UNIVERSITAT POLITÈCNICA DE VALÈNCIA Desarrollo ... - RiuNet

IV. Resultados y discusión. Capítulo II 157
ABSTRACT
Functional advantages of probiotic bacteria combined with the
nutritional interest of almond (Prunus amygdalus L. cv. dulcis) compounds
has been considered to obtain a fermented product, which potentially covers
the current demand of versatile health-promoting foods. Fermentation
process of almond milk with a mixed starter culture Lactobacillus reuteri
ATCC 55730 and Streptococcus thermophilus CECT 986 was studied by
using a Central Composite Design with Response Surface methodology
(RSM) to optimise the values of different growth factors (glucose, fructose,
inulin and starter culture addition). The response variable was the final
viable cell population in the fermented product. The optimal formulation
obtained was characterised throughout cold storage time (28 days) as to pH,
acidity, particle size distribution, -potential, serum retention capacity,
rheological behaviour, colour properties and probiotic viability. The product
was also submitted to sensory analysis to determine the optimal product
shelf life. The formulated product allowed starter survival above the
minimum suggested to ensure health benefits and be able to be considered
as a functional food. This viability was maintained during the whole typical
shelf life of this kind of products (28 days). No differences in the sensory
acceptability of the product were found between 1 and 28 storage days.
Key words: L. reuteri, prebiotic, response surface methodology, survivals,
sensory analysis.