gistfile1.cs

Regex rxnum = new Regex(@"(\d+(?! */))? *-? *(?:(\d+) */ *(\d+))?.*$");
Match numMatch = rxnum.Match(ingredient);
if (numMatch.Success)
{
   amount = (!string.IsNullOrEmpty(numMatch.Groups[1].Value) ? numMatch.Groups[1].Value : string.Empty) + (!string.IsNullOrEmpty(numMatch.Groups[2].Value) ? " " + numMatch.Groups[2].Value + "/" + numMatch.Groups[3].Value : string.Empty);
   // do something with the amount...
}