The author uses this term, romantic, several times, but doesn't specify what he means by it, although this section implies a little about what he seems to mean. Based on Wikipedia's entry on Romanticism, it refers to an intellectual and artistic movement starting in the late 1700s in Europe that emphasized "emotion and individualism" and glorified nature and the past. What's probably most relevant about this movement is that it originated during, and in response to, the industrial revolution.
There's a clear link between this definition and what Pratt is talking about in terms of glorifying (or even fetishizing?) certain places and practices as more directly related to traditional agricultural practices and placing higher value on food commodities that can be directly linked to the specific places or people that produced them.
Interestingly, authenticity seems to have been a feature of the Romantic movement as well. The Wikipedia article says that adherents of Romanticism "emphasized intense emotion as an authentic source of aesthetic experience" (no citation is given for this assertion, however).