Microstructural analysis of fresh-cut red bell pepper (Capsicum annuum L.) for postharvest quality optimization

• Autor(a) principal: Fonseca, Susana C.
• Data de Publicação: 2005
• Outros Autores: Silva, Cristina L. M., Malcata, F. Xavier
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.14/6733
• topic: Quality; Microstructure; SEM; Image analysis

The main objective of this work was to evaluate the microstructure of fresh-cut red bell pepper (Capsicum annuum L.) after cutting, when maintained (for 0,4 and 7 d) under refrigerated storage (2°C). In order to assess the microstructure of the product, scanning electron microscopy (SEM) was applied; however, to improve this technique, preparation procedures and quantitative image analysis were specifically developed. Since sample preparation affects deeply image quality, three sample preparation procedures (viz. freezing by immersion in liquid nitrogen and subsequent storage at -80°C, freezing by storage at -80 °C and subsequent freeze-drying, and freezing by immersion in liquid nitrogen and subsequent freezedrying) were tested. One could also test (with success) a methodology of quantitative image analysis via a panel – a large number of people (N=25) rated the degree of cellular destruction, using a continuous scale (from 1- no cellular destruction to 9-extreme cellular destruction). Statistical analysis of the experimental data revealed that frozen samples exhibited higher cellular destruction than via the other two procedures; no statistically significant differences were observed between these two other procedures. Red bell pepper samples stored for 4 and 7 d presented (as expected) higher degree of cellular destruction than initial day samples. This work allowed one to develop appropriate preparation procedures of sample and quantitative image analysis – that will permit the application of this microscopy technique in future work in this area.