comparison of production of agitated yogurts(high fat onion shallot yogurt) by traditional and industrial methods
Subject Areas : Dail
mahbube
basi
1
(MSc in Agricultural Engineering, Food Science and Industry, Sawadkoh Branch, Islamic Azad University, Sawadkoh, Iran.)
mohammad mehdi
parsapur
2
(Assistant Professor of the Department of Food Science and Industry, Sawadkoh Branch, Islamic Azad University, Sawadkoh, Iran.)
Keywords: Stirred Yogurt, Industrial Production, Traditional Production, Commercial Stabilizer, Condensed Yogurt,
Abstract :
Introduction: Significant properties of concentrated yogurt as compared to regular yogurt has increased the demand for its production and consumption. In this study, high fat flavored yogurt produced traditionally and industrially were compared.Materials and Methods: Stirred yogurt was prepared in a traditional way using a cloth bag and in the industrial way using condensed milk with dry milk and other additives. Finally, physicochemical properties (pH, acidity, hydration and percentage of dry matter), nutritional value and sensory test of the products were compared.Results: The results showed that changes in pH and acidity in traditional yogurt and industrial yogurt were insignificant (P≤0.05), and the amount of water released in traditional yogurt was significantly higher than the industrial yogurt (P≥0.05). Concerned with sensory evaluation, the industrial yogurt was evaluated higher than the traditional yogurt. Traditional yogurt scored better in terms of protein and calcium contents; In term of ash content, the industrial yogurt had a better position.Conclusion: The results of the current research indicated that the production of concentrated yogurt in an industrial way in terms of physicochemical properties, sensory and microbial evaluation, is more suitable than the production of this product by the traditional method, while from the nutritional point of view, the traditional concentrated yogurt had high content of protein and calcium than that of industrial yogurt. This problem of industrial yogurt might be solved and corrected through the use of protein-based stabilizers in the formulation or by enriching the product with calcium.
Abu-Jdayil, B. & Mohameed, H. (2002). Experimental and modelling studies of the flow properties of concentrated yogurt as affected by the storage time. Journal of Food Engineering, 52(4), 359-365.
Alirezalu, K., Hesari, J., Azadmard, D. S., Farajnia, S. & Fathi, A. B. (2017). Evaluation of Chemical and Microbiological Properties of Concentrated “Tuluq” and “Torba” Yoghurts during Storage. Journal of food science and technology, 13 (59), 37-47. [In Persian]
Al-Kadamany, E., Toufeili, I., Khattar, M., Abou-Jawdeh, Y., Harakeh, S. & Haddad, T. (2002). Determination of shelf life of concentrated yogurt (Labneh) produced by in-bag straining of set yogurt using hazard analysis. Journal of dairy science, 85(5), 1023-1030.
Al-Kadamany, E., Khattar, M., Haddad, T. & Toufeili, I. (2003). Estimation of shelf-life of concentrated yogurt by monitoring selected microbiological and physicochemical changes during storage. LWT-Food Science and Technology, 36(4), 407-414.
Amatayakul, T., Halmos, A. L., Sherkat, F. & Shah, N. P. (2006). Physical characteristics of yoghurts made using exopolysaccharide-producing starter cultures and varying casein to whey protein ratios. International Dairy Journal, 16(1), 40-51.
Alsaed, A. K., Ahmad, R., Aldoomy, H., Abd El-Qader, S., Saleh, D., Sakejha, H. & Mustafa, L. (2013). Characterization, concentration and utilization of sweet and acid whey. Pakistan Journal of Nutrition, 12(2), 172.
Andiç, S., Boran, G. & Tunçtürk, Y. (2013). Effects of Carboxyl Methyl Cellulose and Edible Cow Gelatin on Physico-chemical, Textural and Sensory Properties of Yoghurt. International Journal of Agriculture & Biology, 15(2).
Buchholz, A. C. & Schoeller, D. A. (2004). Is a calorie a calorie?. The American journal of clinical nutrition, 79(5), 899S-906S.
Beal, C., Skokanova, J., Latrille, E., Martin, N. & Corrieu, G. (1999). Combined effects of culture conditions and storage time on acidification and viscosity of stirred yogurt. Journal of dairy science, 82(4), 673-681.
Badis, A., Guetarni, D., Boudjema, B. M., Henni, D. E. & Kihal, M. (2004). Identification and technological properties of lactic acid bacteria isolated from raw goat milk of four Algerian races. Food Microbiology, 21(5), 579-588.
Crispín-Isidro, G., Lobato-Calleros, C., Espinosa-Andrews, H., Alvarez-Ramirez, J. & Vernon-Carter, E.J. (2015). Effect of inulin and agave fructans addition on the rheological, microstructural and sensory properties of reduced-fat stirred yogurt. LWT-Food Science and Technology, 62(1), pp.438-444.
Foroughinaia, S., Abbasi, S. & Hamidi Esfahani, Z. (2007). Effect of individual and combined addition of salep, tragacantin and guar gums on the stabilisation of iranian Doogh. Iranian Journal of Nutrition Sciences & Food Technology, 2(2), 15-25. [In Persian]
Founden, R., Mogensen, G., Tanaka, R. & Salimen, S. (2000). Culture containing dairy products-effect on intestinal Microfelora, human nutrition and health-current knowledge and future perspectines. Bull. International Dairy Federation, 35, 21-37.
Güler, Z., & Şanal, H. (2009). The essential mineral concentration of Torba yoghurts and their wheys compared with yoghurt made with cows’, ewes’ and goats’ milks. International Journal of Food Sciences and Nutrition, 60(2), 153-164.
Giraffa, G. & Bergère, J. L. (1987). Nature du caractère épaississant de certaines souches de Streptococcus thermophilus; étude préliminaire. Le lait, 67(3), 285-297.
Guizani, N., Kasapis, S. & Al‐Ruzeiki, M. (2001). Microbial, chemical and rheological properties of laban (cultured milk). International journal of food science & technology, 36(2), 199-205.
Jozedaemi, F., Ghorbani, M., Sadeghi Mahonak, A.R. & Hagh Nazari, S. (2010). Evaluation of sensory and physico-chemical properties of fruit beverage prepared by yoghurt whey. Electron J Food Process Preserv, 1(4), 63-78. [In Persian]
Kashaninejad, M., Najaf Najafi, M., Ghods Rohani, M. & Kashaninejad, M. (2019). Optimization of labane (concentrated yogurt) formulation produced by wheyless process using mixture‐process variable experiments. Journal of Food Processing and Preservation, 43(11), e14193.
Ladjevardi, ZH., Gharinzadeh, M. & Mousavi, M. (2015). Development of a stable low-fat yogurt gel using functionality of psyllium (Plantago ovata Forsk) husk gum. Carbohydrate polymers, 125. 272-280. [In Persian]
Mazaheri, T. M., Razavi, S. M. A. & Talakar, H. (2008). Effect of Increasing Solids Non-Fat Milk and Calcium chloride in Physicochemical and Sensory Properties Concentrated Yoghurt. Iranian Food Science and Technology Research Journal, 4(1), 69-76. [In Persian]
Maiorella, B. L. & Castillo, F. J. (1984). Ethanol, biomass and enzyme production for whey waste abatement. Process Biochem;(United Kingdom), 19(4).
Mahdian, E., Mazaheri, T. M. & Karazhian, R. (2006). Effect of fat content of milk on the growth and metabolic activity of starter cultures and quality of concentrated yoghurt.
Journal of Food Science and Technology, 3(8), 59-66. [In Persian]
Meilgaard, M.C., Civille, G.V. & Carr, B.T (1999). Sensory Evaluation Techniques (3rd ed.) CRC press, LLC, U.S.A. P.416.
Okoye, J.I. & Animalu, I.L. (2009) Evaluation of physicochemical and microbiological properties of stirred yoghurt stabilized with sweet potato (Ipomea Batata) Continental. Journal of Microbiology, 3, 27-30.
Nsabimana, C., Jiang, B. & Kossah, R. 2005. Manufacturing, properties and shelf life of labneh: a review. International Journal of Dairy Technology, 58, 222-231.
Nergiz, C. & Seçkin, A. K. (1998). The losses of nutrients during the production of strained (Torba) yoghurt. Food Chemistry, 61(1-2), 13-16.
Ozer, B. H., Robinson, R. K., Grandison, A. S. & Bell, A. E. (1997). Comparison of techniques for measuring the rheological properties of labneh (concentrated yogurt). International Journal of Dairy Technology, 50(4), 129-133.
Ozer, B. H., Robinson, R. K., Grandison, A. S. & Bell, A. E. (1998). Gelation properties of milk concentrated by different techniques. International Dairy Journal, 8(9), 793-799.
Ozer, B. H., Bell, A. E., Grandison, A. S. & Robinson, R. K. (1998). Rheological properties of concentrated yoghurt (labneh). Journal of Texture Studies, 29(1), 67-79.
Ott, A., Germond, J. E., Baumgartner, M. & Chaintreau, A. (1999). Aroma comparisons of traditional and mild yogurts: headspace gas chromatography quantification of volatiles and origin of α-diketones. Journal of Agricultural and Food Chemistry, 47(6), 2379-2385.
Pereira, R., Matia-Merino, L., Jones, V. & Singh, H. (2006). Influence of fat on the perceived texture of set acid milk gels: a sensory perspective. Food Hydrocolloids, 20(2-3), 305-313.
Pishbahar, E. & Kheirinataj, F. M. (2015). Evaluation of hedonic pricing of dairy products. Journal of Food Research, 24 (4), 579- 588. [In Persian]
Razmkhah, S., Razav, S. M. A., Behzad, K. & Mazaheri Tehrani, M. (2010). The effect of pectin. sage seed gum and basil seed gum on physicochemical and sensory characteristics of non fat concentrated yoghurt. Iranian Food Science and Technology Research Journal, 6(1), 27-36. [In Persian]
Ramchandran, L. (2009). Physico-chemical and therapeutic properties of low-fat yogurt as influenced by fat replacers, exopolysaccharides and probiotics.
Salji, J. P. (1991). Concentrated yoghurt: A challenge to our food industry. Food science and technology today, 5, 18-19.
Sodini, I., Montella, J. & Tong, P. S. (2005). Physical properties of yogurt fortified with various commercial whey protein concentrates. Journal of the Science of Food and Agriculture, 85(5), 853-859.
Supavititpatana, P., Wirjantoro, T. I. & Raviyan, P. (2010). Characteristics and shelf-life of corn milk yogurt. Journal of Natural Science, 9(1), 133-147.
Shirmohammadi, M., Alami, M., Maghsoudlou, Y. & Khomeyri, M. (2021). Evaluation of the nutrient losses during the production of concentrated yoghurt and labneh cheese at industrial level and in separating method. Journal of Food Research, 31(2), 1-16. [In Persian]
Shihata, A. & Shah, N. P. (2000). Proteolytic profiles of yogurt and probiotic bacteria. International Dairy Journal, 10(5-6), 401-408.
Şahan, N., Var, I. Ş. I. L., Say, D. İ. L. E. K. & Aksan, E. (2004). Microbiological properties of labneh (concentrated yoghurt) stored without vegetable oil at room or refrigeration temperatures. Acta alimentaria, 33(2), 175-182.
Şahan, N. & Say, D. (1998). Hatay ilinde üretilen tuzlu yoğurtlar üzerine bir araştırma. V. Süt ve Süt Ürünleri Sempozyumu “Geleneksel Süt Ürünleri, 21-22.
Say, D. & Sahan, N. (2002). The microbiological properties of Labneh (concentrated yoghurt) stored with oil at room and refrigerator temperatures. Milchwissenschaft, 57 (9/10).
Tamime, A. Y. & Robinson, R. K. (1999). Yoghurt. Science and Technology. Cambridge, UK: Woodhead Publishing Limited England.
Tamime, A. Y., Davies, G., Chehade, A. S. & Mahdi, H. A. (1991). The effect of processing temperatures on the quality of labneh made by ultrafiltration. International Journal of Dairy Technology, 44(4), 99-103.
Tamime, A. Y., Barrantes, E. & Sword, A. M. (1996). The effect of starch based fat substitutes on the microstructure of set‐style yogurt made from reconstituted skimmed milk powder. International Journal of Dairy Technology, 49(1), 1-10.
Tamime, A. Y. & Robinson, R. K. (2007). Tamime and Robinson's yoghurt: science and technology. Elsevier.
Tamime, A. Y., Davies, G., Chehade, A. S. & Mahdi, H. A. (1989). The production of ‘Labneh’by ultrafiltration: a new technology. International Journal of Dairy Technology, 42(2), 35-39.
Tamime, A. Y., Kalab, M. & Davies, G. (1989). Rheology and microstructure of strained Yoghurt (Labneh) made from cow's milk by three different methods. Food Structure, 8(1), 15.
Tamime, A.Y. (1993). In Encyclopaedia of Food Science, Food Technology and Nutrition, Vol. 7, Ed. byMaCrae, R., Robinson, R.K. and Sadler, M.J., Academic Press, London, 4972– 4977.
Wouters, J. T. M., Ayad, E. H. E., Hugenholtz, J. & Smit, G. (2002). Microbes from raw milk for fermented dairy products. International Dairy Journal, 12, 91-109.
Wood, B. J. & Holzapfel, W. H. N. (Eds.). (1992). The genera of lactic acid bacteria (Vol. 2). Springer Science & Business Media.
Yeganehzad, S., Mazaheri-Tehrani, M. & Shahidi, F. (2007). Studying microbial, physiochemical and sensory properties of directly concentrated probiotic yoghurt. African Journal of Agricultural Research, 2(8), 365-369. [In Persian]
_||_Abu-Jdayil, B. & Mohameed, H. (2002). Experimental and modelling studies of the flow properties of concentrated yogurt as affected by the storage time. Journal of Food Engineering, 52(4), 359-365.
Alirezalu, K., Hesari, J., Azadmard, D. S., Farajnia, S. & Fathi, A. B. (2017). Evaluation of Chemical and Microbiological Properties of Concentrated “Tuluq” and “Torba” Yoghurts during Storage. Journal of food science and technology, 13 (59), 37-47. [In Persian]
Al-Kadamany, E., Toufeili, I., Khattar, M., Abou-Jawdeh, Y., Harakeh, S. & Haddad, T. (2002). Determination of shelf life of concentrated yogurt (Labneh) produced by in-bag straining of set yogurt using hazard analysis. Journal of dairy science, 85(5), 1023-1030.
Al-Kadamany, E., Khattar, M., Haddad, T. & Toufeili, I. (2003). Estimation of shelf-life of concentrated yogurt by monitoring selected microbiological and physicochemical changes during storage. LWT-Food Science and Technology, 36(4), 407-414.
Amatayakul, T., Halmos, A. L., Sherkat, F. & Shah, N. P. (2006). Physical characteristics of yoghurts made using exopolysaccharide-producing starter cultures and varying casein to whey protein ratios. International Dairy Journal, 16(1), 40-51.
Alsaed, A. K., Ahmad, R., Aldoomy, H., Abd El-Qader, S., Saleh, D., Sakejha, H. & Mustafa, L. (2013). Characterization, concentration and utilization of sweet and acid whey. Pakistan Journal of Nutrition, 12(2), 172.
Andiç, S., Boran, G. & Tunçtürk, Y. (2013). Effects of Carboxyl Methyl Cellulose and Edible Cow Gelatin on Physico-chemical, Textural and Sensory Properties of Yoghurt. International Journal of Agriculture & Biology, 15(2).
Buchholz, A. C. & Schoeller, D. A. (2004). Is a calorie a calorie?. The American journal of clinical nutrition, 79(5), 899S-906S.
Beal, C., Skokanova, J., Latrille, E., Martin, N. & Corrieu, G. (1999). Combined effects of culture conditions and storage time on acidification and viscosity of stirred yogurt. Journal of dairy science, 82(4), 673-681.
Badis, A., Guetarni, D., Boudjema, B. M., Henni, D. E. & Kihal, M. (2004). Identification and technological properties of lactic acid bacteria isolated from raw goat milk of four Algerian races. Food Microbiology, 21(5), 579-588.
Crispín-Isidro, G., Lobato-Calleros, C., Espinosa-Andrews, H., Alvarez-Ramirez, J. & Vernon-Carter, E.J. (2015). Effect of inulin and agave fructans addition on the rheological, microstructural and sensory properties of reduced-fat stirred yogurt. LWT-Food Science and Technology, 62(1), pp.438-444.
Foroughinaia, S., Abbasi, S. & Hamidi Esfahani, Z. (2007). Effect of individual and combined addition of salep, tragacantin and guar gums on the stabilisation of iranian Doogh. Iranian Journal of Nutrition Sciences & Food Technology, 2(2), 15-25. [In Persian]
Founden, R., Mogensen, G., Tanaka, R. & Salimen, S. (2000). Culture containing dairy products-effect on intestinal Microfelora, human nutrition and health-current knowledge and future perspectines. Bull. International Dairy Federation, 35, 21-37.
Güler, Z., & Şanal, H. (2009). The essential mineral concentration of Torba yoghurts and their wheys compared with yoghurt made with cows’, ewes’ and goats’ milks. International Journal of Food Sciences and Nutrition, 60(2), 153-164.
Giraffa, G. & Bergère, J. L. (1987). Nature du caractère épaississant de certaines souches de Streptococcus thermophilus; étude préliminaire. Le lait, 67(3), 285-297.
Guizani, N., Kasapis, S. & Al‐Ruzeiki, M. (2001). Microbial, chemical and rheological properties of laban (cultured milk). International journal of food science & technology, 36(2), 199-205.
Jozedaemi, F., Ghorbani, M., Sadeghi Mahonak, A.R. & Hagh Nazari, S. (2010). Evaluation of sensory and physico-chemical properties of fruit beverage prepared by yoghurt whey. Electron J Food Process Preserv, 1(4), 63-78. [In Persian]
Kashaninejad, M., Najaf Najafi, M., Ghods Rohani, M. & Kashaninejad, M. (2019). Optimization of labane (concentrated yogurt) formulation produced by wheyless process using mixture‐process variable experiments. Journal of Food Processing and Preservation, 43(11), e14193.
Ladjevardi, ZH., Gharinzadeh, M. & Mousavi, M. (2015). Development of a stable low-fat yogurt gel using functionality of psyllium (Plantago ovata Forsk) husk gum. Carbohydrate polymers, 125. 272-280. [In Persian]
Mazaheri, T. M., Razavi, S. M. A. & Talakar, H. (2008). Effect of Increasing Solids Non-Fat Milk and Calcium chloride in Physicochemical and Sensory Properties Concentrated Yoghurt. Iranian Food Science and Technology Research Journal, 4(1), 69-76. [In Persian]
Maiorella, B. L. & Castillo, F. J. (1984). Ethanol, biomass and enzyme production for whey waste abatement. Process Biochem;(United Kingdom), 19(4).
Mahdian, E., Mazaheri, T. M. & Karazhian, R. (2006). Effect of fat content of milk on the growth and metabolic activity of starter cultures and quality of concentrated yoghurt.
Journal of Food Science and Technology, 3(8), 59-66. [In Persian]
Meilgaard, M.C., Civille, G.V. & Carr, B.T (1999). Sensory Evaluation Techniques (3rd ed.) CRC press, LLC, U.S.A. P.416.
Okoye, J.I. & Animalu, I.L. (2009) Evaluation of physicochemical and microbiological properties of stirred yoghurt stabilized with sweet potato (Ipomea Batata) Continental. Journal of Microbiology, 3, 27-30.
Nsabimana, C., Jiang, B. & Kossah, R. 2005. Manufacturing, properties and shelf life of labneh: a review. International Journal of Dairy Technology, 58, 222-231.
Nergiz, C. & Seçkin, A. K. (1998). The losses of nutrients during the production of strained (Torba) yoghurt. Food Chemistry, 61(1-2), 13-16.
Ozer, B. H., Robinson, R. K., Grandison, A. S. & Bell, A. E. (1997). Comparison of techniques for measuring the rheological properties of labneh (concentrated yogurt). International Journal of Dairy Technology, 50(4), 129-133.
Ozer, B. H., Robinson, R. K., Grandison, A. S. & Bell, A. E. (1998). Gelation properties of milk concentrated by different techniques. International Dairy Journal, 8(9), 793-799.
Ozer, B. H., Bell, A. E., Grandison, A. S. & Robinson, R. K. (1998). Rheological properties of concentrated yoghurt (labneh). Journal of Texture Studies, 29(1), 67-79.
Ott, A., Germond, J. E., Baumgartner, M. & Chaintreau, A. (1999). Aroma comparisons of traditional and mild yogurts: headspace gas chromatography quantification of volatiles and origin of α-diketones. Journal of Agricultural and Food Chemistry, 47(6), 2379-2385.
Pereira, R., Matia-Merino, L., Jones, V. & Singh, H. (2006). Influence of fat on the perceived texture of set acid milk gels: a sensory perspective. Food Hydrocolloids, 20(2-3), 305-313.
Pishbahar, E. & Kheirinataj, F. M. (2015). Evaluation of hedonic pricing of dairy products. Journal of Food Research, 24 (4), 579- 588. [In Persian]
Razmkhah, S., Razav, S. M. A., Behzad, K. & Mazaheri Tehrani, M. (2010). The effect of pectin. sage seed gum and basil seed gum on physicochemical and sensory characteristics of non fat concentrated yoghurt. Iranian Food Science and Technology Research Journal, 6(1), 27-36. [In Persian]
Ramchandran, L. (2009). Physico-chemical and therapeutic properties of low-fat yogurt as influenced by fat replacers, exopolysaccharides and probiotics.
Salji, J. P. (1991). Concentrated yoghurt: A challenge to our food industry. Food science and technology today, 5, 18-19.
Sodini, I., Montella, J. & Tong, P. S. (2005). Physical properties of yogurt fortified with various commercial whey protein concentrates. Journal of the Science of Food and Agriculture, 85(5), 853-859.
Supavititpatana, P., Wirjantoro, T. I. & Raviyan, P. (2010). Characteristics and shelf-life of corn milk yogurt. Journal of Natural Science, 9(1), 133-147.
Shirmohammadi, M., Alami, M., Maghsoudlou, Y. & Khomeyri, M. (2021). Evaluation of the nutrient losses during the production of concentrated yoghurt and labneh cheese at industrial level and in separating method. Journal of Food Research, 31(2), 1-16. [In Persian]
Shihata, A. & Shah, N. P. (2000). Proteolytic profiles of yogurt and probiotic bacteria. International Dairy Journal, 10(5-6), 401-408.
Şahan, N., Var, I. Ş. I. L., Say, D. İ. L. E. K. & Aksan, E. (2004). Microbiological properties of labneh (concentrated yoghurt) stored without vegetable oil at room or refrigeration temperatures. Acta alimentaria, 33(2), 175-182.
Şahan, N. & Say, D. (1998). Hatay ilinde üretilen tuzlu yoğurtlar üzerine bir araştırma. V. Süt ve Süt Ürünleri Sempozyumu “Geleneksel Süt Ürünleri, 21-22.
Say, D. & Sahan, N. (2002). The microbiological properties of Labneh (concentrated yoghurt) stored with oil at room and refrigerator temperatures. Milchwissenschaft, 57 (9/10).
Tamime, A. Y. & Robinson, R. K. (1999). Yoghurt. Science and Technology. Cambridge, UK: Woodhead Publishing Limited England.
Tamime, A. Y., Davies, G., Chehade, A. S. & Mahdi, H. A. (1991). The effect of processing temperatures on the quality of labneh made by ultrafiltration. International Journal of Dairy Technology, 44(4), 99-103.
Tamime, A. Y., Barrantes, E. & Sword, A. M. (1996). The effect of starch based fat substitutes on the microstructure of set‐style yogurt made from reconstituted skimmed milk powder. International Journal of Dairy Technology, 49(1), 1-10.
Tamime, A. Y. & Robinson, R. K. (2007). Tamime and Robinson's yoghurt: science and technology. Elsevier.
Tamime, A. Y., Davies, G., Chehade, A. S. & Mahdi, H. A. (1989). The production of ‘Labneh’by ultrafiltration: a new technology. International Journal of Dairy Technology, 42(2), 35-39.
Tamime, A. Y., Kalab, M. & Davies, G. (1989). Rheology and microstructure of strained Yoghurt (Labneh) made from cow's milk by three different methods. Food Structure, 8(1), 15.
Tamime, A.Y. (1993). In Encyclopaedia of Food Science, Food Technology and Nutrition, Vol. 7, Ed. byMaCrae, R., Robinson, R.K. and Sadler, M.J., Academic Press, London, 4972– 4977.
Wouters, J. T. M., Ayad, E. H. E., Hugenholtz, J. & Smit, G. (2002). Microbes from raw milk for fermented dairy products. International Dairy Journal, 12, 91-109.
Wood, B. J. & Holzapfel, W. H. N. (Eds.). (1992). The genera of lactic acid bacteria (Vol. 2). Springer Science & Business Media.
Yeganehzad, S., Mazaheri-Tehrani, M. & Shahidi, F. (2007). Studying microbial, physiochemical and sensory properties of directly concentrated probiotic yoghurt. African Journal of Agricultural Research, 2(8), 365-369. [In Persian]