Limits...
Quality changes and freezing time prediction during freezing and thawing of ginger.

Singha P, Muthukumarappan K - Food Sci Nutr (2015)

Bottom Line: Fresh ginger was found to contain 3.60% gingerol and 18.30% zingerone.Slow freezing damaged ginger's cellular structure.Computer simulation for predicting freezing time may help in developing proper storage system of ginger.

View Article: PubMed Central - PubMed

Affiliation: Department of Agricultural and Biosystems Engineering South Dakota State University Brookings South Dakota 57007.

ABSTRACT
Effects of different freezing rates and four different thawing methods on chemical composition, microstructure, and color of ginger were investigated. Computer simulation for predicting the freezing time of cylindrical ginger for two different freezing methods (slow and fast) was done using ANSYS (®) Multiphysics. Different freezing rates (slow and fast) and thawing methods significantly (P < 0.05) affected the color and composition of essential oil in ginger. Fresh ginger was found to contain 3.60% gingerol and 18.30% zingerone. A maximum yield of 7.43% gingerol was obtained when slow frozen gingers when thawed by infrared method. Maximum zingerone content of 38.30% was achieved by thawing slow frozen gingers using infrared-microwave method. Microscopic examination revealed that structural damage was more pronounced in slow frozen gingers than fast frozen gingers. Simulated freezing curves were in good agreement with experimental measurements (r = 0.97 for slow freezing and r = 0.92 for fast freezing). Slow freezing damaged ginger's cellular structure. Data obtained will be helpful in selecting appropriate thawing method to increase desirable essential oil components in ginger. Computer simulation for predicting freezing time may help in developing proper storage system of ginger.

No MeSH data available.


Related in: MedlinePlus

Electron micrograph of (A) slow frozen, (B) fast frozen, (C) slow frozen‐room temperature thawed, (D) slow frozen‐microwave thawed, (E) slow frozen‐infra red thawed, (F) slow frozen‐infrared microwave thawed, (G) fast frozen‐room temperature thawed, (H) fast frozen‐microwave thawed, (I) fast frozen‐infrared thawed, and (J) fast frozen‐infrared microwave thawed gingers. Scale bar = 300 μm.
© Copyright Policy - creativeCommonsBy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4930496&req=5

fsn3314-fig-0007: Electron micrograph of (A) slow frozen, (B) fast frozen, (C) slow frozen‐room temperature thawed, (D) slow frozen‐microwave thawed, (E) slow frozen‐infra red thawed, (F) slow frozen‐infrared microwave thawed, (G) fast frozen‐room temperature thawed, (H) fast frozen‐microwave thawed, (I) fast frozen‐infrared thawed, and (J) fast frozen‐infrared microwave thawed gingers. Scale bar = 300 μm.

Mentions: To gain insight into the effects of freezing and thawing on the structure of ginger, scanning electron microscopic (SEM) images were obtained to provide visual evidence of the changes in structure. Figure 6 shows microscopic image of fresh sample of ginger rhizome, which did not receive any other treatment other than preparation for SEM. The impacts of freezing on quality of food are directly related with the growth of ice crystals which can break cellular walls (Anzaldua‐morales et al. 1999). Ginger rhizome typically contains 85–89% moisture (wb). When ginger was subjected to slow freezing large ice crystals were formed which disrupted the cells. Figure 7A shows the structural damage caused due to formation of large ice crystal during slow freezing. Contrary to this, fast or rapid freezing leads to formation of smaller ice crystals and hence causes minimum damage to cellular structure (Fig. 7B). Rapid freezing is appropriate to retain the tissue structure. This is in agreement with Delgado and Rubiolo (2005).


Quality changes and freezing time prediction during freezing and thawing of ginger.

Singha P, Muthukumarappan K - Food Sci Nutr (2015)

Electron micrograph of (A) slow frozen, (B) fast frozen, (C) slow frozen‐room temperature thawed, (D) slow frozen‐microwave thawed, (E) slow frozen‐infra red thawed, (F) slow frozen‐infrared microwave thawed, (G) fast frozen‐room temperature thawed, (H) fast frozen‐microwave thawed, (I) fast frozen‐infrared thawed, and (J) fast frozen‐infrared microwave thawed gingers. Scale bar = 300 μm.
© Copyright Policy - creativeCommonsBy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4930496&req=5

fsn3314-fig-0007: Electron micrograph of (A) slow frozen, (B) fast frozen, (C) slow frozen‐room temperature thawed, (D) slow frozen‐microwave thawed, (E) slow frozen‐infra red thawed, (F) slow frozen‐infrared microwave thawed, (G) fast frozen‐room temperature thawed, (H) fast frozen‐microwave thawed, (I) fast frozen‐infrared thawed, and (J) fast frozen‐infrared microwave thawed gingers. Scale bar = 300 μm.
Mentions: To gain insight into the effects of freezing and thawing on the structure of ginger, scanning electron microscopic (SEM) images were obtained to provide visual evidence of the changes in structure. Figure 6 shows microscopic image of fresh sample of ginger rhizome, which did not receive any other treatment other than preparation for SEM. The impacts of freezing on quality of food are directly related with the growth of ice crystals which can break cellular walls (Anzaldua‐morales et al. 1999). Ginger rhizome typically contains 85–89% moisture (wb). When ginger was subjected to slow freezing large ice crystals were formed which disrupted the cells. Figure 7A shows the structural damage caused due to formation of large ice crystal during slow freezing. Contrary to this, fast or rapid freezing leads to formation of smaller ice crystals and hence causes minimum damage to cellular structure (Fig. 7B). Rapid freezing is appropriate to retain the tissue structure. This is in agreement with Delgado and Rubiolo (2005).

Bottom Line: Fresh ginger was found to contain 3.60% gingerol and 18.30% zingerone.Slow freezing damaged ginger's cellular structure.Computer simulation for predicting freezing time may help in developing proper storage system of ginger.

View Article: PubMed Central - PubMed

Affiliation: Department of Agricultural and Biosystems Engineering South Dakota State University Brookings South Dakota 57007.

ABSTRACT
Effects of different freezing rates and four different thawing methods on chemical composition, microstructure, and color of ginger were investigated. Computer simulation for predicting the freezing time of cylindrical ginger for two different freezing methods (slow and fast) was done using ANSYS (®) Multiphysics. Different freezing rates (slow and fast) and thawing methods significantly (P < 0.05) affected the color and composition of essential oil in ginger. Fresh ginger was found to contain 3.60% gingerol and 18.30% zingerone. A maximum yield of 7.43% gingerol was obtained when slow frozen gingers when thawed by infrared method. Maximum zingerone content of 38.30% was achieved by thawing slow frozen gingers using infrared-microwave method. Microscopic examination revealed that structural damage was more pronounced in slow frozen gingers than fast frozen gingers. Simulated freezing curves were in good agreement with experimental measurements (r = 0.97 for slow freezing and r = 0.92 for fast freezing). Slow freezing damaged ginger's cellular structure. Data obtained will be helpful in selecting appropriate thawing method to increase desirable essential oil components in ginger. Computer simulation for predicting freezing time may help in developing proper storage system of ginger.

No MeSH data available.


Related in: MedlinePlus