The Atlantic crossing could take anything from 3-8 weeks depending on crossing conditions, and without any sophisticated way of controlling the temperature of fresh produce, how did importers of the time manage to import a wide variety of exotic fruit and vegetables without them spoiling, in order to sell on European markets?
Many thanks in advance!
Interesting question. It depends what time period you're talking about. If you're talking about pre-1800s, the answer is "there was almost no exotic fruit in Europe." Anything found would have been a one-off, probably imported over land, and would probably have arrived in Europe only through luck or some kind of anti-ripening process (like wrapping stems, in the case of bananas). In fact, I can only find two instances of bananas being sighted in Europe before 1700.
In the early 1800s, ships used a mixture of salt and ice in insulated hulls to haul fresh fruits and vegetables. Ice was brought in large quantities to the Caribbean, where the hold was filled with produce and shipped back.
Another thing to keep in mind is that mechanical refrigeration was actually invented earlier than you might expect. John Hadley and Benjamin Franklin managed to freeze water down to -14C (~7 farenheit) in 1758. It took a fair bit of time for the technology to be commercialised and widely adopted, but by the late 1800s, ships equipped with steam-powered compression fridges were able to transport meat between Europe and Australia/NZ without issue.
Edit: one thing I should have mentioned is that some exotic fruits (like the pineapple) were cultivated in hothouses in Europe, after their invention in 1720.
Refrigeration is very old, and you don't need any kind of sophisticated controller to just pack ice on ships. Properly insulated, ice will keep a long time. In the 19th century, it was shipped from New England all the way to the Caribbean. I don't know about fruits and vegetables, but meat was just shipped along with ice.
The first ship fitted with a compression refrigerator was the Dunedin in 1881. By the 1900s, ammonia-cycle refrigerators were widespread. You don't need any fancy temperature control because the temperature it reaches is controlled by the refrigerator's design.
According to Flayhart's The American Line (1871-1902), the SS Ohio tried to ship peaches across the Atlantic in 1875:
"The ASC had hoped to keep the fruit fresh during the transatlantic crossing by installing steam powered blowers to circulate an air current over the peaches through several tons of ice, but the ice was soon melted by heat from the ship's boilers and the sunny weather. By the time the ship reached Liverpool, the shipment of peaches had completely decomposed and was utterly worthless."