In 2016, the International Agency for Research on Cancer (IARC) classified the drinking of very hot beverages above 65 °C as “probably carcinogenic to humans” (Group 2A), with esophageal squamous cell carcinoma (ESCC) particularly associated with the habit. As this finding may have practical implications for the coffee industry, there appears to be a need to critically reassess the often extremely high standard brewing and serving temperatures used in coffee preparation. This study presents a summary of the most recent IARC assessment on very hot beverage consumption and investigates the influence of brewing temperatures (80, 86, and 93 °C) and roasting degrees (light, medium, and dark) on the sensory profile of manual drip coffee. As the evidence linking very hot beverage consumption to increased ESCC risk has grown stronger, the IARC classification is likely to be upgraded in coming years. As the roast intensity increased, assessors preferred coffees brewed at lower temperatures and most of them were not able to distinguish brews extracted at different temperatures. Given these results, the potential for lowering the brewing temperature in commercial settings is clear. This approach not only enhances consumer safety, but also positions businesses as leaders in health-conscious practices, potentially redefining standards across the industry for the optimal temperature of coffee serving that aligns with both flavor and health research findings.

The United States is the largest coffee consuming country worldwide. Recently, in addition to cup quality, the focus on health promotion has increased significantly in the country, with launching of many brands with health claims, mainly highlighting the antioxidative and stimulating properties of the beverage. On the other hand, mycotoxins and, to a lesser extent, acrylamide, have raised concerns among consumers and health authorities. This study investigated the contents of the main bioactive compounds (caffeine, chlorogenic acids and their 1,5-γ-quinolactones, and trigonelline) in health performance coffees and compared them to those of conventional roasted coffees available on the U.S. market. The following categories were compared by ANOVA at p ≤ 0.05, followed by Fisher's test: 1 – health performance, 2 – gourmet and 3 – traditional, totaling 127 samples. As complementary results, the contents of acrylamide and ochratoxin A were evaluated in part of the samples (n = 58). The mean contents (g per 100 g) of bioactive compounds for categories 1 to 3, respectively, were 1.09, 1.11 and 1.07 for caffeine; 1.75, 1.88 and 1.34 for chlorogenic acids/lactones, and 0.63, 0.64 and 0.56 for trigonelline. The mean contents (μg kg⁻¹) of acrylamide for categories 1 to 3, respectively, were 82, 71 and 85. Only about 7% of the evaluated samples presented quantifiable amounts of OTA and all of them were within the maximum limits established by health authorities. In general, the contents of bioactive and potentially harmful compounds were not consistently different among categories, with high and low individual amounts in all of them. Most health claims on labels related to the amount of bioactive compounds in health performance coffees were unjustified, suggesting the need for improvement in coffee labeling regulation in the U.S.

This study aimed to investigate: (1) the bioactive profile of seeds, husks, and leaves of selected conilon coffee genotypes (n = 42) from three consecutive crops for the selection of plants to meet health interests, (2) the variability in the content of these bioactive compounds over the crops, and (3) possible correlations among the contents of the evaluated compounds in the different parts of the plant. Selected conilon plants were reproduced by clonal propagation. Bioactive compounds were analyzed using HPLC-DAD. Eight chlorogenic acids (CGA), caffeine, trigonelline, and minor phenolic compounds were quantified (dry basis) in all extracts. CGA contents in seeds, husks, and leaves ranged between 3.71 and 9.71 g/100 g, 0.43 and 1.65 g/100 g, and 0.80 and 2.22 g/100 g, respectively. Caffeine contents ranged between 1.21 and 2.63 g/100 g, 0.13 and 0.84 g/100 g, and 0.33 and 2.01 g/100 g in seeds, husks, and leaves, respectively. Trigonelline contents ranged between 0.83 and 1.12 g/100 g, 0.59 and 1.24 g/100 g, and 0.74 and 1.84 g/100 g, respectively. Variation among the three crops was observed to be higher for CGA. A discrete correlation between CGA and caffeine was observed in the seeds (r: 0.72, p = 0.003). Some of the genotypes showed consistently higher contents of these bioactive compounds than others (not only in the seeds but also in the husks and leaves), being good candidates for cultivar registration to meet various market demands in the food and pharmaceutical industries. Studies that evaluate the potential use of new genotypes and byproducts are important for diversification and maximum use of coffee plants, promoting sustainability and financial return to the farmers and the producing country.

Kombucha is traditionally produced by fermenting Camellia sinensis tea and sugar in a consortium of microorganisms called SCOBY (Symbiotic Culture Of Bacteria and Yeasts). Short- and medium-chain fatty acids and other organic acids in K are mainly produced by acetic acid bacteria, which contribute to the typical K taste. Coffee is one of the most widely consumed beverages in the world and one of the most traded commodities globally. Harvesting during coffee production generates tons of byproducts generally considered of low value, including cascara (CC), composed of dried pulp and skin, and leaves (CL). To date, few studies have investigated the production of short- and medium-chain fatty acids and monosaccharide’s profile during traditional kombucha fermentation, and their composition in kombuchas prepared from substrates other than C. sinensis is even scarcer. This study followed the changes in sugars and the production of short- and medium-chain fatty acids during K fermentation of black tea (BT), CC, and CL and associated their concentrations with physicochemical parameters (total soluble solids (TSS), pH, and titratable acidity (TA)) and the perceived acidity of the beverages evaluated by a trained panel and untrained consumers. BT K, a SCOBY, and 10% sucrose were added to infusions of arabica CC, CL, or BT. The mixture was fermented for 0, 3, 6, and 9 days. Organic acids were analyzed by GC-MS; sucrose and monosaccharides were analyzed by HPLC-RID. The Rate All That Apply (RATA) test was used for sensory analysis. Results were treated by ANOVA–Fisher and Pearson correlation tests with significance at p < 0.05. Glucose, fructose, arabinose, xylose, cellobiose and glycerol were identified in the infusions. On average, sucrose concentration decreased by 28% up to day 9, considering all K samples, accompanied by TSS decrease. Eight organic acids were semi-quantified, with acetic being the major acid in all beverages (8.4 to 1971 mg L⁻¹) and isovaleric being the lead minor acid (0.7 to 17.7 mg L⁻¹). Additional acids identified were: butanoic, 2-methylpropanoic, pentanoic, 3-methylpentanoic, hexanoic, and octanoic acids. TA values and sourness perceived by consumer assessors increased generally, even though in CC Ks, the acid concentration decreased by day 9. TA, sourness, and sparkling and fizzy mouthfeel correlated positively in all Ks. In general, although the total acid concentration was mainly higher on days 3 or 6, CO₂ formation, among other organic acids, probably increased TA and sourness on day 9. Although it is generally accepted that pH and organic acid concentrations are directly associated with sour taste, it is not possible to accurately predict and modify sour taste intensity in kombucha based only on these parameters, given that other factors, such as the production of CO_2, the existence of buffer systems, and the presence of sugars and other soluble solids, will probably affect the perceived acidity and sourness.