Aspergillus niger time to growth in dried tomatoes

Area of Science:

• Food Science
• Microbiology
• Agricultural Science

Background:

• Controlling mold growth, specifically Aspergillus niger, is crucial for dried tomato shelf-life.
• Water activity (aw) and natural antimicrobials are key factors influencing microbial spoilage.
• Mexican oregano essential oil shows potential as a natural food preservative.

Purpose of the Study:

• To investigate the individual and combined effects of water activity (aw) and Mexican oregano essential oil on Aspergillus niger growth time in dried tomatoes.
• To develop predictive models for mold growth based on these factors.
• To establish optimal preservation strategies for dried tomatoes.

Main Methods:

• Dried tomatoes were inoculated with Aspergillus niger and stored at 25°C for 100 days.
• Various water activity (aw) levels and concentrations of Mexican oregano essential oil were applied.
• Time to growth (TTG) was recorded, and regression analysis was used to model the data.

Main Results:

• Mexican oregano essential oil significantly inhibited A. niger growth.
• Effective concentrations varied with aw: 1,000 ppm at aw 0.96, 500 ppm at aw 0.91, and 250 ppm at aw 0.78.
• A predictive model showed high accuracy (correlation coefficient > 0.98) between experimental and predicted TTG.

Conclusions:

• Mexican oregano essential oil is an effective natural preservative against A. niger in dried tomatoes.
• TTG modeling accurately predicts mold growth, aiding in shelf-life determination.
• This research supports optimizing preservation strategies using essential oils and controlling aw for food safety.