Melting Point, MP

I hate this test

The official method used is by AOCS Cc3-25

AOCS - American Oil Chemists Society - reputable
CC 3- method numer

25??? hehe stand for 1925

At this age palm oil industry is still using method formulated about 100yrs ago because at that time there is no better instrumentation for testing the plasticity.

Take a capillary tube, filled up the fat, solidified for 16 hr and melt slowly in a beaker of water and at the point where the fat is ABOUT to melt and melting, take the temperature

sound simple but there are so many factors affecting it making the reproducibility so difficult. The American couldn't be bother as they are only interested in Tallow which is high melting and easier to handle. Palm Oil, with the liquid fractio Olein 24deg C, is a nightmare

When I first joined, Madam Siew WL conducted the 1st round round-robin and give a reproducibility of 0.5 deg C. Very good indeed - bec if selected few lab run by experienced and dedicated chemists - the first generation

There I come along with a bunch new chemists and the second cross check is 1 deg C.

A lot of commercial pressure eventually chemists called each other to "cross-check" before reporting to the round-robin .....eventually ..... but life goes on...... but then we produced SuperOlein - MP 18, how to test even in air-cond lab of ambinet 24degC. Some jungle mill the lab has no air-cond and site next to the stainless tank of Crude Palm Stearin ----it's an oven.
Until today Msia lab still report 18 for SuperOlein but the Chinese Conter-part say it is 15 deg C

Years ago certain surveyor-laboratory always report mp 1 deg C than rest of the community - generally complied but producing mp around 23 so that the surveyor will report 24 which is within the Poram specs..... they live happily ever after until one day a big buyer open a spec of mp 22 max

The smart shipper who got the contract distribute the contract to 4 other shipper and of course all five are declare off-spec - So it is the surveyor vs the community
Actually both are correct. The method called for "stir slowly with agitation during melting" The Surveyor chemist - being a slow motion person, when being asked to do something slowly, stir extremely slow and results in reporting a higher mpt.

If only we can get rid of the spec especially for low melting oil

For Palm Oil it is rather useful - going back to the IV problem. Generally there is an IV-MP loose correlation. A normal cpo will have 51-52 IV and 36-37 MP. It is rather unfortunate that Poram spec give allowance for MP 33-39 & IV 50-55. Some smart Indian/Pakistan trader takes advantage of this yr ago but blending 5-10% Sterin into PO given a 50.1 IV and 38.8 MP to the sub-continent. The Indian/Pakistan fight back by imposing the melting point 37 max and IV 51 - 54.

Melting Point for Stearin is ok until you sell soft or blended Stearin of IV 42 MP 48 - its a nightmare with the Middle East market - the mt is on the so-called inflection point - highest interlab error of 2-3 deg C.