Journal of Food and Nutrition Research, 2020, Vol. 8, No. 10, 575-584 Available online at http://pubs.sciepub.com/jfnr/8/10/6 Published by Science and Education Publishing DOI:10.12691/jfnr-8-10-6 Extended Storage of Yoghurt by Using Water Extract of Coriander Seeds Qaswaa Yousif Jameel 1 , Nameer Khairullah Mohammed 2,* 1 Department of Food Science, Colleges of Agricultural and Forestry, Mosul University, Mosul, Iraq 2 Department of Food Science, College of Agriculture, Tikrit University 3400, Tikrit, Iraq *Corresponding author: Received September 16, 2020; Revised October 18, 2020; Accepted October 25, 2020 Abstract The objective of this study was to evaluate the effects of coriander seed extract on the chemical and sensory properties of yoghurt during storage. Coriander seed extract was incorporated in yoghurt at different concentrations, 18 mg/ml (T1C1), 36 mg/ml (T2C2), and 54 mg/ml (T3C3), while a sample without extract (T0C0) was used as a control. Samples were stored at 4°C and were assessed every seven days. The values of lactose, fat, pH, protein, tyrosine, acid degree value, acid value, free fatty acid, and sensory properties for all samples containing extract give higher scores than those of yoghurt without extract. Chemical and sensory evaluations of the yoghurt without plant extract revealed a significant degradation beyond days 28 of storage due to high acidity, and an unpleasant flavour. By contrast, the concentrations of 18, 36 and 54 mg/ml, were shown to have remarkable preservation activity in yoghurt at 42 days. The formulation T3C3, fortified with coriander seed extract at 54 mg/ml, had the highest value in preserving the chemical properties of yoghurt after 42 days, compared with formulas T1C1 and T2C2, which contained 18 mg/ml and 36 mg/ml respectively. Results suggest that coriander extract can be added to dairy products as a natural food preservative, to improve stability during storage. Keywords: coriander seeds, water extract, yoghurt, natural preservative, storage period Cite This Article: Qaswaa Yousif Jameel, and Nameer Khairullah Mohammed, “Extended Storage of Yoghurt by Using Water Extract of Coriander Seeds.” Journal of Food and Nutrition Research, vol. 8, no. 10 (2020): 575-584. doi: 10.12691/jfnr-8-10-6. 1. Introduction Fermented dairy products are considered to be rich in nutrients and in probiotics, which have a promising potential for cancer prevention and management [1]. Yoghurt is a fermented dairy product with significant nutritional benefits; it is a world-famous functional food product that provides a sufficient number of viable probiotic bacteria; these are important in assessing yoghurt 's health enhancing properties [2]. It not only protects against osteoporosis, but also enhances intestinal microbiota and supports digestion [3]. Spices have been used traditionally as colouring agents, flavouring agents, preservatives and food additives [4]. Coriander (Coriandrum sativum L.), which belongs to the Apiaceae family, is a seed of annual small plants harvested before flowering; it is usually referred to as cilantro or Chinese parsley, and is a worldwide valuable crop of vegetables. Coriander has high levels of nutrients, and is high in Carotene and Vitamin C [5]. Coriander is an edible vegetable, and its seeds can be used as spices; it also contains many ingredients with high medicinal value [6]. Coriander seeds contain potent antimicrobial agents against foodborne pathogens [7]. The qualitative bioactive analysis of the constituents of the ethanolic extracts of coriander showed the presence of specific phytochemicals such as steroids, flavonoids, saponin, tannin, alkaloids, coumarin and anthocyanin [8]. Many studies have identified its biological properties and pharmacological actions in some human pathologies [9], such as hypocholesterolemic and antioxidant effects [10]. Coriander seeds contain thymoquinone, phenolic acids and diosgenin [11], including chlorogenic acid, caffeic acid and kaempferol [12]. Yoghurt cannot be stored beyond 21 days at refrigeration temperature, due to bacterial spoilage; this can endanger people’s health [13]. Cooling temperature and storage time have significant effects on the quality of natural yoghurts [14]. Improper storage conditions lead to a decrement in the nutritional value and give rise to deterioration of sensory characteristics of yoghurts [15]. Storage temperature may cause a change in the number and mutual proportions of lactic acid bacteria to the typical composition for the yoghurt, thus to its acidification and pH [16]. The recommended storage temperature of yoghurt ranges from 1°C to 8°C, but its stability may be extended by storing at 4°C or less during the whole shelf life [17]. The easiest and most efficient way of prolonging food shelf-life is to use natural or artificial preservatives; however, evidence indicates that most artificial preservatives damage the human body in various degrees [18]. In addition, certain chemical preservatives have a certain effect on the sensory quality