An evaluation of effect of Camellia sinensis (Black & Green Tea) and Hibiscus sabdariffa (Sour Tea) on Klebsiella pneumoniae and Salmonella typhimurium in plain ice cream

Abstract

Introduction: The increased foodborne diseases and food poisoning, as well as its health problems, have led to the development of studies on the use of new antimicrobial agents. Functional foods are the topic of interest in this regard. Among the functional foods, natural food additives have attracted the attention of consumers. Objective: The aim of this study was to evaluate the effect of Camellia sinensis (Black & Green Tea) and Hibiscus sabdariffa (Sour Tea) on Klebsiella and Salmonella in ice cream. At the same time, by improving the sensory properties of the product, a step towards increasing the health of the community and the production of novel products using a natural additive. Materials and Methods: Evaluation of antioxidant, antimicrobial and sensory properties of, Green, Black and Sour tea extracts (4%, 4.5%, 10%) in ice cream examined for 90 days. Half-McFarland standard was used to concentration 1.5×108 CFU/ml of Klebsiella pneumoniae and Salmonella typhimurium in icecream. For bacterial counting surface cultivation method was used. For evaluation of anti- oxidant activity of (4%, 4.5%, 10%) of Green, Black and Sour tea extracts were prepared and measured by DPPH method respectively. All tests were performed in 3 replications. Statistical analysis was performed using SPSS software. Significant statistically difference was also determined at the level of 0.05. Results: Antioxidant activity of ice cream samples significantly increased by adding green, black and sour tea extracts with different percentages (4%, 4.5%, 10%) (p<0.05). Different percentages of tea extract during 90 days of cold storage reduced the number of Klebsiella pneumoniae and Salmonella typhimurium in plain icecream. Conclusion: The results obtained in this study showed that green, black and sour tea extracts had high antioxidant and antimicrobial properties that can be used in the food and drug industry for human health. The antimicrobial and antioxidant activity of the sample containing 4% green tea extract was higher than other treatments. Also, adding 10% sour tea creates the best taste in plain ice cream. Therefore, results of this study showed high antioxidant and antimicrobial activity against Klebsiella pneumoniae and Salmonella typhimurium in icecream formulations.