Volume: 5, 2026
5th International PhD Students’ Conference at the University of Life Sciences in Lublin, Poland:
ENVIRONMENT – PLANT – ANIMAL – PRODUCT
Abstract number: F007
DOI: https://doi.org/10.24326/ICDSUPL5.F007
Published online: 22 April 2026
Strawberry pomace and enriched cookies: effects of drying method and temperature on color properties
Anna Krajewska*1 and Dariusz Dziki2
1 Department of Food Engineering and Machines, University of Life Sciences in Lublin, 28 Głęboka St., 20‑612, Lublin, Poland
2 Department of Thermal Technology, University of Life Sciences in Lublin, 28 Głęboka St., 20-612 Lublin, Poland
* Corresponding author: anna.krajewska@up.edu.pl
Strawberry pomace is increasingly utilized as a functional ingredient in food formulations. However, its incorporation can significantly affect product color, a critical attribute influencing consumer acceptance. The aim of this study was to investigate the effect of drying method and temperature on the color parameters (L*, a*, b*) of strawberry pomace and cookies enriched with pomace powders. Strawberry pomace was obtained using a twin-screw juicer and dried by freeze-drying at shelf temperatures of 20, 40, and 60 °C or by contact drying at 40, 60, and 80 °C, followed by grinding into powders. Each drying variant was incorporated into shortbread cookies at 20% wheat flour replacement, alongside control samples, and baked at 200 °C for 15 min. Color parameters of pomace powders and cookies were determined using a colorimeter in the CIELAB system. The color of both pomace powders and enriched cookies was significantly affected by drying method and temperature. Freeze-dried pomace, particularly when dried at lower shelf temperatures (20 and 40 °C), exhibited higher lightness and redness compared to contact-dried samples, while increasing temperature resulted in decreased lightness in both methods. Cookies enriched with pomace were darker, more reddish, and less yellow than the control. Moreover, cookies enriched with freeze-dried pomace exhibited more intense red and yellow tones compared to those containing contact-dried pomace. These findings indicate that drying method is a key factor influencing the color characteristics of strawberry pomace powders and enriched cookies.
This research was funded in whole by the National Science Centre, Poland (2023/49/N/NZ9/00218).
Keywords: CIE Lab; contact drying; freeze-drying; fruit by-products; food powders
How to cite
Krajewska A., Dziki D., 2026. Strawberry pomace and enriched cookies: effects of drying method and temperature on color properties. In: 5th International PhD Students’ Conference at the University of Life Sciences in Lublin, Poland: Environment – Plant – Animal – Product. https://doi.org/10.24326/ICDSUPL5.F007