EAST RUTHERFORD - Jeffrey Striks has bitten into a new niche of the American kosher food market: sports stadiums. He got his start seven years ago, offering kosher food at baseball concession stands at Shea Stadium and Yankee Stadium in New York. Business is so good that he’s expanded his company, Strikly Kosher, and now operates kosher stands at Giants Stadium and Continental Airlines Arena in New Jersey, Nassau Coliseum in Long Island and the Yankees’ minor league ball park in Staten Island. His core market is observant Jews who follow the laws of kashrut, which restricts what food can be eaten and how it is prepared. But he’s also attracting customers who aren’t Jewish and perceive that kosher food is healthier. They are buying his knishes, chicken nuggets and ``knockwurst’’ - not the traditional German sausage but a chicken product designed to look like a hot dog. Since typical stadium fare is hot dogs, selling kosher food at sports venues is a logical market, said Marcia Mogelonsky, a senior research analyst at Mintel, a market research firm in Chicago that estimates the American kosher food market to be $40 billion. Others are capitalizing on the growing kosher market in stadiums. Striks plans to move outside the New York area, and a competitor, Kosher Sports Inc., has already moved into stadiums in Philadelphia, Baltimore and Washington, D.C. Both companies have menus that are glatt kosher, a stricter designation that usually applies to meat. The most observant Jews will eat only glatt kosher foods. Opening a glatt kosher stand has its risks. Often, kosher food products cost more than the non-kosher ones. It also means not being open on Shabbat - Friday nights and Saturdays - and holidays including eight days over Passover and three high holidays. Steve Spencer of Livingston, N.J., is Jewish and doesn’t keep kosher, but likes the idea. ``If I’m going to buy a hot dog, I’ll find the kosher stand,’’ said Spencer, 47, as he waited in line at a Jets game against the Chicago Bears. ``I like the taste better. I assume the quality is better.’’ Joel Felderman, an observant Jew, said the kosher stadium stands allow him to enjoy games more. A Jets season ticket holder for more than 30 years, he had always eaten before games because he didn’t have glatt kosher alternatives in the stadium. ``It makes me feel like I’m a real fan,’’ said Felderman, 53, an accountant from Oceanside, N.Y. ``I can buy a hot dog like everyone else and not compromise my religious beliefs. I can get the total experience.’’ That’s exactly the message that Aramark, the company that manages food services and contracts for vendors at many of the nation’s stadiums, wants to hear. Aramark is offering more kosher choices at stadiums in other markets by contracting with more companies, including Kosher Sports Inc. of Englewood, N.J. Other stadiums offer kosher products, but not to the degree of glatt kosher. Hebrew National hot dogs are an all-beef kosher product but is not glatt kosher, said Regina DeMars, a spokeswoman for ConAgra, the company that owns the brand. Fans of the Denver Broncos and Colorado Rockies can also buy kosher dogs from Zaler’s Kosher Korner at Invesco Field and Coors Field. Over the last year, the company has expanded at Invesco from one stand to 13, said owner Arnie Zaler. The stands are not glatt kosher but Zaler said most of his customers don’t care because they are not Jewish. ``People are so nervous about what they’re eating,’’ said Zaler, whose family has run the business for 94 years. ``They’re not sure what kosher is, but they know they won’t get a lot of junk in their hot dog.’’ That’s why Becca Murphy, who is not Jewish, waited in line at the Strikly Kosher stand at the Jets game. ``Sometimes it sounds nicer than a hot dog filled with grossness,’’ said Murphy, 26, a teacher from Eatontown, N.J. ``Sometimes you pay for quality.”