10 research outputs found
Blanching Leafy Vegetables With Electromagnetic Energy
WOS: A1994PP03500026Application of radio frequency, microwave, microwave-steam and infrared energy for blanching of leafy vegetables (endive and spinach) was studied and compared with conventional hot water and steam blanching. The quality of vegetables both frozen and sterilized was evaluated by instrumental and sensory analysis. Effects of blanching methods were most pronounced in frozen products. No quality differences occurred for infrared and radio frequency treatments. However, microwave energy alone or in combination with steam in the blanching process improved vitamin C retention, gave higher Instron force values and better sensory characteristics
Degradation kinetics of peroxidase enzyme, phenolic content, and physical and sensorial characteristics in broccoli (brassica oleracea L. ssp. Italica) during blanching
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