Kevin Stewart insisted the move would eradicate the "postcode lotteries" that currently exist across Scotland.
He made the comments as the first annual National Care Service forum took place in Perth.
The event gave social care users, families, carers and staff the opportunity to share their thoughts about the proposals, which ministers have described as the most ambitious reform of public services since the creation of the NHS.
The move would make ministers accountable for adult social care in Scotland.
Councils would no longer run social care services, while "care boards" would be created to fulfil a similar function to existing health boards.
Trade unions have strongly criticised the plans, with Unite calling them an "all-out assault on local democracy".
Cosla, the local government body, has said it would mean diverting urgently needed funding towards “disruptive structural reform”.
Speaking to The Scotsman, Mr Stewart said: "I disagree that it's centralisation and I disagree that we will lose the local aspect – far from it, in fact.
"That's why we will establish local care boards and they will have the flexibility to shape services that are right for their area."
He said he was determined people with lived experience "will play their part in those local care boards and that they will have a vote at the table, which they don't currently have".
Asked why he thought Cosla opposed the plans, Mr Stewart said: "Often people don't like change, I understand that. But this change is required.
"We have listened to people. They are hungry for change, and we want to ensure that we put in place the accountability, the national, high-quality standards that folk want to see, and to eradicate those postcode lotteries."
Earlier, he said: "People want to see a situation where there is more accountability.
"People have told us that they want ministerial accountability, which there hasn't been thus far.
"We have listened to people and that is why we are taking the steps that we are.
"The key thing in all of this is the national, high-quality standards to end postcode lotteries.
"The only way that that can be done is through ministerial accountability.
"However, what we want to see is services continuing to be shaped at a local level, with the flexibility that's required locally."
The proposed National Care Service is being created after an independent review of adult social care services in 2021.