| Summary: | The effect of corn silk or Zea mays extract on the physicochemical changes of virgin coconut oil was studied during three consecutive days of deep frying. There were three types of oil blend systems used: virgin coconut oil without antioxidant as control system; virgin coconut oil with butylated hydroxytoluene (BHT) as synthetic antioxidant and virgin coconut oil with Zea mays extract as natural antioxidant. The oil quality was assessed by measuring the colour, viscosity, peroxide, p-anisidine, free fatty acids, totox and iodine value. The results show that Zea mays extract delayed the oil deterioration. The Zea mays extract significantly (p<0.05) lowered the rate of oxidation in virgin coconut oil compared to control oil and was comparable to BHT. Zea mays extract did not change the sensory profiles of French fries which was shown by insignificant difference (p<0.05) between Zea mays and control fries for all sensory attributes (colour, taste, aroma, crispiness, oiliness and overall quality). In general, the Zea may extract was capable of extending the stability and quality of virgin coconut oil and therefore has potential as new source of natural antioxidant for use in deep frying. | | Kesan ekstrak sutera jagung (Zea mays) ke atas perubahan fizikokimia minyak kelapa dara semasa penggorengan telah dikaji selama tiga hari berturut-turut. Terdapat tiga jenis campuran minyak yang digunakan: minyak kelapa dara tanpa antioksidan sebagai kawalan, minyak kelapa dara bersama butylated hydroxytoluene (BHT) sebagai antioksidan sintetik dan minyak kelapa dara bersama ekstrak Zea mays sebagai antioksidan semula jadi. Kualiti minyak dinilai dengan mengukur warna, kelikatan, nilai peroksida, nilai asid lemak bebas, nilai totox dan nilai iodin. Keputusan kajian menunjukkan bahawa ekstrak Zea mays telah melewatkan kadar kerosakan minyak. Ekstrak Zea mays telah menurunkan kadar pengoksidaan minyak secara signifikan (p<0.05) berbanding dengan minyak kawalan dan setara dengan minyak bercampur BHT. Ekstrak Zea mays tidak mengubah profil sensori kentang jejari sebagaimana ditunjukkan dalam keputusan kajian bahawa tidak ada perbezaan yang signifikan (p<0.05) berbanding kawalan pada semua attribut sensori (warna, rasa, aroma, keranggupan, rasa berminyak dan kualiti keseluruhan). Secara keseluruhan, ekstrak Zea mays mampu memanjangkan kestabilan dan kualiti minyak kelapa dara dan dengan itu mempunyai potensi sebagai sumber baru antioksidan semula jadi untuk digunakan dalam penggorengan.
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