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Advisor(s)
Abstract(s)
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 welldescribed
by the Arrhenius law.
Description
Keywords
Broccoli Blanching Quality parameters Kinetics modeling
Citation
"Journal of Agricultural and Food Chemistry". ISSN 1520-5118. 57: 12 (2009) 5370–5375
Publisher
American Chemical Society