Effect of baking conditions on the physical properties of bread incorporated with green coffee beans (GCB)

Abstract

Most of nutrients can be found in normal breads but there is lack of antioxidant rich polyphenolic compounds. Green coffee bean (GCB) is chosen as functional ingredients to be incorporated in the bread as it contains high amount of phenolic acid namely chlorogenic acid which contributed to antimutagenic, anticarcinogenic and antioxidant activities. Therefore, GCB was chosen as natural sources in order to enrich the wheat bread with their phenolic antioxidant’s characteristics. The objective of this study is to investigate the effect of concentration of green coffee bean, baking temperature, and baking time on the physical properties of the incorporated bread. The physical properties such as moisture content, volume, colour, and texture were analysed. The data obtained were statistically analysed using Analysis of Variance (ANOVA). The results show that the incorporation of GCB has a positive influence on the physical properties of the bread especially on moisture content and volume. The factors with the largest effect on the moisture content were the baking temperature and GCB concentrations (p < 0.05). The use of high baking temperature causes higher moisture content and volume of bread after baking. While for bread crust and crumb colour, it was observed that increasing the baking temperature and time resulted in dark crust colour and reduced the colour saturation. For crumb colour, the addition of GCB powder caused a slight decreased in lightness and yellowness, whereas the redness of bread was almost unchanged. Nevertheless, the incorporation of green coffee bean had a little influence on the texture of the bread. High hardness of the bread demonstrated from the high baking temperature and high baking time. From optimization process, it could be concluded that the optimum baking temperature was found at 180°C, baking time of 40 minutes and GCB concentration of 1 wt% in order to get the better quality of the bread. In conclusion, GCB has a great potential as functional ingredient in bread. The addition of GCB does not only affect the antioxidant properties of the bread but also increase the quality of the bread itself.