Sensory evaluation and antimicrobial properties of bread enriched with green coffee beans

Recently, the trend of enhancing daily consumed foods with functional ingredients to add supplementary value of foods have been increasing. Bread, being one of the oldest and most popular food in the world, is a sound choice when choosing the food to be supplemented. Research has been done to improve quality, taste, functionality, and bioavailability of food products. Green coffee beans are known for their green color, which is the color of coffee beans prior to roasting. It is said to taste unpleasant and ‘green’ when consumed after being prepared the same way roasted coffee beans are prepared. The aroma is also described as mild, green, and bean-like, which deters many from trying to consume the product. The caffeine content also decreases after roasting, which means green coffee beans contain more caffeine than roasted coffee beans. This experiment is conducted to determine the sensory response of people after consuming green coffee beans incorporated into bread and to study the physiological effect of caffeine incorporated in bread on sensory panel. The bread is baked with three (3) parameters varied which were concentration of green coffee bean powder, time of baking, and baking temperature. The effect of time on bacteria growth is also observed on a petri dish. It is observed that the parameters do indeed have a significance on the antimicrobial properties of bread. The baking time however, holds less significance compared to the temperature and concentration. Higher concentration and lower temperature are the optimal conditions for desirable antimicrobial properties to exhibit. The optimum baking temperature was determined to be 205.27 °C, 37.3 minutes baking time, and GCB concentration of 2.84 wt%. The sensory evaluation of the bread determined that there are indeed some noticeable differences in all aspects of appearance, aroma, taste, and texture. Where the most significant differences would be that the bread with GCB was darker in color, has a more distinctive wood, caramel, and smoke smell, more pungent and less salty but also more bitter, and harder with a stronger aftertaste when compared to bread without GCB.