Influence of Coffee Roasting Degree from Four Mexican Regions on In Vitro Antioxidant Activity and Digestive Enzyme Inhibition and Its In Vivo Effects on Carbohydrate and Lipid Absorption

Coffee is among the most consumed beverages worldwide and is recognized for its bioactive compounds, which exert diverse physiological effects. This study evaluated the impact of roasting degree on the in vitro antioxidant activity and digestive enzyme inhibition of brews from four Mexican regions, as well as their in vivo effects on carbohydrate and lipid absorption. Antioxidant capacity was assessed through radical scavenging and lipid peroxidation inhibition, while inhibition of lipase, α-amylase, and α-glucosidase was also determined. Oral starch (OSTT) and lipid (OLTT) tolerance tests were conducted in healthy Wistar rats. Antioxidant activity was strongly influenced by region and roasting degree. All coffee samples exhibited radical scavenging activity and lipid peroxidation inhibition. With respect to enzyme inhibition, all coffees showed ~67–70% inhibition of lipase activity. For amylase, unroasted coffee from Oaxaca displayed the highest inhibition (34%, p < 0.001). For glucosidase, unroasted samples showed low inhibition (~6–19%), which increased substantially at the medium roast degree (~55% across all samples) but decreased again at the high roast degree (~27%). In OSTT, serum glucose levels were reduced after 120 min by ~20%, 21%, and 18% in rats treated with unroasted, medium-roast, and high-roast coffee, respectively, compared with the negative control. In OLTT, serum triglycerides decreased by ~26% (Chiapas), ~58% (Colima), ~32% (Oaxaca), and ~54% (Hidalgo). Crop region and roasting degree influence the phytochemical profile and bioactivity of Mexican coffee. Although unroasted coffees had the highest concentration of bioactive compounds, roasting enhanced specific bioactivities, particularly enzyme inhibition and lipid-lowering effects in vivo.