Sains Malaysiana 45(12)(2016): 1939–1945

http://dx.doi.org/10.17576/jsm-2016-4512-19

 

Ciri Fizikokimia Filem Boleh Makan dan Filem Polietilena Bagi Ubi Keledek (Ipomoea batatas) Goreng

(Physicochemical Properties of Edible Films and Polyetylene Film on Fried Sweet Potatoes (Ipomoea batatas))

 

RIZAFIZAH OTHAMAN*, KAUSAR AHMAD FUAD, FARHAN MOHD NOR

& ROZIDA MOHD KHALID

 

Pusat Pengajian Sains Kimia dan Teknologi Makanan, Fakulti Sains & Teknologi

Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan, Malaysia

 

Received: 13 June 2016/Accepted: 17 October 2016

 

 

ABSTRAK

Penyelidikan dijalankan bagi menilai kesan penggunaan filem boleh makan dan filem polietilena (PE) sebagai bahan penyalut untuk ubi keledek (Ipomoea batatas) goreng. Kepingan ubi keledek disalut dengan lapisan filem boleh makan yang terdiri daripada 0.045 g/mL selulosa metil (MC), 0.045 g/mL selulosa hidroksipropil metil (HPMC) dan 0.16 g/mL jagung zein (CZ) sebelum digoreng di dalam minyak sawit pada suhu 170-180°C selama 3 min. Manakala ubi keledek juga disalut dengan filem tak boleh makan iaitu polietilena (PE) (nisbah PE kepada minyak 1:100 g/g) sebagai perbandingan. Ubi goreng tanpa salutan filem digunakan sebagai sampel kawalan. Ciri fizikokimia ubi goreng bersalut dianalisa. Keputusan menunjukkan semua filem melekat pada permukaan ubi setelah digoreng. Penggunaan filem CZ menjadikan permukaan filem licin dan wujud tanpa sebarang retakan. Filem MC pula memberi lapisan permukaan yang tidak rata tetapi menyaluti permukaan sampel dengan sekata. Tambahan pula, ubi bersalut MC menunjukkan peratusan lemak paling sedikit (13.6%) selain kandungan kelembapan yang paling tinggi (17.5%) berbanding sampel lain. Secara keseluruhan, MC merupakan filem yang terbaik untuk mengekalkan kelembapan bahan goreng dan mengurangkan penyerapan lemak.

 

Kata kunci: Hidroksipropil metil selulosa; jagung zein; polietilena; selulosa metil; ubi keledek

 

ABSTRACT

 

This study was carried out to evaluate the effect of edible film and polyethylene film (PE) on fried sweet potato (Ipomoea batatas) coating. Slices of sweet potato were coated with edible films which were 0.045 g/mL methylcellulose (MC), 0.045 g/mL hydroxypropyl methylcellulose (HPMC) and 0.16 g/mL corn zein (CZ) before being fried at 170-180°C in palm oil for 3 min. The sweet potato was also coated with inedible polyethylene (PE) film (ratio of PE to oil 1:100 g/g) as comparison. Fried potato without film coating was used as a control sample. The physicochemical characteristics of the coated sweet potato were analyzed. The results indicated that all films could be coated on the surface of the sweet potato. CZ film gave a smooth surface without any crack. MC film gave a non-uniform surface but coated the whole surface of the sample evenly. In addition, MC coated sweet potato showed the least fat percentage (13.6%) and the highest moisture content (17.5%) compared to other samples. Overall, MC is the best edible film to retain moisture and reduce the absorption of fat of fried products.

 

Keywords: Corn zein; hydroxypropyl methylcellulose; methylcellulose; polyethylene; sweet potato

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*Corresponding author; email: rizafizah@ukm.edu.my