How coconut sugar composition varied across three Indonesian regions
Hari Purnomo’s 1992 analysis compared coconut sugar from Malang, Yogyakarta, and Denpasar. The study used HPLC to quantify sucrose, glucose, and fructose and measured water activity, providing early comparative data on coconut sugar composition.
What the study did and found
Hari Purnomo’s 1992 paper, Sugar components of coconut sugar in Indonesia, examined cottage-industry coconut sugar made from Cocos nucifera sap. Samples came from Malang (East Java), Yogyakarta (Central Java) and Denpasar (Bali). Sugars were extracted using 85% ethanol and measured by HPLC; water activity was determined with a Novasina sensor.
Malang samples contained 70.85% sucrose, 3.00% glucose and 2.92% fructose, with water activity of 0.69. Yogyakarta samples contained 78.97% sucrose, 3.45% glucose and 3.12% fructose, also with water activity of 0.69. Denpasar samples contained 70.52% sucrose, 8.96% glucose and 9.00% fructose, with water activity of 0.63.
Sucrose predominated in all three groups, while Denpasar showed higher glucose and fructose levels. The study measured composition, not health effects or glycemic response.
Why it is cited
Later research cites Purnomo’s findings as early quantitative evidence of coconut sugar variability. A 2014 Journal of Food Science study reported the earlier ranges of approximately 70–79% sucrose and 3–9% glucose and fructose. A 2019 LWT analysis of 107 samples also referenced the 1992 study.
The findings describe specific Indonesian samples, not a universal coconut sugar composition. Differences in production, sap quality and processing can influence results.
The 2019 analysis documented variability and signs of added ingredients in some commercial samples. A 2023 review also discussed processing effects and analytical methods for identifying adulteration. These findings support treating the 1992 measurements as historical regional data rather than fixed values for modern products.
The topic today
Current coconut sugar research examines processing, chemical composition, flavor development and authenticity. Chromatography, stable-isotope analysis and other methods help identify product differences and potential adulteration.
The 1992 study remains a useful regional reference, while newer research provides broader evidence about composition, production conditions and quality control.