Identification of antioxidant and flavour marker compounds in Kalosi-Enrekang Arabica brewed coffee processed using different postharvest treatment methods.

This research aims to predict the presence of marker compounds that differentiate tubruk brew from coffee beans with different postharvest processing. This research also aims to predict compounds correlating with antioxidant activity and sensory flavour attributes. This research used Kalosi-Enrekang Arabica coffee beans, which were processed with three different postharvest processing (honey, full-washed and natural), roasted at medium level, and brewed using the tubruk method. Each brew was analyzed for chemical profiles using LC-MS and GC-MS, antioxidant analysis using the DPPH IC50 and FRAP methods, and sensory analysis for flavour using the QDA and SCAA methods for cupping scores. OPLS-DA analysis revealed the presence of marker compounds from each brew, and the dried fruit flavour attribute was to be an inter-process marker. After that, OPLS analysis showed marker compounds that correlate to antioxidant activity and flavour attributes. Rhaponticin is thought to be one of the marker compounds in natural coffee brews and is one of the compounds that correlates to the antioxidant activity of the DPPH method (IC50); prunin is thought to be one of the marker compounds for full-washed coffee brews and is one of the compounds that correlates to the activity antioxidants of FRAP method. Triacetin, which is thought to be a marker compound in natural brewed coffee, correlates with fruity flavour. 3-acetylpyridine, as a marker in honey-brewed coffee, correlates with nutty flavour. Even though there are differences in dominant flavours, the cupping score shows the brew is categorized as a specialty. This research shows that different post-harvest processing processes influence the compound profile, antioxidant activity and flavour attributes of Tubruk brewed coffee. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-024-05948-8.

Detection of Markers in Green Beans and Roasted Beans of Kalosi-Enrekang Arabica Coffee with Different Postharvest Processing Using LC-MS/MS.

Our study is aimed at evaluating the effect of postharvest processing (natural, honey, and fully washed) on the compounds profile in green beans and roasted beans of Kalosi-Enrekang Arabica coffee and determining the marker compounds for each process. These beans were extracted using boiling water, and the extract was analyzed using LC-MS/MS. The results of this work confirmed the significant impact of postharvest processing on compounds in the coffee beans, and each process has a marker compound. Green beans by natural processing have 3 marker compounds, honey processing has 6 marker compounds, and fully washed processing has 2 marker compounds. Meanwhile, roasted beans by natural processing have 4 marker compounds, honey processing has 5 marker compounds, and fully washed processing has 7 marker compounds. In addition, our research identified caffeoyl tyrosine in green beans from natural and honey processing, which was previously only identified in Robusta coffee. These marker compounds can differentiate postharvest processing (natural, honey, and fully washed). These results can also help understand the effect of postharvest processing on the chemical composition of green and roasted beans.

Verification of autoclaving-cooling treatment to increase the resistant starch contents in food starches based on meta-analysis result.

Autoclaving-cooling is a common starch modification method to increase the resistant starch (RS) content. The effect of this method varies depending on the type of crop and treatment condition used. The objectives of this study were to verify the autoclaving-cooling treatment based on a meta-analysis result and to evaluate the physicochemical properties of modified starches. The meta-analysis study used 10 articles from a total of 1,293 that were retrieved using the PRISMA approach. Meta-analysis showed that the optimal treatments of autoclaving-cooling process that increase the RS content significantly, was in starch samples from the cereal group (corn, oats, rice) (SMD: 19.60; 95% CI: 9.56-29.64; p < 0.001), with water ratio 1:4 (SMD: 13.69; 95% CI: 5.50-21.87; p < 0.001), using two cycles of autoclaving-cooling (SMD: 16.33; 95% CI: 6.98-25.67; p < 0.001) and 30 min of autoclaving heating (SMD: 12.97; 95% CI: 1.97-23.97; p < 0.001) at 121°C (SMD: 12.18; 95% CI: 1.88-22.47; p < 0.001). Verification using corn flour and corn starch showed a significant increase in RS contents from 15.84 to 27.78% and from 15.27 to 32.53%, respectively, and a significant decrease in starch digestibility from 67.02 to 35.74% and from 76.15 to 28.09%, respectively. Treated sample also showed the pasting profile that was stable under heating and stirring.