By Sean Henahan, Access Excellence

SAN FRANCISCO- Food researchers have developed a modified chocolate that is less fattening and easier to manufacture, according to a report at the annual meeting of the American Institute of Chemical Engineers.

"Semi-sweet chocolate is basically a concentrated suspension of cocoa and sucrose particles dispersed in a continuous fat phase. The primary component of this fat is cocoa butter, which also happens to be the most expensive ingredient. The key is to minimize the fat content while still retaining chocolate's unique physical properties and flavor," notes Greg Ziegler, an associate professor of food science at Pennsylvania State University.

Previous chocolate research has concentrated on the size of cocoa and sugar particles suspended in the fat, crucial factors for the taste experience. The Penn State researchers have gone further, by designing the particle size distribution to optimize the flow properties of the chocolate.

Considerable research has been dedicated to the characteristics of flow behavior in chocolate. This is important in the molding of chocolate into Santas and bunny rabbits, and enrobing chocolate bars. It is also a key in the manufacture of perfect chocolate chips and in the design of bulk handling systems, notes Ziegler.

The viscosity of the chocolate, the key to its flow behavior, is determined by its fat content. Food researchers would like to e able to maintain the flavor of chocolate while lowering its fat content, now around 30 percent for most chocolate.

In an exhaustive series of experiments the Penn State researchers examined four distinct particle size distributions- narrow unimodal, wide unimodal, bimodal, and control. Viscosity was then measured at four nominal fat contents - ranging from 25% to 34%- while maintaining a mean particle size.

The results suggested that a bimodal distribution (i.e. two distinct particle sizes) produced a lower viscosity and higher yield value compared with traditional unimodal distributions. Moreover, the effect was greater as the fat content decreased. These results are consistent with a physical model of packing efficiency in suspensions, said Ziegler, adding:

"This means cocoa butter content can be reduced while maintaining nearly identical flow properties, resulting in a cost savings to manufacturers, and perhaps more importantly, reducing the caloric content."

Transmitted: 94-12-30 15:52:07 EST

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