The Effects of Freezing and Thawing on Food Quality

Effect of processing on the texture and sensory attributes of raspberry (cv. Heritage) and blackberry (cv. Thornfree)

“…The fastest freezing rate produced a less drastic effect on the cellular structure of blackberry tissue, although as was found in raspberry, a lower freezing rate (2.2°C min À1 ) did little damage to the structure, with probably hardly any rupturing of cell walls or loss of internal cell pressure. It is generally accepted that quality is better retained with fast than with slow freezing rates (Partmann, 1975). From the results presented, it seems obvious that the ultra rapid freezing of both fruits produced unfavourable effects.…”

Microstructure affects the rate of chemical, physical and color changes during storage of dried apple discs

“…The freezing rate is a variable recognized as responsible for tissue damage (Fuchigami, Kato, & Teramoto, 1997). It is generally accepted that high freezing rates retain the quality (and thus, the structure) better than slow freezing rates (Partmann, 1975). Slow freezing rate causes severe changes in product microstructure, SF/FD samples presented broken surfaces, as shown in Fig.…”

Microstructural changes in strawberry after freezing and thawing processes

“…Studies on the structure/processing relationship in edible plant materials have been critically reviewed in the literature (Alzamora et al, 1997). In particular, ultrastructural changes associated with freeze-thaw and blanching have been studied in several types of tissue by Partmann (1975); Bomben and King (1982); Moreno, Chiralt, Escriche and Serra (2000) and Roy, Taylor and Kramer (2001). In general terms all these workers described a gradual breakdown in the organization of the protoplasmic structure and, in most cases, the rupture of the plasmalemma with subsequent loss of turgor pressure in cells.…”