#Coffee & Related Research from Early 2020: #FilterHeight Matters | #Leaves Better Than Beans | #Probiotic Coffee
|Coffee junkies, recoice! The SuppVersity is back ... and how can this be celebrated? With a research update on ☕ - a review discussing the latest science from coarsness to leaf-extracts, and beyond.|
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- Beyond grinding your coffee coarser | based on Khamitova 2020 -- You probably will have read that coarser grinds make better espressos in the SuppVersity news or other news outlets. The grind is yet not the only set-screw for espresso quality (I've discussed several of them in my Coffee 101). That is also what the latest study from the University of Camerino in Italy suggests, a study that also shows clear benefits of finer particle size, when it comes to bioactive components (the previously referenced study investigated taste).
The Italians' research aimed to investigate ground beans at specific particle sizes in three variously designed filter (new!) baskets and to compare the concentration of bioactive compounds while decreasing the amount of ground coffee.
Filter baskets and various heights of perforated disc influenced EC extraction.
As you can see in Table 1, the caffeine, trigonelline and chlorogenic acids (3-CQA, 5-CQA and 3,5-CQAs) content of the final product was significantly affected by the heights of perforated disc used for the espresso machines filter basket.
Table 1: Milligrams of caffeine, trigonelline and chlorogenic acids (3-CQA, 5-CQA and 3,5-CQAs) obtained in Arabica EC samples (n = 3, RSD% < 5.86) by using 12 and 14 g of ground coffee with various heights of perforated disc used for filter basket A at a constant time (25sec) and volume (50 ml for double EC) | from Kamitova et al. 2020.
- Coffee's a hitherto largely ignored prebiotic prowesses - How to optimize/control the effect? | based on Sales 2020 -- First study to investigate the effects of coffee species, roast degree and decaffeination on in vitro probiotic bacterial growth, and to identify the major coffee compounds responsible for such effects.
Figure 1: In view of its myriad of proven health benefits, it should hardly surprise you that coffee will also affect your microbiome in a positive way.
"Overall, after 48 h incubation, the medium roasted arabica coffee extract increased the growth of GG, LA and BA (range: Δlog CFU/mL = 0.5 to 1.8), while the dark roasted arabica coffee extract increased BB12 growth (range: Δlog CFU/ml = 0.9 to 1.7), in a dose dependent manner. Improved performances of GG, LA and BA were promoted by higher polysaccharides and CGA concentrations, with better performance for Lactobacillus sp," ...the authors report. As far as the mechanisms are concerned, they were able to show that the tested coffee bioactive compounds promoted the poor growth of BB12. Plain caffeine did not promote Bifidobacterium sp. growth and limited the growth of Lactobacillus sp.
What's important though, is this downside of decaffeinating coffee, i.e. the fact that arabica and robusta (learn more about differences) extracts inhibited the growth of the pathogenic E. coli bacteria, while the decaffeinated extracts promoted its growth - clearly not ideal!
- 😮 "a beverage prepared from leaves (coffee leaf tea) could be a rich source of phytochemicals and antioxidants with therapeutic and pharmacological values for human health" | quote from Acidri 2020 -- In fact, the leaves outperformed the beans with respect to their antioxidant effects (TEAC and TROLOX assays).
Table 2: Total phenolic content (TPC) and antioxidant capacity of the coffee plant organs | from Acidri 2020
You are at a loss of how to prepare those leaves? Well, the thedailytea.com offers some orientation. The guys also know: "This tasty infusion has been consumed in Ethiopia for over 200 years. Sumatrans also drink coffee leaf tea rather than roasting beans because they believe it to be more nutritious" (thedailytea.com).
- Acidri, Robert, et al. "Phytochemical Profile and Antioxidant Capacity of Coffee Plant Organs Compared to Green and Roasted Coffee Beans." Antioxidants 9.2 (2020): 93.
- Khamitova, Gulzhan, et al. "Optimization of espresso coffee extraction through variation of particle sizes, perforated disk height and filter basket aimed at lowering the amount of ground coffee used." Food Chemistry (2020): 126220.
- Sales, Amanda, et al. "Effect of regular and decaffeinated roasted coffee (Coffea arabica and Coffea canephora) extracts and bioactive compounds on in vitro probiotic bacteria growth." Food & Function (2020).