Optimization of the rheological and sensorial characteristics of probiotic yogurts supplemented with dairy proteins

• Grant number: 07/03588-8
• Support Opportunities: Regular Research Grants
• Start date: October 01, 2007
• End date: September 30, 2009
• Field of knowledge: Agronomical Sciences - Food Science and Technology - Food Technology
• Principal Investigator: Marice Nogueira de Oliveira
• Grantee: Marice Nogueira de Oliveira
• Host Institution: Faculdade de Ciências Farmacêuticas (FCF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The use of the functional foods as vehicle of promotion of the well-being and health and, at the same time, as reducer of the risks of some diseases, has been motivating researches of new natural components and the development of new ingredients. Among the functional ones fermented milks containing probiotic and recently prebióticos are the main ones. This project aims to optimize the rheological and sensorial properties of probiotic yoghurts supplemented with milk proteins. In order to study the optimization of the use of milk proteins in probiotic yogurts, an experimental design type centroid simplex will be used, for mixture modeling. The interactions among the ingredients (concentrate whey protein, sodium caseinate and skim milk powder) will be studied. It includes seven experiments being three with the pure ingredients, two corresponding to the binary mixtures and one to the ternary one. In parallel to the seven delineated experiments, a control trial will be accomplished with milk non supplemented. The milks will be fermented at 42°C until pH 4,5 using the cultures Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus acidophilus and Bifidus lactis, and the kinetics of acidification will be followed. The fermented milks will be submitted to the physico-chemical analyses (total solids, lactose, fat, protein, pH and titrable acidity), texture determination (firmness, consistency, cohesivity and breaking point) and rheological characterization (flow tests, yield stress, storage module, G´, loss module, G´´, area of linear visco-elasticity, LVE and structural recovery). The structures of the fermented milks will be determined and the probiotic bacteria will be enumerated 24h after fermentation. To the results of the analytic answers - time of fermentation (tpH4.5), texture parameters (firmness, G ', G ' '), and enumeration of the probiotic cultures will be adjusted through three regression models (linear, quadratic and cubic special) applied to mixtures. The fit of the models to the experimental results will be evaluated in relation to lack of fit, variance analysis and the comparison among the experimental and observed values in a selected mixture. Confirmation tests will be conducted in the obtained optimal area that is, with the milk whose percentage of ingredients (concentrated whey protein, sodium caseinate and skim milk powder), satisfy, simultaneously, all the interest answers. Finally, comparative experiments will be carried out with this same milk supplemented with lactulose (2 to 4%; amount to be established in function of previous trials) and with the control milk (without supplementation). Sensorial analysis of the developed products will be accomplished. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MARAFON, A. P.; SUMI, A.; GRANATO, D.; ALCANTARA, M. R.; TAMIME, A. Y.; NOGUEIRA DE OLIVEIRA, M.. Effects of partially replacing skimmed milk powder with dairy ingredients on rheology, sensory profiling, and microstructure of probiotic stirred-type yogurt during cold storage. JOURNAL OF DAIRY SCIENCE, v. 94, n. 11, p. 5330-5340, NOV 2011. (07/03588-8)

MARAFON, ANA PAULA; SUMI, ADRIANA; ALCANTARA, MARIA REGINA; TAMIME, ADNAN Y.; DE OLIVEIRA, MARICE NOGUEIRA. Optimization of the rheological properties of probiotic yoghurts supplemented with milk proteins. LWT-FOOD SCIENCE AND TECHNOLOGY, v. 44, n. 2, p. 511-519, MAR 2011. (07/03588-8)