Texture and Histological Structure of Carrots Frozen at a Programmed Rate and thawed in an Electrostatic Field

Abstract

To investigate the most suitable rate of freezing and method for thawing, raw and blanched carrots were frozen with LN, (freezing rate: -5°C or -2Y%in, final temp: -30°C) using a program freezer (PF), or were frozen using conventional freezers (F: -8O"C, -30°C and -20°C). Then, they were thawed in five different ways: electrostatic thawing (ET, -3"C, 17 hr); -3"C, 17 hr, YC, 17 hr, 2O"C, 30 min; lOO"C, 3 min. Firmness of thawed carrots and amount of undamaged tissues by LM and TEM observations were greatest to least: PF -SYXnin>PF-2Y!/ min>-80°CF>-300CF>-200CF, and EXL-3"C~5"C>20"C> loo"C, respectively. Results suggest the optimum rate of freezing was -5"U min. The frozen disks were defrosted comparatively fast even at -3°C by ET. Drip, cell damage and softening of disks were prevented by ET.

Changes in texture, microstructure and nutritional quality of carrot slices during blanching and freezing

“…The textural changes in carrots during blanching have been investigated by Fuchigami et al, 12 Glasscock et al 32 and Rahman et al 14 Glasscock et al 32 found higher shear values for carrots following microwave blanching than following water blanching after one month of frozen storage. The same tendency in the textural attributes was seen in the present study.…”

Chinese Cabbage Midribs and Leaves Physical Changes as Related to Freeze‐processing

“…The optimum freezing rate of carrots has been established as -YC/min, using a programmable freezer and based on texture and histological structure. (Fuchigami et al, 1994(Fuchigami et al, , 1995b. Chinese cabbage leaves cracked when frozen rapidly with liquid nitrogen (LN,).…”

The use of image analysis in observing mechanically deforming notched and un‐notched onion epidermal cellular structures

“…Cell size and shape are known to change with growth, 3 maturation and ripening 4,5 and turgor. 6 These and other studies used a range of microscopies 7 to image the cells such as light after staining and embedding and transmission electron after staining and cryo-scanning electron after etching.…”