## 2 Materials and Methods  
### Samples  
Ripe tomatoes belonging to 6 indigenous tomato varieties from the Republic of Croatia were collected from experimental fields of the Faculty of Food Technology Osijek, Josip Juraj Strossmayer University of Osijek. Tomato varieties were assigned by accession numbers VEG00356-VEG00362, available at the Croatian Plant Genetic Resources Database [22]. Tomatoes were washed, chopped, and submitted to a hot break process (60 min of boiling) and subsequent sieving to separate the tomato sauce. TPW remaining after juice extraction and sieving consisted of seeds, peel, and parts of the pericarp and placenta of the fruit. Different dried conditions were applied: convective air drying at 70 \({}^{\circ}\)C and 50 \({}^{\circ}\)C in a laboratory dryer; for 36 and 48 h, respectively (Inko, Zagreb, Croatia); vacuum dryer at 35 \({}^{\circ}\)C for 72 h ([PERSON], 21 GV, 130 Milan, Italy) and lyophilization for 20 h ([PERSON], Epsilon 2-4 LSC plus, Osterode am Harz, Germany) Drying times were chosen to achieve the final moisture content of \(<\)10%. The 50-70 \({}^{\circ}\)C temperature range is commonly applied for air drying plant materials because it represents the balance between drying efficiency, enzyme inactivation, and preservation of bioactive compounds. Inefficient air-drying, due to too low temperatures, might lead to the spoilage of the raw material or enzymatic degradation of bioactive compounds, while exposure to too high drying temperatures can cause thermal degradation of valuable compounds such as polyphenols and carotenoids, particularly lycopene [23]. The grinding process was carried out in a Polymix(r) PX-MFC 90 D mill (Kinematica AG, Malters, Switzerland) at 6000 rpm with a 2.00 mm sieve, resulting in a fine powdered material, to conduct physicochemical composition of TPW. In addition, to investigate the impact of grinding degree and particle size on the content of TPW bioactive substances, the dried sample was ground for 5 s, 9 s, 18 s, and 40 s. The grinding duration was selected based on preliminary experiments, which demonstrated that a grinding time of 40 s resulted in sufficiently low Dx 90 values (529 \(\upmu\)m). Grinding beyond 40 s led to noticeable heating of the sample. Therefore, 40 s was established as the maximum grinding time to prevent unnecessary heat buildup. Shorter grinding intervals were also tested and selected randomly, guided by preliminary findings indicating that the most significant reduction in particle size occurs within the first 15-20 s of grinding.  
As presented in Figure 1, the study was conducted in two phases. In the first phase, TPW was separated into peel (TPW-PEEL) and seed fractions (TPW-SEED), which were then used to assess and compare their suitability as secondary raw materials. This evaluation was based on several criteria: (1) sanitary safety, (2) nutritional composition, (3) bioactive compounds content, and (4) seed oil characteristics. To investigate the effect of higher drying temperatures on specific properties, the entire TPW was also lyophilized (freeze-dried) (TPW-LIO), and the results of these analyses were compared with those from samples dried at 70 \({}^{\circ}\)C (TPW-70). For this part of the investigation, we used TPW collected in the season 2022/2023. Given the significant differences observed in the content of certain compounds between TPW-70 and TPW-LIO, the second phase of the study compared the impact of various drying methods and TPW particle size distributions on the content/extractability of the bioactive TPW compounds (total antioxidants, total polyphenols (TPs), particular phenolic compounds, \(\beta\)-carotene, and lycopene). For this part, TPW collected in the season 2023/2024 was used.