Kaedah pengekstrakan ultrasonic telah digunakan untuk mengekstrak minyak daripada buah keras. Keadaan optimum bagi pengekstrakan ditentukan dengan menggunakan kaedah satu faktor pada satu masa (OFAT) dan kaedah sambutan permukaan (RSM) melalui rekabentuk komposit berpusat. Keadaan optimum bagi pengektrakan yang diperolehi daripada OFAT ialah masa pengekstrakan 120 minit, paras kuasa ultrasonic 140% dan suhu pengekstrakan 45°C. Pengekstrakan buah keras yang dijalankan pada keadaan ini menghasilkan 57.53% minyak. Analisis statistik menunjukkan terma linear dan kuadratik bagi ketiga-tiga pemboleh ubah tak bersandar mempunyai kesan yang signifikan terhadap hasil minyak. Terdapat juga interaksi antara paras kuasa ultrasonik dan suhu pengekstrakan yang mempengaruhi hasil minyak. Keadaan optimum bagi RSM adalah 150 minit masa pengekstrakan, paras kuasa ultrasonic 120% dan suhu pengekstrakan 40°C. Keadaan pengekstrakan ini memberi hasil minyak sebanyak 59.93%. Pengesahan bagi pengoptimuman menunjukkan perbezaan peratusan ralat antara nilai eksperimen dan nilai ramalan adalah antara 0.29-4.31%. Tiga persamaan empirik bernama persamaan hukum kuasa, persamaan resapan parabolik dan persamaan Naik telah dicadangkan dan disahkan. Keputusan pengekstrakan minyak daripada buah keras mendapati bahawa persamaan Naik berpadanan dengan data eksperimen dan mempunyai R2= 0.999 dan nilai RMSD 0.0998. Ekstrak minyak daripada buah keras juga mengandungi asid lemak seperti asid palmitik, asid linoleik dan asid oleik.
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Ultrasonic extraction method was employed to extract oil from the candlenut seed. The optimal extraction conditions for the extraction of candlenut seed oil were determined using one-factor-at-a-time (OFAT) method and Response Surface Methodology (RSM) via Central Composite Design (CCD). The optimal extraction condition obtained from OFAT method were extraction time of 120 min, ultrasonic power level 140% and extraction temperature 45°C. Extraction of candlenut seed oil under these conditions gave an oil yield of 57.53%. Statistical analysis showed that the linear and quadratic terms of these three independent variables had significant effects on the oil yield. There was also an interaction between the ultrasonic power level and the extraction temperature which affected the oil yield. The optimal conditions for RSM were extraction time 150 min, ultrasonic power level 120% and extraction temperature 40°C. This extraction conditions gave an oil yield of 59.93%, one fold higher than the OFAT method. The verification of the optimization showed that the percentage error differences between the experimental and predicted values were in the range of 0.29-4.31%. Three empirical models namely Power law, Parabolic diffusion and Naik models were proposed and validated. Results showed that for the extraction of candlenut seed oil, the Naik model fitted the experimental data well with R2 = 0.999 and RMSD value 0.0998. The extracted candlenut seed oil contains fatty acids such as palmitic acid, linoleic acid and oleic acid.
Ultrasonic extraction of candlenut seed essential oil / Faiznur Mohd Fuad