PHILADELPHIA — The frozen food aisle has become a hotspot for innovation. Established and emerging brands are expanding in the set, tapping into consumer demand for convenient meals and snacks, globally inspired fare, premium experiences and plant-based offerings.

Several examples stood out at Natural Products Expo East, held Sept. 21-23 in Philadelphia. Among them, Rudi’s Bakery, Boulder, Colo., unveiled several new items that will mark its expansion into the freezer case, including breakfast sandwiches and Texas toast, debuting at Whole Foods Market.

The brand also is adding frozen peanut butter and jelly sandwiches, made with its white bread and strawberry or grape spread. Two nut-free options feature a roasted seed blend, supplied by startup Voyage Foods and containing sunflower kernels, grape seeds, rice, buckwheat and chickpeas.

“When I rejoined Rudi’s, one of my first goals was to identify ways we could expand our food offerings and grow the brand to reach more consumers,” said Jane Miller, chief executive officer, who previously led the business for six years and returned two years ago. “We soon noticed there was a huge growth opportunity in the frozen section to do just that, as many of the food options quite frankly were using sub-par products and under-delivering on taste and nutritional value. That’s why we created our Texas Toast, Breakfast Sandwiches and Sandos Portable Sandwiches, which deliver delicious, nutritious versions of comfort food to the freezer section.”

The new products coincide with the addition of Justin Gold as chief innovation and strategy officer. Mr. Gold founded nut butter brand Justin’s, which was sold to Hormel Foods Corp. seven years ago.

Caulipower, Los Angeles, shared a glimpse of its forthcoming frozen food launches at the show, including baked cauliflower coated pizza bites with fewer calories and less fat than traditional offerings, according to the company. The brand also showcased its “over-the-top” pizzas with ingredients such as spicy chicken sausage and truffle oil.

Frozen food startup Blue Zone Kitchens, based in Austin, Texas, debuted at Expo East, sampling its four single-serve meals made with ingredients linked to longevity. The brand was co-founded by Dan Buettner, a National Geographic Fellow, host of Netflix’s “Living to 100” and New York Times best-selling author, who coined the term “blue zones,” referring to regions of the world’s healthiest and happiest populations.

“When it comes to longevity, there’s no short-term fix,” Mr. Buettner said. “That’s why we created meals formulated with a maniacal focus on deliciousness. Because I’ve learned that if people love the taste of food, they’ll eat it for the long run.”

The plant-based line includes a burrito bowl, minestrone casserole, sesame ginger bowl and heirloom rice bowl, made with organic beans, vegetables, grains and spices.

“People have been seeking solutions for longevity for centuries, yet today’s solutions are typically pills,” said Scott Marcus, CEO of Blue Zones Kitchen. “We’re pleased to offer amazing foods created to help support long, vibrant lives, based on decades of research.”

Also at Expo East, Portland, Ore.-based Brazi Bites featured its new line of frozen gluten-free waffles, including what the company claims is the first-to-market cheesy waffle. Canadian startup Lift Bar presented its assortment of high-protein frozen dessert novelties formulated with collagen, coconut cream, egg yolk and coconut oil. RoRo’s Baking Co., Dallas, highlighted its frozen cinnamon rolls and dinner rolls based on a grandmother’s recipes. Cappello’s, Denver, introduced bakery-style gluten-free cookie dough and biscuits made with almond flour. Xinca Foods, Arlington, Wash., featured its Salvadorian-style frozen pupusas, filled with refried beans and cheese. Seal the Seasons, Durham, NC, displayed its range of “locally grown, locally frozen and locally sold” fruits and vegetables. The recently rebranded Myles Comfort Foods, McLean, Va., served its gourmet macaroni and cheese meals. Laoban Dumplings, Washington, shared its restaurant-inspired retail brand of pork, beef and vegetable dumplings.