The company has improved the quality of its Dairy Milk chocolate bar packaging, changing from regular foil-wrap to a triple-layered, poly-coated aluminium foil, inside the outer wrapper.
Said Bharat Puri, managing director, Cadbury India: "We want to reassure the consumer that he can eat the bar blindfolded."
Puri said that in consumer research, Bachchan emerged as the one celebrity that "personifies the Cadbury brand the best" - he is trusted, has been a part of Indian popular culture for a long time, and consumers believe they can rely on him.
The first phase of communication shows Bachchan visiting a Cadbury factory, and declaring his faith in the brand, along with a demo shot of the new 'purity seal' packaging. This will run nationally for two or three weeks, with a target frequency of five OTS (Opportunity To See, or number of times the target audience is exposed to the ad).
It will be followed by theme communication, again featuring Bachchan, that will embody Cadbury's brand values.
Cadbury said response from distributors as well as consumers has been positive.
"This is a gentleman who has a high amount of trust and confidence," said Puri. "We definitely plan on a long-term relationship with him."
He described Bachchan as "very much a part of Team Cadbury".
The commercials were shot by Santosh Sivan, and the agency on the account is Ogilvy & Mather, which also handles Cadbury's Perk.