Structural, physical, functional and nutraceutical changes of freeze-dried fruit

Abstract

This review examines the structural, physical, functional and nutraceutical changes of lyophilized fruits. Collapse, porosity, color, glass transition temperature, rehydration capacity, ability to retain water, volatile compounds, phenolic compounds, ascorbic acid, and beta-carotene, were defined, and the causes of changes in these parameters, during freeze-drying, were analyzed. Advantages and limitations of the freeze-drying, were shown, and strategies to reduce the costs associated with its use were proposed. It was concluded that lyophilized fruit retained to a greater proportion characteristics of fresh fruits, compared with other methods of dehydration. The effects of freeze-drying on physical and chemical properties vary in accordance with factors intrinsic to the fruit, and with extrinsic properties inherent to process. Most fruits maintain their color using freeze-drying. The porosity of freeze-dried fruit depends on the freezing speed. The glass transition temperature of dry solid would be an important optimization parameter for the freezing-drying process. The majority of phenolic acids and volatile compounds were conserved in freeze-drying. Freeze-drying increases the rehydration capacity of dried fruits, to a greater extent the hydrophilic groups which are responsible for interaction with water. However, dried fruits by freeze-drying can show structural collapse. The long processing time and energy costs are limiting the application of technology. The researchers recommend using combined to potentiate the benefits of freeze-drying and to lessen their limiting technologies.

Effect of the Extraction Process on the Biological Activity of Lyophilized Apricot Extracts Recovered from Apricot Pomace

“…This decrease in the polyphenols content in lyophilized fruits and vegetables products could be due to the rupture of the cell wall caused by ice crystals formation and the subsequent release of hydrolytic and oxidative enzymes (which are not fully deactivated) which cause a degradation in phenolic compounds [ 22 , 23 , 24 ]. However, in our study a liquid extract was subjected to lyophilization and, thus, no cells were found in the lyophilized sample.…”

Effect of Freeze-Drying Pressure and Operating Time on Mass Balance and Characteristics of Freeze-Dried Mango Slices

“…Researches have stated that freeze-drying can retain the physical properties of dried products. However, the freezedrying method is not without its limitations, as it requires an extended drying time, which translates into high energy costs (Liliana et al, 2015). Apart from drying time, the operating temperature and pressure also affect the product quality during freezedrying.…”

INVESTIGATING NATURAL TRANSITION METAL COORDINATION ANTHOCYANIN COMPLEX IN JAVA PLUM (Syzygium cumini) FRUIT AS FREE RADICAL SCAVENGING

“…The freeze-dried java plum fruit powder process indicating a chemical reaction did not exist. However, there was a possibility that the position of atoms nearby formed an order of crystal 31 . Crystal is a material which has an organized three-dimension regular pattern with a directional atomic bonding and a tight order.…”