In present study, response surface methodology was used to optimize extraction condition of phenolic compounds from licorice root by microwave application. Investigated factors were solvent (ethanol 80 %, methanol 80 % and water), liquid/solid ratio (10:1-25:1) and time (2-6 min). Experiments were designed according to the central composite rotatable design. The results showed that extraction conditions had significant effect on the extraction yield of phenolic compounds and antioxidant capacities. Optimal condition in microwave assisted method were ethanol 80 % as solvent, extraction time of 5-6 min and liquid/solid ratio of 12.7/1. Results were compared with those obtained by soxhlet extraction. In soxhlet extraction, Optimum conditions were extraction time of 6 h for ethanol 80 % as solvent. Value of phenolic compounds and extraction yield of licorice root in microwave assisted (MAE), and soxhlet were 47.47 mg/g and 16.38 %, 41.709 mg/g and 14.49 %, respectively. These results implied that MAE was more efficient extracting method than soxhlet.

Bread is one of the most widely consumed food products in the world and bread making technology is one of the oldest technologies known. Sensory and nutritional qualities of bread can be affected by the type of ingredients and employed bread making technology. The amount of sweetener addition to produce sweet bread with optimum quality attributes (colour, texture and sensory properties) was investigated using response surface methodology. A central composite rotatable design with three independent variables, the amount of honey (0-10%), sugar (0-14%) and stevia (0-1.5 ml), was used to study the response variables including L* (Y1), a* (Y2) and b* (Y3) for colour, hardness (Y4) and chewiness for texture (Y5), flavour (Y6) and appearance (Y7). Data analysis showed that the addition of honey improved the colour, texture and sensory attributes of sweet bread, while sugar had a negative effect on the colour of bread and stevia considerably improved the sensory properties of the bread. Applying a desirability function method, the optimum parameters were: addition of 6-7% honey, 4-5% sugar and 1.5 ml stevia. This optimum point lead to the production of highly quality bread in respect to colour, texture and sensory properties. The experimental values were very close to the predicted values and were not statistically different (P>0.05).