| Sorption properties of healthy vegetable snacks preserved by freeze-drying Agnieszka Ciurzyńska1; Monika Janowicz2; 1WARSAW UNIVERSITY OF LIFE SCIENCES - SGGW, Warsaw, Poland; 2WARSAW UNIVERSITY OF LIFE SCIENCES, Warsaw, Poland; PAPER: 114/AdvancedMaterials/Regular (Oral) SCHEDULED: 18:15/Mon. 28 Nov. 2022/Saitong ABSTRACT: A gel-based cellular structure should be characterized by appropriate physical and sorption properties according to its intended use [1]. Both the method of preparation and storage of ingredients, semi-finished and finished products are of great importance in shaping the quality and health safety of prepared meals. It is during storage that a number of processes, e.g. microbiological, biological, chemical, biochemical or physical, occur that cause qualitative changes in them. Researchers were investigating the effect of drying methods and conditions, different equipment solutions and the storage conditions on the quality of final product [2, 3]. The aim of this work was to investigate physical properties of three-layer freeze-dried vegetable snacks in the form of bar stored in different relative humidity conditions. Bars were obtained based on waste unused during proper production of frozen vegetables. Presented research are the stage of the project BIOSTRATEG 3/343817/17/NCBR/2018 “Development of healthy food production technologies taking into consideration nutritious food waste management and carbon footprint calculation methodology”. Sodium alginate, and a mixture of xanthan gum and locust bean gum were used for the formulation of vegetable gels with cauliflower, broccoli, carrot, potato, green and yellow bean, corn, chives, pepper, dill. Vegetable gels were frozen (–40 °C/2) and freeze-dried (30 °C/63 Pa/72 h). The physical properties of freeze–dried bars included determination of: sorption isotherms, water activity, porosity and shrinkage. The studies showed that the type of hydrocolloids and vegetables influence the sorption properties of freeze-dried vegetable snacks based on frozen vegetables not used during the proper production of frozen foods. Samples obtained on the base on xanthan gum and locust bean gum mixture were characterized by lower sorption properties than bars obtained with the sodium alginate, especially when water activity in desiccators were above 0,529). Also, vegetable types influence the sorption properties of freeze-dried gels stored in different relative humidity conditions. Such storage conditions (water activity in desiccator 0-093) changed structure which influenced the shrinkage and porosity of freeze-dried vegetable bars after storage during 5 months. References: 1. Galus, S., Turska, A., & Lenart, A. (2012). Sorption and wetting properties of pectin edible films. Czech Journal of Food Science, 30(5), 446-455. 2. Ruiz, N.A.Q.; Demarchi, S.M.; Massolo, J.F.; Rodoni, L.M.; Giner, S.A. Evaluation of quality during storage of apple leather. LWT Food Sci. Technol. 2012, 47, 485–492. [CrossRef] 3. Raab, C.; Oehler, N. Making Dried Fruit Leather Fact Sheet; Oregon State University Extension Service: Corvallis, OR, USA, 1999; Volume 232, pp. 1–4. |
