The first New York outpost of Trader Joe’s – the West Coast grocery chain famous for its cheap and cheerful sensibility – opened on Friday near Union Square to massive crowds. But with a Whole Foods Market just one block away, there’s a battle royale shaping up for your gourmet dollar. Is it worth braving the throng at Trader Joe’s to see what all the fuss is about? I decided to put my taste buds to the test.

Trader Joe’s has built a cult-like following for its inexpensive house brand and signature products sold in self-service stores by Hawaiian shirt-clad staff. Founded in 1967, the California-based company has 253 stores in 19 states. It’s billed as “neighborhood grocery stores with food and beverages from the exotic to the basic.” For Manhattan devotees of Trader Joe’s cheese-and-green-chili tamales or 100% wild blueberry juice, the opening is big news.

A year ago, it was also big news when the 48,000 square-foot Whole Foods Market opened on Union Square. Whole Foods describes itself as “the world’s leading natural and organic foods supermarket.” Whole Foods has a cult following of its own, with 180 stores in America, Canada, and Britain. Two more stores, one on East Houston Street and one in TriBeCa, are slated to open soon in New York City.

On Friday evening I shopped at Trader Joe’s and at Whole Foods, buying identical groceries for a simple spaghetti dinner for two. I bought only house brands, organic whenever possible. Even though the checkout line at Trader Joe’s snaked through the store and almost out the door, it only took 10 minutes to get to the register.The store does not take American Express or give a “green” credit for bringing your own shopping bag, as Whole Foods does. There was also an inexplicable 33 cents in tax. At Whole Foods, there were three lines of about 10 people each, with a wait time of only a few minutes.

The dinner results were a tie, though there were clear winners in each group. I started dinner off with a salad of fresh mozzarella and cherry tomatoes, tossed with extra-virgin olive oil and balsamic vinegar. The simplicity of this salad showcased the flavors and textures of each ingredient, and the winner was Trader Joe’s. The mozzarella was creamier in flavor and texture. The tomatoes sweeter, and the olive oil fruitier and brighter.The vinegars were practically identical, even though the Trader Joe’s was aged for 10 years and Whole Foods’ house brand 365 was aged for an unspecified period of time.

My main course was organic spaghetti with organic marinara sauce. I cooked the pasta in salted water, but used no other ingredients to season the sauce. In this case, the winner was Whole Foods.The 365 spaghetti had perfect al dente texture, while the Trader Joe’s was mushy. The 365 marinara sauce had pieces of tomato and a nice flavor of olive oil and spices. The Trader Joe’s sauce was virtually flavorless.

To finish up, I served apple pie. “They’re both awful,” my dinner companion said. In spite of the lists of fresh and organic ingredients, the crusts were soggy and gummy: Both had strange unpleasant flavors to the fillings. Fortunately, I had picked up some chocolate-covered espresso beans as well, which removed the bad apple pie taste from our mouths. The winner? Whole Foods. Its chocolate had a better melt and mouth-feel and the beans tasted fruitier. The Trader Joe’s beans had a slight burnt taste.

To wash it all down, we had the much-anticipated blueberry juice. And here the winner was Trader Joe’s. The juice has bits of blueberry pulp and a tart flavor that makes it seem healthy. While the 365 Blueberry Juice is organic, it’s a blend of other fruits.

In terms of doing the shopping, store preference will depend on what kind of products you buy most and how you shop. Trader Joe’s is much smaller (12,000 square feet compared to 48,000 at Whole Foods) with a limited selection of unique and proprietary products. Whole Foods carries products for babies, household cleaning, and cookware. If you’re a one-stop shopper, then Whole Foods is for you.

Will Trader Joe’s affect Whole Foods? “We coexist in many markets.It’s not really a big impact,” Whole Foods’ regional president, Christina Minardi, said. When Whole Foods opened last year, the big question was the store’s potential impact on the Union Square Greenmarket. “We got tons of calls from media and customers,” the publicity manager of the market, Gabrielle Langholtz, said. Devotees of local farmers will be happy to know the market is just fine and recently added five new meat and cheese stands, bringing the total number of stands to 70. “For us, it’s more of a lifestyle question,” Ms. Langholtz said. “Are people going to buy produce to cook, or prepared foods? It’s roasted cauliflower versus a head of cauliflower.”

But in all these discussions, no one mentions the potential impact on the Food Emporium that’s been at 10 Union Square – located almost equidistant between the two specialty stores – for more than two decades. “We don’t consider them competition,” Ms. Minardi said.

Trader Joe’s, 142 E. 14th St., between Park and Third avenues, 212-529-4612. Whole Foods Market, 4 Union Square South, 212-673-5388.