Description
Aim:Frozen vegetables are a sustainable way of providing year-round healthy products to consumers: frozen storage requires relatively low energy consumption and strongly reduces food waste of seasonally produced products. The sustainability of the current frozen vegetable processing chain can however be significantly improved, a goal that is embraced by industrial partners involved in this project. A ‘hotspot’ analysis was carried out, and indicated that the blanching process is the most impactfull process that could potentially be changed.
Aim of this study is to evaluate if blanching intensity of green beans can be reduced, either by changing blanching temperature and time combinations, or by changing blanching technology, to make the blanching process more sustainable, without compromising the final product quality.
Method:
Fresh green beans were harvested, washed, cut, blanched and cooled, before freezing. Different blanching temperature-time combinations and methods were evaluated, including immersion in hot-water, spraying and steaming. Different blanched beans were assed by determining texture after cooling, while hexanal content and remaining enzymes activity (lipoxygenase, LOX; pectinmethylestase, PME and peroxidase, POD) were determined after freezing. Samples were reheated and texture and sensorial evaluation was done, to evaluate final quality like a consumer would perceive it. Different temperaturate-time combinations were expressed as heat load, to facilitate comparison between the different technologies and to the standard processing conditions used by industry.
Results:
Results show that avoiding blanching before freezing is no option, as beans will have an unpleasant taste, due to the high LOX activity. Dependent on the different blanching temperature-time combinations LOX can be inactivated successfully. PME activity was altered after blanching as well, which resulted in different textures. The different blanching technologies show variations in effectivity to inactivate the enzymes, resulting in different textures.
Conclusion:
Relationship between temperature, time and heat transfer of different blanching technologies on the quality of green beans was established, which can be used to select optimal blanching conditions. With these insights energy consumption during blanching and/or water consumption can be reduced.
| Period | 12 Nov 2024 → 14 Nov 2024 |
|---|---|
| Event title | 38th EFFoST International Conference 2024: Future Food Systems: Innovation through Progress at Scientific Interfaces |
| Event type | Conference/symposium |
| Location | Bruges, BelgiumShow on map |
| Degree of Recognition | International |
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