Fruit and juice quality of several lemon accessions grown in subtropical Florida

Authors: FREITAS, THAIS - Oak Ridge Institute For Science And Education (ORISE); Jeffries, Kristen; Plotto, Anne; Mattia, Matthew; Bai, Jinhe

Submitted to: Journal of Horticultural Science and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/11/2024
Publication Date: 12/30/2024
Citation: Freitas, T.P., Jeffries, K., Plotto, A., Mattia, M., and Bai, J. Fruit and juice quality of several lemon accessions grown in subtropical Florida. Journal of Horticultural Science and Biotechnology. 100:1. 2024. https://doi.org/10.1080/14620316.2024.2443022
DOI: https://doi.org/10.1080/14620316.2024.2443022

Interpretive Summary: Huanglongbing (HLB), also known as citrus greening, has devastated Florida’s citrus industry, severely affecting nearly all commercial citrus species, including oranges and grapefruit. In contrast, lemon exhibits a degree of tolerance to the infection caused by the presumed HLB pathogen, Candidatus Liberibacter asiaticus, and even shows recovery capabilities from the disease. This relative resilience suggests that lemons could emerge as a sustainable alternative for Florida’s citrus industry, potentially becoming an HLB-tolerant addition to both the juice and fresh fruit markets. This study examined the juice quality of eight accessions from the USDA breeding collection and two commercial cultivars grown in Florida. Except for ‘Eureka’, all lemons exhibited a soluble solids content (SSC) higher than the FDA standard (6%) for lemon juice. Some accessions, such as ‘Ichang’, ‘Lemon 62.67’, ‘Monachello’, and ‘Vangasay’ produced juice with low acidity juice (<4.5%) and potentially bitter taste due to elevated limonoid levels. Cluster analysis of the VOC profiles grouped the accessions into two major clusters: ‘Des 4 Saisons’ and ‘Villafranca’ were similar to ‘the commercial cultivars, ‘Bearss’ and ‘Eureka’, while the other accessions, including ‘Lemon 62.67’ and ‘Malta’ formed a separate group, with ‘Ichang’ and ‘Monachello’ further distinguished from the rest. The results not only highlighted the juice quality of different lemon accessions but also provides valuable insights for future lemon breeding and potential diversification in the lemon juice market.

Technical Abstract: Lemons have shown some tolerance to the citrus greening disease, presenting a promising future for Florida’s citrus industry. The State’s current lemon industry is relatively small, and the juice of many varieties has not yet been fully evaluated. This study examined the juice quality of eight accessions from the USDA breeding collection and two commercial cultivars grown in Florida. Except for ‘Eureka’, all lemons exhibited a soluble solids content (SSC) higher than the FDA standard (6%) for lemon juice. Some accessions, such as ‘Ichang’, ‘Lemon 62.67’, ‘Monachello’, and ‘Vangasay’ produced juice with low acidity juice (<4.5%) and potentially bitter taste due to elevated limonoid levels. Notably, ‘Monachello’ yield juice with a high SSC, low limonoids, and elevated ester volatiles compared to the other accessions. All lemons shared a volatile organic compound (VOC) profile high in monoterpenes, which is typically associated with citrus/lemon/herbal aromas. However, the quantity of these volatiles varied significantly across accessions. Cluster analysis of the VOC profiles grouped the accessions into two major clusters: ‘Des 4 Saisons’ and ‘Villafranca’ were similar to ‘Bearss’ and ‘Eureka’, while the other accessions, including ‘Lemon 62.67’ and ‘Malta’ formed a separate group, with ‘Ichang’ and ‘Monachello’ further distinguished from the rest. Principal component analysis revealed that while most lemons grouped together, ‘Monachello’ and ‘Ichang’ had the most distinct aroma profiles. This study not only highlights the juice quality of different lemon accessions but also provides valuable insights for future lemon breeding and potential diversification in the lemon juice market.