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Abstract The paper attempts to determine the best storage conditions for green and roasted coffee beans. Coffee beans were processed in various ways—some of them were washed or left in their natural state after harvesting, then they were stored in two types of packaging with different permeability, i.e. jute bag and GrainPro polymer bag, ensuring stable conditions in three temperature chambers, i.e. − 10, 10 and 20 °C. The grains treated in this way were evaluated after 3, 6, 9, and 12 months. The selection of the analyzed parameters (in roasted coffee—cupping and 3 selected volatile organic compounds; in green coffee—average water activity, content of volatile fatty acids, 6 selected volatile organic compounds) was to monitor the ongoing processes, and thus the qualitative changes taking place in grains. The research shows that grain stored at 20 °C ages the fastest. Grains stored in − 10 °C and 10 °C chambers perform similarly well. The evaluation of the parameters shows that among the grains stored in these two chambers, the method of grain processing (Natural/Washed) had a greater impact on the results, while the type of packaging did not differentiate the grains to such a significant extent.

Abstract Currently, there is no technology for the storage of green coffee (GrC), that results in obtaining high-quality roasted coffee (RC). The aim of this study was to evaluate the effects of storage temperature (− 10, 5, 10, 18, 20 °C), postharvest treatment method (natural (N), washed (W)) and type of packaging material (GrainPro (G), jute (J) bags) on the content of chlorogenic acids (CQAs), caffeine and trigonelline as well as the sensory profile of RC from the specialty sector after 12 months of regulated storage. Sensory analysis showed that natural coffees have better taste and higher quality than washed coffees after 12 months of storage. The highest total scores were obtained from the natural coffee stored in a GrainPro bag at − 10 °C followed by coffee stored in a jute bag at 10 °C which had the smallest decreases compared to the initial recorded values. No notable differences among CQA contents in washed coffees stored in either type of bag was seen but natural coffees stored in jute bags at 10 °C and 18 °C displayed the lowest drops relative to the initial values.

Abstract 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.