Blending palm kernel oil, extracted by supercritical carbon dioxide, and palm oil leads to new cocoa butter replacers (CBR), offering cheaper alternatives with good physical and chemical properties.
As cocoa butter continues to run at a relatively high price, and crops and price will always be vulnerable to climatic and political change, the use of cheaper vegetable fat replacers should be a convincing argument for international chocolate firms such as Nestle, Cadburys and Hershey.
But it would appear that change, at least in the eyes of the marketer, may not please the consumer. As the slow cocoa butter replacer uptake in Europe suggests, chocolate makers suspect that the consumer will not opt for the vegetable fat/cocoa butter mix, preferring instead the 100 per cent cocoa butter recipe. But there is also the argument that consumers will be tempted by low prices, made possible through cheaper ingredients.
"The cocoa bean only contains small amounts of CB, and thus the price of CB is one of the highest among all commercial fats and oils. As only a few countries cultivate cocoa, supply can be unstable," explained researchers from Tohoku University in Japan and Universiti Sains Malaysia.
"Therefore, industries are looking for CB replacers (CBRs) or alternatives to CB. Palm kernel oil (PKO) could provide such a replacement as it is regarded as food-grade oil that is of high quality," they said.
In palm kernel oil (PKO), lauric acid (C12) makes up about 48 per cent of the oil, but in cocoa butter (CB) it represents only about 12 per cent. Moreover, the longer chain acids (palmitic acid (C16), stearic acid (C18.0), and oleic acid (C18.1)) are found in large amounts in CB but in small amounts in PKO.
The researchers behind the new study, to be published in an upcoming issue of the Journal of Food Engineering and already available on-line, used supercritical carbon dioxide fractionation of palm kernel oil to decrease the C12 and C14 (myristic acid) concentrations, and then blended this with palm oil to produce new CBRs.
The use of the supercritical carbon dioxide technique reduced the C12 concentration from 48 to 28 per cent. This was further reduced by blending with palm oil (Wilmer edible oil) and commercial C18.0 (palmac 98-18) and C18.1 (palmac 760), both obtained from Palmco Holdings.
Ten blends were produced, with PKO content ranging from five to 50 per cent, and PO from 60 to 20 per cent. The remaining was made up of the C18.0 and C18.1 (usually 15 per cent each).
The researchers report that, despite the continued presence of C12 and C14 constituents, all of the blends"could be recommended as CBRs in respect to the physico-chemical properties like fatty acids constituent, [and] slip melting point (SMP)."
"The other properties like iodine value (Iv), saponification value (Spv) and acid value (Av) for the blends 110 were found to be closer to that of commercial CB," they said.
"All blends were found to be able to use as CBRs."
The authors were not available for comment prior to publication, and it is not known if such blends will be developed further and made available commercially.
The research was sponsored by a grant from the Malaysian government.
The first European Union chocolate directive was agreed in 1973 and allowed the then new entrants to the European Community, the UK, Ireland and Denmark, to use a small amount of vegetable fats in their chocolate. Since this time, other European countries, notably Germany, have been fighting with chocolate puritans' notably France, Belgium and Italy - for the right to use vegetable fats and still call their products chocolate.
The fight ended in 2000, and in August 2003 Europe enforced new legislation that allows manufacturers to replace up to 5 per cent of chocolate's cocoa butter content with vegetable fats.
Source: Journal of Food Engineering February 2007, Volume 78, Issue 4, Pages 1397-1409 "Blending of supercritical carbon dioxide (SC-CO2) extracted palm kernel oil fractions and palm oil to obtain cocoa butter replacers"
Authors: I.S.M. Zaidul, N.A. Nik Norulaini, A.K. Mohd Omar and R.L. Smith