Drying of α-amylase by spray drying and freeze-drying - a comparative study

Abstract

-This study is aimed at comparing two traditional methods of drying of enzymes and at verifying the efficiency of each one and their advantages and disadvantages. The experiments were performed with a laboratory spray dryer and freeze-dryer using α-amylase as the model enzyme. An experimental design in star revealed that spray drying is mainly influenced by the inlet air temperature and feed flow rate, which were considered to be the main factors influencing the enzymatic activity and water activity; the long period of material exposure to high temperatures causes a partial activity loss. In the experiments of freeze drying, three methods of freezing were used (freezer, acetone and dry ice, and liquid nitrogen) and samples subsequently freeze-dried for times ranging between 0-24 hours. The product obtained from the two techniques showed high enzymatic activity and low water activity. For the drying of heat-resistant enzymes, in which the product to be obtained does not have high added value, spray drying may be more economically viable because, in the freeze drying process, the process time can be considered as a limiting factor when choosing a technique.

Effect of Heat Exposure on Activity Degradation of Enzymes in Mango Varieties Sindri, SB Chaunsa, and Tommy Atkins during Drying

“…The degradation rate accelerated 3.84-fold during drying at 60 °C and 10.58-fold at 80 °C, compared to 40 °C. Similar explanations regarding enzyme inactivation at different temperatures were also found in previous studies [ 33 , 54 , 55 ]. In addition, when drying at 40 °C, 60 °C, and 80 °C, an increase in air velocity of 1.4 ms −1 increased the destruction rate k d by 8.77–31.42%.…”

“…The enzyme degradations were expressed by a first-order kinetic model [ 66 , 67 ]: A/A o = exp (−k d × t), where A is the residual activity after the treatment time t (min), A o is the initial activity, and k d is the deactivation or destruction rate constant (min −1 ). The deactivation rate constant (k d ) is temperature dependent according to the Arrhenius equation [ 54 ]: k d = k do × exp (−E d /RT), where k d is the deactivation rate constant at the process temperature (min −1 ), k do is the pre exponential factor, E d is the energy of deactivations (J·mol −1 ), R is the universal gas constant 8.314 (J·mol −1 ·K −1 ), and T is the absolute temperature in (K).…”

“…where A is the residual activity after the treatment time t (min), A o is the initial activity, and k d is the deactivation or destruction rate constant (min −1 ). The deactivation rate constant (k d ) is temperature dependent according to the Arrhenius equation [54]:…”

Microencapsulation of Lipase and Savinase Enzymes by Spray Drying Using Arabic Gum as Wall Material

“…A low outlet temperature is necessary to avoid loss of activity. In order to have a suitable operational policy, it is important to consider that the outlet temperature increased with increasing inlet temperature and decreased with increasing liquid feed rate [25] [26] [27]. In our study we have optimized parameters such as inlet temperature, suction power and mass relation in order to obtain microcapsules with adequate morphology and high encapsulation efficiency and, we calculated the enzyme concentration in microcapsules in order to observe the loss enzyme activity in the best microcapsules.…”

Microencapsulation of Aspergillus niger phytases produced in triticale by solid fermentation and microencapsulates characterization

“…It provides protection by carriers and additives by means of spray drying and, in this way, avoiding enzyme inactivation. Nowadays, many different compounds have been dried by this method like some oils (Aghbashlo et al, 2012;Gangurde et al, 2015;Koç et al, 2015), lactobacillus (Eckert et al, 2017), DNA (Alexakis et al, 1995), food (Pérez-Alonso et al, 2009), volatile aromas (Brückner et al, 2007), enzymes (Anjani et al, 2007;Dutta and Bhattacharjee, 2017;Estevinho et al, 2014;Gupta et al, 2014;Jesus and Filho, 2014), among others. The greatest challenge in the spray drying of proteins is denaturalization due to heating.…”