Location: Healthy Processed Foods ResearchTitle: Sugar and organic acid content of astringent, non-astringent, and pollination variant persimmons (abstract)
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/22/2016
Publication Date: 4/2/2017
Citation: Vilches, A.M., Sedej, I., Olsen, C.W., Smith, J.L., Woods, R., Preece, J.E., Milczarek, R.R., Breksa Iii, A.P. 2017. Sugar and organic acid content of astringent, non-astringent, and pollination variant persimmons [abstract].
Technical Abstract: Although persimmons are native (Diospyros virginiana) to the United States, commercial production consists almost exclusively of the Asian persimmon, Diospyros kaki. Cultivars within this species are classified by their astringency type; non-astringent, astringent, and pollination variant. In the U.S., California is the largest producer of persimmons and the location of the United States Department of Agriculture’s persimmon collection. In an effort to characterize the persimmon collection and to compare the fruit quality traits to cultivars in commercial production, we collected samples from commercial growers and the National Clonal Germplasm Repository, Davis, CA, and evaluated them by HPLC for their sugar and organic acid content. For some samples, multiple harvests of ripe fruit were collected to evaluate the influence of harvest time. With the exception of the Diospyros virginiana samples, sucrose was the most abundant sugar, followed by glucose and then fructose. For Diospyros kaki cultivars, sucrose content ranged from 47.2 g/Kg FW (Unnamed) to 177.3 30.2 g/Kg (‘Ichikeijiko’). On average sucrose content was two to four times the concentration of glucose or fructose. Fructose and glucose were well correlated (0.961), whereas neither showed a strong correlation with sucrose. The average total carbohydrate content (sucrose + glucose + fructose) for astringent, variant, and non-astringent types was 138.9 ± 29.0, 138.6 ± 20.6, and 126.4 ± 15.9 g/Kg FW, respectively. Malic, citric and fumaric acids were detected in all of the persimmon samples evaluated. Concentrations of malic and citric acids were two to three orders of magnitude greater than that of fumaric acid. Malic acid content ranged from 469.8 mg/Kg FW (Unnamed) to 3,312.5 mg/Kg FW (‘Lampadina’) and for citric acid the range was from 363.4 mg/Kg FW (‘Maru’) to 3,013.4 mg/Kg FW (‘Korean’), respectively. The average total organic acid content (malic + citric + fumaric) for astringent, variant, and non-astringent types was 3,183.2 ± 457.0, 2,851.2 ± 715.1, and 2,424.6 ± 759.6 mg/Kg FW, respectively. No significant correlation was found between the malic, citric and fumaric acids. Harvest time did not significantly influence the organic acid or sugar contents of ripe fruit. Astringency type is not a predictor of either organic acid or sugar content. Organic acid and sugar content appear to be cultivar-specific.