Julia Rodríguez-García

Optimisation of oat milk formulation to obtain fermented derivatives by using probiotic Lactobacillus reuteri microorganisms

Functional advantages of probiotics combined with interesting composition of oat were considered as an alternative to dairy products. In this study, fermentation of oat milk with Lactobacillus reuteri and Streptococcus thermophilus was analysed to develop a new probiotic product. Central composite design with response surface methodology was used to analyse the effect of different factors (glucose, fructose, inulin and starters) on the probiotic population in the product. Optimised formulation was characterised throughout storage time at 4 ℃ in terms of pH, acidity, β-glucan and oligosaccharides contents, colour and rheological behaviour. All formulations studied were adequate to produce fermented foods and minimum dose of each factor was considered as optimum. The selected formulation allowed starters survival above 107/cfu ml to be considered as a functional food and was maintained during the 28 days controlled. β-glucans remained in the final product with a positive effect on viscosity. Therefore, a new probiotic non-dairy milk was successfully developed in which high probiotic survivals were assured throughout the typical yoghurt-like shelf life.

Optimizing Mixing during the Sponge Cake Manufacturing Process

Sponge cakes have traditionally been manufactured using multistage mixing methods to enhance potential foam formation by the eggs. Today, use of all-in (single-stage) mixing methods is superseding multistage methods for large-scale batter preparation to reduce costs and production time. In this study, multistage and all-in mixing procedures and three final high-speed mixing times (3, 5, and 15 min) for sponge cake production were tested to optimize a mixing method for pilot-scale research. Mixing for 3 min produced batters with higher relative density values than did longer mixing times. These batters generated well-aerated cakes with high volume and low hardness. In contrast, after 5 and 15 min of high-speed mixing, batters with lower relative density and higher viscosity values were produced. Although higher bubble incorporation and retention were observed, longer mixing times produced better developed gluten networks, which stiffened the batters and inhibited bubble expansion during mixing. As a result...

Effect of gums in microstructure and rheological behaviour of thickened food matrices

Dysphagia is defined as the difficulty in swallowing. Treatment for dysphagia generally begins with a behavioural intervention, such as diet modification, where thickened foodstuffs are used to control the flow rates during oral manipulation and swallowing. The objective of this work is to understand the effect of gums presence in the microstructure and rheological behaviour of thickened food matrices, such as water, apple juice, and tomato juice. The presence of gums in starch based thickeners influences the viscoelastic behaviour of the resulting beverages, providing less firm pastes. Microscopic images showed that this could be attributed to the disruption of the swollen starch granules distribution by the gums, especially at lower concentrations in water and apple juice. These differences decreased when increasing concentration. Moreover, significant changes were observed in the behaviour of the systems during swallowing.