How to check if String contains any of the strings in List/Array

Question

I currently have a an ASP.Net Website. This website retrieves RSS-Feeds from different Sources and outputs its own RSS-Feed. But is the article contains some word they must be 'blacked out' (Censorship as you might say). The words are contained in a blacklist managed by that ASP.Net Website.

My current solution:

foreach (SyndicationItem rssItem in syndFeed.Items.OrderByDescending(x => x.PublishDate).ToList())
{
    //if is on blacklist
    bool isValid = true;
    foreach (String blacklistItem in MyBlacklist)
    {
        if(rssItem.Title.Text.contains(blacklistItem))
            isValid = false;
        if(rssItem.Summary.Text.contains(blacklistItem))
            isValid = false;
    }

    if (isValid)
    {
        writer.WriteStartElement("item");

        //Write Elements
        writer.WriteElementString("PubDate", rssItem.PublishDate.ToString("yyyy-MM-dd HH:mm:ss"));
        writer.WriteElementString("title", rssItem.Title.Text);
        writer.WriteElementString("description", rssItem.Summary.Text);
        writer.WriteElementString("link", rssItem.Id.ToString());

        writer.WriteEndElement();
    }
}

Question: Is there a more performant way to do this search? How can i write the following code more simple using LINQ/ Any other Stringoperations?

    foreach (String blacklistItem in MyBlacklist)
    {
        if(rssItem.Title.Text.contains(blacklistItem))
            isValid = false;
        if(rssItem.Summary.Text.contains(blacklistItem))
            isValid = false;
    }

Based on the following examples from Java:

Checking if a string contains any of the strings in an array

How to check string with array of strings in java?

Test if a string contains any of the strings from an array

Answer 1

bool isValid = !myBlackList.Any(s=> rssItem.Title.Text.contains(s) || rssItem.Summary.Text.Contains(s))

Or

bool isValid = myBlackList.All(s=> !rssItem.Title.Text.Contains(s) && !rssItem.Summary.Text.Contains(s))