Effect of Processing Conditions on Oil Point Pressure of Calabash Nutmeg (Published)
The oil point pressure of calabash nutmeg (Monodora myristica) was investigated considering particle size, moisture content, heating temperature and heating time. Freshly harvested seeds obtained from a local market in Ibadan were decorticated and cleaned of all extraneous matter. The kernels obtained were milled and graded into fine and coarse aggregates. The experiment was a central composite design in which two levels of moisture content (17 and 21%wb), heating temperature (50 and 70 ̊C) and time (5 and 15 mins) were considered. The data obtained were analyzed using Design Expert Version 6.0.8. The results showed that oil point pressure increased with time but decreased as heating temperature and moisture content increased. For fine aggregates, the minimum oil point pressure of 0.116 MPa was obtained at a temperature, time and moisture content combination of 60 ̊C, 10 mins and 23%wb, respectively. However, for coarse aggregates, the minimum oil point pressure of 0.144 MPa was obtained at 70 ̊C, 5 mins of heating time and moisture content of 21% (w.b). The results showed that the oil point pressure of fine aggregates was lower than that of the coarse aggregates. From the analysis of variance, heating time had significant effect on the oil point pressure (p<0.05). The minimum oil point pressure of calabash nutmeg was obtained as 0.116 MPa at an optimal temperature, time and moisture content of 64 ̊C, 5 mins and 21% (w.b), respectively.
Keywords: Monodora myristica, Oil expression, Oil point pressure, Processing conditions., optimization
Optimization of the Production of Structured Lipid by Enzymatic Interesterification from Coconut (Cocos Nucifera) and Sesame (Sesamum Indicum) Oils Using Response Surface Methodology (Published)
Blends of coconut (Cocos nucifera) oil (CO) and sesame (Sesamum indicum) oil (SO) were enzymatically interesrerified using aqueous lipase derived from Rhizomucor miehei and the reaction conditions, namely, temperature (45-65 °C), time (16-48 h) and mass ratio of oils (CO:SO; 70:30 – 50:50) were optimized using Response Surface Methodology (three-factor, three-level central composite design). Degree of interesterification (DI), and the ratio of monounsaturated and polyunsaturated fatty acids (MUFA:PUFA) of triacylglycerols were used as response variables. The linear effects of all factors were significant for the DI while for MUFA:PUFA, the linear effect of oil ratio and interaction effect of time and oil ratio showed significant effects. The conditions, temperature; 57.12 °C, time; 16 h and weight ratio of oil (CO:SO); 50:50 were found to be the optimum. The R2 value for DI and MUFA:PUFA ratio were 0.80 and 0.82, respectively. Models fitted for both DI and MUFA:PUFA ratio were significant with non-significant lack of fit. Therefore, the constructed models and data provide useful information to produce structured lipid from interesterification of CO and SO in up-scaled level. The produced novel lipid containing beneficial fatty acids from both oils could be used to produce healthy fat based products.
Keywords: coconut oil, interesterification, lipase, optimization, sesame oil
Optimization of Screw Press Extraction of Citrillus Lanatus Seed Oil and Physicochemical Characterization (Published)
The aim of this study was to optimize the extraction of C. lanatus seed oil using a screw press. Response surface methodology (RSM) was employed to describe the effects of pressing temperature and restriction diameter on oil yield and residual oil content using a Doehlert design. The seed oil extracted was characterized to determine its quality. Results showed that the experimental data were adequately fitted into the second-order polynomial model. The pressing temperature and restriction diameter had a significant effect on the screw press performance. The optimum conditions within the experimental domain were the pressing temperature of 92 °C and restriction diameter close to 4 mm. Under these conditions, the oil yield was 38.79%. The colour of clarified oil was light yellow. Its physical and chemical properties come up to the required standard for edible oil. Therefore, C. lanatus seed oil extracted by screw press could have important applications in human nutrition
Keywords: Citrullus Lanatus, Oil Yield, Screw Press, Seed Oil, optimization
Optimization of Extraction Process for Total Polyphenols from Adlay (Published)
The single-factor experiment and an orthogonal experiment design were adopted to optimize the extracting technology of polyphenols from adlay. The results showed that, the impact order of the influence factors was ethanol concentration > extraction time > extraction temperature, and that ethanol concentration and extraction time have significant difference (p<0.05). The optimum extraction conditions were ethanol concentration 60%, extraction time 1.5 h, extraction temperature 40 oC and ratio of liquid to material 15:1. Under the optimized conditions, the yield of total polyphenols from adlay was 2.84 mg/g.
Keywords: Adlay, Extraction process, Polyphenols, optimization