Role of pulp in flavor release and sensory perception in orange juice.

This work elucidates the role of suspended solids in sensorial perception and flavor release in orange juice. The coarsest pulp (insoluble particles with a diameter of >2 microm) accounted for two major physicochemical effects in orange juice samples: it retained large amounts of aroma compounds, including terpenes and aldehydes, and modified the rheological properties of the juice matrix. These phenomena strongly affected the chemical composition of the vapor phase in the juice samples. On the other hand, orange juice cloud (finest insoluble particles with a diameter of <2 microm) also showed a strong retention effect on ethyl butanoate or hexanal, probably due to the occurrence of molecular interactions with cloud macromolecules. The amount and the size of the suspended solids critically modified not only the texture perception but also the odor and the overall flavor perception, including the "freshly squeezed" and the "artificial flavor" descriptors. The addition of a natural pulp to low-pulp juices increases the fresh orange juice character, a finding that is explained by both physicochemical (fresh pulp contains high amounts of key aroma compounds, including acetaldehyde and mono- and sesquiterpenes) and cognitive effects, mainly due to the tactile properties of the pulp.