Influence of type and content of fat on acoustic properties of shortbread
 okładka_kolor_2.jpg)
|
|
||||||||
PDF 175.42 KB
|
|||||||||
| Authors: | Agata Marzec1, Hanna Kowalska1, Sylwia Suwińska1 1Department of Food Engineering and Process Management, Faculty of Food Science, SGGW – Warsaw University of Life Sciences ul. Nowoursynowska 159C, 02-776 Warszawa |
||||||||
|---|---|---|---|---|---|---|---|---|---|
| Abstract : | The aim of this study was to investigate how the type and the share of fat in the shortbread recipe influences the acoustic properties. Margarine (80% fat) and butter (82% fat) were used, in an amounts from 19.2 to 82.0% relative to flour. Measurements of water content and water activity of shortbread were taken, and sensory evaluation was performed with the scoring method. Acoustic emission (EA) generated during the three-point breaking test of the material at a speed of 20 mm min-1 was registered with the contact technique. The sound was analysed in the frequency range from 1 to 18 kHz. Analysis was performed of the acoustic descriptors: number of AE events, acoustic energy, energy of one AE event, the maximum of one AE event, sound duration, amplitude, partition power spectrum slope, and of sensory parameters: loudness, hardness, overall quality, flavour. Statistical analysis of results was conducted with the principal components method (PCA). The type and the share of fat in the shortbread recipe affected the acoustic characteristics. Shortbread with margarine generated sounds of higher energy than shortbread with butter. The spectral characteristic of the AE signal presented activity in 1-3 kHz and 13-14 kHz for shortbread with margarine, and in 1-2 kHz and 15-16 kHz for shortbread with butter. Analysis of the acoustic descriptors of shortbread performed with the statistical method of principal component (PCA) allowed the separation of two groups of shortbread with different acoustic properties. A group with fat content in the shortbread recipe from 19.5 to 32.0%, and a group with fat share from 52.8 to 82.0%. The higher share of fat in the shortbread recipe caused the generation of a small number of events of short duration and low energy of event. Shortbread with the higher share of fat in the recipe were perceived as tastier and received higher sensory scores overall than shortbread with the lower the share of fat in the recipe. The method of registering acoustic emission during the breaking can be used for instrumental texture evaluation of shortbread. |
||||||||
| Keywords : | shortbread, fat, acoustic properties | ||||||||
| Language : | Polish | ||||||||