Microstructural Changes in Vanilla planifolia Beans after Using High-Hydrostatic-Pressure Treatment in the Curing...

Area of Science:

• Food Science
• Postharvest Technology
• Biotechnology

Background:

• Vanilla bean curing is crucial for developing characteristic aroma and flavor.
• The initial 'killing' step significantly impacts enzyme and compound release for vanillin production.
• Understanding microstructural changes is key to optimizing vanilla processing.

Purpose of the Study:

• To evaluate the effect of high hydrostatic pressure (HHP) as a novel killing method on vanilla bean microstructure.
• To compare HHP treatment with traditional scalding on cellular changes during curing.
• To quantify microstructural alterations using advanced microscopy and digital image analysis.

Main Methods:

• Application of high hydrostatic pressure (100-400 MPa) and scalding (100 °C) as killing techniques.
• Analysis of microstructural changes in three bean sectors (total, annular, core) across curing cycles (C0-C20).
• Utilized stereomicroscopy (SM), confocal laser scanning microscopy (CLSM), and environmental scanning electron microscopy (ESEM) with digital image analysis (DIA).

Main Results:

• HHP treatment induced more numerous microstructural changes compared to scalding.
• The core area of vanilla beans was most affected by HHP, particularly at 400 MPa.
• Maximum decrease in total bean area was observed at the C16 curing stage.

Conclusions:

• Microscopy and DIA effectively characterized microstructural changes in HHP-treated vanilla beans.
• HHP shows potential as an alternative killing method influencing vanilla bean microstructure and potentially vanillin development.
• The study provides insights into optimizing vanilla processing for enhanced flavor and aroma profiles.