Decision tree scoring system to guide selection for consumer preference in sweetpotato breeding trials

Authors: NAKITTO, MARIAM - International Potato Center; REUBEN, SSALI - International Potato Center; Johanningsmeier, Suzanne; MOYO, MUKANI - International Potato Centre; DE KOCK, HENRIETTE - University Of Pretoria; BERGET, INGUNN - Norwegian Institute For Food Research; OKELLO, JULIUS - International Potato Center; MAYANGA, SARAH - International Potato Center; TINYIRO, SAMUEL EDGAR - National Agricultural Research Laboratories; MENDES, THIAGO - International Potato Centre; BUGAUD, CHRISTOPHE - Cirad, France

Submitted to: Journal of the Science of Food and Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/18/2023
Publication Date: 6/1/2024
Citation: Nakitto, M., Reuben, S., Johanningsmeier, S.D., Moyo, M., De Kock, H., Berget, I., Okello, J., Mayanga, S., Tinyiro, S., Mendes, T., Bugaud, C. 2024. Decision tree scoring system to guide selection for consumer preference in sweetpotato breeding trials. Journal of the Science of Food and Agriculture. 104(8):4615-4625. https://doi.org/10.1002/jsfa.12883.
DOI: https://doi.org/10.1002/jsfa.12883

Interpretive Summary: Sweetpotato is a nutritious root vegetable and a staple crop in some regions, such as sub-Saharan Africa, where the introduction of more orange-fleshed sweetpotatoes could help prevent vitamin A deficiency. The adoption of new sweetpotato varieties depends on market acceptance, so breeding tools that account for sensory characteristics of sweetpotato are needed for development of varieties with consumer-desired traits. Regional consumer studies were conducted to identify target values for sweet taste, sweetpotato aroma and flavor, firmness, and mealiness that relate to high overall liking and product acceptability. These target values were used to create a decision tree for obtaining an eating quality score for sweetpotato that can be used to facilitate selection of varieties from Ugandan sweetpotato breeding trials.

Technical Abstract: BACKGROUND: Previously, a lexicon and protocol for quantitative descriptive analysis (QDA) was established for the Uganda sweetpotato breeding program. The implication of QDA scores for priority sensory attributes on consumer preference should be determined to interpret results efficiently and make decisions effectively. The present study aimed to develop a gender-responsive decision tree to obtain an overall sweetpotato eating quality score to facilitate demand-led targeted breeding selection. It focused on Kamuli and Hoima districts (Uganda) and uses pre-lease advanced clones (‘NKB3’, ‘NKB105’, ‘NKB135’, ‘D11’ and ‘D20’), released varieties (‘NASPOT 8’ and ‘NAROSPOT 1’) and landraces (‘Muwulu-Aduduma’, ‘Umbrella’). RESULTS: Including boiled sweetpotato sensory characteristics, namely mealy, sweet taste, sweetpotato smell, firm and not fibrous, in breeding design would benefit end-users, especially women given their role in varietal selection, food preparation and marketing. ‘D20’, ‘NASPOT 8’ and ‘NAROSPOT 1’ were most liked in both districts. ‘NKB3’ and ‘D11’ were the least liked in Hoima, whereas ‘Muwulu-Aduduma’ was the least liked in Kamuli. There was a positive correlation between color and overall liking (r^2 = 0.8) and consumers liked the color (average rating greater than or equal to 6 on a nine-point hedonic scale) of all genotypes. Threshold values (average rating on 11-point scales) for consumer acceptability were identified (sweet taste = 6, sweetpotato aroma and flavor = 6, firmness = 3, and mealiness = 4). A regression decision tree tool was created to calculate an eating quality selection index when screening lines in breeding programs using the values. CONCLUSION: Decision trees that include consumer needs and gender considerations would facilitate demand-led breeding and make varietal selection in sweetpotato breeding programs more effective.