Before the three-tone air horn finishes its melody, the seniors at Dr. Armando Badia Senior Center are already making their way to the burbling truck in the parking lot with money in hand.

Bagged fruit hanging from the white truck’s open back are still swaying precariously when Arturo Tamayo hops out of the driver seat to fold down the metal side that reveals baskets of fresh fruits and vegetables he bought at the produce market at 4 a.m. Customers pool around the produce, shopping out of the cubbies as if browsing the aisles at Sedano’s.

Whirring begins almost immediately inside the truck. Tamayo’s wife, Nancy Hernandez, already has four orders for batidos, smoothies made from shaved ice and fresh mango, papaya, pineapple and other fresh fruit she has been cutting up since daybreak.

This bodega on wheels is a common sight throughout Miami, an import of Latin American culture where the convenience stores come to shoppers. It’s the original food truck.

Grocery bags are soon full of the basics. Dried red or black beans. Homestead Tommy Atkins mangoes and chayotes. Bags of Frisbee-sized crackers. Garlic bulbs and malanga, yuca and boniato roots. Green and ripe plantains. Even cans of Goya tomato sauce, evaporated milk and plastic bottles of dry, white cooking wine — essentials in any Latin household.

“You have to carry a little bit of everything,” Tamayo said.

HIS CLIENTELE IS ENTIRELY LATIN AMERICAN

Every morning, Tamayo shops Allapattah’s wholesale produce markets at 4 a.m., where perishables arrive by shipping container and big rig, from Homestead to Latin America. At that hour, forklifts dash across darkened streets like alley cats, and warehouses open their doors to light the night with day-glow fluorescence like UFOs.

Tamayo, 50, picks through papayas and pineapples, checking every piece of fruit. He picks out melons, calabaza squash and black-spotted plantains nearly sweet enough to fry into platanitos maduros. Tamayo shops for a clientele that is entirely Latin American — mostly Cuban.

By 9 a.m., Tamayo has returned home to stock up his truck, picked up his wife who has dropped off their 17-year-old daughter at school (“Everyone is on their feet by 3 a.m.,” he said) and started his deliveries. He visits daycare centers for the elderly and homebound customers first.

Many have come to rely on him for the nine years he has been visiting this location of Badia Senior Center. He takes credit cards and even accepts food stamps.

“I’m a very independent person, but if I had to go out in this heat?” says Iraida Arias, 82, with a bag full of groceries as she awaits a mixed-fruit batido. “I’m not 15 anymore.”

Nearby, another woman shops for an older senior center visitor who can’t manage to walk out to the truck. For $23, she buys packaged ham, white cheese, two shakes and a bag of Cuban crackers. Jesus Naranjo relies on it for his daily lunch of tamales and a fruit shake.

“Remember to pass by Olga’s house!” Arias yells to Tamayo as he begins to close up his truck.

One regular had a doctor’s appointment and is at home nearby with a caregiver. So Tamayo backs out of the lot, mesh bags of fruit swinging behind him, and winds down Flagami streets to a salmon-colored bungalow, where a woman in polyester slacks and a flowery blouse rocks in chair on her front porch. She waves to him from behind the sliding metal fence.

“What do you need today, corazon?” he says from the truck to Olga Moreno, 94, as her caregiver fills up on groceries.

THERE’S ALWAYS A CROWD AROUND THE VIANDERO

Before 11 a.m, Tamayo’s truck is trundling down Southwest Eighth Street toward 80th Avenue, where a neighbor, Juana Santos, is saving a space for him to park his truck. She parks her car across from her house, in the swale between two shopping centers, and rushes out to move it when she sees him turn up the block.

Santos is his first customer every morning, and she hangs out with him for the two hours or so he is there. Her granddaughter, on her way to work in medical scrubs, stops in for a batido of strawberries, papaya and mango.

“I have no reason to go to the grocery store with him here,” says Santos, who has lived across the street for 33 years.

Soon, the truck is surrounded.

Grocery bags are filling with fruits and vegetables, and Hernandez’s blender is spinning non-stop. Even the owner of a nearby restaurant, Mojitos Cuban Cuisine, stops in for a pair of shakes.

“This is such a typical Cuban thing,” said Carlos Salman, the restaurant co-owner. “We grew up with this in Little Havana, looking forward to the viandero coming every week. It’s a staple in the Cuban community. They work hard. You have to support them. Plus, they have great products.”

Aurora Perez hands Tamayo the $8 she owes him. When she realized she’d left her wallet the day before and couldn’t pay for her bananas, lychees and pineapple juice, he told her to take the groceries and pay him back another day.

“I had been haggling with him for a better price and then he just let’s me take it,” she said sheepishly.

A SMALL-BUSINESS OPPORTUNITY

Tamayo understands. He and his wife have been in this line of work since Cuba, where they grew up in Madruga, the southeastern growing region of Havana province. He was 17, she 14, when he asked for her hand, and they’ve been working together and supporting one another ever since.

Together they were running a mobile car wash within a year of immigrating, their kids, Alejandra and Arturo Jr., soaping up cars alongside them. A year later, they were each selling melons out of separate trucks. Then they went all in on this larger truck that he maintains himself. (“Everyone in Cuba learns to be a mechanic,” he jokes.)

“You always have to look out for the next opportunity,” he said. “This is the country of opportunities.”

Tamayo’s heather gray T-shirt is soaked in sweat by 2 p.m., his ruddy, tanned arms glowing red.

A ‘TASTE OF MIAMI CULTURE’

By the time Tamayo arrives at his final location of the day, at the corner of Northwest Seventh Street and 72nd Avenue, his retired uncle who lives nearby is waiting for him.

Drivers on their way home from work need only pull over to the side of the road and Evelio Gutierrez, 85, shuffles over to take their order. A white BMW wants three bunches of bananas, and Gutierrez quickly picks and bags them, and takes $3 in return before they’re off.

They know one regular, Manuel Acosta, will be by soon to buy a papaya. Then Jose Hernandez will stop in for a serving of syrupy sweet calabaza china, a candied wax gourd often that makes for a sweet treat. “My wife loves them. If I buy 100 of them, she’ll eat 100,” he said.

They stand around and gossip, as if outside a Cuban coffee window in Miami’s Little Havana neighborhood. Just then, a car honks as it whips by. It’s Tamayo’s daughter waving on her way home from school. Everyone waves back.

People gather around the viandero truck any time it stops. Everywhere it goes, it takes with it a taste of Miami culture.