A review on traditional Turkish fermented non-alcoholic beverages: Microbiota, fermentation process and quality characteristics Filiz Altay ⁎, Funda Karbancıoglu-Güler, Ceren Daskaya-Dikmen, Dilek Heperkan Istanbul Technical University, Faculty of Chemical and Metallurgical Engineering, Department of Food Engineering, Maslak, Istanbul 34469, Turkey abstract article info Available online 20 June 2013 Keywords: Shalgham drink Hardaliye Boza Ayran Kefir Lactic acid bacteria Shalgam juice, hardaliye, boza, ayran (yoghurt drink) and kefir are the most known traditional Turkish fermented non-alcoholic beverages. The first three are obtained from vegetables, fruits and cereals, and the last two ones are made of milk. Shalgam juice, hardaliye and ayran are produced by lactic acid fermentation. Their microbiota is mainly composed of lactic acid bacteria (LAB). Lactobacillus plantarum, Lactobacillus brevis and Lactobacillus paracasei subsp. paracasei in shalgam fermentation and L. paracasei subsp. paracasei and Lactobacillus casei subsp. pseudoplantarum in hardaliye fermentation are predominant. Ayran is traditionally prepared by mixing yoghurt with water and salt. Yoghurt starter cultures are used in industrial ayran produc- tion. On the other hand, both alcohol and lactic acid fermentation occur in boza and kefir. Boza is prepared by using a mixture of maize, wheat and rice or their flours and water. Generally previously produced boza or sourdough/yoghurt are used as starter culture which is rich in Lactobacillus spp. and yeasts. Kefir is prepared by inoculation of raw milk with kefir grains which consists of different species of yeasts, LAB, acetic acid bacteria in a protein and polysaccharide matrix. The microbiota of boza and kefir is affected from raw materials, the origin and the production methods. In this review, physicochemical properties, manufacturing technologies, microbiota and shelf life and spoilage of traditional fermented beverages were summarized along with how fermentation conditions could affect rheo- logical properties of end product which are important during processing and storage. © 2013 Published by Elsevier B.V. 1. Introduction Fermented food products play an important role in human diet around the world due to their health benefits. Fermentation is one of the oldest and most economical methods used in food preserva- tion. The earliest records indicate that human were intaking ‘soured milks’ as long as 2000 years ago (Naidu et al., 1999). The beneficiary health effect of fermented milk products on humans was popularized by Elie Metchnikoff, who was a Nobel laureate for his works on con- cept of probiotics (Klaenhammer, 2007). The history of fermentation and modern fermented foods was well summarized by Hutkins (2006). In addition, fermentation enhances mineral bioavailability and the digestibility of proteins and carbohydrates and improves organoleptic qualities of the product (Hancioglu and Karapinar, 1997; Reddy and Pierson, 1994). Lactic acid bacteria (LAB) have been used in various fermented foods. The preservative and health benefits of such traditional foods have been known for a long time (Hutkins, 2006; Klaenhammer, 2007; Naidu et al., 1999). The combination of this ancient method of bio-preservation with the current biotechnology tools should result in controlled fermentation processes and the selection of starter cultures to increase the consumption of fresh-like vegetables and fruits (McFeeters, 2004) and milk and milk-related components. This review aimed to evaluate the microbiota of shalgam drink, hardaliye, boza, ayran and kefir known as traditional Turkish fermented non-alcoholic beverages in terms of their manufacturing technology. Quality characteristics and their affecting factors were summarized along with the spoilage of these beverages. Rheological characteristics of the beverages as a means of quality parameters and how they affected by the fermentation process were discussed for the first time in the literature. 2. Fermented non-alcoholic lactic acid beverages The trends towards natural (minimally processed or without addi- tives), highly nutritional value, health-promoting and flavor rich foods and beverages have been increased with consciousness of consumers. In this context, traditional Turkish fermented non-alcoholic beverages have been taking great attention from researchers and consumers re- cently due to their probiotic characteristics. The physicochemical prop- erties, manufacturing technology, microbiota and spoilage of shalgam juice, hardaliye, boza, ayran and kefir were reviewed in this section, respectively. International Journal of Food Microbiology 167 (2013) 44–56 ⁎ Corresponding author. Tel.: +90 212 2856948; fax: +90 212 2857333. E-mail address: lokumcu@itu.edu.tr (F. Altay). 0168-1605/$ – see front matter © 2013 Published by Elsevier B.V. http://dx.doi.org/10.1016/j.ijfoodmicro.2013.06.016 Contents lists available at ScienceDirect International Journal of Food Microbiology journal homepage: www.elsevier.com/locate/ijfoodmicro