Demands for bread of consistent quality with a long shelf life have led to the use of additives in products, including emulsifiers, enzymes, reductants and antioxidants.
Datem emulsifiers (diacetyl tartaric esters of mono-glycerides) are been used to improve bread volume, texture and dough stability. However the researchers, from the University of New South Wales in Australia, say there is more interest in using enzymes instead, since the enzymes are denatured in baking and are not detectable in the finished products. This means they can be used in ‘clean label’ products that do not list E numbers (additives) on the ingredients list.
Moreover, Datem enzymes are said to have certain drawbacks: during storage and transportation Datem tends to cake. Although this can be avoided by use of a gel, the gel loses its efficacy over time.
For the study accepted for publication in the Elsevier journal Food Chemistry, the research team set out to test claims that Datem emulsifiers can be partially or totally replaced with lipase enzymes, which have fungal or bacterial sources and hydrolyse triglyceride esters to produce mono- or do- glycerides, glycerol and free fatty acids.
They baked loaves with white wheat flour using a Datem and three different generations of lipase enzymes of commercial quality, which have slightly different actions.
The first generation enzymes were Novozyme’s Lipopan 50-BG and Danisco’s Gryndamyl Excel 16, used at levels of 27.5ppm and 115ppm respectively. The second generation enzyme was Lipopan F-BG, used at 15ppm; and the third was Lipopan Xtra-BG, at 27.5ppm.
The Datem was Danisco’s Panodan A2020, at a level of 4500ppm.
Recipe and testing
The researchers’ recipe included 1000g of white wheat flour, 20g salt6, 650g water. 10g instant dry yeast, 30g sucrose, 16g malt flour and 500 ppm ascorbic acid.
Trails were made using short and long fermentation periods. For the short methods, the dough was put in a prover at 40ºC at 80 per cent humidity until height in the 350g tins reached 10.3cm (around one hour). In the long method the temperature was 30 ºC for around 150 minutes (until it reached the same height), and the dough was punched 42 and 87 minutes in.
The loaves were baked at 210ºC for 30 mins, after which they were analyses for bread volume, crust colour, crumb texture and colour, oven rise and flavour and aroma.
The team concluded that both the Datem and the enzymes led to a significant increase in rise and volume, with the exception of Lipopan 50-BG, which did not improve loaf volume when short fermentation was used.
With the longer fermentation time however, the Datem and all the enzymes except Lipopan-Xtra were seen to increase volume.
The researchers did say, however, that although the trials were done in duplicate and should be replicable, the function of bread improvers differs according to flour types, processes and formulation.
“Therefore, application of the test enzymes to a particular process requires optimisation of the dosage. Optimisation for each flour type and baking procedure can be gained through further baking trials.”
Food Chemistry (Elsevier), published online ahead of print
“Bread improvers: comparison of a range of lipases with a traditional emulsifier”
Authors: S. Moayedallaie, M. Mirzaei and J. Paterson