The various rapid freezing technologies have been investigated to control the size, shape, and distribution of ice crystal for high-quality frozen food, especially meat. Because of the fast freezing rate, air-blast freezing has been thought to make the quality of frozen food improve. In this study, ...
The various rapid freezing technologies have been investigated to control the size, shape, and distribution of ice crystal for high-quality frozen food, especially meat. Because of the fast freezing rate, air-blast freezing has been thought to make the quality of frozen food improve. In this study, the change of effects of air-blast freezing (0, 1.5, and 3 m/s) during decreasing temperature (-20, -30, and -40ºC) was investigated to confirm the advantages of the combination of the deep freezer with air-blast freezing technology. Normal freezing time (NFT; an indicator of phase transition time, the period from nucleation to -5ºC) was decreased as decreasing freezing temperature and increasing air flow rate at each temperature. Observation of microstructure showed notably a decrease of ice crystal size depending on the increase of air flow only at -20ºC (P < 0.05). While decreased freezing temperature affected NFT, thawing loss, cooking loss, redness, yellowness, shear force, and ice crystal diameter, increased the air flow rate affected only NFT and ice crystal diameter (P < 0.05). This study suggested that the combination of the deep freezer (under -30ºC) with air blast freezing is not comfortable for rapid freezing which improves the quality of frozen food.
A subsequent study investigated the ice crystal forming factors and the effects of precooling conditions on the ice nucleation phenomena of water and semisolid matrices (i.e., gelatin and agar gels). In the case of water, the ice nucleation temperature was affected by the precooling rate, while the difference in the ice nucleation temperature was 0.9°C even if the precooling rate was changed by 10-fold. For a semisolid matrix, the impact of the precooling rate on the ice nucleation temperature was observed when a constant temperature was applied, whereas this relationship was diminished under stepwise cooling conditions with large temperature intervals (2~8°C). Linear precooling could be achieved by applying stepwise cooling with a 0.5°C temperature interval. Ice nucleation could be manually obtained at varying temperatures, and the results indicated that the nucleation temperature affected the phase transition time and the size of the ice crystals for completely frozen gelatin gel. Consequently, this study demonstrated a possible application of precooling conditions in the design of a feasible and novel freezing technique.
The various rapid freezing technologies have been investigated to control the size, shape, and distribution of ice crystal for high-quality frozen food, especially meat. Because of the fast freezing rate, air-blast freezing has been thought to make the quality of frozen food improve. In this study, the change of effects of air-blast freezing (0, 1.5, and 3 m/s) during decreasing temperature (-20, -30, and -40ºC) was investigated to confirm the advantages of the combination of the deep freezer with air-blast freezing technology. Normal freezing time (NFT; an indicator of phase transition time, the period from nucleation to -5ºC) was decreased as decreasing freezing temperature and increasing air flow rate at each temperature. Observation of microstructure showed notably a decrease of ice crystal size depending on the increase of air flow only at -20ºC (P < 0.05). While decreased freezing temperature affected NFT, thawing loss, cooking loss, redness, yellowness, shear force, and ice crystal diameter, increased the air flow rate affected only NFT and ice crystal diameter (P < 0.05). This study suggested that the combination of the deep freezer (under -30ºC) with air blast freezing is not comfortable for rapid freezing which improves the quality of frozen food.
A subsequent study investigated the ice crystal forming factors and the effects of precooling conditions on the ice nucleation phenomena of water and semisolid matrices (i.e., gelatin and agar gels). In the case of water, the ice nucleation temperature was affected by the precooling rate, while the difference in the ice nucleation temperature was 0.9°C even if the precooling rate was changed by 10-fold. For a semisolid matrix, the impact of the precooling rate on the ice nucleation temperature was observed when a constant temperature was applied, whereas this relationship was diminished under stepwise cooling conditions with large temperature intervals (2~8°C). Linear precooling could be achieved by applying stepwise cooling with a 0.5°C temperature interval. Ice nucleation could be manually obtained at varying temperatures, and the results indicated that the nucleation temperature affected the phase transition time and the size of the ice crystals for completely frozen gelatin gel. Consequently, this study demonstrated a possible application of precooling conditions in the design of a feasible and novel freezing technique.
주제어
#cooling rate ice nucleation postcooling phase transition time ice crystal
※ AI-Helper는 부적절한 답변을 할 수 있습니다.