ORIGINAL PAPER Rheology of Ice Cream Mix Flavored with Black Tea or Herbal Teas and Effect of Flavoring on the Sensory Properties of Ice Cream Safa Karaman & Ahmed Kayacier Received: 14 April 2011 /Accepted: 18 October 2011 /Published online: 10 November 2011 # Springer Science+Business Media, LLC 2011 Abstract Rheological characteristics and physicochemical properties of ice cream mix flavored with black tea or some herbal teas and sensory profile of flavored ice cream was investigated. In this respect, black tea and three different herbal tea samples (sage, chamomile, and linden) were used to produce a new ice cream formulation. Some physicochemical properties and sensory characteristics of samples were determined. Total phenolic content of ice cream samples increased with the use of tea or herbal teas and it was in the range of 123.37–415.20 mg kg -1 . Incorporation of black tea and herbal tea except chamomile decreased the sensory scores of ice cream compared to control sample. The apparent viscosities of samples were measured as a function of shear rate and consistency coefficient and flow behavior index were calculated by using power law model. All ice cream mix samples showed non-Newtonian pseudoplastic behavior. The apparent viscosities of ice cream mixes treated with no tea at the shear rate of 50 s -1 were 1.13, 0.91, and 0.76 Pa s at 10, 20, and 30 °C, respectively. The activation energy for the viscosity change of the samples ranged between 10.87–20.25 Jmol -1 at 50 s -1 . Keywords Ice cream . Aromatization . Rheology . Tea . Total phenolic content Introduction Ice cream is a frozen dairy product which is composed of milk, protein fortifiers (whey protein concentrate, skim milk powder, etc.), sweeteners, stabilizers, emulsifiers, and flavorings and it is manufactured with pasteurized mix containing ice cream constituents; then aging at low temperature and finally freezing aged mix with the incorporation of air at proper conditions (Frost et al. 2005; Guner et al. 2007a, b). Ice cream is a valuable food containing high nutritive constituents for human health. It has cooling effect, hence it is commonly preferred in the hot summer days by consumers of all ages (Demirci & Simsek 1997). There are many kinds of ice cream available in the market and in the recent years, the researches on ice cream technology focus on the development of new ice cream formulations. Tekinsen (1987) reported that there were 240 different types of ice cream with high quality consumed in any season. There are various studies reported in the literature related to addition of new food ingredients for the development of new ice cream formulations. Different ingredients such as cola extracts (Dervisoglu & Yazici 2001), soy protein (Friedeck et al. 2003), flaxseed oil (Goh et al. 2006), citrus fiber (Dervisoglu & Yazici 2006), and hazelnut skin and flour (Dervisoglu 2006) were studied as a new ingredient for the development of new ice cream formulation with peculiar flavor, taste, and texture charac- teristics. Also, numerous ice cream formulations with functional properties have been developed, for example, probiotic ice cream and yogurt ice cream (Akin et al. 2007; Soukoulis & Tzia 2008), ice cream enriched with dietary fiber (Cody et al. 2007; Soukoulis et al. 2009), and ice cream containing natural antioxidants (Hwang et al. 2009). Black tea and herbal teas are plant products that are consumed as beverage after brewing in hot water. The consumption of black tea or herbal teas is associated with positive health effects. Several studies reported that black tea and green tea possess anticancer, antimicro- bial, and antioxidant properties (Liebert et al. 1999; Weisburger et al. 1998). Many studies have been reported that herbal teas have many important positive health S. Karaman : A. Kayacier (*) Engineering Faculty, Food Engineering Department, Erciyes University, 38039 Kayseri, Turkey e-mail: akayacier@erciyes.edu.tr Food Bioprocess Technol (2012) 5:3159–3169 DOI 10.1007/s11947-011-0713-5