In the study published in LWT Food Science and Technology, researchers replaced whole egg yolk with three granule mixes in gluten-free muffins to study the nutritional and functional impact.
The researchers used the granular fraction of egg yolk – rather than the plasmatic fraction – because of its low cholesterol levels and good emulsifying properties.
Findings showed cholesterol levels could be slashed by around 75%.
Muffins made using whole egg yolk contained 463.17 mg cholesterol per 100 g of batter but when replaced with 100% granules, this dropped to 107 mg/100 g.
Using 60% granules as a replacement decreased cholesterol levels even further to 64.182 mg/100 g.
Fat levels were also reduced using 100% granules, with total lipids down to 26.08 mg/ 100 g compared to 27.83 mg/100 g when using a whole yolk.
Such cholesterol reductions were important in gluten-free bakery, the researchers said, particularly those products made using eggs because of the high caloric content. Whole yolks, they explained, were made up of 33% fat.
“For this reason, in order to make dietary recommendations, the total amount of fat and cholesterol consumed must be taken into consideration and therefore the elaboration of low-fat and cholesterol egg-dependent recipes is desirable.”
It was the granular fraction of the egg yolk, the researchers said, that enabled such reductions. “This fraction has been used previously in the elaboration of mayonnaise recipes as a substitute for whole egg yolk, maintaining the functional and organoleptic properties and reducing the cholesterol and saturated-fat content.”
However, the researchers said there were some textural differences to overcome despite batter rheology remaining similar when using egg yolk granules.
“During the cooking process, the higher protein content and the reduction in lipids of this egg yolk fraction produced noticeable changes in the viscoelastic behavior of the batter due to the interactions promoted by these granular components,” they said.
“This effect was translated to the cooked muffin in form of a bakery product which exhibits more hardness and some color differences in comparison to the whole egg yolk recipe.”
They said acceptability tests should be performed to see if the hardness in the muffins was negatively perceived by consumers.
Source: LWT Food Science and Technology
Published online ahead of print, doi: 10.1016/j.lwt.2014.08.031
“Egg yolk granules as low-cholesterol replacer of whole egg yolk in the preparation of gluten-free muffins”
Authors: I. Marcet, B. Paredes and M. Diaz