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Effects of water and salt level on rheological properties of ayran, a Turkish yoghurt drink
Abstract
Ayran is a yoghurt drink traditionally manufactured by mixing yoghurt with water and salt. The effects of different levels of water and salt on the rheological properties and serum separation during storage of traditionally manufactured ayran were investigated. Ayran samples were prepared by the addition of water at levels of 30 or 50 g 100 g−1 and salt at levels of 0, 0.5 or 1 g 100 g−1 and stored at 4°C. All samples exhibited non-Newtonian behaviour with shear-thinning and slight thixotropy was observed in some of the 30 g 100 g−1 water-containing samples. The rheological properties of ayran samples were determined by using the power law model. The consistency coefficient decreased and the flow behaviour index increased dramatically with increasing levels of water and salt. Increasing the levels of added water and salt resulted in more serum separation. Proper adjustment of the amount of water and salt during the manufacture of ayran was necessary to obtain optimum consistency and to prevent serum separation during storage.
... Serum separation occurs as a result of the precipitation of casein micelles by forming aggregate. In this regard, Köksoy and Kılıç (2003) have asserted that increasing water and salt levels in the composition of ayran enhance serum separation. Moreover, Gursoy et al. (2016) have reported that developing acidity throughout the storage of ayran triggers whey separation. ...
... Yogurt powder is used in a wide variety of food products as a nutritional supplement, texture enhancer, and flavor improver (Koç et al., 2010;Song and Aryana, 2014). Another advantage is that yogurt powder can be used by diluting it at the desired rate in the production of ayran, which has a very short shelf life (15-30 days) (Köksoy and Kılıç, 2003;Soysona Ar and Ocak, 2022). ...
... For this analysis, ayran samples were stored in 50 mL graduated cylinders at 4 °C for 28 days. Serum separation was calculated by the volumetric proportioning of the whey separated at the top and the results were provided as a percentage (%) (Köksoy and Kılıç, 2003). ...
To extend the shelf life of yogurt and to use it in different formulations, a drying process is performed. Among the drying processes, lyophilization comes to the forefront in terms of preserving the properties of dried products at a high level. In this study, the effect of different lyophilization pressures (0.5 and 1.0 mbar) on the physicochemical properties of reconstituted ayran samples (0.5A and 1.0A) was investigated during 28 days of cold storage. Besides, sensory analyses of the reconstituted ayran samples were also performed. The outcomes were compared with the ayran produced directly (control). According to the results, serum separation increased more in reconstituted samples, however, syneresis declined with decreasing lyophilization pressure. The highest viscosity was determined in the control sample (6.97 mPa.s), followed by 0.5A (5.56 mPa.s) and 1.0A (4.66 mPa.s), respectively. Consequently, the increased lyophilization pressure negatively affected the physicochemical and sensorial properties of reconstituted ayran.
... bulgaricus to standardized milk for fermentation (Altay et al. 2013). Ayran is drunk as a refreshing (Köksoy and Kılıç 2003), especially in summer season (Altay et al. 2013). ...
... New bottles were used for each day. Commercially produced ayran has a shelf life of 10-15 days (Köksoy and Kılıç 2003) to one month (Baruzzi et al. 2016) at 4°C. On the other hand, the shelf life of traditionally produced shalgam is limited to three months at 4°C; however, this period could be prolonged by heat pasteurization or use of preservatives (Erten et al. 2008) for commercially produced shalgam. ...
... Serum separation was monitored by using the method of Köksoy and Kılıç (2003). All the mixtures individually were placed in 50 mL of graduated cylinders for 28 days and the volume of separated serum was recorded at each week. ...
Ayran, a dairy-based fermented beverage, and shalgam, a plant-based fermented beverage were mixed [25% ayran + 75% shalgam (v/v), 50% ayran + 50% shalgam (v/v) and 75% ayran + 25% shalgam (v/v)] and rheological data were obtained at different temperature levels (4–12 °C). Power law model was used to describe the data. Temperature had no effect on the flow behavior index, but it affected the consistency index of the mixtures. Ayran–shalgam mixtures had similar flow behavior index with that of shalgam irrespective of the levels of ayran or shalgam. However, consistency index increased as the amount of ayran increased in the mixtures at a constant temperature. Mixture with the higher amount of ayran [75% ayran + 25% shalgam] had the highest scores in sensory evaluation. Shelf life analyses up to 4 weeks at 4 °C indicated that serum separation increased till the second week and then stabilized for all mixtures. Slight increase (0.05–0.1 unit) in pH was observed during the first week then pH values were stabilized just like the serum separation. Microbiological analyses revealed that mixtures had a similar shelf life with that of ayran. Consequently, mixture of two different fermented beverages could be possible with similar flow behavior and shelf-life, and ayran–shalgam mixture has a huge potential for commercial production. This study may be a basis for designing new products to fulfill the healthy diet demands.
... It has special concern in Iran due to its healthy properties, although the interactions among various constituents like proteins and lipids electrolytes need to be well balanced so that a stable system evolves. As it has been mentioned by Foroughinaia et al. (2007) and Koksoy and Kilic (2003), the main physical problem of Doogh is the serum separation due to its low pH and presence of salt in this type of dairy based drinks, which leads to aggregation of caseins. Therefore, compounds like gums, which are called hydrocolloid, are common additives being used to prevent phase separation in Doogh (Ziaolhagh and Jalali 2017;Foroughinaia et al. 2007;Azarikia and Abbasi 2010;Koksoy and Kilic 2004). ...
... As it is shown in Fig. 2c, viscosity of Doogh samples was in the range from 33.2 to 41 mPa s which was in agreement with the results of Koksoy and Kilic (2003) and Shirkhani et al. (2015). . This wide range of reported viscosity can be attributed to the different fat, protein and dry matter content of the Doogh samples produced in other research, the different measurement conditions of viscosity including the shear rate, temperature and spindle number used, effects of processes such as homogenization and pasteurization as well as the presence or activity of probiotic bacteria and prebiotic compounds. ...
... However, the reported value for viscosity of Doogh in published research is very wide and ranges from 2 to 400 mPa s(Foroughinaia et al. 2007;Hasheminya et al. 2013;Azarikia and Abbasi 2010;Joudaki et al. 2013;Gonzalez et al. 2011;Koksoy and Kilic 2003;Shirkhani et al. 2015) ...
The objective of this study was to determine the effects of using ginger extract and gum arabic as a prebiotic on the viability of Bifidobacterium bifidum and physico chemical properties of Doogh (yogurt drink) during storage at 4 °C for 30 days. The results showed that by increasing the amounts of gum arabic to 0.5%, B. bifidum count increased significantly (P < 0.05), but further increasing of the gum arabic, had no significant effect on B. bifidum count (P > 0.05). By increasing the amounts of gum arabic, the viscosity of the Doogh samples was increased and phase separation was reduced significantly (P < 0.05). The Doogh sample containing 0.25% gum arabic and 0.25% ginger extract had the highest number of probiotic population. Results showed that addition of B. bifidum increased acid development (°D) in Doogh samples during storage. In addition, phase separation in Doogh enriched by gum arabic was slower compared to control sample and the samples containing ginger extract. Doogh samples containing 0.25–1% gum arabic alone showed acceptable stability during storage time at 4 °C. In general, Doogh sample containing 0.25% ginger extract and 0.5% gum arabic gained the highest overall acceptability score in comparison with the other samples.
... To examine serum separation, ayran samples were stored in sterile 50 mL graduated cylinders at 4 °C for 21 days. At each analysis day of the storage period, the volume of the whey separated at the top was recorded and the percentage (%) of serum separation was calculated by dividing this separated portion to the whole ayran volume [29]. ...
... However, in this study, the resulting data for all viable cell counts comply with the Turkish Food Codex, in which the minimum number of specific microorganisms in fermented milk products is accepted as 10 7 CFU mL −1 [64]. Generally, the shelf life of ayran is between 10 and 20 days under cold storage conditions [29]. In this respect, it may be recommended to use C. crispus or C. crispus and C. vulgaris together to extend the shelf life of the ayran due to their potential positive effects on yogurt bacteria. ...
Considering the high consumption rate of fermented milk products, the fortification of these products will increase their nutritional and functional values, thereby contributing to the protection and improvement of human health. Regarding this, algae are utilized as innovative supplementation sources that provide precious nutritional and functional components. This study aimed to evaluate 0.25% Chondrus crispus, 0.25% Chlorella vulgaris, and 0.25% of their mixture (w:w) in ayran production. To that end, the physicochemical and microbiological properties of experimental samples were investigated during the 21 days of cold storage period. Besides, the fermentation process and sensorial properties of samples were evaluated. The use of 0.25% C. vulgaris and 0.25% algae mixture shortened the fermentation time by 30 min. With the supplementation of 0.25% C. vulgaris, the protein and fat contents of ayran samples increased by 43% and 34%, respectively. The viscosities of the samples containing C. vulgaris were found to be higher. Samples containing algae maintained a higher rate of yogurt bacteria as compared to the control during the cold storage period. All sensory scores of all ayran samples decreased with the addition of algae. However, among samples containing algae, the sample containing both C. vulgaris and C. crispus had a slightly higher overall acceptability score. Overall, it can be concluded that the mixture of C. vulgaris and C. crispus or just C. vulgaris can be used as natural ingredients in the production of novel ayran with improved technological, microbiological, and nutritional properties.
... Ayran as of a fermented dairy product is the second most widespread consumed and liked product after yoghurt in Turkey. It is traditionally prepared by diluting yoghurt with water at a level of 30-50% (Köksoy et al., 2003); it is also be industrially produced by the fermentation of the milk standardized to 8% dry matter content, the addition of yoghurt starter culture and table salt at a maximum level of 1%. Although plain ayran as a national dairy beverage has several advantages like better nutritional value, easy digestion, refreshing effect, and satisfying thirstiness, the preference of consumer turns toward carbonated beverages at restaurant and hotels during the summer compared to fermented dairy beverages. ...
... Fat contents of ayrans with powdered peppers were significantly higher than that of sliced pepperadded and control samples. The mean fat ratio in the ayrans with peppers was similar to those previously reported by Köksoy and Kılıç (2003). The effect of pepper form and concentration did not significantly affect the protein contents of ayrans (p>0.05). ...
Cayenne peppers (Capsicum annuum L.) were incorporated to ayran aiming to obtain a health promoting ayran with different flavour. The effects on the physico-chemical characteristics, antioxidant and phenolic capacity, counts of Streptococcus, Lactobacillus, yeast, moulds and coliforms, sensory and volatile compounds analysis were performed. Ayran samples with powdered peppers had significantly higher antioxidant and total phenolic contents than the ayrans with sliced pepper. Pepper addition increased Lactobacillus and Streptococcus counts compared to control ayrans. The dominant bacteria during the storage period (7.61-8.88 log CFU/ml) was Streptococcus. Panelists rated flavour, texture, appearance and color properties of ayran samples with sliced pepper similar to control samples. Ayran samples with 15% sliced peppers had the maximum overall scores.
... Syneresis measurement. The syneresis index of different samples was determined according to the methodology proposed by Koksoy and Kilic [34]. Dinking yogurt (40 g) was weighed in sterile scaled plastic containers and the samples were stored at 4°C. ...
... Dinking yogurt (40 g) was weighed in sterile scaled plastic containers and the samples were stored at 4°C. After 28 days of storage at 4°C, a clear layer of serum, in case of having serum, was separated by Pasteur pipettes and it was weighed and the percentage of serum separation was calculated [34]. ...
Milk and dairy products have a rich nutritional value and they are the main constituents of a human diet. In recent years, the consumption of dairy drinks containing water, sugar syrups and flavorings has been common. So it is important to find a natural alternative sweetener to remove sugar. Therefore, the purpose of this study is to produce flavored drinking yogurt with natural sweeteners like date syrup and fig syrup as a sugar substitute. The study was made of the comparing physicochemical properties and also of opinions about the general acceptance of flavored drinking yogurt with date and fig syrups. The physicochemical properties such as pH, titratable acidity, viscosity, total solid, syneresis and the sensory evaluation of samples were determined weekly at 4°C for 28 days. The results showed that the samples that contained fig syrup had a lower acidity and syneresis percentage while their viscosity was higher compared to the samples that contained date syrup. It can be concluded that flavored drinking yogurt with 10% fig syrup and 1% pectin was chosen as the best treatment since it was rated the highest in general acceptance compared to other samples
... 'Synbiotic' refers to a synergism between probiotics and prebiotics. Adding of hydrocolloid prebiotics such as inulin [14] may improve the consistency by reducing the syneresis (serum separation) which is a common occurrence during storage of ayran [15]. In general, a functional food product design considers several aspects, such as functional properties of the product, sensory appeal, shelf-life, physicochemical stability, health claim approval and safety evaluation [16]. ...
... In the case of liberation of sodium ions into the medium, increased sodium may stimulate the separation of the serum in ayran and reduce the system stability. An increased amount of sodium was reported to be a stimulator of syneresis [15]. However, sodium content in all samples measured during storage complied with the declared salt content in the conventional product of 0.4%, indicating good stability of the functional ayran samples. ...
This study aimed to develop a probiotic/synbiotic ayran with a sufficient number of live bacteria Lactobacillus casei 01 (L. casei 01) during the product shelf-life. Under conditions of refrigerated storage for 15 days, probiotic survival and organic acid (lactic, acetic, propionic and butyric acid) production were evaluated. Simultaneously, pH, titratable acidity, total solids, and carbohydrate, protein, fat and mineral contents of the samples were examined. Overall results of the chemical analyses indicated the quality of the prepared samples to be comparable with the conventional ayran used as a matrix for probiotic/synbiotic supplementation. L. casei 01 survived better in ayran containing synbiotic chitosan–Ca–alginate microparticles compared to samples enriched with non-encapsulated probiotic alone or with synbiotic (L. casei 01 + oligofructose-enriched inulin), followed by increased production of lactic, acetic and propionic acid. Probiotic/synbiotic ayran may contribute to a healthy diet for consumers, while the sample enriched with microencapsulated formulation is advantageous in terms of probiotic activity.
... One of the most important forms of consumption in association with yogurt is ayran or yogurt drinks, taking an important place in human nutrition. Ayran is a fermented milk beverage derived from yogurt, which is obtained by diluting yogurt or fermenting certain diluted milk as well as subsequently mixing until salt becomes homogeneous after its addition (Koksoy & Kilic, 2003). Although ayran is a drink mostly associated with the Turkish, it is produced and marketed in the form of a yogurt drink in many countries. ...
Fermented dairy products are formed during the acidification of milk through fermentation by suitable microorganisms; it contains different microorganisms in sufficient numbers and in an active state. A wide range of fermented milk products are produced and consumed around the world, including yogurt, kefir, koumiss, and yogurt beverages. There are various health benefits associated with the consumption of fermented dairy. Many studies reported that some fermented milk products have antimicrobial, antimutagenic, anticarcinogenic, and antihypertensive properties as well as provide benefits on mineral metabolism, reduce lactose intolerance symptoms and cholesterol levels. In addition to these effects, it has many other beneficial effects such as positive effects on type 2 diabetes and hypertension, antimutagen and antioxidant effects, and reduction of allergic symptoms. Dairy products including fermented milk are known to be the main carrier of probiotic microorganisms, and many clinical studies show the effects of probiotic strains on health. In this study, the effects of fermented milks on human nutrition and health are mentioned.
... HHP-treated and heat-treated samples showed a non-significant change in pH and LA% at 4°C storage, while a significant decrease in pH and LA % was observed similar to untreated samples. The increase in K values (online Supplementary Table S1) in corresponding samples during both storage temperature could be explained by the increase in electrostatic force between casein micelles due to decreasing pH value (Köksoy and Kılıç, 2003). ...
The effects of high hydrostatic pressure (HHP) and heat treatments on antimicrobial protein stability and on the physico-chemical, microbiological, rheological and shelf-life properties of donkey milk were investigated. Although heat treatment at 75°C for 2 min resulted in 1.50 log CFU ml ⁻¹ microbial inactivation, losses in activities of lysozyme (58%) and lactoferrin (82%) were observed due to whey protein denaturation. By contrast, HHP application at 400 MPa caused lower enzyme activity losses (22 and 37% respectively) whilst maintaining a significant reduction of microbial load (1.80 log CFU ml ⁻¹ ). Color analyses showed that the lightness values of all samples decreased during storage. Higher flow consistency (viscosity) and lower flow behavior indexes were observed in heat-treated samples compared to untreated and HHP-treated ones, which can be explained by advanced protein denaturation during heat-treatment. The results suggest that HHP is a more suitable process than heat treatment for preservation of donkey milk within the conditions studied.
... Various studies investigated the effects of different factors on the chemical and microbial quality of ayran. In a study by Köksoy and Kılıç (2003), the impact of varying levels of water (30 or 50 g/100 g) and salt (0, 0.5 or 1 g/ 100 g) on rheological properties of ayran during storage were evaluated. The results showed a decrease in consistency index and an increase in serum separation by increasing the level of water and salt. ...
... Viscosity values were found using a Brookfield viscometer (DV-II + Pro, Brookfield Engineering Laboratories, Middleboro, MA, USA) and a spindle No. S61 at 4 ± 1°C at 100 rpm, and the results were measured at 15 sec and expressed in pascal second. Whey separation values were identified according to the method by Köksoy and Kılıç (2003). ...
The present study was conducted to evaluate the production of ayran by adding freeze‐dried black carrot fiber at different ratios (0%, 0.25%, 0.5%, and 1%), followed by its storage for 14 days. It turned out that the more the amount of black carrot added, the more the amounts of Na, Mg, K, and Ca, though the sensory scores decreased. While pH, titratable acidity, viscosity, whey separation, and acetaldehyde contents of ayran were not affected by black carrot addition ( p > .05), water‐holding capacity, volatile fatty acids, L *, a *, and b * values appeared to be significantly affected ( p < .05). The highest and lowest a * values were determined on the 1st (A1: 7.09) and 14th (C: −1.24) days, respectively. Higher L *, b *, and volatile fatty acid values were found in the ayran sample containing 0.25% black carrot fiber (A1) following the control samples. Apart from the water‐holding capacity of ayran, no significant change occurred in other properties during storage ( p > .05). The highest water‐holding capacity was observed in A2 (19.53%) on the 14th day of storage. The ayran‐containing 0.25% black carrot fiber presented the best results. Fortification of ayran with black carrot fiber is likely to make a significant contribution to the diversification of functional dairy products.
Novelty impact statement
Freeze‐drying of black carrot will enable to obtain rich color substances in its composition, reduce transportation, and storage costs, and provide a product with a longer shelf life. This study has aimed to increase the consumption of high‐fiber black carrot, which is freeze‐dried and powdered, by adding it into ayran, and to benefit from the rich nutritional content of black carrot, as well as developing a natural, nutritious, and highly appealing product for consumers. As a consequence, an important contribution will be made to the product diversification in the dairy industry. The functional properties that black carrot will bring to ayran will ultimately benefit public health.
... Shanina is a fermented homemade yogurt beverage. This beverage has several versions in the Middle Eastern countries such as Ayran in Turkey [36] and Doogh in Iran [37]. These beverages are prepared by two methods: method one requires fermenting milk for a short time to form weak curd, while method two requires fermenting milk for a long time to prepare yogurt and then diluting it with water and adding salt. ...
The tradition of making fermented foods and beverages in Iraq dates back to 7500 BC. These fermented foods and beverages are represented by meat-, milk-, vegetable-, and fruit-based products reflecting diversity of agricultural production in ancient Iraq (Mesopotamia). Although the recipes for some fermented foods and beverages were lost throughout history, those remaining foods and beverages occupy a noticeable position in modern Iraqi cuisine. In this review, knowledge and techniques for preparation of 5 traditional fermented foods, i.e. Basturma, Smoked Liban, Aushari cheese, Turshi, and Sour Khobz, and 3 fermented beverages, i.e. Shanina, Sharbet Zbeeb, and Erk Sous in Iraq, are documented. Traditional fermented foods and beverages have multiple health benefits because of high content of probiotics and bioactive compounds. Traditional fermented foods and beverages are made using the back-slopping technique which ensures safety of production and maintains organoleptic properties. The review highlights the potential of fermented foods and beverages for their large-scale commercialization.
... (30). The increase in phase separation during storage is explained by the increase in electrostatic force between casein micelles due to the addition of salt and decreasing pH value (31). Although the addition of RWP led to an increase in the dry matter of milk, the physical stability of the product became poorer. ...
Research background. In industrial ayran production, milk is diluted to the desired protein content (2% (m/V)) prior to fermentation by yogurt starter cultures by partial replacement of cheese whey in reconstituted form with potable water. This may be an alternative way of protein recovery from cheese by-products as well as reducing the production costs since less milk is used in ayran production. On the other hand, the balance between milk caseins and whey proteins is disturbed when cheese whey is added to milk for ayran production, which likely leads to a time-dependent phase separation during cold storage. Modification of ayran matrix by enzymatic crosslinking of proteins may be a solution to overcome this potential physical instability of ayran. This topic has not been explored to date, and the present study was designed to investigate the possibilities of utilization of reconstituted whey powder (RWP) and microbial transglutaminase (MTG) in ayran production.
Experimental approach. Milk was diluted to obtain 2% protein level using RWP and potable water. The aim of utilization of RWP was to meet 5, 10 or 15% of the protein content of the final product. RWP solutions were obtained by calculating the amounts of whey powder required to meet the specified ratios and mixing it with the water required for dilution. We prepared eight different ayran samples divided in three groups, namely group A: prepared by partially diluting milk with RWP to obtain 5, 10 or 15% of total protein amount in the product, group AMTG: prepared by adding microbial transglutaminase (0.5 U per g of protein) to group A samples, and control group without RWP and with or without the addition of MTG. The gross composition, physical (phase separation and viscosity, chemical (volatile and peptide profiles and SDS-PAGE electrophoresis patterns) and sensory properties of the samples were evaluated throughout 15 days of storage with weekly intervals.
Results and conclusions. Since the amounts of whey powder used to obtain RWP were different, dry matter levels of the samples differed. Using RWP in ayran production increased the phase separation slightly. Incorporation of MTG affected the physical properties of the ayran samples positively and prevented phase separation at a satisfactory level. SDS-PAGE electrophoretograms revealed that cross-linking between proteins triggered by MTG formed intense bonds at high molecular mass regions. The remaining parameters were not affected by MTG. Results revealed that the samples with 10% RWP with and without addition of MTG were determined as the formulations with the highest commercialization potential.
Novelty and scientific contribution. Utilizing RWP in the production of ayran to reduce the protein content of the final product to the desired level is a new approach. Since complete replacement of RWP with potable water to dilute milk to reach 2% (m/V) protein likely leads to lower sensory scores, we have investigated a possibility of partial replacement of RWP with potable water. A time-dependent phase separation is the major challenge of industrial ayran production. This physical problem was largely eliminated by means of MTG-mediated cross-linking of milk proteins. The proposed novel ayran production method offers dairy industry reduction of production costs and contributes to sustainability in milk production since smaller volume of milk is used to reach desired protein content in the final product.
... Depolamada yoğurt bakterilerinin ve probiyotik bakterilerin faaliyetleri sonucunda proteinler hidrolize uğramakta ve kazein miselleri tarafından tutulan serum, protein-protein etkileşimlerinin yeniden düzenlenmesiyle serbest kalmaktadır. Depolama süresince artan asitlikle birlikte kazein misellerinin biraraya toplanmasını önleyen elektron yüklü gruplar itici kuvvetler oluşturarak serumun ayrılmasını teşvik edilmektedir [59,60]. Konu ile ilgili yapılan çeşitli çalışmalarda da benzer şekilde depolama süresince ayranda serum ayrılmasının arttığı belirtilmiştir [45,50,61]. ...
Bu araştırmada, probiyotik bakteriler olarak Lactobacillus acidophilus ATCC 4356 veya Bifidobacterium bifidum DSM 20456 kullanılarak iki farklı üretim yöntemi ile üretilen probiyotik ayran örneklerinin fizikokimyasal ve mikrobiyolojik özellikleri belirlenmiştir. Çalışmada içilebilir nitelikte su ile kurumaddesi ayarlanan sütün fermente edildikten sonra tuz ilave edilmesiyle ayran üretimi (standardize sütten ayran üretimi) ve probiyotik yoğurda içilebilir nitelikte su ve tuz ilave edilmesiyle ayran üretimi (yoğurttan ayran üretimi) olmak üzere iki farklı üretim yöntemi kullanılmıştır. Üretiminde probiyotik bakteri kulllanılmayan ayran örnekleri çalışmanın kontrol gruplarını oluşturmuştur. Ayran örnekleri 4°C'de 30 gün süresince depolanmıştır. Üretim yönteminin ayran örneklerinin fizikimyasal ve mikrobiyolojik özellikleri üzerinde önemli etkisi olduğu saptanmıştır. Standardize sütten üretilen ayran örneklerinin titrasyon asitliği ve viskozite değerlerinin yoğurttan üretilen ayran örneklerine göre daha düşük, serum ayrılması ve pH değerlerinin ise daha yüksek olduğu bulunmuştur. Depolama süresince, üretiminde L. acidophilus kullanılan ayran örneklerindeki L. acidophilus sayısının 7.6-8.7 log kob/mL arasında değiştiği, üretiminde B. bifidum kullanılan ayran örneklerindeki B. bifidum sayısının ise 6.9-8.7 log kob/mL arasında değiştiği saptanmıştır. Üretimlerinde probiyotik bakteri kullanılan ayran örneklerinin 30 günlük depolama sonunda >106 kob/mL probiyotik bakteri içerdiği tespit edilmiştir. Sonuç olarak, probiyotik ayran üretiminde her iki probiyotik bakterinin de kullanılabileceği, ancak üretim yöntemi olarak yoğurttan ayran üretim yönteminin daha uygun olduğu belirlenmiştir.
... The set pH value (4.2) was selected based on the expected amount of lactic acid at the point of completed milk fermentation by lactic acid bacteria in mixed-culture milk products (pH 4.2-4.6), such as kefir and ayran [59,60]. Freshly prepared microcapsules (2 mL), prepared by mixing 1 mL cell suspensions with 1 mL of 4% alginate) or 1 mL (8 log cfu/mL) of free cell suspensions, were introduced in 40 mL of MRSLL, sealed with an airlock and incubated at 28 • C. ...
Adverse environmental conditions are severely limiting the use of microorganisms in food systems, such as probiotic delivery, where low pH causes a rapid decrease in the survival of ingested bacteria, and mixed-culture fermentation, where stepwise changes and/or metabolites of individual microbial groups can hinder overall growth and production. In our study, model probiotic lactic acid bacteria (L. plantarum ATCC 8014, L. rhamnosus GG) and yeasts native to dairy mixed cultures (Kluyveromyces marxianus ZIM 1868) were entrapped in an optimized (cell, alginate and hardening solution concentration, electrostatic working parameters) Ca-alginate system. Encapsulated cultures were examined for short-term survival in the absence of nutrients (lactic acid bacteria) and long-term performance in acidified conditions (yeasts). In particular, the use of encapsulated yeasts in these conditions has not been previously examined. Electrostatic manufacturing allowed for the preparation of well-defined alginate microbeads (180–260 µm diameter), high cell-entrapment (95%) and viability (90%), and uniform distribution of the encapsulated cells throughout the hydrogel matrix. The entrapped L. plantarum maintained improved viabilities during 180 min at pH 2.0 (19% higher when compared to the free culture), whereas, L. rhamnosus appeared to be less robust. The encapsulated K. marxianus exhibited double product yields in lactose- and lactic acid-modified MRS growth media (compared to an unfavorable growth environment for freely suspended cells). Even within a conventional encapsulation system, the pH responsive features of alginate provided superior protection and production of encapsulated yeasts, allowing several applications in lacto-fermented or acidified growth environments, further options for process optimization, and novel carrier design strategies based on inhibitor charge expulsion.
... The Food and Agriculture Organization (FAO) defines it as "a savory yogurt-based beverage popular in Iran, Afghanistan, Armenia, Iraq, and Syria [2]. Similar dairy beverages are common in other countries, for example, ayran (Turkey) [3], koumiss (China) [4], and kefir (Argentina) [5]. Different aspects of fermented dairy beverages have been studied by researchers. ...
... The viscosity of samples was evaluated using a Brookfield viscometer (Brookfield DV-II +) by spindle No. 64 at 30 rpm during 1 min according to the study of Köksoy and Kılıç (2003). The viscosity is expressed in the unit of Pascal second (Pa s), and all experiments were performed at 25 AE 2°C. ...
Ayran is a traditional fermented dairy drink that is manufactured by mixing yoghurt with water. In this research, the development of phytosterol-enriched probiotic Ayran, the efficacy of various concentrations of phytosterol (0, 0.5 and 1 mg/L) and inoculation type (free or encapsulated) were investigated. The viability of Lactobacillus casei L26 and physicochemical indices of samples during storage time was studied. Samples with encapsulated probiotics showed lower serum separation due to the hydration of encapsulated agents. Sensory scores revealed that phytosterols are suitable for the enrichment of the probiotic Ayran. Moreover, phytosterol showed no significant changes in pH, acidity and viscosity during storage.
... Table 3 also shows that the value of the power-law index was below 1 for all samples, which indicated the non-Newtonian behavior of kefir samples. Non-Newtonian behavior of kefir and other fermented milk beverages was also reported by other researchers [29,31]. ...
Curcumin is the hydrophobic yellow pigment in turmeric with considerable health-promoting effects. However, its low water solubility and stability limit its application. In the current study, curcumin within Persian gum (PG) nanoparticles at 0.5%, 1%, and 1.5% PG concentrations were encapsulated. The size of the nanoparticles was in the range of 326.0 - 397.4 nm. Based on the TEM images of curcumin-loaded nanoparticles, all samples had a spherical shape and existed in a par-ticular form without aggregation. Encapsulation efficiency was in the range of 86.0-94.0%. In-creasing PG concentration enhanced the encapsulation efficiency of curcumin. PG nanoparticles provided good protection on curcumin against light, hydrogen peroxide, and acidic pH. The lowest stability was related to free curcumin, and the highest was related to PG nanoparticles at 1.5% concentration. Curcumin-loaded nanoparticles at 1.5% concentration were added to kefir at 1%, 2%, and 3% concentrations. No significant differences were observed between acidity, pH, apparent viscosity, and consistency index of fortified and unfortified kefir samples. All kefir samples showed non-Newtonian behavior. Feeding rats with fortified kefir samples caused a lower level of low-density lipoprotein (LDL), total cholesterol (TC), and triglycerides (TG) compared to feeding with a standard diet.
... bulgaricus to pasteurized and standardized milk [31]. In other words, the blending of yoghurt with 30-50 % of water and 0.5-1 % of salt results in the generation of the beverage called ayran [32]. ...
The fact that foods can provide additional medicinal health benefits beyond basic energy requirements and nutritional needs for survival, has been proven through rigorous scientific researches over the years. Although Turkey is historically believed to be the ancient origin of a
decent number of fermented probiotic foods and beverages, there is still little awareness amongst the overall populace regarding the usefulness of these medicinal products also known as functional foods. Hence, the current review article discusses probiotics as a top notch variety of functional foods and encapsulates their history as well as some proven beneficial effects of some known probiotic microorganisms on human health. More importantly, greater emphasis
is placed on elucidating scientific data on seven fermented traditional probiotic beverages of Turkish origin namely boza, kefir, ayran, shalgam, hardaliye, koumiss and gilaburu juice. The paper concisely describes their main characteristics, probiotic microbiota composition,
production techniques as well as nutritional properties and some potential health benefits derivable from their consumption.
... Buttermilk is especially consumed salt yogurt drink popular during the summer months in Turkey (Salameh et al., 2016). Ayran has traditionally been produced at home in Anatolia for hundreds of years by mixing yogurt with water and salt (Altay, Karbancıoglu-Güler, Daskaya-Dikmen, & Heperken, 2013;Koksoy & Kilic, 2003). According to the Turkish Food Codex, buttermilk is defined as "fermented milk product prepared by adding water in yogurt or by adding S. thermophilus and L. delbrueckii subsp. ...
Fermentation is one of the oldest and most economical methods used to preserve and improve shelf-life, flavor, texture, and functional properties of foods. In general, lactic acid bacteria of various breeds predominate in food fermentation, including Lactococcus, Lactobacillus, Enterococcus, Streptococcus, Leuconostoc, and Pediococcus. However, in addition to these bacteria, yeast, and fungi also contribute to food fermentation. In Turkey, the most widely produced and consumed traditional foods are yogurt, buttermilk, kefir, kımız, tarhana, boza, pickles, shalgam juice, hardaliye, and sucuk. This review aims to identify the most common traditional fermented products and to emphasize some microbiological characteristics as well as the health effects of fermented products.
... The viscosity (Table 2) With increased percentage of bitter orange peel extract, dry matter content of flavored milk samples increased (unreported data) and dry matter content and viscosity are directly related. These results confirm the results obtained by Boulenguer and Laurent (2003) and Koksoy and Kilic (2003) regarding the increase viscosity of acidic dairy drinks with elevation of dry matter content in them. ...
In this study, the effects of adding Gaz‐angubin at three different levels (5%, 10%, and 15% w/v) and bitter orange peel extract with three different concentrations (0.025%, 0.050%, and 0.075% w/v) on selected characteristics of the flavored milk were investigated during 10‐day storage at 4°C. The results showed that increasing the level of Gaz‐angubin and bitter orange peel extract increased viscosity, antioxidant activity, and total polyphenol content, decreased total microbial count, and improved the sensory characteristics of the flavored milk (p < .05). Generally, the flavored milk sample containing 15% Gaz‐angubin and 0.075% bitter orange peel extract was selected as the best treatment. Gaz‐angubin could be considered as the potential antioxidant and antibacterial ingredient in healthy food products. The flavored milk containing 15% w/v Gaz‐angubin and 0.075% w/v bitter orange peel extract was selected as the best treatment.
... In the present study, the highest apparent TA B L E 3 Changes of total phenolic content (mg GAE/L) and total antioxidant activity (µmol TE/L) of ayran samples during storage In our study, it was found that flow behavior index decreased and consistency coefficient increased with an increase in quinoa flour. In a study examining the rheological properties of ayran using different levels of water and salt, the researchers explained that ayran showed non-Newtonian behavior based on the power law model (Köksoy & Kılıç, 2003). ...
In this study, some physical, chemical, microbiological, and sensory properties of ayran produced from quinoa flour addition at different ratios (0.1, 0.2, 0.3, and 0.4%, w/v) were investigated. The effect of quinoa addition and storage time on pH, titration acidity, serum separation, L values and microorganism counts were statistically significant (p < .05). The counts of Streptococcus salivarus subsp. thermophilus and Lactobacillus delbruecki subps. bulgaricus had a wide range between 7.13 and 7.52 log CFU/mL and 3.62 and 3.98 log CFU/mlL At the end of the storage, the general appreciation score of the sample containing 0.2% quinoa flour was found to be higher than the other samples. The total antioxidant activity of ayran samples was observed between 10.38 (µmol TE/L) and 19.89 (µmol TE/L) during storage period. Addition of quinoa flour up to 0.2% in ayran production had a positive effect on Lactobacillus delbruecki subps. bulgaricus development. While quinoa flour in ayran production was increased, consistency coefficient of samples increased.
... After storage at 4⁰C, the volume of the layer of clear serum at the top was recorded as an indication of instability. Measurements taken performed in duplicate [17]. Dry matter was determined according to gravimetric method AOAC, [15]. ...
This study was aimed to assess the nutritional value and texture of the yoghurt with the addition of different concentrations of rice flour. Yoghurt samples were processed by added rice flour at 0, 2, 4 and 6%. The results indicated that the highest moisture content in the control sample was 86.86% and the lowest one in 6% was 84.41% of rice flour. The protein content of yoghurt samples was 4.16, 4.20, 4.57 and 4.83%, the protein contents increased significantly (p<0.005) by addition rice flour. The fat content in yoghurt samples was 2.19, 2.21, 2.21 and 2.23% in control, 2, 4 and 6%, respectively. The minerals content was not affected significantly (p<0.005) by added rice flour. The ash content was 0.26, 0.35, 0.52 and 0.72% in control, 2, 4 and 6%, respectively were increased significantly (p<0.005) by addition rice flour. Titratable acidity was decreased significantly (p<0.005), while the pH value increased by added rice flour. The viscosity of yoghurt samples the highest one in control sample was 4212 cps and lowest in 6% was 3766 cps. The serum separation of yoghurt samples with rice flour was 5.32, 4.47, 4.20 and 3.70 ml, respectively, decreased significantly (p<0.005), while the dry matter of yoghurt sample increased by addition rice flour, the highest one was recorded in the yoghurt sample produced by 6% was (15.42%) by rice flour. The microbiological analysis of yoghurt samples indicated the total count bacteria, mould and yeast no affected significantly (p<0.005) by addition rice flour and no growth of coliform and Salmonella. The sensory evaluation indicated that yoghurt samples with 4% rice flour had the highest consumer acceptability scores.
... bulgaricus into milk (TFC, 2009). Whenever, ayran is prepared from yoghurt, is produced by mixing of yoghurt with water (between 30-50%) and is salt (0.-1%) (Köksoy and Kılıç, 2003). ...
This study aims to monitor the effect of whey protein hydrolysate (WPH) on the growth and activity of probiotic bacteria (Streptococcus thermophilus, Lactobacillus delbrueckii spp. bulgaricus, Lactobacillus acidophilus, and Bifidobacterium lactis) in ayran, and also to enhance the functionality of ayran by addition of the probiotics. Effects of WPH and probiotics addition as 0%, 0.25%, 0.5% and 1% on the growth of probiotic bacteria were studied before and after the fermentation and 7th, 14th, and 21st days of the storage. WPH and probiotics had a significant effect (p<0.05) on the growth of target microorganisms and the biochemical variables. The addition of WPH and probiotics significantly (p<0.05) increased the growth of probiotics compared to the control after the fermentation up to the 21st day of storage. The samples containing different WPH levels had lower (p<0.05) pH levels compared to the control during the study time. The mixing of WPH at 1% had the highest total solids and protein content compared to the control samples. The WPH decreased (p<0.05) the viscosity and Hunter color parameters in added the samples. Results indicated that WPH had great potential for enhancing the growth of probiotic bacteria and the nutritional of ayran.
... The addition of stabilizers at high concentrations increased the thixotropy of liquid yogurt. However, the salt in milk drinks is added to reduce casein particle aggregation and apparent viscosity (Köksoy & Kılıç, 2003). Table 4. ...
Second-grade dates can be valorized by its uses in the production of nutritive foods with health benefits. Date syrup (DS), date powder (DP), and their different concentrations, using D-optimal mixture design, were used for the formulation of dairy desserts: syrup dairy dessert (SDD) and mixture dairy dessert (MDD). The optimized mixture proportions of the best dairy dessert formulation, containing
date syrup (14%) and powder (2%) as a sugar substitute (0%), were determined to achieve the desired sensory for the effective formulation process. Significant differences in water, protein, fat, and sugar contents were found between SDD, MDD, and commercial dairy dessert (CDD) used as standard, respectively. SDD exhibited the highest total phenolic content (0.65 ± 0.04 mg GAE/g), DPPH inhibition (4.00 ± 0.82%), and reducing power (2.75 ± 0.10%) followed by MDD and CDD. The absence of germs indicated a high microbiological quality of dairy desserts. Rheological measurements revealed that all samples exhibited a weak gel structure and shear thinning behavior. Desserts supplemented with dates led to desserts with an homogeneous structure.
... Simple salt reduction in T1 sample increased firmness, work of shear, and stickiness. This indicates a lower spreadability of the sample with re- Köksoy and Kiliç (2003) investigated the effect of sodium chloride content on the properties of fermented milk systems. They found that reduction of the sodium chloride content causes increase in the viscosity of the acidic milk gel and other acidic dairy products. ...
The present study was performed to investigate the possibility of sodium reduction in cream cheese by partial reduction and substitution of sodium by potassium based salt. Four salt treatment were selected by preliminary study: 100 % NaCl (control), NaCl reduced to 65 % (T1), 35 % of NaCl substituted by KCl (T2), and KCl-based salt mixture Salut® which contains offflavours masking compound (T3). The study was evaluated physico-chemical attributes, colour, spreadability, sensory acceptance, as well as level of intensity of specific attributes of low-sodium cream cheese. Sodium reduction not influenced on the protein, fat and moisture content, water activity, acidity and the colour of cream cheese (P>0.05). However, sodium reduction significantly influenced to mineral composition, spreadability and sensory properties. The use of potassium salt substitutes significantly increased the value of K:Na ratio. Cheese containing commercial salt replacer Salut® had the closest hedonic score to control cheese compared to other replacers. The current research demonstrates that sodium content can be reduced by 35 % in cream cheese using a nutritionally valuable potassium-based salt mixture, without compromising the consumer acceptance.
... Sometimes exopolysaccharide producing starter cultures are used to obtain a viscous coagulum (Koksoy and Kilic, 2004). The fermentation is continued until pH 4.4-4.6 is obtained (Köksoy and Kılıç, 2003). After the fermentation, the coagulum is mixed with around 35% water and 1% (w/w) salt. ...
... Higher fat content causes aggregation of fat droplets, and results in non-Newtonian behavior (Mineshita et al., 1980;García et al., 1988). The size, shape, and volumetric percentage of solids, particularly proteins, can influence the stability and rheological properties considerably (Köksoy and Kılıç, 2003;Kiani et al., 2008;Sedlmeyer et al., 2004). Jeurnink and De Kruif (1993) reported that the viscosity of skim milk increased after heat treatment at temperatures above 70°C due to denaturation of whey proteins. ...
... The pH of ayran fortified with black carrot powder was in the ranged from 4.42% to 4.68% and the highest value was observed in control sample (A), followed by D, B and C, respectively. pH values were higher than the values reported by Atamer et al. (1999), Köksoy and Kılıç (2003), Koçak et al. (2006), Patır et al. (2006), Tonguç (2006), Şimsek et al. (2007), Tamuçay Özünlü and Koçak (2010b), Şanlı et al. (2011), Ayar andBurucu (2013), Erkaya et al. (2015) for ayran samples. Polat (2009) and Tamuçay Özünlü and Koçak (2010a) reported that pH values of production of ayran with using different cultures and samples of ayran ending the incubation at different pH were found as 4.36-4.46 ...
Ayran is a traditional Turkish salty drinkable fermented product prepared by the addition of water to yogurt or by the addition of yogurt culture to standardized milk. Black carrot is well known and very rich source of anthocyanins and combining with ayran was obtained a product that is natural, nutritious and highly attractive for consumer. In this study, black carrots were dried and powdered by freeze drying method and four batches of ayrans were manufactured by adding dried black carrots powder into the milk at increasing rates. One batch was treated as a control sample without black carrot powder addition and three batches of ayrans were manufactured by adding black carrot powder at the rates of 0.25%, 0.5% and 1%. All of the samples were pasteurized at 90°C for 5 minutes. Following the pasteurization, milks were cooled to 46±1°C and then inoculated with starter culture. Inoculated milks were incubated until the pH became 4.6-4.7. Ayran samples were cooled down and 0.5% salt was added. The mixture was homogenized and filled into 200 g of cups and stored at 4oC before analyses. At the 5th and 20th minutes, the lowest antioxidant activity values were found to be 5.88% and 6.08% for control sample, while the highest antioxidant activity values were found 19.90% and 21.6% for ayran with 1% black carrot powder. Increasing concentrations of added black carrot into the milk, resulted higher antioxidant activity in ayran as determined by DPPH method (p<0.05). However, pH, dry matter, fat, protein and salt contents of the ayran samples were not influenced by black carrot powder addition (p>0.05).
... In these countries, the product can be produced in two technological schemes, depending on the chosen method for standardization and coagulation. Ayran is a fermented beverage, which is traditionally prepared by blending yoghurt with water (30-50%) and salt (0.5-1.0%) [38,39]. The ayran can be produced in two methods, either by adding some water to yoghurt or by adding some water to the milk at first, after which a subsequent fermentation of diluted milk takes place [40,41]. ...
Traditional fermented milk products have been prepared since ancient time by various civilization. Despite their long history, popularity, and nutritive and healthy value, the acceleration and industrialization of food production leads to increase of the diversity of fermented milk products in the Balkan Peninsula. As a result of the multitude of food‐microbe combinations, there are thousands of different types of fermented milk products ‐ yoghurts, yogurt‐like products and various types of cheeses with proven health benefits. Among those products is the domestic Bulgarian yoghurt “kiselo mlyako”, whose anti‐aging effect has been scientifically studied yet at the beginning of 20th century. The current review summerizes the wide range of traditional fermented milk products at the Balkan countries, which are the primary source for their production.
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... The change of shear stress versus the shear rate shows that the FHM was a non-Newtonian pseudoplastic flow behavior with a beginning resistance against the flow, as revealed by the calculated yield stress. This behavior of FHM is in agreement with the findings of previous studies (Koksoy and Kilic 2003;Janhøj et al. 2008;Kök 2010). Herschel-Bulkley model parameters of FHM, R 2 , the yield stress, consistency coefficient and flow behavior index values were found to be 0.99, 0.21, 0.06 and 0.57 respectively, the R 2 value was very close to 1, which means that the Herschel-Bulkley function well fitted to the flow behavior of FHM. ...
Raw hazelnut milk were used to develop new plant-based fermented product using commercial starter mix containing Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus strains in order to address the current demand for health promoting and functional plant-based dairy-like products. The pH, titratable acidity (TA), serum separation (SS), protein content, fat content and ash content of fermented product were found to be 4.95, 1.25 g lactic acid/ 100 mL, 28.00%, 2.60%, 7.03% and 0.66%, respectively. Fermented hazelnut milk demonstrated non-Newtonian pseudoplastic flow behavior and it’s structure was more predominantly elastic than viscous. Sensory analysis showed that some attributes of fermented hazelnut milk such as color, aroma, consistency, typical yoghurt odor and overall acceptability were less appreciated than Ayran (commercial cow milk yogurt drink) whereas some other attributes were found as satisfying.
The objective of this study is to increase the functional qualities of Ayran by using honey from various sources. The goal of the research is to ascertain the physicochemical, rheological, and aroma composition of Ayran made with honey addition, as well as to assess the effect of different types of honey added to Ayran. Two types of honey (flower and pine) and an equal blend of these honey at a mixing ratio of 10% were utilized in making of Ayran samples. The pH values of the Ayran samples were higher in the honey-added samples compared to the control group. According to the statistical data obtained, the difference between L*, a* and b* values in Ayran samples was significantly different (p<0.05). Adding honey to Ayran samples increased the number of Lactobacillus delbrueckii subps. bulgaricus towards the end of storage. The floral and combination honey samples were found to be more viscous than the samples of pine honey. It was determined that the flower honey sample had a total hydrocarbon content close to the control group and the sample containing the highest total terpene among the other samples. Higher amounts of aldehydes, ketone, and carboxylic acids were found in Ayran samples of pine honey. The Ayran with mixed honey had the greatest levels of total ester and alcohol. Honey enhances the qualities of Ayran; thus, both flower and pine honey can be added to Ayran. Although Ayran's smoothness and sweetness had no adverse effects on sensory characteristics, it was decided that 10% or a little less honey could be added. Cite this article as: İnce YN, Çelebi M, Şimşek B. Microbiological, rheological properties and aroma composition of flower and pine honey-added ayran. Sigma J Eng Nat Sci 2025;43(1):34−46.
Bu çalışmada, süzme yoğurt üretiminden elde edilen yoğurt suyu (YS), ayran üretiminde, sütün seyreltilmesinde kullanılan içme suyunun %0, %6, %12.5 ve %25’i yerine ilave edilmiş ve ayranların 14 günlük depolama süresince bazı özellikleri incelenmiştir. YS ilavesi ile örneklerin toplam kurumadde içerikleri ve titrasyon asitliği değerleri artmış, yağ, protein, kül içerikleri ve pH değerleri ise değişmemiştir. YS’nin kıvam indeksi değerlerini artırdığı, serum ayrılması değerlerini ise azalttığı belirlenmiştir. Renk özelliklerinden a* değeri, YS ilavesi ile azalmış, L* ve b* değerlerinde ise farklılık görülmemiştir. Örneklerin tamamının depolama süresince 107 kob/ml’nin üzerinde laktik asit bakteri içeriğine sahip olduğu belirlenmiştir. Duyusal analiz sonuçlarına göre, ayranlar arasında görünüş, renk ve koku özellikleri bakımından farklılık görülmemiş, kıvam ve tat özellikleri bakımından ise en yüksek puanları en yüksek YS içeriğine sahip örnek almıştır. Çalışmadan elde edilen sonuçlar, ayran üretiminde YS kullanımının uygun olduğunu göstermiştir.
In this study, chia seed mucilage powder (MP) was added into ayran drinks at different ratios (0.05, 0.10 and 0.15 %, w/v), and its effect on physicochemical, rheological, microbiological and sensory properties of ayran drinks was determined during 10 days of storage at 4±1 °C. MP addition did not influence their major chemical composition significantly (p>0.05). Increasing MP ratio in drinks decreased the colour L* values of drinks while increasing their colour a* and b* values. Addition of 0.05, 0.10 and 0.15 % MP reduced serum separation values of drinks by 25, 67 and 83 %, respectively. The apparent viscosity value of control samples was 103.20 cP and increased to 134.25, 185.35 and 223.38 cP in ayran drinks with 0.05, 0.10 and 0.15% MP, respectively. The obtained results indicated that chia seed MP up to 0.05% can be used in ayran drink production to reduce serum separation and improve viscosity without any adverse effect on sensory liking scores.
In this study, the properties of the milk treated with solution plasma (SP) processing combine with pulsed electric field (PEF) for different periods (5 and 10 min.) was investigated. The microbiological, physicochemical and sensory properties of the probiotic drinking yogurt (Ayran) produced from these milks were determined during storage. PEF was performed at voltage 3500 V, repitation 17000 Hertz and pulse width 2.58 μs on the raw milk. Lactobacillus acidophilus and Bifidobacterium animalis subsp. lactis probiotic cultures were used in production with conventional yoghurt bacteria Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus. In addition to the probiotic viability, texture and sensory quality in terms of consumer preference were investigated. It was determined that the viscosity and dry matter values of the solution plasma treated samples were lower compared to the samples produced by heat treatment, and these values decreased further with the increase in plasma application time. It was also found that the maximum increase in L* and b* values of all samples during storage was in the samples treated with plasma for 10 minutes. The viability of the probiotic bacteria in probiotic ayran samples were determined to be within the therapeutic level (>6.27 log10 cfu mL‐1) with higher scores for sensorial qualifications.
Ayran is a salty drinkable yoghurt, but lactose in ayran induces lactose intolerance. This can be overcome by production of lactose-free or lactose-reduced ayran. Milk with 50% and 100% lactose hydrolysis by β-galactosidase was therefore used for alternative lactose-reduced or lactose-free ayran production. Physicochemical, microbiological, and sensory analyses were performed during storage at 4 °C for 28 days. Syneresis and flow behaviour index values increased, and apparent viscosity and consistency coefficient values decreased with increasing lactose hydrolysis level, salt content (0.5 and 1%), and storage period. No significant effects of lactose hydrolysis level and salt content on the counts of S. thermophilus and L. delbrueckii subsp. bulgaricus were found, while counts of these bacteria decreased during the storage period. Sensory evaluation highlighted that the 1% salt-containing ayran samples, which had higher scores of overall liking than 0.5% salt-containing ones, were significantly different from commercial ayran within the storage period.
Drinking yogurt (ayran) is one of the valuable traditional Anatolian dairy products. Ayran is prepared traditionally through adding water and salt to yogurt or manufactured industrially by fermentation of yogurt culture added diluted milk. Nowadays, interest and consumption of traditional different fermented dairy products have spread rapidly around the world. Although cucumber-yogurt (cacik), soda ayran, fruitful ayran have a commercial face, there is still locally consumed drinking yogurt ayran types. One of the locally consumed ayran types is herby-hot ayran from Puturge-Malatya. In the preparation of herby-hot ayran, the flavoring herbs/spices are added to the ayran in earthenware pots then buried under the soil and left to ferment spontaneously for at least 15 days. The objectives of this study were to determine physicochemical, microbiological, and sensory properties of traditional purslane and/or Cayenne pepper added drinking yogurt from Puturge-Malatya, Turkey. The analysis results were found total dry matter 5.80-7.03 %, pH 3.77-4.30, titratable acidity 0.61-1.17 % lactic acid, serum separation 11.17-21.5 mL (50 mL)-1. Levels of lactic acid bacteria (LAB) ranged from 7.00 to 8.04 log cfu mL-1 and the mold and yeast (MY) levels varied from 5.25 to 6.98 log cfu mL-1 for studied samples. Properties of traditional herby-hot ayran are found different from plain ayran. The results demonstrated that this product may have the potential for consumer preference. To reveal the changes occurring in product characteristics during the fermentation period would be thus of interest.
In this study, lactic acid bacteria (LAB) communities in 68 samples of spontaneously-fermented dairy products from Tajikistan, Kyrgyzstan and Uzbekistan were investigated using traditional culture methods combined with PacBio single-molecule real-time (SMRT) sequencing technology. In the 518 LAB strains isolated using the culture-dependent method, the dominant species was Lactobacillus delbrueckii subsp. bulgaricus. A total 75 species of LAB were identified using SMRT sequencing; amongst these Lactobacillus delbrueckii (50.85%) was the predominant species. We compared the LAB communities from different countries (Tajikistan, Kyrgyzstan, Uzbekistan) and different milk sources (fermented cows’ milk, fermented mares’ milk, cheese). Our results showed that variation in LAB communities from spontaneously-fermented dairy products from Tajikistan, Kyrgyzstan and Uzbekistan depended on geographical location. These data provide the basis for development and use of LAB resources. Moreover, this study provides new insights that can be applied in starter culture development as well as microbial functionality studies.
Turkey is a home country for a good number of fermented beverages derived from milk, cereals, fruits and vegetables, and several studies have reported the probiotic potentiality of these beverages. Probiotics, otherwise known as beneficial microorganisms possess the ability to exert antimicrobial effects, which is one of the most important selection criteria for their use in commercial products. In the current study, the antimicrobial activities of potential probiotic bacteria isolated from five fermented traditional Turkish beverages (boza, kefir, ayran, shalgam juice and hardaliye) were evaluated. The bacterial isolates were morphologically characterized and genotypically identified by 16S rRNA gene sequence analysis. The antimicrobial effects of the isolates against selected human pathogens were assessed using spot-on-the-lawn and agar well diffusion assays. Eighteen of the twenty-two strains displayed varying degrees of antagonism against the tested pathogens. Amongst the isolates, the strongest antimicrobial effects were exhibited by strains from boza, kefir and shalgam which can be attributed to their greater microbiota diversity. Strain specificity in the activities of the obtained isolates and specificity with the different indicator pathogens tested was observed. The impressive antimicrobial effects exhibited by boza, kefir and shalgam isolates offer a promising health benefit to consumers of these fermented probiotic products.
In this research, the effects of different homogenization pressure levels (15, 40, 15/3 and 40/8 MPa) and heat treatments (95°C for 90 s and 300 s) of milk containing 1.5 and 2.5% of fat on some physical properties of ayran were investigated during storage at 4°C for 30 days. The individual effects of fat content of milk, homogenization, heat treatment, and storage period on the syneresis, apparent viscosity, consistency constant and thixotropy values of the ayran samples were statistically significant. Based on the results of rheological analysis, the power law model was more appropriate for all ayran samples.
The effects of microbial transglutaminase enzyme (m-TG) and Persian Gum (PG) on physicochemical, microbial and sensory properties of kefir were investigated. The addition of m-TG-PG to kefir lead to an increase in pH, particle size and viscosity, while causing a decrease in titratable acidity, syneresis and zeta potential. The lactic acid bacteria decreased about 1-1.5 log units and yeast counts increased about 2 log units during storage, while treated samples lower populations. Fifty-one volatile compositions were isolated and identified with SPME-GC/MS with most of them belonging to acids, alcohols, esters, ketones, and aldehydes, respectively. Alcohol and acid compounds increased, while esters, ketones, and aldehydes decreased during storage. Sensory evaluation results showed a preference for treated samples; although storage time had a negative effect on the all sensory attributes. Use of m-TG with PG could be recommended to improve the quality properties of kefir.
The effects of coriander extract (CE) and cress seed gum (CSG) on viability of Lactobacillus plantarum LS5 and physicochemical properties of drinking yogurt (Doogh) were evaluated. The CE contained 18 mg GAE/g and was shown by the DPPH radical assay to have remarkable antioxidant activity. The CE was added at concentrations of 0%, 0.05%, 0.1%, and 0.25%, and the levels of added CSG were 0%, 0.1%, 0.25%, and 0.5%. Doogh samples were analyzed after 1, 2, and 3 weeks of storage at 4°C. By increasing the amounts of CSG, the viscosity of the Doogh samples was increased and phase separation was reduced significantly (p < .05). The results also showed that by increasing the levels of CSG to 0.5%, L. plantarum count increased significantly (p < .05). Doogh sample containing 0.05% CE and 0.5% CSG gained the highest probiotic count, overall acceptability score, and lowest lipid oxidation and phase separation in comparison with the other samples. To increase health benefits, dairy products can be formulated with probiotics and antioxidants for production of functional foods. The effects of coriander extract (CE) and cress seed gum (CSG) on viability of Lactobacillus plantarum LS5 and physicochemical properties of drinking yogurt (Doogh) were evaluated.
Traditional food is defined as a food having specific property, which differentiate it evidently from other similar foods in the way of the utilization of conventional ingredients or traditional composition or traditional type of manufacturing and/or processing method. Traditional foods are important elements of cultural heritage. They support the development and sustainability of countryside and lead to significant product differentiation potential for food manufacturers. Since ancient times, different fermented and unfermented traditional beverages including tea, coffee, ayran, kefir, shalgam juice, boza, salep, lemonade, gilaburu juice, etc. have been consumed. Raw materials such as myriad fresh fruits, plant seed, dried barks, flowers, roots, cereals, dairy products, and water have been used for preparation of those traditional beverages. Moreover, sherbets are known as popular traditional beverage, made from a mixture of a variety of fruits (tamarind, date, pomegranate, cranberry, red grape, rosehip, locust bean, etc.), spices (black cumin, cinnamon, ginger, cardamom, clove, etc.), and flowers (rose leaves, carnation, etc.), and further sweetened with the addition of honey or sugar. Traditional beverages have been drunk for quenching thirst or providing delight, and some are consumed for cultural and religious ritual, as well as for also used as a curing agent in medicine due to its health benefits. The main ingredients of those traditional beverage are well known to be rich sources of antioxidant components that may provide protection against oxidative damage, and thereby reducing risk of several degenerative diseases, lowering total and low-density lipoprotein cholesterol levels, improving intestinal flora, and having antimicrobial activity. Therefore, those traditional beverages could certainly be considered as a promising functional drink which could regain their popularity among health-conscious consumers. Recent researches are supporting their nutraceutical and therapeutic effects as well. This chapter highlights composition of Turkish traditional beverages and their preparation methods. Moreover, recent research findings on their functional properties are discussed.
L’objectif de la thèse est de caractériser la poudre du kishk libanais, un lait fermenté traditionnel, et d’optimiser sa technologie de transformation dans une démarche d’industrialisation. Des échantillons de poudre de kishk traditionnel ont été collectés, et leurs propriétés physico-chimiques, rhéologiques, microbiologiques et sensorielles ont été étudiées, en fonction du type de lait utilisé. Il en résulte que le kishk préparé à base de lait de chèvre est plus riche en matières grasses que les autres types. La distribution granulométrique est très large, quel que soit le type de lait, avec présence simultanée de fines particules à forme irrégulière et d’agrégats de grande taille. Les particules de poudre sont revêtues d’une épaisse couche de lipides leur conférant un caractère cohésif et une grande résistance au cisaillement. Il s’avère aussi que la soupe de kishk présente un comportement rhéofluidifiant, et ses propriétés sensorielles sont fortement liées à la région de production et au type de lait. L’effet des conditions de production optimisée sur les propriétés de la poudre et de la soupe de kishk a été également étudié. Les résultats sont prometteurs et montrent que la structure de la poudre de kishk et son comportement rhéologique n’ont pas été altérés. En effet, les deux poudres de kishk présentent des propriétés rhéologiques quasi similaires, avec une faible aptitude à l’écoulement, malgré des différences au niveau de la composition chimique et la taille des particules. Au niveau rhéologique et sensoriel, la soupe de kishk issue de la production optimisée semble plus épaisse et consistante que la soupe traditionnelle, sans dépréciation notable des qualités organoleptiques du kishk.
The physicochemical (pH, fat and total solids content), sensory (appearance, consistency and taste), and rheological characteristics of five different commercial brands of lactic beverages were determined. Rheological measurements were obtained at 5°C and 25°C using a Brookfield rheometer. The experimental data were described by the power law and Herschel–Bulkley models. The ANOVA of the results were conducted using an incomplete block design, and using Tukey test. Samples showed a significant difference (P⩽0.05%) for fat content and pH. There was a significant difference in total solids content only among Nestlé (A), Batavo (C), and Parmalat (D) samples. Sensory evaluation showed more global acceptability for Nestlé; however, Nestlé and Vigor (E) lactic beverages obtained better results for appearance than for consistency and taste. Batavo obtained the best score for taste. All test samples exhibited non-Newtonian behavior, with thixotropy. Upward curves showed pseudoplastic behavior, while downward curves showed dilatant behavior with the exception of the Nestlé sample, at 25°C. Lactic beverages from all brands analyzed showed similar rheological behavior.
The formation of a casein gel by gradual acidification is the basis for producing fermented dairy products. Caseins mainly contribute to the development and stability of texture that are specific for each product. The composition and technology of producing casein gels affect those texture properties that are based on the microstructure of the products. The aim of the present study was to establish the connections existing between texture properties and the microstructure of milk-based acid gels under various conditions. The concentration of minerals, e.g. NaCl, was set to varying amounts prior to acidification in order to examine the effect on casein aggregation. Furthermore, the influence of rennet action and pH on gel properties was determined.The addition of NaCl to milk leads to an enhanced serum-holding capacity and decreased viscosity of casein gels. This phenomenon is attributed to the lower tendency of casein micelles to aggregate as observed by electron microscopy. The influence of minerals can be eliminated by adding rennet or lowering the pH down to 3.5 since these measures reduce the number of the charged sites on casein micelle surfaces. The serum-holding capacity and viscosity of casein gels is higher, if the pH is set to 3.5 instead of pH 4.6. It was concluded from electron microscopy that the gel strands are less compact at pH 3.5 and incorporate more serum than those at pH 4.6.
Rheological data at 5 °C is presented for buttermilk, a cultured skim milk product. The material exhibits time dependent rheological behaviour. The time dependent behaviour of the product can be characterised using a simple Herschel Bulkley model, modified to include a structural parameter λ to account for time dependent effects. The resulting equation of state takes the form: τ = λ(τy + K⋗gn). The second order rate constant for the decay of the structural parameter with time was found to be relatively independent of shear rate in the range 10–500 s−1, and for periods of shear up to 30 min. By taking the rate constant to be independent of shear rate, the rate equation for the decay of the structural parameter λ was integrated to yield an equation of state for shear stress that depends only on shear rate and time of shear. This equation was used to successfully predict the behaviour of buttermilk in constant and varying shear rate conditions. Such information can be used for the analysis of buttermilk flow in pipelines during start-up and steady state conditions. This type of analysis is valuable for the proper design of pipes and pumps in buttermilk processing plants.
The effects of temperature on the rheological be- havior and surface tension of commercial samples of skim milk, 3.5% milk, 38% cream, two different cul- tured buttermilk products, and buttermilk powder solution were studied using a controlled stress rheom- eter and the Wilhelmy plate method, respectively. The rheology of the dairy fluids was greatly in- fluenced by temperature but to varying degrees de- pending on the product tested. The rheological data for skim milk, 3.5% milk, buttermilk powder solution, and 38% cream could be fitted to the Bingham model at all temperatures, and the cultured buttermilk products could be fitted to the power law model. For the uncultured products, viscosity and yield stress decreased as temperature increased. The dairy products exhibited great variation in surface tension, which also was strongly dependent on temperature. For 38% cream, the measurements of surface tension indicated a high degree of instability as temperatures varied, which suggests that the milk fat globule mem- brane was destabilized at the interface between air and water. This study demonstrates the effect of tem- perature on bulk and interfacial properties of dairy fluids as fat content and milk fat globule fragments vary.
The effect of storage time on the flow properties of concentrated yogurt (labneh) was investigated using a rotational viscometer. Commercial labneh samples were stored at 8 °C. Experiments were performed at 25 °C after 0, 1, 2, 5, 8, 10 or 14 days after the packaging date. The apparent viscosity of fresh sample was then measured as a function of shear rate. For a given shear rate, the apparent viscosity was measured as a function of shearing time. The completely destructed labneh flow properties were also measured after subjecting the labneh samples to a high shear rate for 2 h. The increase in the apparent viscosity of fresh labneh with storage time is attributed to the further development of the gel structure occurred. It was also found that, labneh samples exhibited shear-thinning and thixotropic behaviours with different storage times. The shear-thinning behaviour is fitted well by the power-law model, and the effect of storage time on the power-law parameters was determined. The thixotropic behaviour of labneh was modelled using the structural kinetic approach. For the completely destructed labneh, the effect of storage time on the flow properties was insignificant, and the flow properties were modelled well by the power-law model.
An integrated study was conducted on the effects of temperature, pH, salt type and concentration on the functionality of sodium caseinate, calcium caseinate and rennet casein. At 5.6 less-than-or-equal-to pH less-than-or-equal-to 6.2, all proteins exhibited greatest solubility when sodium phosphate was added. Viscosities under these conditions were one to two orders of magnitude greater than solutions at pH < 4.6. Protein solutions and viscosities with added sodium phosphate were not temperature dependent.
Syneresis of casein gels made by acidification with glucono-δ-lactone (GDL) was studied in relation to gel structure as derived from permeametry and confocal scanning laser microscopy (CSLM). Gels made at 40 °C exhibited ‘spontaneous syneresis’ with wheying-off almost immediately after gelation, while those formed at 30 °C exhibited little syneresis and only after it was initiated by wetting the surface. Syneresis decreased with a reduction in the pH of gels (increasing amount of GDL added). Gels cooled to 5 °C (before initiating syneresis) and low pH gels exhibited ‘negative syneresis’, i.e. an increase in the height of the gel after wetting. Addition of NaCl had little effect on syneresis, except at pH values > 4.6, where gels with added NaCl exhibited stronger syneresis than those made without added NaCl. Higher gelation temperatures resulted in a far greater permeability coefficient (B), indicating the presence of large pores in these gels. Gels formed at low temperatures had a very low B. Addition of NaCl, at all gelation temperatures, markedly reduced B. Confocal scanning micrographs showed that gels made at high gelation temperatures had large pores, many > 20 μm. At low gelation temperatures, the pores were small, mostly < 5 μm. Fractal aggregation theory was used to explain some of the results, especially the rearrangement of aggregated particles at an early stage of the gelation process, i.e. over relatively short distances. It was concluded that gelation temperature had a large effect on this rearrangement. At low temperatures (e.g. 20 °C), rearrangement did not occur, whereas it was already extensive at 30 °C, implying that the ‘building blocks’ of the fractal gel consisted of dense aggregates of, say, 25 casein particles. This resulted in increased permeability. It was also concluded that the syneresis occurring at 30 °C is primarily due to consolidation of the gel network under its own weight, which is soon counteracted by the stress induced by the deformation of this network. Gels formed at higher temperatures may be unstable and show spontaneous syneresis, presumably because some of the strands in the gel network were weak enough to break. No conclusive explanation could be given for the effects of NaCl concentration and pH on the properties of acid casein gels.
Food texture and viscosity: Concept and mea-surement (pp Time dependent rheological characterisation of buttermilk a 5 C
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Determination of rheological properties of several ayrans sold in Istanbul area
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- E Fıratlıgil-Durmuş
- O Evranuz
Lokumcu, F., Fıratlıgil-Durmu-s, E., & Evranuz, O. (2002). Determi-nation of rheological properties of several ayrans sold in Istanbul area. In Proceedings of seventh Turkish food congress (pp. 257–265).
Experimental and modeling studies of the flow properties of concentrated yoghurt as affected by the storage time
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- H Mohameed
Abu-Jdayil, B., & Mohameed, H. (2002). Experimental and modeling studies of the flow properties of concentrated yoghurt as affected by the storage time. Journal of Food Engineering, 52(4), 359–365.
TS 3810 standard of ayran
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