I don't think Windows Azure PowerShell Cmdlets has a readymade Cmdlet to do that. If you're open to use 3rd party product, you can try Cerebrata's Azure Management Cmdlets
. It has a Set-BlobProperties
cmdlet using which you can set the content type.
You can also do it through code as well. Essentially what you would do is fetch blobs from the blob container using ListBlobs
or ListBlobsSegmented
method and then iterate over these blobs and update the blob's properties via SetProperties
method of CloudBlockBlob.