Cold brewing coffee has gained increasing popularity as a novel brewing method. A completely different flavour profile during cold brewing extraction (smooth and mild) is a result of the low-energy process, prolonged water-grind contact times and long preparation time. The aim of our research was to compare coffee drinks obtained with an innovative device for a faster, dynamic cold coffee extraction process (Hardtank) to drinks prepared traditionally in 24 h and hot brewed drinks. This study investigated the differences in chemical composition (volatile, non-volatile and lipid compounds), sensory properties and antioxidant capacity of coffee drinks from various extraction processes carried out at variable brewing temperatures, times and percolation modes. The results showed that the new cold maceration technique using coffee bed percolation (Hardtank) improved the quality of cold coffee drinks, making them similar in taste to hot coffee drinks. Among the studied extractions, the combination of a lower temperature (19.3 °C) and percolation process appeared to be the ideal setting for the most efficient extraction of compounds such as chlorogenic acids, gallic acid, caffeine, trigonelline, 5-(hydroxymethyl)furfural and lipids and consequently for their intake. In addition, FTIR spectra indicated an even 4 times greater quantity of lipids in Hardtank drinks than in classic cold brew and up to 5 times more lipids than in hot brew coffee, which contribute to the formation of the aroma and flavour. The decreased extraction time and use of coffee bed percolation could be beneficial for the quality and taste of cold brew products.

This work presents the possibility of using computer image analysis to assess the quality of fine-grained food mixtures. The research was carried out using a mixture of wheat flour and algae. These types of ingredients are used, among others, to produce pasta, which is a functional food due to its enrichment with algae. The tests were carried out for mixtures with different shares of algae: 2%, 3% and 4% w/w. Mixing was carried out in a 3D mixer (Turbula^® mixer), in which 20, 40 and 60 mL mixing vessels were placed. At the end of the process, samples were taken from four parts (sectors) of the mixing vessels, and then photos were taken with a digital camera. For this purpose, a specially prepared chamber was used, ensuring stable conditions for taking photos. The obtained images were analyzed in the Patan^® program, determining the color on the RGB-256 scale. The obtained values were compared with the previously prepared reference specimen (simple linear regression formula). Based on this, it was possible to determine the share of algae in the samples taken and thus to estimate the homogeneity of the tested mixtures. The obtained results indicate the high reliability of the proposed solution.

Wykorzystano zjawisko fluorescencji do oceny homogeniczności mieszanin ziarnistych i sypkich, w celu uzyskania odpowiedzi na pytanie, czy proponowana metoda może mieć swoje zastosowanie w przypadku mieszanin wieloskładniowych. Do tego celu użyto paszy piętnastoskładnikowej. Dotychczasowe badania prowadzono dla mieszania układów trójskładnikowych1). Do paszy jako traser wprowadzano kukurydzę oraz kardi, które pokryto określonymi we wcześniejszych obserwacjach roztworami substancji fluorescencyjnych (Tinopal 0,3%, Uranina 0,3% i 0,5%, Rodamina 0,01%). Testy przeprowadzono zgodnie z wypracowaną poprzednio metodyką. Uzyskane wyniki wskazują, że zjawisko fluorescencji może służyć do oceny udziału trasera i homogeniczności wieloskładnikowych mieszanin ziarnistych. Zadowalające wyniki otrzymano dla wszystkich przeprowadzonych serii badań.