Proses Fermentasi Oncom: Studi tentang Mikroorganisme dan Faktor-Faktor yang Mempengaruhi Kualitas

Oncom, a traditional Indonesian fermented food, is a testament to the power of microbial activity in transforming simple ingredients into a nutritious and flavorful delicacy. This article delves into the fascinating world of oncom fermentation, exploring the diverse microorganisms involved and the crucial factors that influence its quality. Understanding the intricate interplay between these elements is essential for producing oncom that is not only safe for consumption but also boasts desirable characteristics like texture, aroma, and flavor.

The Microbial Symphony of Oncom Fermentation

Oncom fermentation is a complex process driven by a diverse community of microorganisms, primarily fungi and bacteria. The most prominent fungal species involved are *Rhizopus oligosporus* and *Rhizopus microsporus*, which are responsible for the characteristic white color and texture of oncom. These fungi break down the protein in the substrate, primarily cassava or soybean, into simpler compounds, contributing to the unique flavor profile of oncom. Alongside fungi, various bacteria, including *Bacillus* species, *Lactobacillus* species, and *Acetobacter* species, play significant roles in the fermentation process. These bacteria contribute to the development of the sour taste, the production of organic acids, and the breakdown of carbohydrates. The interplay between these microorganisms creates a dynamic ecosystem that transforms the raw substrate into a palatable and nutritious food.

The Influence of Substrate on Oncom Quality

The choice of substrate significantly impacts the quality of oncom. Cassava and soybean are the most common substrates used in oncom production. Cassava, with its high starch content, yields a softer and more crumbly oncom, while soybean, rich in protein, produces a firmer and more compact oncom. The quality of the substrate itself is crucial. Fresh, unblemished cassava or soybean ensures optimal fermentation and prevents the growth of undesirable microorganisms. The moisture content of the substrate is another critical factor. Excessive moisture can lead to the growth of spoilage organisms, while insufficient moisture can hinder the growth of beneficial microorganisms.

Temperature and Time: Key Determinants of Oncom Fermentation

Temperature plays a crucial role in oncom fermentation, influencing the growth rate and activity of the microorganisms involved. The optimal temperature range for oncom fermentation is between 25°C and 30°C. At temperatures below this range, the fermentation process slows down, while temperatures above this range can lead to the growth of undesirable microorganisms and spoilage. The duration of fermentation is another critical factor. The fermentation process typically takes 12 to 24 hours, depending on the substrate, temperature, and the desired level of fermentation. Over-fermentation can result in a bitter taste and a mushy texture, while under-fermentation can lead to an incomplete breakdown of the substrate and a less desirable flavor.

The Importance of Hygiene in Oncom Production

Maintaining proper hygiene throughout the oncom production process is essential for ensuring food safety and preventing the growth of harmful microorganisms. This includes using clean equipment, washing the substrate thoroughly, and ensuring a clean and sanitized environment. The use of starter cultures, which contain a specific blend of beneficial microorganisms, can further enhance the quality and safety of oncom. Starter cultures help to establish a dominant population of beneficial microorganisms, suppressing the growth of undesirable organisms and ensuring a consistent and predictable fermentation process.

Conclusion

Oncom fermentation is a fascinating example of how microbial activity can transform simple ingredients into a nutritious and flavorful food. The diverse community of microorganisms involved, the choice of substrate, temperature, time, and hygiene practices all play crucial roles in determining the quality of oncom. By understanding these factors, producers can optimize the fermentation process, ensuring the production of safe, high-quality oncom that delights consumers with its unique flavor and texture.