## 4 Conclusions  
The aim of the study was to assess the effects of shelf temperature (10, 25 and 40 \({}^{\circ}\)C) during freeze drying on the foam-mat drying process of kiwiberry pulp and the quality of the obtained product evaluated on the basis of moisture content, water activity, hygroscopicity, solubility, microstructure and spectral properties using the FTIR method. The results demonstrated that the shelf temperature influenced the kiwiberry foam-mat properties. With an increasing shelf temperature, drying time, water activity and hygroscopicity, the total porosity decreased, while the dry matter content and solubility increased.  
The higher shelf temperatures (25 and 40 \({}^{\circ}\)C) during the freeze drying of foam-mat kiwiberry pulp reduced the drying by 37.3 and 40.7%, respectively, compared to the foam mat dried at the lowest temperature (10 \({}^{\circ}\)C). This is a positive phenomenon due to the lower energy consumption.  
Kiwiberry foam-mat dried at the highest temperature (40 \({}^{\circ}\)C) was characterized by the lowest water activity (0.159). Also, due to the low total porosity (57.7%), the hygroscopic properties for that foam mat were the lowest (1.41 g water/100 g d.m.). This is  
Figure 6: Percentage distribution of walls (dashed lines) and pores (solid lines) of thickness of freeze-dried foam-mat kiwiberry pulp: green lines (10 \({}^{\circ}\)C), black lines (25 \({}^{\circ}\)C), red lines (40 \({}^{\circ}\)C).  
positive from a technological point of view, as it ensures the greater stability of the material during storage.  
As the shelf temperature increased, the solubility of the analyzed kiwiberry foam mats increased. This is a positive advancement, suggesting that it can be used as an ingredient in the production of food in a powder form such as baby food, cake premixes and dietary supplements.  
Nevertheless, further research is necessary to investigate the impact of such an additive on the properties of the food product in question and to determine the bioactive properties of freeze-dried foam-mat kiwiberry pulp.  
Conceptualization, E.G. and D.W.-R.; methodology, R.B. and K.R.; software, R.B. and K.R.; validation, E.G. and M.N.; formal analysis, E.G. and K.R.; investigation, E.G. and R.B.; resources, D.W.-R.; data curation, R.B., K.R. and E.G.; writing--original draft preparation, R.B., M.N. and E.G.; writing--review and editing, R.B., M.N., E.G. and D.W.-R.; visualization, R.B. and M.N.; supervision, E.G., D.W.-R. and M.N.; project administration, E.G.; funding acquisition, D.W.-R. All authors have read and agreed to the published version of the manuscript.  
The research for this publication was carried out with the use of research equipment purchased as part of the \"Food and Nutrition Centre--modernisation of the WULS campus to create a Food and Nutrition Research and Development Centre (CZiZ)\" co-financed by the European Union from the European Regional Development Fund under the Regional Operational Programme of the Mazowieckie Voivodeship for 2014-2020 (project no. RPMA.01.01.00-14-8276/17).  
Not applicable.  
The original contributions presented in the study are included in the article; further inquiries can be directed to the corresponding author.  
The authors would like to thank [PERSON] for his help.  
The authors declare no conflicts of interest.