Optimization of a Nutritious Liquid Seasoning Based on Lemon Extract and Phenolic Compounds of Lemon Waste, Including Gellan, Xanthan and Pectin Hydrocolloids

 The objectives of this study were to produce a nutritious stable condiment with uniform quality based on lime juice that could improve the quality of commercial lime juices in food products and investigate independent effects and interactions of hydrocolloids on the final product.

Novel formulations were developed by adding two types of gums, including gellan gum (0–0.1%), xanthan (0–0.1%) with pectin (0–0.2%) and phenolic compounds (constant) extracted from lime pulp wastes to the emulsion part of the final product. Seventeen combined treatments were reported by central composite rotatable design and physicochemical characteristics (flavonoids, antioxidant activity, viscosity, physical instability) and sensory characteristics (stability and general acceptability) have been analyzed. 

 Independent effects of the three hydrocolloids on the level of antioxidant activity were verified as the most significant coefficient in the final model belonged to pectin. All the three gums showed negative independent effects on the level of physical instability and no interactions were seen. The 2F1 statistical model was suggested for the viscosity parameter. Thus, each additive positively affected viscosity and negative interactions between pectin and gellan were verified. Moreover, sensory analysis data showed that by increasing the quantity of gellan, the degree of stability and overall acceptance of the product decreased, significantly.

 Due to the negative interactions between gellan and pectin and its adverse effects on the sensory characteristics, the current statistically optimal formulation was developed and suggested without gellan, containing xanthan and pectin with maximum desirability.