Abstract—The consumption of functional foods is very common. For this reason, many products which are probiotic, prebiotic, energy reduced and fat reduced are developed. In this research, physicochemical and microbiological properties of functional kefir, kefir yogurt and chickpea yogurt were examined. For this purpose, pH values, titration acidities, viscosity values, water holding capacities, serum separation values, acetaldehyde contents, tyrosine contents, the count of aerobic mesophilic bacteria, lactic acid bacteria count and mold-yeast counts were determined. As a result of performed analysis, the differences between titration acidities, serum separation values, water holding capacities, acetaldehyde and tyrosine contents of samples were statistically significant (p < 0.05). There were no significant differences on pH values, viscosities, and microbiological properties of samples (p > 0.05). Consequently industrial production of functional kefir yogurt and chickpea yogurt may be advised. Keywords—Chickpea yogurt, kefir, kefir yogurt, milk. I. INTRODUCTION ILK is a nutrient that has many ingredients for growing and developing of the organism and ensuring continuity of life [1]. The consumption of dairy products is very important because of the absence of alternative products [2]. Vitamin A, Vitamin D, calcium and phosphorus contents of milk are very high [3]. For this reason, milk and other dairy products are one of the most important foods that should be consumed. Drinking milk which is obtained by raw milk is at the first subgroup of dairy products. Yogurt and ayran are at the second subgroup and cheeses such as white cheese, Kasar cheese, Cokelek, Lor cheese (traditional Turkish cheeses) etc. are at the third subgroup. Butter is at the fourth subgroup, milk powder is at the fifth subgroup and lastly ice cream is at the sixth subgroup [4]. Yogurt is the most produced milk product subsequent to cheese [5] and the most demanded yogurt type is plain yogurt in Turkey. However, fruity and flavored yogurt types are generally preferred at western countries [6]. It is important to investigate dairy product varieties. These researches are generally about functional and natural products [7]-[12] Kefir yogurts and chickpea yogurts may be examples for these products. However further scientific researches about these are required. According to Turkish Food Codex Fermented Milk N. Güzeler is with Cukurova University Agricultural Faculty Food Engineering Department, Adana, Turkey (corresponding author, phone: +905325570179; e-mail: nsahan@cu.edu.tr). E. Arı, G. Konuray, and Ç. Özbek are with Cukurova University Agricultural Faculty Food Engineering Department, Adana, Turkey (e-mail: ari.elif33@gmail.com, gkonuray@cu.edu.tr, cglaayldrm@gmail.com). Products Notification, kefir is a fermented dairy product and kefir culture ferments lactose by different strains of Lactobacillus kefiri, Leuconostoc, Lactococcus and Acetobacter [13]. The distinguishing property of kefir with other fermented dairy products is producing of it by kefir grains which are biologic and live organisms [14]. Kefir is a source of Vitamin B 1 , Vitamin B 12 , Vitamin K, calcium, amino acids, folic acid and biotin [15]. In the formation of kefir, microorganisms break down proteins in milk into peptone, peptide and aminoacids and lactose into lactic acid and alcohol. Final product can be easily digested [16]. The lactose content of kefir is lower than milk. For this reason, kefir may be a good solution for people who have lactose intolerance [17], [18]. In last years, kefir yogurt is produced by fermenting milk with kefir culture and incubating at 44 ℃. Kefir yogurt has taken place in the markets with name of Yofir which is produced in Güney Milk plant in the Mediterranean region of Turkey in 2016. The inoculum amount and incubation time are higher for this product. Chickpea yogurt is another new functional and enriched milk product. For enrichment purpose, chickpea (Cicer arietinum), which is a legume of the family Fabaceae, subfamily Faboideae, is used [19]. The protein, mineral, vitamin and dietary fiber contents of chickpea are very important [20]. There is no scientific research about production of fermented milk product by directly using chickpea. However, there are some researches about fermented milk products that were produced by using chickpea extracts. In a research, chickpea which was kept in water at room temperature for one night is grounded. After this mixture was filtered, it was mixed with milk with 1:1 ratio and fermented with 6% of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. Finally it was reported that using chickpea in yogurt production leads to obtain a product with high nutritional value [21]. In another research, enriched yogurt which has high nutritional value and biological quality was produced by adding chickpea extract to cow and camel milk. As a result of this research, it was reported that these yogurts may be evaluated as functional food in food industry [22]. The information about production of yogurt (fermented milk) by using chickpea was introduced at press and it became more common in last years. However there is no industrial production of this product [23]-[25]. In this research, kefir, kefir yogurt and chickpea yogurt were produced in three replications and their pH, titration acidities, viscosities, serum separation amounts, water holding capacities, acetaldehyde contents, tyrosine contents, aerobic mesophyll bacteria counts, lactic acid bacteria count, mold and Physicochemical and Microbiological Properties of Kefir, Kefir Yogurt and Chickpea Yogurt Nuray Güzeler, Elif Ari, Gözde Konuray, Çağla Özbek M World Academy of Science, Engineering and Technology International Journal of Nutrition and Food Engineering Vol:13, No:7, 2019 189 International Scholarly and Scientific Research & Innovation 13(7) 2019 ISNI:0000000091950263 Open Science Index, Nutrition and Food Engineering Vol:13, No:7, 2019 waset.org/Publication/10010536