Degradation Kinetics of Peroxidase Enzyme, Phenolic Content, and Physical and Sensorial Characteristics in Broccoli (Brassica oleracea L. ssp. Italica) during Blanching
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- 作者：Elsa M. Gonalves ; Joaquina Pinheiro ; Carla Alegria ; Marta Abreu ; Teresa R. S. Brando ; Cristina L. M. Silva
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2009
- 出版时间：June 24, 2009
- 年：2009
- 卷：57
- 期：12
- 页码：5370-5375
- 全文大小：760K
- 年卷期：v.57,no.12(June 24, 2009)
- ISSN：1520-5118
文摘
The effects of water blanching treatment on peroxidase inactivation, total phenolic content, color parameters [−a*/b* and hue (h°*)], texture (maximum shear force), and sensory attributes (color and texture, evaluated by a trained panel) of broccoli (Brassica oleracea L. ssp. Italica) were studied at five temperatures (70, 75, 80, 85, and 90 °C). Experimental results showed that all studied broccoli quality parameters suffered significative changes due to blanching treatments. The vegetal total phenolic content showed a marked decline. Degradation on objective color and texture measurements and alterations in sensorial attributes were detected. Correlations between sensory and instrumental measurements have been found. Under the conditions 70 °C and 6.5 min or 90 °C and 0.4 min, 90% of the initial peroxidase activity was reduced. At these conditions, no significant alterations were detected by panelists, and a small amount of phenolic content was lost (ca. 16 and 10%, respectively). The peroxidase inactivation and phenolic content degradation were found to follow first-order reaction models. The zero-order reaction model showed a good fit to the broccoli color (−a*/b* and h°*), texture, and sensory parameters changes. The temperature effect was well-described by the Arrhenius law.