Microbial Load of Fresh Blueberries Harvested by Different Methods

Area of Science:

• Food Science
• Microbiology
• Agricultural Engineering

Background:

• Increasing adoption of over-the-row machine harvesters for fresh market blueberries.
• Need to assess microbial contamination associated with different harvesting techniques.

Purpose of the Study:

• To evaluate the microbial load of fresh blueberries harvested by machine versus manual methods.
• To identify harvesting factors influencing microbial contamination in blueberries.

Main Methods:

• Collected blueberry samples (n=336) using conventional and prototype machine harvesters, and hand harvesting (gloved/ungloved).
• Assessed populations of total aerobes (TA), yeasts and molds (YM), and total coliforms (TC).
• Analyzed microbial load at different harvest times and across two blueberry cultivars.

Main Results:

• Harvest method significantly influenced total aerobes and total coliform counts (p < 0.05).
• Harvest time significantly affected yeast and mold counts.
• Blueberry cultivar did not significantly impact microbial load for any indicator organism.

Conclusions:

• Machine harvester cleaning protocols are crucial for minimizing microbial contamination in fresh blueberries.
• Findings provide insights for improving food safety practices in blueberry production.
• Results are applicable to other fresh fruit producers utilizing mechanical harvesting.