Fermented Local Food ‘Dali Ni Horbo’ from North Sumatra: Laboratory Formulation and Development of E-Flipbook for Biotechnology Subject

Abstract

Biotechnology is a fascinating and essential topic in high school education, requiring hands-on laboratory practices and the development of up-to-date teaching materials. Integrating conventional biotechnology with local wisdom can enhance its relevance and appeal. One traditional fermented product with educational potential is Dali Ni Horbo (DNH), a Batak dairy product produced through natural milk coagulation. Its fermentation characteristics make it suitable as a contextual medium for biotechnology learning, yet practical and innovative resources involving local products remain limited. This study aims to formulate DNH using cow's milk and goat's milk combined with natural coagulants, namely pineapple juice (Ananas comosus L.), papaya leaf juice (Carica papaya L.), and bilimbi juice (Averrhoa bilimbi L.), as well as to determine the optimal formulation based on organoleptic tests, evaluate the effect of different formulations on DNH quality, and assess the feasibility of DNH laboratory guidelines in the form of an E-Flipbook through expert validation and student feedback. The study employed an experimental research design integrated with the Research and Development (R&D) methodology. Data were analyzed using descriptive statistics, Two-Way ANOVA, and Welch tests. Organoleptic testing by five panelists indicated that the optimal formulation was the SSN10 treatment, consisting of 200 mL cow’s milk and 10 mL pineapple juice, with a favorability score of 3.6%. Further analysis showed that the type of milk and natural coagulant used had no significant effect on the color, aroma, texture, or taste of DNH. The developed E-Flipbook demonstrated strong feasibility, receiving ratings of 95% (“Very Good”) from material validators, 93.3% (“Very Good”) from media validators, and 78% (“Good”) from language validators. Student responses were “Very Positive,” with an approval rating of 84.31%. These findings suggest that DNH can function as an effective learning material, providing practical fermentation applications while supporting the preservation of local cultural heritage.