Jurnal Pembelajaran dan Biologi Nukleus
Vol 12, No 2: Jurnal Pembelajaran Dan Biologi Nukleus June 2026

Fermentation Time-Dependent Changes in Bioactive Compounds and Physicochemical Properties of Starfruit (Averrhoa carambola L.) Kombucha

Ifah Izzati Harjilah (Universitas Muhammadiyah Surakarta)
Ambarwati Ambarwati (Universitas Muhammadiyah Surakarta)



Article Info

Publish Date
01 Jul 2026

Abstract

Background: The rising prevalence of hypertension drives the development of local functional beverages. Starfruit (Averrhoa carambola L.) is a potential kombucha raw material due to its vitamin C and antioxidants, which increase through fermentation. This study analyzes the rarely researched effect of fermentation duration on starfruit kombucha's biochemical traits. Methodology: An experimental Completely Randomized Design (CRD) evaluated 4, 6, and 8-day fermentation durations with two replications. Fermentation occurred at room temperature (20-27°C) using SCOBY (Symbiotic Culture of Bacteria and Yeast). Tested parameters included vitamin C (iodometric titration), antioxidant activity (DPPH), alcohol content (alcoholmeter), and pH. Data were analyzed using descriptive quantitative methods. Findings: Longer fermentation increased vitamin C, antioxidant activity, and alcohol content, but decreased pH due to rising acidity. The 8-day fermentation yielded optimal bioactivity: 167.405 mg/100g vitamin C, 80.630% antioxidant activity, and the lowest pH (4.470). However, its alcohol content reached 0.584%, slightly exceeding the 0.5% non-alcoholic limit. Thus, fermentation duration significantly alters the biochemical profile of starfruit kombucha. While an 8-day fermentation maximizes bioactive compounds, process optimization is needed to reduce alcohol levels to meet food safety standards. Contribution: The novelty of this research lies in assessing starfruit kombucha's biochemical characteristics across varying fermentation durations, an area rarely reported previously

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Journal Info

Abbrev

nukleus

Publisher

Subject

Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Education Environmental Science Immunology & microbiology Languange, Linguistic, Communication & Media

Description

Jurnal Pendidikan Biologi merupakan jurnal elektronik yang merupakan wadah penerbitan artikel penelitian original yang terkait dengan penelitian pendidikan biologi. Jurnal ini dikelola oleh Program Studi Pendidikan Biologidibawah naungan LPPM Universitas Labuhanbatu. Jurnal ini diterbitkan dua kali ...