Developing a prebiotic yogurt: Rheological, physico-chemical and microbiological aspects and adequacy of survival analysis methodology

• Published in: Journal of food engineering 2013-02, Vol.114 (3), p.323-330
• Main Authors: Cruz, A.G., Cavalcanti, R.N., Guerreiro, L.M.R., Sant’Ana, A.S., Nogueira, L.C., Oliveira, C.A.F., Deliza, R., Cunha, R.L., Faria, J.A.F., Bolini, H.M.A.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Food engineering; Food industries; Fundamental and applied biological sciences. Psychology; General aspects; Lactobacillus bulgaricus; Milk and cheese industries. Ice creams; Oligofructose; Rheology; Streptococcus thermophilus; Survival analysis; Yogurt
• ISSN: 0260-8774; 1873-5770
• DOI: 10.1016/j.jfoodeng.2012.08.018

► Yogurt manufactured with increased levels of oligofructose. ► Weak gel, showing thixotropy and pseudoplastic behavior was observed. ► Survival analysis methodology indicated addition of 2.58% wt.v−1 of oligofructose. 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 28days 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.