Glass Transition of Rainbow Trout and Effect of Cryoprotectants on Some Changes

Abstract

Sucrose (2%), sorbitol (2%), mannitol (2%), gum arabic (0.15%), carrageenan (0.15%) 8 and meat stabilizer (0.5%) were blended with ground rainbow trout and stored for 6 months separately at −9, −13C (glass transition temperature [Tg] of rainbow trout determined by differential scanning calorimetry) and −18C. Total volatile basic nitrogen (TVB‐N) and thiobarbituric acid‐reactive substances (TBARS) were determined at first, third and sixth months of storage periods. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) was conducted on isolated myofibrillar proteins for first, third and sixth months. Biopolymers and storage period had a significant effect (P < 0.05) on the TVB‐N and TBARS values. Tg (−13C) and −18C showed the same effects on TVB‐N and TBARS values, but −9C had statistically different effect on them. SDS‐PAGE characteristics of myofibrillar proteins revealed that the samples with gum arabic, sucrose and sorbitol were different from the other samples. PRACTICAL APPLICATIONS Glass transition is a second‐order time–temperature dependent on phase transition. It assists in identifying food stability during storage, as well as selecting suitable conditions of temperature for processing. In the present study, total volatile basic nitrogen and thiobarbituric acid‐reactive substance values of the samples stored at Tg (−13C) and −18C were determined as statistically the same. Both from the economical and quality retention point of view, this situation is important to practical applications.

Quality changes of frozen mango with regard to water mobility and ice crystals during frozen storage

“…Freezing is a suitable method to preserve the quality attributes of mango and extend its shelf life (Zhao et al, 2017). It is well documented that at temperatures below the glass transition temperature, the molecular diffusion and the rates of deteriorative reactions are significantly reduced, and thus foods are relatively stable in the glassy sate (Aktaş & Akköse, 2011; Roos, 1998). For frozen foods (high water content foods), their maximum stability can be obtained when the freezable water transforms into ice crystals and the temperatures are maintained below their characteristic glass transition temperatures (Fabra, Talens, Moraga, & Martínez‐Navarrete, 2009).…”

Application of biopolymers for improving the glass transition temperature of hairtail fish meat

“…Many physical properties of food stored below its T g would be better maintained, whereas food would deteriorate sharply as the temperature increased above T g . Besides, the activity of enzyme in samples stored at or below T g was restrained and significantly lower than that above T g , while the biopolymers could cause the stabilizing effects associated with stabilizers, which had been widely explained by biopolymer interaction and glass transition, since chemical and enzyme activity were inhibited by the addition of biopolymers so that the TVB‐N value was much lower. On the other hand, TVB‐N is closely related to microorganism growth.…”

“…Moreover, trehalose at 40% could increase the T g of ice cream to −42.6 °C . Aktas and Akkose also found that the T g of rainbow trout muscle was −13.0 °C and rainbow trout blended with sucrose and sorbitol could be stored for 6 months with a lower total volatile basic nitrogen (TVB‐N) of 14.72 mg 100 g −1 and thiobarbituric acid reactive substances of 5.75 mg kg −1 .…”

“…Addition of biopolymers could increase the T g of food systems so that foods could be stored at higher temperature with greater stability and longer storage life with respect to diffusion‐limited reactions . Maity et al .…”