Near-term approaches of using alternative HLB-tolerant cultivars for increased production and improved juice quality

This project started on Nov. 1st, 2019. So, this is the third quarterly report (5/1/20-7/31/20). There are two objectives in this project. The progress of each objective is listed here:

Objective 1. Evaluation of blended juice using released HLB-tolerant sweet orange/mandarin cultivars via analyses of sensory and consumer acceptance.

Sensory for Sugar Belle blended with Hamlin were completed in the second quarter. At the end of April, we have harvested Valencia and have processed Valencia. Sensory study will be conducted in the coming Fall semester due to COVID-19, but in the third quarter, we have submitted IRB paperwork for the approval of running sensory with special measures during the pandemic. All the paperwork has been approved, so we are clear for the following processes.

Objective 2. Identify more tolerant cultivars resembling the quality of Valencia for the juice market, and identify a chemistry definition of consumer accepted orange flavor

We collected about 20 mandarin hybrids, pure mandarins and sweet orange in the first quarter and these cultivars have been identified with the great field performance. The trained sensory panel study started in the first quarter but stopped for the second quarter due to COVID-19. In the second quarter, we started analytical chemistry. Volatile compounds (i.e. aromas) have been analyzing using gas chromatography–mass spectrometry (GC-MS). Non-volatile compounds (i.e. sweet, sour, bitter compounds) have been analyzing using Liquid chromatography–mass spectrometry (LC-MS). In the third quarter, we continued trained panel study for differentiating citrus flavor attributes such as sweet, citrusy, fruity, and flora etc. Different from sweet oranges, mandarins were mainly characterized with bitter, sour and terpene like attributes, which is consistent with the fact that terpenes play essential roles in the characterization of mandarin flavor. However, some mandarin hybrids were more sweet-orange like. Their sensory profile was much similar to the sweet orange profile. We have been continuing working on volatile and non-volatile analysis in the third quarter.