangi

43000 Kajang, Selangor D.E., Malaysia

S. Zawiah & Y.B. Che Man

Faculty of Food Science and Technology, Universiti Putra Malaysia

43400 UPM Serdang, Selangor D.E., Malaysia

Diserahkan: 25 Jun 2009 / Diterima: 10 Mac 2010

ABSTRACT

Samples of trans-free vegetable ghee were made using palm oil/palm stearin/palm olein (PO/POs/POo) blends (set A) and using palm oil/palm stearin/palm kernel olein (PO/POs/PKOo) blends (set B). Palm stearin of iodine value (IV) 30 was used in this study. The products were evaluated for their physical and chemical properties. Changes in quality during storage were monitored during a period of 16 weeks. Most of the vegetable ghee were granular (grainy) and had a shiny appearance. Chemical analyses indicated that vegetable ghee consisting of PO/POs/POo had higher IV (47.7-52.4) than the PO/POs/PKOo vegetable ghee due to their higher content of unsaturated fatty acids, 46.0-50.0% compared to 36.6-45.0% in Set B. Decreasing the amount of palm oil while increasing palm stearin in the formulations resulted in higher slip melting point (SMP) and higher yield values. Eutectic interaction was noted in PO/POs/PKOo blends. The crystals in samples PO/POs/POo (set A) were predominant in the §’ polymorphic form. One formulation in set B (B4) exhibited § crystallinity. Free fatty acids (FFA) were lowest in samples PO/POs/POo 80:5:15 (A4) and PO/POs:/PKOo 80:5:15 (B4) throughout storage. There was no clear trend on anisidine value (AV) while IV remained almost constant. Selected vegetable ghee, A4 wasused to shallow fry roti canai and for cooking nasi minyak. Sensory evaluation on these two products revealed that there was no significant difference (P < 0.05) in texture, taste and overall quality between samples A4 and B4.

Keywords: Palm stearn; vegetable ghee

ABSTRAK

Sampel minyak sapi sayuran yang bebas asid lemak trans dibuat menggunakan adunan set A iaitu minyak sawit/stearin sawit/olein sawit (PO/POs/POo) dan adunan set B iaitu minyak sawit/stearin sawit/olein isirung sawit (PO/POs/PKOo). Stearin sawit dengan nilai iodin (IV) 30 digunakan dalam kajian ini. Produk-produk dinilai daripada segi ciri-ciri fizikal dan kimia. Perubahan kualiti semasa penyimpanan dikaji selama 16 minggu. Kebanyakan sampel mempunyai hablur yang kasar dan permukaan yang kelihatan berkilat. Analisis kimia menunjukkan sampel minyak sapi sayuran berasaskan PO/POs/POo mempunyai nilai iodin lebih tinggi (47.7-52.4) daripada sampel berasaskan PO/POs/PKOo disebabkan kandungan asid lemak tidak tepu yang lebih tinggi, 46.0-50.0% berbanding 36.6-45.0% dalam set B. Apabila kandungan minyak sawit dikurangkan dan kandungan stearin sawit ditingkatkan di dalam formulasi, didapati takat lebur dan penghasilan meningkat. Interaksi eutektik dilihat pada adunan berasaskan PO/POs/PKOo. Hablur dalam sampel PO/POs/PKOo (set A) kebanyakannya dalam bentuk β’. Satu formulasi dalam set B (B4) menunjukkan hablur dalam bentuk β. Kandungan asid lemak bebas adalah paling rendah dalam sampel PO/POs/PKOo 80:5:15 (A4) dan PO/POs/PKOo 80:5:15 (B4) sepanjang tempoh kajian. Tiada corak yang jelas tentang nilai anisidin (AV) tetapi nilai iodin (IV) tidak banyak berubah. Minyak sapi sayuran sampel A4 digunakan untuk menggoreng roti canai dan membuat nasi minyak. Penilaian deria ke atas produk-produk ini menunjukkan tiada perbezaan yang bererti (P < 0.05) dari segi tekstur, rasa dan kualiti keseluruhan antara sampel A4 dan B4.

Kata kunci: Minyak sapi; stearin sawit

RUJUKAN

Jeyarani, T. & Reddy, Y. S. 2005. Physiochemical evaluation of vanaspati marketed in India. Journal of Food Lipids 12(3): 232-242.

MPOB Test Methods. 2005. Malaysian Palm Oil Board.

Nor Aini, I., Che Maimon, C.H., Hanirah, H., Zawiah, S. & Che Man, Y.B. 1999. Trans-free vanaspati containing ternary blends of palm oil-palm stearin-palm olein and palm oil-palm stearin-palm kernel olein. J. Am. Oil Chem. Soc. 76(5): 643-648.

Wilson, E. 2004. Trans fat update. Manuf. Confect. 84: 73-78.

*Pengarang untuk surat-menyurat; email: aini@mpob.gov.my