We report on the analysis of volatile compounds by SPME-GC-MS for individual roasted coffee beans. The aim was to understand the relative abundance and variability of volatile compounds between individual roasted coffee beans at constant roasting conditions. Twenty-five batches of Arabica and robusta species were sampled from 13 countries, and 10 single coffee beans randomly selected from each batch were individually roasted in a fluidised-bed roaster at 210 °C for 3 min. High variability (CV = 14.0–53.3%) of 50 volatile compounds in roasted coffee was obtained within batches (10 beans per batch). Phenols and heterocyclic nitrogen compounds generally had higher intra-batch variation, while ketones were the most uniform compounds (CV < 20%). The variation between batches was much higher, with the CV ranging from 15.6 to 179.3%. The highest variation was observed for 2,3-butanediol, 3-ethylpyridine and hexanal. It was also possible to build classification models based on geographical origin, obtaining 99.5% and 90.8% accuracy using LDA or MLR classifiers respectively, and classification between Arabica and robusta beans. These results give further insight into natural variation of coffee aroma and could be used to obtain higher quality and more consistent final products. Our results suggest that coffee volatile concentration is also influenced by other factors than simply the roasting degree, especially green coffee composition, which is in turn influenced by the coffee species, geographical origin, ripening stage and pre- and post-harvest processing.
Background: While mucosal healing has been proved to predict relevant clinical outcomes in Crohn's disease (CD), little is known about the long-term significance of transmural healing.
Aims:To prospectively assess the 1-year clinical outcomes in CD patients achieving transmural healing following treatment with biologics, and to compare them with those in patients reaching only mucosal healing or no healing.Methods: Observational longitudinal study, evaluating 1-year outcomes in terms of steroid-free clinical remission, rate of hospitalisation and need for surgery in a group of CD patients treated with anti-tumour necrosis factor (TNF) alpha for 2 years.Bowel sonography was used in all patients to determine transmural healing.Results: Of 218 patients who completed a 2-year treatment course with anti-TNF alpha, 68 (31.2%) presented transmural (plus mucosal) healing (bowel wall thickness ≤3 mm at bowel sonography), 60 (27.5%) mucosal healing only, and 90 (41.3%) did not achieve any intestinal healing. Transmural healing was associated with a higher rate of steroid-free clinical remission (95.6%), lower rates of hospitalisation (8.8%) and need for surgery (0%) at 1 year compared to mucosal (75%, 28.3% and 10%, respectively) and no healing (41%, 66.6% and 35.5%, respectively) (P < 0.001). Furthermore, transmural healing was associated with longer intervals until clinical relapse (HR, hazard ratio 0.87, P = 0.01), hospitalisation (HR 0.88, P = 0.002) and surgery (HR 0.94, P = 0.008) than mucosal healing. Also among patients discontinuing treatment with biologics, transmural healing predicted better clinical outcomes at 1 year than mucosal healing (P = 0.01).
Conclusions:Transmural healing is an ambitious and powerful treatment goal associated, to a greater extent than mucosal healing, with improvement of all clinical outcomes. Additionally, transmural healing is associated with better long-term clinical outcomes than mucosal healing also after discontinuation of biologics.
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