The Halacha addresses the Mukse status of food which is "Assur B'hanah"-forbidden to benefit from. That is, it may not be consumed, sold or given to animals or non-Jews. Examples include "Orlah"-fruit grown on trees in the first three years, "Klai Hakerem"-crossbreeding in a vineyard and "Basar B'Halav"-forbidden mixtures of meat and milk. All these foods are deemed Mukse Mahamat Gufo and may not be handled on Shabbat for any purpose whatsoever.
Also included in this category is "Tevel"-fruits from which Terumot and Ma'asrot were not taken, even though that Misva is only M'drabanan (Rabbinic) today. Likewise, the separated Teruma and Teruma Gedola separated from the fruits are Mukse, since the Kohanim cannot benefit from them today, because they are Tameh (impure).
Regarding bread from which Hallah was not separated, there is a difference between Eres Yisrael and Hus La'ares. In Israel, the bread is Mukse, since it may not be eaten. However, elsewhere, the bread may be consumed on Shabbat as long as a small portion is left at the end and becomes designated as Hallah after Shabbat. Therefore, it does not become Mukse. This would not apply to bread on Shabbat which is Ereb Pesah, since on Mosa'eh Shabbat, the Hallah is Hames and may not be separated.
SUMMARY
Foods which are forbidden to benefit from are Mukse and may not be moved for any reason on Shabbat. Bread from which Hallah was not separated is not Mukse outside of Israel.
