Title: Optimization of the concentration of freeze-dried vegetable extracts in order to extent the shelf-life of lamb meat patties

Biography:

She has completed his PhD at Extremadura University and Postdoctoral Studies at the KVL in Copenhagen. She is a Senior Professor at the Agricultural Engineering School in Extremadura (Spain). She has published more than 25 papers in reputed journals.

Abstract

In a previous study Andrés et al., (2017) observed that freeze-dried vegetable extracts from tomato, olive, grape and pomegranate could extend shelf-life of meat patties. The aim of this work was to optimize the concentration of freeze-dried vegetable extracts (tomato, olive, grape and pomegranate) in order to extent shelf life of meat patties. Color (a*-value), lipid oxidation index (TBARs by Sorensen & Jorgensen, 1996) and microbial counts (mesophiles) were analyzed. Design Expert (10.0) was used to for experimental design, data analysis and model building by Response Surface Methodology (RSM). The significance of the regression model was tested by carrying out ANOVA for Response Surface Model using Expert design (version 10.0). Response surface and contour plots were obtained using the fitted model.

Regarding colour, a* evolution depended on extract concentration (P<0.05). The results indicated that, contrary to what it would be expected, for olive and grape extracts lower concentrations appeared to promote higher a* values. TBARs values was dependent of concentration (P<0.001), the higher the concentration, the lower the TBARs values. As for mesophile counts are concerned, these were lower as the concentration increased for every treatment (P<0.05).

The optimum processing conditions regarding the concentration of extracts was achieved using the numerical optimization technique in the Design Expert software in order to obtain the maximum red colour, and the minimum oxidation and mesophile count after 6 days. The optimum extract and its concentration to keep a maximum red colour and lipid stability as well as a minimum mesophile count after 6 days of storage was Olive Extract (OLI) at a concentration of 2708.92 mg kg-1.