The research was conducted by Tiara Auliya Putri, Dr. I Nyoman Rai, and Anak Agung Gede Sugiarta from the Agroecotechnology Study Program, Faculty of Agriculture, Udayana University. The experiments took place between July and October 2023 using freshly harvested Tejakula tangerines from Buleleng Regency, Bali.
The findings are important for Indonesia’s horticulture sector because postharvest fruit losses remain a major challenge for citrus farmers and distributors. Tangerines often deteriorate rapidly during storage and transportation, leading to reduced market value and shorter shelf life.
Protecting a Local Citrus Commodity
Tejakula tangerines are a well-known local citrus cultivar from Bali, valued for their sweet flavor, bright aroma, and high vitamin C content. However, like many tropical fruits, the oranges continue to respire after harvest. This natural process gradually reduces moisture, softens the fruit, alters skin color, and lowers nutritional quality.
Postharvest handling therefore plays a crucial role in maintaining the commercial value of the fruit.
The Udayana University research team explored edible coating technology as a natural preservation method. Edible coatings are thin, food-safe layers applied to the surface of fruits to reduce water loss and slow gas exchange.
In this study, the coating was produced using yellow sweet potato starch combined with carboxymethyl cellulose (CMC), glycerol, stearic acid, and red galangal extract. The formulation was designed to create a biodegradable protective barrier that could maintain fruit quality without affecting taste or consumer acceptance.
According to the researchers from Udayana University, the edible coating acts as a semi-permeable layer that slows respiration and transpiration processes in the fruit, helping maintain physicochemical quality during storage.
Four Storage Periods and Multiple Coating Levels
The researchers tested four edible coating treatments:
- No edible coating
- 1.5 percent coating concentration
- 3 percent coating concentration
- 4.5 percent coating concentration
The tangerines were then stored at room temperature and observed over five storage periods:
- Day 0
- 7 days
- 14 days
- 21 days
- 28 days
The study used a randomized complete block design with split plots and three replications. Researchers evaluated several quality indicators, including:
- Fruit weight loss
- Fruit firmness
- Moisture content
- Skin color changes
- Total soluble solids
- Vitamin C levels
- Consumer sensory preferences
The measurements were analyzed statistically using analysis of variance and Duncan’s multiple range test.
Three Percent Coating Produced the Best Overall Results
One of the most significant findings involved fruit weight loss during storage. Tangerines without edible coating deteriorated more quickly, especially after four weeks of storage.
The untreated fruit recorded the highest weight loss at 18.82 percent after 28 days. In contrast, fruit coated with a 3 percent edible coating showed substantially lower weight loss at approximately 13.42 percent during the same storage period.
The researchers identified the combination of one-week storage and 3 percent edible coating concentration as the best treatment overall for minimizing fruit shrinkage.
Fruit firmness also remained higher in coated tangerines. The 3 percent coating treatment produced the highest average firmness values, indicating that the coating slowed tissue softening and maintained texture quality longer than uncoated fruit.
Skin color changes were also delayed. Tangerines without coating turned orange more rapidly during storage, while coated fruit retained a more stable appearance. The 4.5 percent coating concentration produced the slowest color change overall.
Vitamin C Levels Remained More Stable
Another important result involved vitamin C preservation. The study found that edible coating treatments helped maintain vitamin C content during storage by reducing oxygen exposure inside the fruit tissues.
The highest vitamin C content was observed in fruit stored for two weeks with a 1.5 percent edible coating concentration, reaching 53.39 mg per 100 grams.
The researchers explained that limiting oxygen penetration slows oxidative reactions that normally degrade vitamin C during storage.
At the same time, total soluble solids increased during storage, which is a common sign of fruit ripening as carbohydrates break down into simpler sugars. However, coated fruit experienced slower changes, indicating delayed ripening.
Importantly, sensory tests showed that edible coating application did not significantly reduce consumer acceptance. Panelists reported no major differences in taste, texture, or overall preference between coated and uncoated fruit.
Potential Benefits for Sustainable Food Distribution
The findings could have practical implications for Indonesia’s fruit supply chain, especially for local citrus producers in Bali and other tropical regions.
Natural edible coatings may help reduce postharvest losses, extend marketing periods, and improve fruit quality during transportation without relying on synthetic packaging materials.
The use of sweet potato starch is also environmentally beneficial because the material is biodegradable and derived from locally available agricultural products.
The research aligns with broader global efforts to develop sustainable food packaging technologies and reduce food waste in agricultural systems.
The authors noted that future studies should examine edible coating applications at industrial scale, evaluate storage under different temperatures, and include microbiological and antioxidant analyses for more comprehensive quality assessment.
Author Profiles
Tiara Auliya Putri is a researcher from the Agroecotechnology Study Program, Faculty of Agriculture, Udayana University, with research interests in postharvest technology and horticultural crop quality.
Dr. I Nyoman Rai is a lecturer and horticulture researcher at Udayana University specializing in tropical fruit cultivation, plant physiology, and local Balinese citrus development.
Anak Agung Gede Sugiarta is an academic and agricultural researcher at Udayana University focusing on horticultural technology and crop quality management.
Source
Putri, T. A., Rai, I. N., & Sugiarta, A. A. G. (2026). Physicochemical Study of Tejakula Tangerinet Fruit (Citrus Reticulata cv. Tejakula) on the Difference in Edible Coating Concentration to Shelf Life. Formosa Journal of Science and Technology (FJST), Vol. 5, No. 5, 1251–1264.
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