Kombucha Ice Cream anyone?

Scientists in Malaysia recently studied the feasibility and potential of producing low-alcohol, instant kombucha powder through pasteurization and spray drying. They claim their study paves the way for expanding the kombucha market by catering to consumer preferences for convenience and what they call “health-promoting products like kombucha ice cream”.

Here’s a summary of their research project.

Source: Rahman, M. N. A., Masawal, V. V., Qing, R. Y. Y., Narudin, N., Kobun, R., Muhammad, N. H., … & Artasasta, M. A. (September 2024). Innovative Development of Instant Kombucha Drink and Kombucha Ice Cream Using Spray Drying Techniques. International Journal of Advanced Research in Food Science and Agricultural Technology, 2(1), 8-30.

Main Themes

  • Reducing Alcohol Content in Kombucha: The research focuses on developing methods to reduce the alcohol content in kombucha, addressing regulatory concerns and expanding consumer base, especially in regions with strict halal dietary laws.
  • Instant Kombucha Production: The study explores the feasibility of producing instant kombucha powder using spray drying techniques, aiming to improve convenience and market potential.
  • Novel Kombucha Ice Cream Development: The research proposes the innovative application of instant kombucha powder in developing a health-promoting kombucha ice cream.

Key Findings

  • Effective Alcohol Reduction Methods: Pasteurization at 72°C for 20 minutes proved most effective in reducing alcohol content to 0.13% w/w. Cold shock and yeast removal also reduced alcohol levels, albeit to a lesser extent.
  • Pasteurization Yields Optimal Physico-chemical Properties: Pasteurized kombucha exhibited desirable physico-chemical properties, including low alcohol content, optimal total dissolved solids, pH, and titratable acidity.
  • Microbial Safety Ensured: Pasteurization effectively eliminated microbial contamination, with the pasteurized sample showing no detectable CFU/ml.
  • Sensory Evaluation Favors Pasteurized Kombucha: Sensory evaluation revealed a slight preference for the original kombucha due to its sweetness. However, the pasteurized sample received moderate acceptance scores for its color and overall taste, with particular appreciation for its sourness.
  • Spray Drying Produces Viable Instant Kombucha Powder: Spray drying successfully produced instant kombucha powder with desirable characteristics.

Important Facts

  • The study analyzed various physico-chemical properties of kombucha, including pH, sugar concentration, titratable acidity, and ethanol concentration.
  • Proximate analysis was conducted to assess the moisture, protein, ash, and carbohydrate content of different kombucha formulations.
  • Microbial analysis focused on yeast and mold contamination, as well as acetic acid and lactic acid bacteria counts.
  • Sensory evaluation employed a 9-point hedonic scale to gauge consumer acceptance of different formulations and treatments.
  • The research investigated the yield percentage, water activity, color, and solubility of the instant kombucha powder.

Quotes

  • Alcohol Reduction: “Cold shock, pasteurization and yeast removal methods were chosen for use in the kombucha production process due to their high likelihood of effectively reducing alcohol production in this beverage.”
  • Microbial Safety: “Food drying reduces the available moisture to support microbial growth, thereby enhancing the shelf life of the product, which is an ideal solution when appropriate storage is not available.”
  • Sensory Evaluation: “Sensory evaluation of kombucha samples was conducted using acceptance testing in an affective test with 50 untrained panelists.”
  • Suitability for Commercialization: “Overall, pasteurized kombucha is well-suited for commercial purposes due to its low alcohol content, stability against microbial contamination, and extended shelf life through spray drying.”
  • Potential for Kombucha Ice Cream: “Incorporating instant kombucha powder into kombucha ice cream could offer a unique, health-conscious dessert option enriched with probiotics and distinctive flavor characteristics, appealing to consumers seeking innovative and nutritious frozen treats.”

Limitations

The study presents valuable findings on alcohol reduction and instant kombucha production but has some limitations that could be addressed in future research:

  • Limited scope of treatments: While the study investigated cold shock, pasteurization, and yeast removal to reduce alcohol content, other potential methods, such as sugar limitation or the use of specific yeast strains known for low alcohol production, were not explored
  • Potential issues with pasteurization: While pasteurization effectively reduced alcohol content in sample R2, variable acetic acid bacteria (AAB) counts in pasteurized samples suggest inconsistencies in the process. Further optimization of pasteurization parameters is needed to ensure consistent results and product quality.
  • High moisture content: All kombucha samples, especially the control (K), exhibited high moisture content, exceeding the recommended 10% for preventing microbial growth. This raises concerns about product safety and shelf life, especially in regions with high ambient temperatures. Future research should investigate methods to reduce moisture content, such as optimizing drying processes, to enhance product stability and safety.
  • Low and negative protein content: The protein content analysis yielded low and negative values for most samples, likely due to the short fermentation period (seven days). Extending the fermentation time might allow for greater protein production and more accurate analysis. Additionally, alternative protein analysis methods could be explored to ensure accurate quantification.
  • Limited microbial analysis: Although microbial analysis was conducted, it was limited in scope. While the study assessed yeast and mold contamination, further characterization of the microbial communities present in different kombucha formulations and treatments is crucial. Identifying specific yeast and bacterial strains can provide valuable insights into fermentation dynamics, product stability, and potential health benefits.
  • Lack of clarity on CFU/ml standards: The study mentions the maximum limit of plate counts for food and beverages ready for consumption according to Malaysian regulations, but it is unclear if this applies to kombucha. Establishing specific Codex standards for kombucha is essential for regulatory compliance and consumer safety.
  • Subjective sensory evaluation: Sensory evaluation relied on untrained panelists, introducing potential subjectivity into the assessment. Using trained sensory panelists and implementing more robust sensory analysis methods, such as descriptive analysis, could provide a more objective and detailed understanding of the organoleptic properties of different kombucha formulations and treatments.
  • Low solubility of instant kombucha powder: All samples exhibited low solubility percentages. Future research should focus on improving the solubility of instant kombucha powder. This could involve optimizing the spray-drying process, exploring different carrier agents, or investigating alternative drying techniques.
  • Limited investigation of long-term storage effects: The study primarily focused on immediate post-production characteristics. Long-term storage studies are essential to understand how different treatments and formulations impact the microbiological stability, sensory attributes, and nutritional value of kombucha over time.

By addressing these limitations, future research can build upon the study’s findings and contribute to the development of high-quality, safe, and consumer-accepted kombucha products.

Recommendations for Future Research

In addition to the recommendation listed above:

  • Investigate advanced filtration techniques for yeast and SCOBY removal.
  • Conduct detailed microbial analyses to characterize yeast strains and mold contaminants.
  • Optimize fermentation durations to balance low alcohol content with desired sensory attributes.
  • Explore the use of anti-mold preservatives to enhance product safety during storage.
  • Develop and refine kombucha ice cream formulations using instant kombucha powder.
  • Conduct long-term studies to assess the shelf life and stability of instant kombucha products.

Disclaimer

The views and opinions expressed in this posting are solely those of the authors. These views and opinions do not necessarily represent those of this publication. This summary was developed via NotebookLM and is provided for informational purposes only with no guarantee of completeness or accuracy. Please consult the source document to verify.

If you are interested in the growing range of “kombucha” products available see my June 2020 post Kombucha: The Outer Limits — be sure to scroll down to review the Comments.

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