May one smell a Tevel fruit or vegetable?
It is permitted to smell Tevel, and benefit from its smell, so long as one does not damage the fruit in the process. [One is to say a blessing upon smelling Tevel fruits.]
 The reason: Tevel is forbidden in benefits that destroy the Tevel, such as feeding it to an animal [See Michaber Y.D. 331/88; Rama 331/19; Mishneh Dmaiy 1/3] although it is not forbidden in all benefit, as it is permitted to sell Tevel and have any other benefit that does not destroy or damage the food. [Michaber Yore Deah 331/117; Rama 331/19; Mishneh Dmaiy 5/8]
 Admur 308/9 based on Shabbos 126b and 128a regarding Tevel
 Admur ibid; Gemara ibid; M”A 515/3; Tevel is any food which did not have its tithes removed from it. Although Tevel is not forbidden in all benefit, as it is permitted to sell Tevel [Yore Deah 331/117], nevertheless it is forbidden in benefits that destroy the Tevel, such as feeding it to an animal [See 331/88] and hence has no purpose on Shabbos.