Effect of Mold Growth on the pH of Tomato Juice

J Orvin Mundt1

  • 1Department of Food Science and Technology and Microbiology, The University of Tennessee, Knoxville, Tennessee 37916.

Journal of Food Protection
|February 24, 2019
PubMed

Insights

Mold growth on tomato juice significantly increased pH in most species tested. Fungi Imperfecti notably raised pH above 7.0, while Phycomycetes did not.

Area of Science:

  • Microbiology
  • Mycology
  • Food Science

Background:

  • Molds are ubiquitous fungi that can influence the chemical properties of food substrates.
  • Understanding mold's effect on pH is crucial for food preservation and safety.

Purpose of the Study:

  • To investigate the impact of diverse mold species on the pH of tomato juice.
  • To identify specific mold groups that significantly alter pH levels.

Main Methods:

  • Cultivation of 58 mold species from 21 genera on tomato juice for 35 days.
  • Measurement of initial and final pH values of the substrate.

Main Results:

  • Most molds increased the initial pH of 4.1 to a range of 4.9 to over 9.0.
  • 53% of Fungi Imperfecti elevated the pH above 7.0.
  • Phycomycetes did not raise the pH above 7.0.

Conclusions:

  • Mold metabolism generally leads to an increase in tomato juice pH.
  • Fungi Imperfecti show a greater propensity for alkalization compared to Phycomycetes.
  • These findings have implications for mold spoilage and control in tomato-based products.

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