Synbiotic aerated dessert: product development and in vitro probiotic survival

Author(s)

Flávia Carolina Alonso Buriti

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ)
• Defense date: 2009-03-05

Examining board members

Susana Marta Isay Saad; Inar Alves de Castro; Luiz Antonio Gioielli; Alcina Maria Liserre; Ana Lucia Barreto Penna

• Advisor: Susana Marta Isay Saad

Abstract

The aim of the present study was to develop a mousse-type synbiotic aerated dessert with low fat content, supplemented with the Lactobacillus acidophilus La-5 probiotic culture, the prebiotic ingredients oligofructose and inulin and whey protein concentrate (WPC), to be stored refrigerated and frozen, and to compare the effect of these ingredients on the product characteristics and the in vitro resistance of the added probiotic microorganism. Using a simplex centroid design, seven guava mousse-making trials were studied during storage at 4°C for 28 days and at -18°C for 112 days. The highest populations of L. acidophilus were achieved in frozen products, always above 7 log CFU/g at up to 12 weeks of storage at -18°C. L. acidophilus viability was satisfactory up to 28 days in the refrigerated mousses supplemented with WPC, with populations between 6.2 and 7.7 log CFU/g. For the other mousses, the populations decreased around 2 log cycles afier 28 days of refrigerated storage. Reductions in L. acidophilus survival during the in vitro assays were high both for refrigerated and frozen mousses. For the refrigerated mousses, the total or partial substitution of milk fat by inulin increased the probiotic survival during the in vitro assays in the first week. In terms of the whole storage, L. acidophilus survival decreased less during the in vitro assays for the frozen mousses. The substitution of milk fat by inulin and WPC and the frozen storage lead to significant differences in the texture of mousses (p<0.05), without affecting their sensory acceptability. Considering the maximum probiotic populations during storage and the survival under the in vitro simulated gastrointestinal conditions, the best results for the refrigerated product were obtained with the partial substitution of milk fat by WPC at 2 to 3%. The simultaneous addition of inulin and WPC is recommended. However, the total proportion of both ingredients together should not exceed 2.6%, so as to obtain a texture profile and a sensory acceptance similar to the traditional product. Particularly for frozen mousses, the mixture of 2% milk fat and 2% inulin in the formulation is also suggested, for which the best results on probiotic survival in the in vitro assays were observed. (AU)