Optimization of high pressure processing for microbial load reduction in Diospyros kaki 'Fuyu' pulp using response...

Area of Science:

• Food Science
• Food Preservation
• Horticulture

Background:

• Fuyu persimmon (Diospyros kaki L.) is a non-astringent variety with a limited shelf life.
• Conventional preservation methods like pasteurization often degrade fruit quality due to high temperatures.
• There is a need for effective, low-temperature preservation techniques for persimmon pulp.

Purpose of the Study:

• To investigate the efficacy of high pressure processing (HPP) for microbial load reduction in Fuyu persimmon pulp.
• To optimize HPP parameters (pressure, time, temperature) for persimmon pulp preservation.
• To develop a mathematical model for predicting the response of microbial counts to HPP.

Main Methods:

• Response surface methodology with a Box-Behnken design was employed.
• Parameters studied included pressure (200-600 MPa), time (5-15 min), and temperature (20-45 °C).
• Mathematical modeling and analysis of R-squared values were used to assess model accuracy.

Main Results:

• A mathematical model accurately predicted the microbial response to HPP parameters (high R² value).
• Optimal conditions for microbial load reduction were identified as 400 MPa, 20 °C, and 5 minutes.
• This non-thermal minimal processing effectively reduced total plate count and yeast and mold count.

Conclusions:

• High pressure processing (HPP) is a viable non-thermal technology for preserving Fuyu persimmon pulp.
• Low-temperature HPP at 20°C, 400 MPa for 5 minutes effectively reduces microbial contamination.
• This method offers a promising alternative to thermal processing, maintaining persimmon pulp quality.