Quality Properties of Husk Tomato Juice and Its Impact in Stirred Probiotic Yogurt

Background: Thinking about something new that is important for consumer health is a great concern to all those interested in the dairy industry and its products. Husk Tomato is a promising nutritious fruit rich in minerals, vitamins, and antioxidant compounds.

Aim: The objective of this study is to evaluate Husk Tomato Juice (HTJ) constituents, its antimicrobial activity and antioxidant properties. Then utilize it for producing stirred probiotic yogurt (SPY) as a novel fermented product.

Methodology: The main components and sugars of fresh HTJ were analyzed using High Performance Liquid Chromatography (HPLC). Antioxidant activity by DDPH (2, 2-diphenyl-1picrylhydrazil) test as well as total phenolic compounds were also determined. Four treatments of SPY fortified with 20, 30, 40 and 50% (v/v) HTJ & Lb. casei FEGY9973 (as probiotic bacteria) were prepared and served as T1, T2, T3 and T4 respectively were compared against control without juice.

Results: Data revealed that the main compounds of HTJ were Sinapic (8.170 µg/ml), Protocatechuic (6.344 µg/ml) and Cinnamic (4.660 µg/ml). Contents of Fe, Mg, Na and Ca were 1.766, 1.627, 7.436 and 12.14 mg/100 g. Antioxidant activity and total phenolic compounds of fresh HTJ were 68.88% and 319.15 ppm respectively. It was found that HTJ had powerful antimicrobial activity against both of Y. enterocolitica and Ent. faecalies. On the other hand, data revealed that the antioxidant activity of fresh SPY samples were significantly (p<0.05) higher 67.66, 76.93, 69.34 and 69.59% for T1, T2, T3 and T4 in order, compared to control sample (66.57%). While, appearance scores had no significant (p>0.05) for all samples in fresh, 5 and 10 days of storage. All treatment samples possessed acceptable sensory properties.

Conclusion: It could be conducted that SPY fortified with 20 and 30% HTJ had been successfully produced as a healthy dairy product.