The Talmudic sage Abaye explains (Keritut 5b) that on Rosh Hashana it is auspicious to eat symbolic foods, “Simanim”, and this is codified in the Shulhan Aruch (O.H. 583:1). Since this ritual is performed in the evening at the beginning of the meal, there is debate as to whether it should be done between Kiddush and HaMotzi, or after HaMotzi. Normally, the blessing over bread exempts other foods eaten at the meal so that a blessing for other foods is not made from needing a separate blessin. Foods that are not considered to be part of the meal, however, such a candy (even if eaten during the meal), would require a separate blessing.
There is debate among the Moroccan rabbis regarding saying blessings over the symbolic foods. Some of the Simanim, especially vegetables, are cooked and may be considered as being part of the meal, and therefore there is question as to the propriety of saying a separate blessing over them. Rabbi Yedidia Monsonego (Shu”t Pe’at Yam, § 1) and Rabbi Haim Messas (Shu”t Leket HaKemah § 200) both say that one solution is to make a blessing of “HaAdama” over a food that certainly would not be considered part of the meal, such as a banana, and then one can eat the Simanim that normally require “HaAdama” without a blessing. When it comes to “HaEtz”, the custom is to eat the apple, which is not considered part of the meal anyway.
Summary: Although not the mainstream practice, one who wishes to be strict can make blessings over foods that are not part of the meal so as to exempt the Simanim from questionable blessings.