Influence of milk type and addition of passion fruit peel powder on fermentation kinetics, texture profile and bacterial viability in probiotic yoghurts

Abstract

The effect of the addition of passion fruit peel powder (PFPP) on the fermentation kinetics and texture parameters, post-acidification and bacteria counts of probiotic yoghurts made with two milk types were evaluated during 28 days of storage at 4°C. Milks were fermented by Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus (CY340), and one strain of probiotic bacteria: Lactobacillus acidophilus (L10 and NCFM), Bifidobacterium animalis subsp. lactis (Bl04 and HN019). The addition of PFPP reduced significantly fermentation time of skim milk co-fermented by the strains L10, NCFM and HN019. At the end of 28-day shelf-life, counts of B. lactis Bl04 were about 1 Log CFU mLe1 higher in whole yoghurt fermented with PFPP regarding its control but, in general, the addition of PFPP had less influence on counts than the milk type itself. The titratable acidity in yoghurts with PFPP was significantly higher than in their respective controls, and in skim yoghurts higher than in the whole ones. The PFPP increased firmness, consistency (except for the NCFM strain of L. acidophilus) and cohesiveness of all skim yoghurts. The results point out the suitability of using passion fruit by-product in the formulation of both skim and whole probiotic yoghurts

Potentials and Pitfalls on the Use of Passion Fruit By-Products in Drinkable Yogurt: Physicochemical, Technological, Microbiological, and Sensory Aspects

“…Organic acids are powerful antimicrobial agents; therefore, they may affect the survival of microorganisms [47]. Additionally, L. bulgaricus is more sensitive to storage than S. thermophilus, and it usually presents a large decrease in its viable cells [1]. For yogurt, the sum of microorganisms in the starter culture must be at least 10 7 (CFU/g) [48].…”

“…Although some microbiological aspects of yogurts fortified with passion fruit by-products have already been investigated [1] no attention has been paid to the presence of yeast and mold growing, which may also impair the product shelf life. The present study demonstrated that the addition of passion PFF may contribute to the growth of yeast and mold in drinkable yogurt (Table 3).…”

“…Brazil is one of the largest producers and consumers of passion fruit, but exports a large amount of fruit pulp to European and Asian countries. Despite its ample consumption, the economic relevance of passion fruit stems from its processing for juice-making [1].…”

Chemometric approach to texture profile analysis of kombucha fermented milk products

“…Herbal extracts of winter savory, wild thyme, peppermint and stinging nettle are applicable in kombucha fermentation process and obtained beverage can be used for fermented milks production . New studies stress out the importance of fermented milk product's texture to its acceptance by consumer (Bruzone et al 2013) and suggest texture profile analysis as fast and appropriate for determination of milk gel strenght (Kumar and Mishra 2003;do Espírito Santo et al 2012).…”

Some Properties of Bio-Yogurt Enriched with Cellulose Fiber

“…On the other hand, highly water binding capacity of CF may cause to be firmer gel network. Do Espiroto Santo et al [35] also reported that addition of passion fruit peel powder increased firmness and consistency of skim yoghurt. However, Garcia-Perez et al [36] found that the addition of orange fiber below 1% concentration reduce the firmness of skim yoghurt.…”