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High-Pressure Pasteurization of Soy Okara.
Amanda Helstad1, Ali Marefati1, Cecilia Ahlström1
1Department of Food Technology Engineering and Nutrition, Lund University, Naturvetarvägen 12, 223 62 Lund, Sweden.
Foods (Basel, Switzerland)
|October 28, 2023
Summary
High-pressure pasteurization significantly extends the shelf life of okara, a soy by-product. This method reduces microbial growth while maintaining key functional properties, offering a promising food preservation technique.
Area of Science:
- Food Science and Technology
- Microbiology
- Biotechnology
Background:
- Okara, a soy beverage by-product, is rich in protein and fiber but has a short shelf life due to high water content.
- Current uses for okara include animal feed or compost, underutilizing its nutritional value.
- Food safety and extended usability are limited by okara's susceptibility to microbial spoilage.
Purpose of the Study:
- To evaluate the impact of high-pressure pasteurization (HPP) on the microbiological stability and functional properties of okara.
- To determine the optimal HPP conditions for extending okara's shelf life.
- To assess the effects of HPP on okara's water holding capacity, oil holding capacity, viscosity, and thermal properties.
Main Methods:
- Okara samples were subjected to high-pressure pasteurization at 200 MPa, 400 MPa, and 600 MPa.
- Microbiological analysis included total aerobic count, yeast and mold, and lactic acid bacteria.
- Functional properties assessed were viscosity, water holding capacity, oil holding capacity, and thermal properties.
Main Results:
- Treatment at 600 MPa significantly reduced microbial growth (total aerobic count, yeast/mold, lactic acid bacteria) for up to four weeks at 4 °C.
- Pasting properties of okara improved after HPP at 400 MPa and 600 MPa.
- Water holding capacity and oil holding capacity remained largely unchanged (p > 0.05) post-HPP at 400 MPa and 600 MPa.
Conclusions:
- High-pressure pasteurization is a viable technology for enhancing the microbiological safety and shelf life of okara.
- HPP preserves essential functional properties of okara, making it suitable for wider food applications.
- Further research is needed to optimize HPP parameters and fully characterize microbial profiles for complete food safety assurance.
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