Researchers from the National Technical University of Athens report that enzyme-modified bran could retard the staling of bakery products by up to 60 per cent.
According to the findings published in the Journal of Food Science, the enzyme-modified bran-enriched cakes were also more appealing to consumers when tested by a panel of tasters.
“The results of the study show the potential of using enzymes to modify underutilized food sources that can be properly incorporated in baked goods, improving their nutritional value, their quality characteristics, and providing longer shelf life,” explained Dimitra Lebesi and Constantina Tzia.
“The developed procedure and results can be utilized by the bakery industry to make high fibre and low cost bakery products with improved sensorial characteristics that are appealing to the consumers.”
The Greek researchers note that, while staling of bakery products like bread has been widely researched, investigations into the staling of cakes, “which are complex systems where several ingredients interact with each other affecting their texture, has not been so extensively studied”.
Approaches to slow the staling in cakes include a number of different additives, they added, including hydrocolloids, and native, pre-gelatinized or resistant starch.
Cakes were formulated containing untreated bran and bran treated with endoxylanase enzymes (Pentopan Mono BG provided by Novo Nordisk, Denmark). Both rice and oat bran were used at different levels: 0, 70, and 700 ppm.
Proof in the pudding
Results showed that, after seven days of storage cakes made with the enzyme-modified oat bran displayed measured of staling that were between 50 and 60 per cent reduced, compared to cakes formulated with normal bran.
In addition, cakes formulated with the enzyme-treated rice bran had measures of staling that were between 45 and 50 per cent lower than the control cakes, added the researchers.
“The most antistaling effect was induced with 70 ppm [endoxylanase] treatment of oat bran that allowed a signiﬁcant reduction of 59 per cent in the Avrami constant [a measure of staling], and a signiﬁcant reduction of 25 per cent in the crumb ﬁrming rate constant,” they said. .
When the cakes were tasted by a panel of 32 volunteers, the results showed that products made with the enzyme-modified bran scored higher in both the fresh and stored state than the cakes formulated with untreated bran.
“The results of the study proved that the use of enzymic modiﬁed underutilized sources of bran can be effective in producing cakes with improved nutritional characteristics and extended shelf life,” concluded the researchers.
Source: Journal of Food Science
August 2011, Volume 76, Issue 6, pages S380-S387
“Staling of Cereal Bran Enriched Cakes and the Effect of an Endoxylanase Enzyme on the Physicochemical and Sensorial Characteristics”
Authors: D.M. Lebesi, C. Tzia