LONG LIFE BREAD-NEW TECHNOLOGY

Bread making was an art or skill till about 5 decades ago. But enormous strides made by bakery scientists since then in developing more and efficient technologies and reducing the time required to make high quality bread products have resulted in taking guess work and gut feeling out of reckoning. But there is one area where little headway has been made and this is with regard to extending the shelf life of the product without adversely affecting its eating quality. Now comes the news that a bakery company in the US has come out with a claim that it can make bread with 60 days life! Here are some details about the above claim and in absence of much technical data it is very difficult to vouchsafe for the veracity of the claim.

"One of the biggest threats to bread is mould. As loaves are usually wrapped in plastic, any water in the bread that evaporates from within is trapped and makes the surface moist. This provides excellent growing conditions for Rhizopus stolonifer, the fungus that leads to mould. In normal conditions, bread will go mouldy in around 10 days. But an American company called Microzap says it has developed a technique that will keep the bread mould free for two months. At its laboratory on the campus of Texas Tech University in Lubbock, chief executive Don Stull showed off the long, metallic microwave device that resembles an industrial production line. Originally designed to kill bacteria such as MRSA and salmonella, the researchers discovered it could kill the mould spores in bread in around 10 seconds. "We treated a slice of bread in the device, we then checked the mould that was in that bread over time against a control, " he explained. "And at 60 days it had the same mould content as it had when it came out of the oven."

Making a product last long is not a difficult task if the sensory quality of the food product is not kept in focus. There are a few chemical preservatives available to day that can inhibit the growth of most microorganisms but such methods cannot prevent chemical or physical changes that occur in all foods at moisture levels beyond 2% at temperatures above zero degree centigrade. In a product like bread with a moisture content of 40% and under ambient conditions staling is bound to take place and according to present state of knowledge there are no fool proof technology yet to prevent staling. stale bread is characterized by crumbling and powdering with the texture of the product getting lost progressively in a matter of few hours. The new method reported above involves treatment of the packed bread with microwave radiation which is supposed to destroy fungal spores but whether it will affect the typical texture of bread adversely is not clear. Retrogradation of starch grains in the bread during storage is a reversible phenomenon and probably bread preserved with the method reported above may regain its texture if it is reheated under optimum conditions in a kitchen microwave oven.

V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com

BREAD QUALITY IMPROVEMENT-ROLE OF ANTIOXIDANTS

Preservation of quality in bread presents two problems. Most commonly encountered problem is staling which starts within 24 hours of making the product and the other aspect is vulnerability to spoilage as it has high moisture content suitable for bacterial and fungal infection. Now comes the third dimension of bread quality as is being brought out by bakery scientists which highlights the susceptibility of bread to flavor damage because of oxidative chemical reactions taking place in the crumb as well as the crust. It is suggested that incorporation of some of the common antioxidants in bread formulations can arrest such deterioration for a few days.

"The researchers reported that oxidative changes occur in both crumb and crust during extended storage. The oxidative changes in the whole wheat bread were found to be relatively minor, however were significant enough to cause changes to flavour and odour, with attributes characterising the stored bread reported as 'aged', 'dusty', 'rancid', 'sickly sweet', and 'bitter'. The content of lipid hydroperoxides – a primary oxidation product – was found to be significantly higher in stored bread crumb compared to bread crust, and reached a maximum peak after 2-3 weeks of storage. Subsequently, the researchers found a decrease in lipid hydroperoxides after 4 and 5 weeks of storage, which they said indicates that the formation of secondary oxidation products was larger than the production of primary oxidation products. "Bread can be regarded as a product with a relatively high oxidative stability. Despite the high stability the present study clearly showed that oxidative changes occurred in both crumb and crust of whole wheat bread as a consequence of extended storage at room temperature," wrote Jensen and co-workers. "A decrease in the anti-oxidative capacity as a consequence of storage reflects a progress in the oxidative reactions depleting antioxidants … [The] quality of bread with extended shelf life may accordingly be improved by minimising oxidation" they added".

It is some what intriguing as to why this aspect of flavor deterioration had not come to the surface in spite of more than 100 years of research on bread making and the quality of the product. Probably such flavor changes may be hardly perceptible during the first 2-3 days within which bread is normally consumed. It is difficult to imagine that consumers will keep bread for days together as it is more vulnerable to staling, roping and molding. While staling can be reversed to some extent by heating to 60C or retarded by increased gluten level in the formulation or use of mono and diglycerides, bacterial and mold infection can be dangerous. Using preservatives to extend the life of bread is not considered practical because of significant changes in its sensory quality during storage.

V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com