Effect of the extract of persimmon (Diospyros kaki L.) cv. ‘Rama Forte’and rosemary oily extract (Rosmarinus officinalis L.) on the sensory characteristics and color stability of frozen beef burgers

Abstract

This study aimed to evaluate the effect of the extract of persimmon cv. ‘Rama Forte’ and rosemary oily extract on the sensory characteristics and color stability of frozen beef burgers. The crude hydroethanolic extract was prepared and subjected to fractionation resulting in the hexane, chloroform and ethyl acetate fractions as well as residual fraction. For the preparation of the burger samples a basic formulation was prepared and divided into parts: control, standard formulation ( 0.1% of sodium erythorbate), treatment 1 (0.5% of hydroethanolic crude extract), treatment 2 (0.7% of hydroethanolic crude extract), treatment 3 (0.5% of the residual fraction), treatment 4 (0.7% of the residual fraction ) , treatment 5 ( 0.5% of ethyl acetate fraction), Treatment 6 (0.7% of ethyl acetate fraction) and treatment 7 (0.10% of oily extract of rosemary). The beef burger samples were stored at-25° C for 14 months and subjected to sensory analysis (color, aroma, flavor, and texture) at the beginning of the experiment and the measurement of color (parameters L a*, b* and h*) every two months. The addition of the extracts did not promote changes in the sensory attributes of the beef burgers at time zero of storage. A tendency to decrease a* values and increase of the h* values of the samples of frozen beef burgers occurred over the period of storage. Samples added with ethyl acetate fraction (0.5 and 0.7%) and the oily extract of rosemary showed higher a* values than the other samples throughout the storage period and lower h* values than the standard sample at the end of the period evaluated. This indicates that the addition of ethyl acetate fraction and rosemary extract contributed to the retention and stability of the red color of the samples of beef burgers during the storage of the frozen product.