The addition of prebiotics such as oligofructose to yogurt can result in a product with consumer benefits, since they stimulate growth of benefic bacteria present in the intestine and also provide a low calorie product, since one can add less sugar to the formulation due to their sweetening power. This work aimed to evaluate the effect of increasing concentrations of oligofructose addition on physicochemical, rheological and microbiological characteristics of non-flavored yogurt. Furthermore, it was investigated the reaction of consumers with the use of the survival analysis methodology. The addition of oligofructose showed no influence on the pH, proteolysis or the viability of Streptococcus thermophilus or Lactobacillus bulgaricus during 28 days of refrigerated storage (p > 0.05). According to rheological measurements the yogurt supplemented with oligofructose was characterized as a weak gel, showing thixotropic and pseudoplastic behavior. Survival analysis was used to investigate consumer responses with respect to different levels of supplementation of plain yogurt with oligofructose (0%, 2%, 4%, 6% and 8% wt. v-1). Using the survival analysis and considering a rejection by 25% of the consumers, the level of oligofructose that can be added to the yogurt was shown to be 2.58% wt. v-1. © 2012 Elsevier Ltd. All rights reserved.1143323330Allgeyer, L.C., Miller, M.J., Lee, S.-Y., Sensory and microbiological quality of yogurt drinks with prebiotics and probiotics (2010) J. Dairy Sci., 93, pp. 4471-4479Allgeyer, L.C., Miller, M.J., Lee, S.Y., Drivers of liking for yoghurt drinks with prebiotics and probiotics (2010) J. Food Sci., 75, pp. 212-219Arcia, P.L., Costell, E., Tárrega, A., Inulin blend as prebiotic and fat replacer in dairy desserts: Optimization by response surface methodology (2011) J. Dairy Sci., 94, pp. 2192-2200Ares, G., Baixauli, R., Sanz, T., Varela, P., Salvador, A., New functional fibre in milk puddings: Effect on sensory properties and consumers' acceptability (2009) LWT - Food Science and Technology, 42 (3), pp. 710-716. , DOI 10.1016/j.lwt.2008.10.004, PII S0023643808002570Bleiel, J., Functional foods from the perspective of the consumer: How to make it a success? (2010) Int. Dairy J., 20, pp. 303-306Bolye, F.G., Wrenn, J.M., Marsh, B.B., Anderson, W.I., Angelosanto, F.A., McCartney, A.L., Lien, E.L., Safety evaluation of oliogofructose: 13 Week rat study in vitro mutagenicity (2008) Food Chem. Toxicol., 45, pp. 3132-3139Bourne, M.C., (2002) Food Texture and Viscosity: Concept and Measurement, p. 427. , second ed. Academic Press, San Diego, CA2003 Agência Nacional de Vigilância Sanitária, , http://www.anvisa.gov.br, Brasil Aprovar o Regulamento Técnico de Porções de Alimentos Embalados para Fins de Rotulagem Nutricional. Disponível em acessed 13 04 11.)(2007) Ministério da Agricultura, Pecuária e Abastecimento, , http://www.agricultura.gov.br, Brasil Instrução Normativa 46 de 23/10/2007. Regulamento Técnico de Identidade e Qualidade de Leites Fermentados. Available from(2008) Agência Nacional de Vigilância Sanitária, , http://www.anvisa.gov.br, Brasil Alimentos com Alegações de Propriedades Funcionais e/ou de Saúde, Novos Alimentos/Ingredientes, Substâncias Bioativas e Probióticos. Lista de alegações de propriedade funcional aprovadas, atualizada em junho 2008. Disponível em acessed 13 04 11.)Castro, F.P., Cunha, T.M., Ogliari, P.J., Teófilo, R.F., Ferreira, M.M.C., Prudêncio, E.S., Influence of different content of cheese whey and oligofructose on the properties of fermented lactic beverages: Study using response surface methodology (2009) LWT-Food Sci. Technol., 42, pp. 993-997Castro, F.P., Cunha, T.M., Barreto, P.L.M., Amboni, R.D.M.C., Prudêncio, E.S., Effect of oligofructose incorporation on the properties of fermented probiotic lactic beverages (2009) Int. J. Dairy Technol., 62, pp. 74-82Chiavaro, E., Vittadini, E., Corradini, C., Physicochemical characterization and stability of inulin gels (2007) European Food Research and Technology, 225 (1), pp. 85-94. , DOI 10.1007/s00217-006-0385-yChurch, F.C., Swaisgood, H.E., Porter, D.H., Catignani, G.L., Spectrophotometric assay using o-phthaldialdehyde for determination of proteolysis in milk and isolated milk proteins (1983) J. Dairy Sci., 66, pp. 1219-1227Cruz, A.G., Faria, J.A.F., Walter, E.H.M., Andrade, R.R., Walter, E.H.M., Cavalcanti, R.N., Processing optimization of probiotic yogurt containing glucose oxidase using response surface methodology (2010) J. Dairy Sci., 93, pp. 5059-5068Cruz, A.G., Walter, E.H.M., Cadena, R.S., Faria, J.A.F., Bolini, H.M.A., Pinheiro, H.P., Sant́ana, A.S., Survival analysis methodology to predict the shelf-life of probiotic flavored yogurt (2010) Food Res. Int., 43, pp. 1444-1448Cruz, A.G., Cadena, R.S., Granato, D., Walter, E.H.M., Faria, J.A.F., Bolini, H.M.A., Sensory analysis: Relevance for prebiotic, probiotic and synbiotic food development (2010) Compr. Rev. Food Sci. Saf., 9, pp. 358-373Cruz, A.G., Cadena, R.S., Faria, J.A.F., Oliveira, C.A.F., Cavalcanti, R.N., Bona, E., Bolini, H.M.A., Da Silva, M.A.A.P., Consumer acceptability and purchase intent of probiotic yoghurt with added glucose oxidase using sensometrics, artificial neural networks and logistic regression (2011) Int. J. Dairy Technol., 64, pp. 549-556Cruz, A.G., Castro, W.F., Faria, J.A.F., Lollo, P.C.B., Amaya-Farfán, M.Q., Freitas, M.Q., Rodrigues, D., Godoy, H.T., Probiotic yogurts manufactured with increased glucose oxidase levels: Post-acidification, proteolytic patterns, survival of probiotic microorganisms, production of organic acid and aroma compounds (2012) J. Dairy Sci., 95, pp. 2261-2269Cruz, A.G., Castro, W.F., Faria, J.A.F., Celeghini, R.M.S., Lima-Pallone, J., Godoy, H.T., Glucose oxidase: A potential option to decrease the oxidative stress in stirred probiotic yogurt (2012) LWT-Food Sci. Technol., 42, pp. 512-515Cunha, T.M., Castro, F.P., Barreto, P.L.M., Benedet, H.D., Prudêncio, E.S., Avaliação físico-química, microbió logica e reológica de bebida láctea fermentada e leite fermentado adicionados de probióticos (2008) Semina: Ciências Agrárias, 29, pp. 103-116Debon, J., Prudêncio, E.S., Petrus, J.C.C., Rheological and physico-chemical characterization of prebiotic microfiltered fermented milk (2010) J. Food Eng., 99, pp. 128-135Debon, J., Prudêncio, E.S., Petrus, J.C.C., Fritzen-Freire, C.B., Müller, C.M.O., Amboni, R.D.D.M.C., Vieira, C.R.W., Storage stability of prebiotic fermented milk obtained from permeate resulting of the microfiltration process (2012) LWT-Food Sci. Technol., pp. 96-102Drake, M., Sensory analysis of dairy foods (2007) J. Dairy Sci., 90, pp. 4925-4937Elizaquível, P., Sánchez, G., Salvador, A., Fiszman, S., Dueñas, M.T., López, P., Fernández De Palencia, P., Aznar, R., Evaluation of yogurt and various beverages as carriers of lactic acid bacteria producing 2-branched (1, 3)-b-d-glucan (2011) J. Dairy Sci., 94, pp. 3271-3278Fritzen-Freire, C.B., Müller, C.M.O., Laurindo, J.B., Prudêncio, E.S., The influence of Bifidobacterium Bb-12 and lactic acid incorporation on the properties of Minas Frescal cheese (2010) J. Food Eng., 96, pp. 621-627Gambarro, A., Ares, G., Gimenez, A., Shelf-life estimation of apple baby food (2006) J. Sens. Stud., 21, pp. 101-111Gimenez, A., Varela, P., Salvador, A., Ares, G., Fiszman, S., Garitta, L., Shelf life estimation of brown pan bread: A consumer approach (2007) Food Quality and Preference, 18 (2), pp. 196-204. , DOI 10.1016/j.foodqual.2005.09.017, PII S0950329305001552Glibowski, P., Kowalska, A., Rheological, texture and sensory properties of kefir with high performance and native inulin (2012) J. Food Eng., 111, pp. 299-304Gonzalez, N.J., Adhikari, K., Sancho-Madriz, M.F., Sensory characteristics of peach-flavored yogurt drinks containing prebiotics and synbiotics (2011) LWT-Food Sci. Technol., 44, pp. 158-163Gonzalez-Tomas, L., Coll-Marques, J., Costell, E., Viscoelasticity of inulin-starch-based dairy systems. Influence of inulin average chain length (2008) Food Hydrocolloids, 22 (7), pp. 1372-1380. , DOI 10.1016/j.foodhyd.2007.08.001, PII S0268005X07002007González-Tomás, L., Sara Bayarri, S., Coll-Marqués, J., Costell, E., Flow behaviour of inulin-enriched dairy desserts: Influence of inulin average chain length (2009) Int. J. Food Sci. Technol., 44, pp. 1214-1222Guggisberg, D., Cuthbert-Steven, J., Piccinali, P., Bütikofer, U., Eberhard, P., Rheological, microstructural and sensory characterization of low-fat and whole milk set yogurt as influenced by inulin addition (2009) Int. Dairy J., 19, pp. 107-115Hennigsson, M., Östergren, K., Dejmek, P., Plug flow of yoghurt in piping as determined by cross-correlated dual-plane electrical resistance tomography (2006) J. Food Eng., 76, pp. 163-168Hess, J.R., Birkett, A.M., Thomas, W., Slavin, J.L., Effects of short-chain fructooligosaccharides on satiety responses in healthy men and women (2011) Appetite, 56, pp. 128-134Heydari, S., Mortazavian, A.M., Ehsani, M.R., Mohammadifar, M.A., Ezzatpanah, H., Biochemical, microbiological and sensory characteristics of probiotic yogurt containing various prebiotic compounds (2011) Ital. J. Food Sci., 23, pp. 153-163Hough, G., (2010) Sensory Shelf Life Estimation of Food Products, p. 239. , CRC Press, Boca RantonHough, G., Garitta, L., Methodology for sensory shelf-life estimation: A review (2012) J. Sens. Stud., 27, pp. 137-147Hough, G., Puglieso, M.L., Sanchez, R., Da Silva, O.M., Sensory and microbiological shelf-life of a commercial Ricotta cheese (1999) Journal of Dairy Science, 82 (3), pp. 454-459Hough, G., Langohr, K., Gómez, G., Curia, A., Survival analysis applied to sensory shelf life of foods (2003) J. Food Sci., 68 (359-362), p. 2003Isik, U., Boyacioglu, D., Capanoglu, E., Nilufer Erdil, D., Frozen yogurt with added inulin and isomalt (2011) J. Dairy Sci., 94, pp. 1647-1656Jacobo-Velázquez, D.A., Hernández-Brenes, C., Sensory shelf-life limiting factor of high hydrostatic pressure processed avocado paste (2010) J. Food Sci., 76, pp. 388-395Kemal-Seckin, A., Yeliz-Ozkilinc, A., Effect of some prebiotics usage on quality properties of concentrated yogurt (2011) J. Anim. Vet. Adv., 10, pp. 1117-1123Kim, S.H., Lee, S.Y., Palanivel, G., Kwak, H.S., Effect of Dioscorea opposita Thunb. (yam) supplementation on physicochemical and sensory characteristics of yogurt (2011) J. Dairy Sci., 94, pp. 1705-1712Kip, P., Meyer, D., Jellena, R.H., Inulins improve sensoric and textural properties of low-fat yoghurts (2006) Int. Dairy J., 16, pp. 1098-1103Libertino, L.M., López, M.M., Hough, G., Number of consumers necessary for survival analysis estimations based on each consumer evaluating a single sample (2011) Food Qual. Prefer., 22, pp. 24-30MacFie, H.J., Bratchell, N., Greenhoff, K., Vallis, L.V., Designs to balance the effect of order of presentation and first-order carry-over effects in hall tests (1989) J. Sens. Stud., 4, pp. 129-148Marafon, A.P., Sumi, A., Granato, D., Alcântara, M.R., Tamime, A.Y., Oliveira, M.N., Effects of partially replacing skimmed milk powder with dairy ingredients on rheology, sensory profiling, and microstructure of probiotic stirred-type yogurt during cold storage (2011) J. Dairy Sci., 94, pp. 5330-5340Marshall, R.T., (1993) Standard Methods for Examination of Dairy Products, , American Public Health Association, WashingtonMeyer, D., Bayari, S., Tárrega, A., Costell, E., Inulin as texture modifier in dairy products (2011) Food Hydrocolloids, 25, pp. 1881-1890Oliveira, R.P.S., Florence, A.C.R., Silva, R.C., Perego, P., Converti, A., Gioielli, L.A., Oliveira, M.N., Effect of different prebiotics on the fermentation kinetics, probiotic survival and fatty acids profiles in nonfat symbiotic fermented milk (2009) Int. J. Food Microbiol., 128, pp. 467-472Ozcan, T., Horne, D., Lucey, J.A., Effect of increasing the colloidal calcium phosphate of milk on the texture and microstructure of yogurt (2011) J. Dairy Sci., 94, pp. 5278-5288Paseephol, T., Small, D.M., Sherkat, F., Rheology and texture of set yoghurt as affected by inulin addition (2008) J. Texture Stud., 39, pp. 617-634Peng, Y., Horne, D.S., Lucey, J.A., Physical properties of acid milk gels prepared at 37 °c up to gelation but at different incubation temperatures for the remainder of fermentation (2010) J. Dairy Sci., 93, pp. 1910-1917Ramirez-Santiago, C., Ramos-Solis, L., Lobato-Calleros, C., Peña-Valdivia, C., Vernon-Carter, E.J., Alvarez-Ramírez, J., Enrichment of stirred yogurt with soluble dietary fiber from Pachyrhizus erosus L. Urban: Effect on syneresis, microstructure and rheological properties (2010) J. Food Eng., 101, pp. 229-235Rao, V.A., The prebiotic properties of oligofructose at low intake levels (2001) Nutrition Research, 21 (6), pp. 843-848. , DOI 10.1016/S0271-5317(01)00284-6, PII S0271531701002846Roberfroid, M.B., Functional foods: Concepts and application to inulin and oligofructose (2002) Br. J. Nutr., 87, pp. 139-143Ross-Murphy, S.B., (1990) Food Polymers, Gels and Colloids, pp. 357-368. , Dickinson, E. (Ed.) University of Leeds, United KingdomSaavedra, J.M., Tschernia, A., Human studies with probiotics and prebiotics: Clinical implications (2002) Br. J. Nutr., 87 S, pp. 241-246Sato, A.C.K., Da Cunha, R.L., Influence of temperature on the rheological behavior of jaboticaba pulp (2007) Ciencia e Tecnologia de Alimentos, 27 (4), pp. 890-896. , http://www.scielo.br/pdf/cta/v27n4/33.pdf, DOI 10.1590/S0101-20612007000400033Schaller-Povolny, L.A., Smith, D.E., Viscosity and freezing point of a reduced fat ice cream mix as related to inulin content (2001) Milchwissenschaft, 56 (1), pp. 25-29Schramm, G., (1998) Reologia. Podstawy i Zastosowania (Rheology Fundamentals and Practice), , Osrodek Wydawnictw Nawkowygh Pan, Poznán (in Polish)Shama, F., Sherman, P., Identification of stimuli controlling the sensory evaluation of viscosity II. Oral methods (1973) J. Texture Stud., 4, pp. 111-118Soukoulis, C., Lebesi, D., Tzia, C., Enrichment of ice cream with dietary fiber: Effects on rheological properties, ice crystallization and glass transition phenomena (2009) Food Chem., 115, pp. 665-671Steffe, J.F., (1996) Rheological Methods in Food Process Engineering, p. 412. , second ed. Freeman Press, East LansingTabilo-Munizaga, G., Barbosa-Cánovas, G.V., Rheology for the food industry (2005) J. Food Eng., 67, pp. 147-156Tamime, A.Y., (2006) Fermented Milks, , Blackwell Science Ltd., Oxford, EnglandTarrega, A., Costell, E., Colour and consistency of semi-solid dairy desserts: Instrumental and sensory measurements (2007) Journal of Food Engineering, 78 (2), pp. 655-661. , DOI 10.1016/j.jfoodeng.2005.11.003, PII S026087740500751XTárrega, A., Rocafull, A., Costell, E., Effect of blends of short and long-chain inulin on the rheological and sensory properties of prebiotic low-fat custards (2010) LWT-Food Sci. Technol., 43, pp. 556-562Villegas, B., Costell, E., Flow behaviour of inulin-milk beverages. Influence of inulin average chain length and of milk fat content (2007) International Dairy Journal, 17 (7), pp. 776-781. , DOI 10.1016/j.idairyj.2006.09.007, PII S0958694606002226Wada, T., Sugatani, J., Terada, E., Ohguchi, M., Miwa, M., Physicochemical characterization and biological effects of inulin enzymatically synthesized from sucrose (2005) Journal of Agricultural and Food Chemistry, 53 (4), pp. 1246-1253. , DOI 10.1021/jf048711uWaligora-Dupriet, A.-J., Campeotto, F., Nicolis, I., Bonet, A., Soulaines, P., Dupont, C., Butel, M.-J., Effect of oligofructose supplementation on gut microflora and well-being in young children attending a day care centre (2007) International Journal of Food Microbiology, 113 (1), pp. 108-113. , DOI 10.1016/j.ijfoodmicro.2006.07.009, PII S0168160506004326Wang, Y., Prebiotics: Present and future in food science and technology (2009) Food Res. Int., 1, pp. 8-12