BACKGROUND: Nowadays, the interest in functional food has dramatically increased. Herbal plants and functional foods have health-enhancing effects on consumers due to their medicinal, antioxidant, and nutritional properties. Probiotics are one of the most emerging and popular functional food products. OBJECTIVES: This study aims to assess the effect of irradiated and non-irradiated saffron petal extract on the viability of Lacticaseibacillus paracasei (M4PM99) in probiotic yogurt.METHODS The ethanolic extract of irradiated saffron petals with a 10 KGy dose of gamma ray at concentrations of 25, 50, and 75 mg/mL and non-irradiated extract at the same concentrations were used and their effect on the viability of Lacticaseibacilus paracasei and their antioxidant and physicochemical properties in set yogurt were studied. Probiotic survival, pH, acidity, content of total phenolic compounds, DPPH inhibition percentage, and sensory properties on days 0, 7, 14, and 21 were assessed.RESULTS: Both irradiated and non-irradiated saffron extracts significantly increased the viability of probiotic bacteria compared to the control sample (P<0.05). The addition of extracts was effective in increasing acidity and decreasing pH compared to the control (P<0.05). With the increase in the amount of extract, the percentage of DPPH inhibition and phenolic compounds significantly increased in the irradiated samples (P<0.05). The effect of storage time was also significant on these indicators, such that the antioxidant properties and phenolic compounds increased until the 14th day and then decreased (P<0.05). In the sensory evaluation, in terms of taste, odor, and color, the lowest score was related to the sample containing 0.75% extract. No significant difference was observed in other concentrations compared to the control sample.CONCLUSIONS: Saffron petal extract has a positive effect on the viability of probiotics during storage. Gamma irradiation has a significant effect on the amount of total phenolic compounds and the antioxidant activity of saffron petal extract. It can be used as a natural antioxidant in dairy products.

BACKGROUND: The use of additives, such as medicinal plants, may result in improved digestion and fermentation and consequently, animal production. OBJECTIVES: The present experiment was conducted to determine the most appropriate amount of Ziziphora cliniopodiodes plant to be utilized in lamb diet and its effect on digestibility, fermentation, growth performance, blood, and quality of carcass and meat. METHODS: Different amounts of Ziziphora cliniopodiodes (0, 0.2, 0.4, 0.6, 0.8, 1 %) were added to diet of lambs. The best diet was selected based on gas production method and fed to male lambs with an average weight of 41 ± 2 kg in a completely randomized design with three treatments and six replications. The selected diets for feeding lambs included: control diet (Ziziphora cliniopodiodes) and control diet supplemented with 0.2 or 0.4 % Ziziphora cliniopodiodes. Feed intake, digestibility of nutrients, fattening performance, blood and rumen fermentation parameters, protozoan population, and certain meat quality indexes were measured. At the end of the experiment, the carcass traits were studied. RESULTS: The obtained results herein revealed that the potential of gas production, partitioning factor, truly degradable organic matter, dry matter intake, apparent digestibility of dry matter, organic matter, crude protein, neutral detergent fiber, acid detergent fiber, glucose, cholesterol, triglyceride, blood urea nitrogen, and protozoa population were not affected by the experimental diets. There was a significant difference among the experimental diets for daily weight gain, the total weight gain of lambs, and microbial biomass production. The highest records belonged to the diet containing 0.2 % Ziziphora cliniopodiodes. Antioxidant characteristics, colorimetric indices, and pH of meat were not affected by the applied treatments. CONCLUSIONS: In general, according to livestock experiments, the best amount of Ziziphora cliniopodiodes to be employed was 0.2 %, which improved certain fermentative and performance traits.