Investigation the effects of adding carrot pomace and stevia in the formulation of tomato sauce on its quality

Agricultural wastes and food industry’s byproducts are such a high valuable sources of nutrients which unfortunately, they are omitted without any usage or consumed as feeds. On the other hand, huge amounts of bioactive components like dietary fiber in fruit or vegetable pomace after juicing are considered as waste whereas a lot of researches confirmed their various health effects. Carrot pomace is full of dietary fiber and beta-carotene which can be used for food enrichment, hence this research is studied the possibility of applying carrot pomace along with low calorie sweetener, Stevie, in formulation of tomato sauce.

After juicing the carrots, pomace well dried, milled and it was evaluated for moisture, pH, ash, total fiber, particle size and aw. It was used at 0, 10, 20 and 30% and Stevie at 0, 50, and 100% in the formulation of tomato sauce. For studying the effects of these materials on quality of tomato sauce, some properties such as moisture, pH, consistency, apparent viscosity, calorie, colorimetric indices (L*, b*, a* and TCS), syneresis, mold and yeast colony count and sensory evaluation were measured. Also all of the properties were monitored during storage at days 0, 15 and 30.

The results showed that using of carrot pomace increased pH, apparent viscosity and consistency, significantly and on the other hand, it caused to decrease in moisture, syneresis and mold and yeast colony count in tomato sauce samples (p≥0.05). Also, the colorimetric indexes such as, L*, a* and TCS decreased while b* increased due to present of carrot pomace. It is noticeable that because of low amounts of stevia used in the formulations, instead of lowering manner in calorie, its variation wasn’t significant (p>0.05) and adding stevia hadn’t any side effects on qualitative parameters of tomato sauce samples.Also, the colorimetric indexes such as, L*, a* and TCS decreased while b* increased due to present of carrot pomace. It is noticeable that because of low amounts of stevia used in the formulations, instead of lowering manner in calorie, its variation wasn’t significant (p>0.05) and adding stevia hadn’t any side effects on qualitative parameters of tomato sauce samples.

According to studied parameters and their variations during one month, and specially the results of sensory evaluation, it can be concluded that using of carrot pomace at less than 10% along with stevia, is recommended for the formulation of tomato sauce.