Hunting down that obscure Vietnamese place that serves up bánh bao exactly like you'd find in Hanoi, or an Indian joint with dal just like the one you had on that trip to New Delhi, is a not uncommon pursuit in these food-obsessed days. But our culinary hunt for "authentic ethnic" food can be a double-edged sword, says Krishnendu Ray.

Ray is the chair of the food studies program at New York University and author of the new book The Ethnic Restaurateur. When we seek authenticity from a star chef — say, Thomas Keller of the Michelin-starred restaurants The French Laundry and Per Se — what we really want is his signature, his individual creativity evinced through food, and we're willing to shell out big bucks to get it, Ray says.

But that's very different from the authenticity we demand from "ethnic" cuisine. In that case, Ray says, what we really want is a replica, "a true copy of our expectations" — some platonic ideal of what a dish should taste like. It's a definition of authenticity that can trap the immigrant cook in very narrow expectations.

"One of the big constraints, say, for Indian food or Chinese food is that, if it is expensive, it cannot be authentic," Ray says. Immigrant chefs "are trapped for that kind of demand for authenticity — cheap authenticity."

In his book, Ray explores the history of how immigrants in the food industry have shaped American notions of good taste — even as they themselves may occupy the lower echelons of the social hierarchy. How we value a culture's cuisine in our society, Ray says, often reflects the status of those who cook it.

In an increasingly multicultural society, the term "ethnic food," while still commonly used, is now starting to take on an offensive character, lumping all nonwhite people and their cuisines together in a category of "other."

Ethnic, Ray says, started being used to talk about food in the 1950s, partly as a relatively neutral way to acknowledge difference in a racially charged era. "Ethnic was useful back when America was a "white Anglo-Protestant-dominant culture," Ray says. But it always had the underlying connotation of "essential difference, of inferiority," he says, and is starting to feel outdated.

"Once Italians and Greeks and Mexicans and Indians and all these so-called ethnic groups acquired a cultural conscious and visibility in the public space, the word ethnic became inadequate," Ray tells me.

What's more, the concept of who is ethnic is fluid, as American history attests. The waves of Greek and Italian immigrants who came over beginning in the 1880s were once considered ethnics in the sense that they were separate from the dominant Anglo-American culture — working low-paying service jobs, often in the food industry, and living clustered in ghettos. As their lot improved over the decades and they moved up the economic — and social — ladder in America, Ray argues, appreciation for their food changed, too.

"Sometimes, our judgments of good taste has nothing to do with literal taste. It has to do with our notions and conceptions of a class of people," he says.

America has a long history of looking down upon the cuisine of its recent immigrants. For instance, from the 1880s until about the 1920s, Ray notes, social workers and nutritionists cautioned that Italian food was too garlicky and spicy — which they said increased the craving for alcohol. Today, Italian is the most popular ethnic cuisine in America. And it regularly appears among the most expensive and popular cuisines in the Zagat guide, which Ray calls upon as a pretty good window into the tastes of "middle brow" diners.

Each new large wave of immigration has remade American cuisine for the better, making it "more creative and rich," Rays says. He says we're currently going through another culinary transformation, driven by the easing of immigration rules in 1965 that resulted in a large influx of immigrants from Asia and Latin America.

And just as Italian food was once given the side-eye by nutritionists, Chinese food was also derided under the auspices of science. Witness the health scare that began in the 1960s over MSG, commonly used as a flavor enhancer in Chinese cuisine and other foods. As others have noted, the fears were flavored with xenophobia. Many eaters still avoid MSG, despite a lack of scientific evidence that it causes negative health effects.

Of course, learning to appreciate and accept immigrants' food takes time — it happens naturally as cultures learn to adapt to one another. But Ray argues that global forces are also at play.

Take Japanese food. In the late 19th and early 20th century, Ray says, "Japanese folks in Hawaii were always put on the defensive by schoolteachers, by nutritionists, [told] that they're basically eating food that is terrible, that's not good for them. And the children come home from school demanding good American food." Today, Japan is an economic superpower, and Japanese food is considered haute cuisine — often commanding top dollar from diners.

In America, there's long been a duality in how we view the cuisine of immigrants — as both suspect and exotic. In the late 19th and early 20th centuries, for example, rumors that Chinese immigrants used rat meat in their cooking were common. One New York Times story from 1883 pondered, " do the Chinese eat rats?" (Sadly, such tales persist.) Yet artists and other bohemians of the era sought out Chinese restaurants, in part as a sign of their worldliness.

Today, seeking out ever more varied cuisine is still a mark of culinary sophistication. (It's a quest the famed writer Calvin Trillin parodied this week, with unintended consequences.) Finding that hole-in-the-wall joint with the best Filipino food in town is a foodie badge of honor.

"To be a connoisseur today you have to like some elements of non-Anglo ... food," Ray says. And despite his critiques of the search for "authentic ethnic" food, Ray stresses that our elevation of a multicultural approach to eating is a good thing. Opening our mouths to each others' foods can become a gateway to opening our minds to each others' cultures.

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