Tuesday, September 13, 2005
Various factors are related to the quality of bread produced from frozen dough stored for long periods.
The effect of freezing on the yeast properties has been widely studied.
Several researches showed that the yeast viability is strongly influenced by:
- fermentation process prior to freezing
- freezing and thawing velocities
- the duration of frozen storage
- yeast type
Different yeast type also influence the quality of the bread.
In commercial productions of frozen dough, higher amounts of yeast are used, and also no-time bakery procedures, low preparation temperatures and tunnel freezing, in order to minimize the above mentioned effects.
Trehalose and Yeast
The capacity of the yeast to maintain a high fermentative capacity after long periods of low temperature storage is affected by technological and cellular parameters. Trehalose is considered to be an important physiological compound in the resistance of the yeast to cold.
Trehalose has been related to the resistance of the yeast to various types of stress, demonstrating that a high intracellular trehalose content is an advantage for good stability to freezing/thawing after prolonged frozen storage.
A research done with bakery yeast and trehalose concluded that a content of 4-5% (based on the dry weight of the yeast) at the moment of freezing, was sufficient to protect the yeast cells during the sequence of operations comprising pre-fermentation, freezing, frozen storage and thawing.
SALAS-MELLADO, Myriam M. and CHANG, Yoon Kil. Effect of formulation on the quality of frozen bread dough. Braz. arch. biol. technol. [online]. June 2003, vol.46, no.3 [cited 13 September 2005], p.461-468. Available from World Wide Web:
flew into your heart at [11:59 PM]
Angela
Studying at Temasek Poly final year
Favourites
Playing Maple Story...haha
Slack in front of my com
Dislikes
Hate butterflies
Being bored....
Wishlist
Travel to Japan and have a great holiday
Memories
Music playing
*Never Be Replaced
To everyone...
Love is a touch, a gentle embrace
A smile, a laugh, a simple grace
Love is soft skin upon your own
Love is never being alone
Love is patient, Love is pure
Love it one thing I know for sure
Love keeps us close, my friends and I
Love never ends, though we may die
Love is a tear, shed without hate
Love is a heartbeat, felt too late
Love is a feather from an angel's wing
Love is the means by which we sing
Love is wind, Love is rain
It is truth, faith, hope and pain
Love is blind, Love has no bound
Love is silence, Love is sound
Love is you, Love is me
Love is one small word--we
Love is my blind faith in you
Love is a word best felt by two