Can Mandarins Be Blended with Orange Juice and Still Maintain Orange Juice Flavor?

Since the citrus greening disease (aka Huanglongbing, HLB) was detected in 2005, orange (Citrus sinensis) juice production has decreased by more than 80% in Florida. Over the years, some mandarins (C. reticulata) and mandarin-like hybrids with Poncirus trifoliata in their pedigree have shown tolerance to the disease and have the potential to make up the deficit in the volume of oranges. However, current FDA rules allow for only 10% mandarin juice in orange juice. If citrus, other than C. sinensis, could be added to orange juice in amounts greater than 10%, it would give more flexibility to processors under the current production environment where oranges are declining due to citrus greening. The objective of this study was to evaluate the effect of blending mandarins and other citrus hybrids with orange juice on overall orange flavor. In the first year, a 9-member panel was trained to distinguish orange from mandarin flavor using reference standards, rate sweetness, sourness and bitterness, and to describe potential off flavors. Fruits were washed, sanitized, and manually juiced. Blends were made with 60:30 ‘Valencia’:‘Hamlin’ juice, and 10% mandarin juice including ‘Superna’, FF-5-51-2, and a Poncirus introgressed mandarin hybrid, FF-1-89-11. These blends were compared with the standard 60:40 ‘Valencia’:‘Hamlin’ juice. Panelists found no differences in orange flavor among samples. Mandarin flavor was slightly higher in blends containing FF-5-51-2, and sweetness and sourness were higher in blends containing FF-1-89-11, in comparison with the reference 60:40 ‘Valencia’:‘Hamlin’ juice. A similar comparison was performed between 60:40 ‘Valencia’:‘Hamlin’ juice and 60:20:20 ‘Valencia’:‘Hamlin’:mandarin juice, the mandarin being FF-5-51-2, ‘Superna’ or Sugar Belle®. The trained panelists could perceive the mandarin flavor in those blends, but the orange flavor remained unchanged. In the following year, blends were prepared with juice that had been commercially processed and pasteurized and presented to untrained panelists in a difference test (Tetrad). Most panelists could not detect differences between control base juice (60:40 ‘Valencia’:‘Hamlin’) and base juice to which 10%, 15% or 20% of FF-5-51-2 had been added. The test was also performed with commercial juice, and again, untrained panelists could not detect differences between blends and control. From these results, it is unlikely that untrained consumers would perceive mandarin or other hybrid added to orange juice at a level up to 20%.