Effect of Roasting Degree, Extraction Time, and Temperature of Coffee Beans on Anti-Hyperglycaemic and Anti-Hyperlipidaemic Activities Using Ultrasound-Assisted Extraction

Impact of coffee and its bioactive compounds on the risks of type 2 diabetes and its complications: A comprehensive review

BACKGROUND

Coffee beans have a long history of use as traditional medicine by various indigenous people. Recent focus has been given to the health benefits of coffee beans and its bioactive compounds. Research on the bioactivities, applications, and effects of processing methods on coffee beans' phytochemical composition and activities has been conducted extensively. The current review attempts to provide an update on the biological effects of coffee on type 2 diabetes (T2D) and its comorbidities.

METHODS

Comprehensive literature search was carried out on peer-reviewed published data on biological activities of coffee on in vitro, in vivo and epidemiological research results published from January 2015 to December 2022, using online databases such as PubMed, Google Scholar and ScienceDirect for our searches.

RESULTS

The main findings were: firstly, coffee may contribute to the prevention of oxidative stress and T2D-related illnesses such as cardiovascular disease, retinopathy, obesity, and metabolic syndrome; secondly, consuming up to 400 mg/day (1-4 cups per day) of coffee is associated with lower risks of T2D; thirdly, caffeine consumed between 0.5 and 4 h before a meal may inhibit acute metabolic rate; and finally, both caffeinated and decaffeinated coffee are associated with reducing the risks of T2D.

CONCLUSION

Available evidence indicates that long-term consumption of coffee is associated with decreased risk of T2D and its complications as well as decreased body weight. This has been attributed to the consumption of coffee with the abundance of bioactive chemicals.

Antidiabetic Property Optimization from Green Leafy Vegetables Using Ultrasound-Assisted Extraction to Improve Cracker Production

Here we test a method of incorporating of plant extracts into popular snack foods to help control diabetes. Since some fresh vegetables contain antidiabetic compounds, ultrasound-assisted extraction was used to optimize their extraction of from spring onions, bunching onions, and celery for later incorporation into crackers. We compared various concentrations of ethanol used during extraction, after which they were exposed to an ultrasound processor whose amplitude and sonication time were also varied. The optimal extraction conditions were found to be an ethanol concentration of 44.08%, an amplitude of 80%, and a sonication time of 30 min. This resulted in the highest level of α-glucosidase inhibitory activity (i.e., 1,449.73 mmol ACE/g) and the highest extraction yield (i.e., 24.16%). The extract produced from these optimum conditions was then used as a constituent component of crackers at 0.625%, 1.25%, or 2.5% w/w. These biscuits were then produced at baking temperatures of 140°C, 150°C, or 160°C. We then measured the physical characteristics and bioactivities of sample biscuits from each treatment. We found that biscuits containing 2.5% vegetable combination extract and baked at 140°C had the highest total phenolic content, the strongest antioxidant performance, and showed the most substantial antidiabetic and antiobesity effects. Here we establish conditions for the effective extraction of antidiabetic functional ingredients via ultrasound from green leafy vegetables. We also provide a method of using these ingredients to prepare crackers with the aim of developing a functional antidiabetic snack food.

Coffee bean processing: Emerging methods and their effects on chemical, biological and sensory properties

Emerging processing methods have been applied in coffee bean processing for improved sensory quality. The processes focus on optimizing the fermentation process of the coffee cherries and beans. This involves various pathways, including the formation of volatiles, flavor precursors and organic acids and the reduction in the concentrations of bioactive compounds. Comprehensive information regarding the effect of these emerging processes on the chemical, biological and sensory properties of the coffee beans is summarized. Emerging processes affected the coffee bean to various degrees depending on the raw material and the method used. The emerging methods promoted the reduction of bioactives such as caffeine and phenolics in coffee beans. Substantial improvement of these processes is needed to obtain coffee beans with improved biological activities. Effort to simplify the methods and optimize the post-fermentation process is crucial for the methods to be easily accessible by the producers and to produce defect-free coffee beans.

Effects of Enzymatic- and Ultrasound-Assisted Extraction on Physicochemical and Antioxidant Properties of Collagen Hydrolysate Fractions from Alaska Pollack (Theragra chalcogramma) Skin

Collagen hydrolysate were extracted from Alaska pollock skin using enzymatic (EAE), ultrasound (UAE), or combination of enzymatic and ultrasound (EAE+UAE) treatment. Control (C) was not treated with enzymatic or ultrasound. The extracts from C, EAE, UAE, and EAE+UAE were fractionated with ≤3, 3-10, 10-30, and ≥30 kDa. Each fraction was evaluated for biological activity and structural properties. All fractions contained high levels of glycine and proline. The ≤3 kDa fraction of control and ultrasound-assisted extracts exhibited the highest antioxidant activity as measured using Trolox equivalent antioxidant capacity, ferric ion reducing antioxidant power, oxygen radical absorbance capacity, and an assay on the inhibition of nitric oxide production by LPS-induced macrophages. The structurally digested collagen was evaluated using FTIR spectra and SDS-PAGE after Alcalase^® and ultrasound treatments. The microstructure of collagen hydrolysate was assessed using SEM microscopy; the surface morphology was altered according to fraction size and extraction conditions. Overall, it was determined that enzyme treatment in combination with ultrasound is the most effective procedure for obtaining digested collagen hydrolysate, which could be used to further improve biotechnological processing for the addition of value to marine production chains in the future.

Potential Antimicrobial Properties of Coffee Beans and Coffee By-Products Against Drug-Resistant Vibrio cholerae

Vibrio cholerae is the causative organism of the cholera epidemic, and it remains a serious global health problem, particularly the multidrug-resistant strain, despite the development of several generic drugs and vaccines over time. Natural products have long been exploited for the treatment of various diseases, and this study aimed to evaluate the in vitro antibacterial activity of coffee beans and coffee by-products against V. cholerae antimicrobial resistant strains. A total of 9 aqueous extracts were investigated, including light coffee (LC), medium coffee (MC), dark coffee (DC), dried green coffee (DGC), dried red coffee (DRC), fresh red coffee (FRC), Arabica leaf (AL), Robusta leaf (RL), and coffee pulp (CP). The influential coffee phytochemicals, i.e., chlorogenic acid (CGA), caffeic acid (CA), and caffeine, were determined using HPLC. The antibacterial properties were tested by agar well-diffusion techniques, and the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were further determined against 20 V. cholerae isolates. The results revealed that all tested strains were sensitive to coffee extracts, with MIC and MBC values in the range of 3.125-25.0 mg/mL and 12.5-50.0 mg/mL, respectively. With a MIC of 6.25 mg/mL, DGC, DRC, and CP appeared to be the most effective compounds against 65, 60, and 55% of clinical strains, respectively. The checkerboard assay revealed that the combination of coffee extract and tetracycline was greater than either treatment alone, with the fractional inhibitory concentration index (FICI) ranging from 0.005 to 0.258. It is important to note that CP had the lowest FICI (0.005) when combined with tetracycline at 60 ng/mL, which is the most effective dose against V. cholerae six-drug resistance strains (azithromycin, colistin, nalidixic acid, sulfamethoxazole, tetracycline, and trimethoprim), with a MIC of 47.5 μg/mL (MIC alone = 12.5 mg/mL). Time killing kinetics analysis suggested that CA might be the most effective treatment for drug-resistant V. cholerae as it reduced bacterial growth by 3 log10 CFU/mL at a concentration of 8 mg/mL within 1 h, via disrupting membrane permeability, as confirmed by scanning electron microscopy (SEM). This is the first report showing that coffee beans and coffee by-product extracts are an alternative for multidrug-resistant V. cholerae treatment.