Heats mixing and phase separation of polymer mixtures

Imperial Users onl

Preparation of dipalmitin by fractionation method / Normah Ismail, Cheow Chong Seng and Chong Chiew Let

Dipalmitin was prepared by glycerolysis of palmitic acid in the presence of isooctane and Lipozyme RM 1M and was further purified by neutralization followed by fractionation. Dipalmitin containing samples was named as ‘diacylglycerol chemical method’ (DGCHM). The dipalmitin content in DGCHM was 71.83%, however, after fractionation, this percentage was raised to 89.80%. The DGCHM and RBDPO (refined bleached and deodorized palm oil) added with DGCHM were analysed for their crystallization behavior. The complete melting temperature for DGCHM was 70.7°C. The combined DSC and wide-angle XRD of the dipalmitin revealed the polymorphic transformation from α to sub α to α. The yield for DGCHM was 71% (w/w). The purification of dipalmitin by fractionation method was considerably practical due to the higher yield, easier preparation, shorter preparation time and smaller amounts of starting materials required. The addition of 1% DGCHM to RBDPO has a negligible effect on its crystallization and heating properties

Interpretation of triacylglycerol profiles of palm oil, palm kernel oil and their binary blends

The effects of lipase-catalyzed interesterification (IE) on changes in the chemical composition of palm oil (PO), palm kernel oil (PKO) and their binary blends at 3:1, 1:1 and 1:3 (w/w) ratios, using both 1,3 specific Rhizomucor miehei, (Lipozyme™) and non-specific Pseudomonas sp. lipases were evaluated. IE of the native PO and PKO showed very distinct chemical composition changes. Catalysis of PO, using both lipases, caused synthesis of more medium and long chain triacylglycerols (TAG), with MMM/OLL, MMP, OOO and PPP (M, myristic acid; O, oleic acid; L, linoleic acid; P, palmitic acid) increasing in concentration. In contrast, IE of PKO resulted in the formation of more short and medium chain TAG, with LaLaO and LaMO (La, lauric acid; C, capric acid) experiencing noteworthy increments. Both Rhizomucor miehei and Pseudomonas sp. lipases showed high affinity in hydrolyzing PO fatty acids, resulting in high TAG losses and formation of high percentages of partial glycerides while these lipases were found to enhance the synthesis process in IE of PKO. Catalysis of the three binary blends caused similar TAG compositional changes where the synthesis process focussed on the medium chain TAG, while hydrolysis was observed in the short and long chain TAG that showed corresponding decreases. Catalysis of the three blends was influenced by the major fraction of these blends. Among these blends, PO: PKO at a 1:1 ratio exhibited the highest degree of IE. The diversity and quantity of available TAG are postulated to be the main causes of the different catalytic activities in these binary blends with Pseudomonas sp. lipase showing a higher degree and rate of IE than R. miehei

Effect of enzymatic transesterification on the fluidity of palm stearin-palm kernel olein mixtures

In an effort to improve the physical and/or melting characteristics of solid fats, the enzymatic transesterification of palm stearin-palm kernel olein (40:60) in a solvent-free system was investigated. The enzymes used were Celite-bound lipases that include 1,3-specific lipases such as Aspergillus niger, Alcaligenes sp. and nonspecific lipases such as Pseudomonas sp. and Candida rugosa. Commercial immobilized lipase from Rhizomucor miehei (Lipozyme 1M60) was also used. The efficacies of these enzymes for improving the melting behaviour of the oil mixtures were followed by slip melting point (SMP), solid fat content (SFC) and differential scanning calorimetry (DSC) analyses. Results indicated that enzymatic transesterification was able to produce fat mixtures with substantially lower melting points by repositioning the fatty acids of triglycerides in the higher melting range to form lower- or middle-melting components. Pseudomonas lipase-catalyzed mixtures produced the highest degree (152.2%) and rate (50.0 h-1) of transesterification followed by R. miehei lipase at 151.7% and 27.1 h-1, respectively. The highest % FFA liberated was also from the reaction mixture catalysed by Pseudomonas (2.90%) and R. miehei (2.54%) lipases. The Pseudomonas-catalyzed mixture also produced the biggest drop in SMP (12.0°C) and the SFC results showed complete melting at 35°C. Our findings also suggest that the positional specificity of lipases may not play a significant role in producing a more fluid product

Study on Handing Process and Quality Degradation of Oil Palm Fresh Fruit Bunches (FFB)

The main objective of this study is to determine the relationship between quality of oil palm fresh fruit bunches (FFB) and handling processes. The study employs exploratory and descriptive design, with quantitative approach and purposive sampling using self-administrated questionnaires, were obtained from 30 smallholder respondents from the Southern Region, Peninsular Malaysia. The study reveals that there was a convincing relationship between quality of oil palm fresh fruit bunches (FFB) and handling processes. The main handling process factors influencing quality of oil palm fresh fruit bunches (FFB) were harvesting activity and handling at the plantation area. As a result, it can be deduced that the handling process factors variable explains 82.80% of the variance that reflects the quality of oil palm fresh fruit bunches (FFB). The overall findings reveal that the handling process factors do play a significant role in the quality of oil palm fresh fruit bunches (FFB)