Plasma fruit is a food introduced in The Sims 3: Late Night.
These fruits have a pulsing red heartbeat effect and they satisfy vampires' Thirst motive. All Sims can purchase plasma fruit from the local supermarket. Sims can grow this fruit with the gardening skill at level 7. Depending on the quality, plasma fruit will give vampires a designated moodlet. (e.g. Nice quality or higher, Sated; Perfect quality, Sanguine Snack) Vampires have wants about eating plasma fruit. In this case the want will indicate a fruit looking like an apple with a drop of blood under it. Vampires with the Vegetarian trait must live entirely on plasma fruit when not near a refrigerator. Normal Sims get ill when they eat or drink plasma-based foods.
Like other fruits, plasma fruit can be made into nectar. If normal Sims drink the resulting nectar they will get sick, as though eating a plasma fruit. As such, the same care should be taken to keep plasma-based nectar out of their hands.
Plasma fruit can also be used to make cooked food, like pancakes (assuming the vampire has the required cooking skill level). To do so, just put them inside a fridge or the cooking Sim's inventory and make a dish that requires fruit or accepts any ingredient.