Sunday, March 6, 2011

CHOCOLATES-CAN THE MELTING POINT BE RAISED?

Chocolate industry in a tropical country like India is constrained by the hot weather that prevails over most of the regions in the country during major part of the year. Chocolate products have refined Cocoa Mass as the main base and Cocoa fat provides the typical texture and eating pleasure characteristic of these products. Though chocolate making was known since many years, technological advances during the last 4-5 decades have enabled the industry to produce chocolates of uniform and reliable quality. The chocolate consumption is wide spread in western countries enjoying temperate climates when the product quality can be maintained during manufacture and retailing. How ever the warm climates in tropical countries near the Equator adversely affect the characteristics and handling and distribution pose stiff challenges.

Theobroma cacao, the botanical name for Cocoa is grown largely in Africa in countries like Ivory Cost and Ghana but the business of making chocolate is concentrated in the hands of a few multi national companies operating from the US and European Union. Converting raw cocoa pod into cocoa nibs and then to cocoa mass is a technology intensive process and requires a high degree of expertise and large investments. After allowing the pods to ferment for extracting the beans from the mucilaginous matrix, they are dried, roasted, shelled to yield cocoa nibs and finally ground into fine chocolate liquor which the solidifies to a mass at temperatures below 17C. Chocolate mass is then subjected high hydraulic pressure to separate the cocoa butter which is valued very much for its typical melting characteristics.

In a typical formulation of a chocolate product, cocoa mass with additions of cocoa butter and sugar is mixed, tempered and molded to give the final product with a snappy texture. It is the cocoa butter and its crystalline structure that decide the final eating quality of the product. Cocoa butter has six different crystal structure each with a different melting point range between 17C and 36C and the technology and expertise involve creating a homogeneous crystal structure which melts at 34C. This is accomplished by melting the mass to 45C and then slowly cooling to 27C to form a predominant mix of type IV and V crystals. Final procedure involves heating the product from 27C to 31C to eliminate type IV crystals leaving only type V with a melting point of 34C. The chocolates as known to day to connoisseurs cannot be made with any other fat and attempts to replace cocoa butter will definitely end up with products with biting and eating characteristics some what different from normal chocolates.

Many attempts have been made in the past to evolve chocolates with higher melting point amenable for easy handling and storage. Main strategies tried out earlier to produce high melting chocolates include enhancing network microstructure of chocolate, the addition of oil or fat binding polymers to the formula, and increasing the melting point of the fat phase. There are also many techniques that exist to generate a sugar network in chocolate, which may prevent melting. Such techniques include the incorporation of water into formulations, and processing the chocolate in such a way that some surfaces of the sugar remain uncoated by fat. The addition of oat flour, gelatin or cornstarch to chocolate as a binding polymer has also been successful in increasing heat resistance. While achieving heat resistant characteristics is technically feasible, the products so made adversely affect the flavor and texture qualities very significantly. There are many edible fats available to day for use in heat resistant chocolates but their consumer acceptability is very poor. Probably development of truly heat resistant chocolates without compromising on the quality may remain a distant dream for years to come though a little compromise on quality can throw up chocolate-like products with hard texture and changed mouth feel.

V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com

1 comment:

Melting Brownies said...

I'm glad i found your blog sir. I too am currently a student doing my B.Tech in food technology. I found what i was looking for in this article. Thanks a lot!