Purpose: The objective of this study is to evaluate the use of Electron Beam (E-Beam) processing at FDA-approved doses (< 1 kGy) in combination with modified atmosphere packaging (MAP) to determine whether microbial numbers on fresh fruits (watermelon, strawberries, grapes, cherry tomatoes and avocadoes) can be reduced to the neutropenic diet benchmark levels (< 500 CFU/g) while still maintaining sensory qualities.
Methods: Portions of the fruits were packaged under MAP and ambient conditions which then underwent E-Beam processing. Alanine dosimetry was employed to confirm that the delivered doses were below 1 kGy. Aerobic plate count methods were used to determine the bioburden loads of samples (in triplicate) over a 21 day storage period at 4°C. A consumer preference study using 41 untrained panelists and a 9 point hedonic scale was used to measure the acceptability of irradiated samples. Texture analyzer, colorimeter and moisture determination methods were performed to measure any sensory differences in the E-Beam treated and control samples
Results: Under ambient and MAP conditions, the microbial loads of E-Beam treated watermelon, grape, and avocado were below 500 CFU/g for at least 7 days longer than untreated samples. All E-Beam treated fruits were rated as acceptable by consumers in the attributes of firmness, flavor, color and overall likeability with scores averaging 5.7-8.2. However, textural analyses did show that the E-Beam treated tomato samples were significantly less firm (P < 0.05) than non-irradiated samples.
Significance: E-Beam treatment of fruits is a value adding technology that not only extends their shelf life but allows for the fruits to meet neutropenic standards to improve quality of life. The results also demonstrate that E-Beam treatment does not adversely affect consumer preferences.