PRODUCTION OF AEROGEL CONTAINING α-GLYCOSIDASE AND α-AMYLASE ENZYME INHIBITORS FROM OLIVE POMACE WITH A SYMBIOTIC APPROACH AND INVESTIGATION OF THE EFFECT OF LOWERING THE GLYCEMIC INDEX IN FOODS
Project no. 29554 · Status: Kapanmış (Yayın bekleniyor) · 2023
Summary
<p> Global increases in lifestyle-related metabolic disorders have positioned diabetes as one of the most prevalent chronic diseases. A primary factor in the development of conditions such as Type II diabetes and obesity is the rising consumption of high glycemic index (GI) foods. Inhibiting α-amylase and α-glucosidase, the enzymes responsible for carbohydrate digestion, constitutes a critical strategy in managing postprandial hyperglycemia. While active agents like acarbose are effective in controlling hyperglycemia, studies have highlighted significant gastrointestinal side effects. Therefore, researching alternative inhibitors with potent enzyme-inhibiting properties and acceptable side-effect profiles is essential for diabetes prevention. This study investigates the recovery of cellulose, lignin, and phenolic compounds from olive pomace and evaluates the efficacy of these components within aerogel carrier systems designed for enzyme inhibition. In the initial phase, cellulose, lignin, and cellulose nanofibers (CNF) were extracted from pomace and characterized via SEM, FTIR, and XRD. Yields were determined as 33.04% for cellulose, 47.56% for lignin, and 74.67% for CNF; notably, the crystallinity index increased from 27.1% to 55% during the transition from cellulose to CNF. In the second phase, the phenolic extraction process was optimized using Response Surface Methodology (RSM). Under optimal conditions (50% ethanol, 30 °C, and 15 min), maximum values for total antioxidant activity (139.12 mg TE/g), total phenolic content (102.30 mg GAE/g), total flavonoid content (0.0013 mg CE/g), and FRAP (21.38 mM Ferrous equivalent) were achieved. Furthermore, the lowest IC50 values for α-amylase and α-glucosidase inhibition (0.402 mg/ml and 1.218 mg/ml, respectively) were recorded in the extract produced under these conditions. In the third phase, aerogels were synthesized using these optimized extracts, CNFs, and lignin (at 6%, 7%, and 8% solid-solvent ratios, 7:1 CNF:lignin ratio, containing 50 or 100 mg of phenolic extract or acarbose). Characterization confirmed the porous structure of the aerogels, with the highest enzyme inhibition performance observed in samples containing 8% CNF-lignin and 100 mg of extract. In vitro digestion tests revealed that the addition of 400 mg of aerogel to pizza dough—selected as a model food—reduced its GI value to 48.14, reclassifying it as a low glycemic index food. These results demonstrate that the developed system offers an efficacy comparable to acarbose (GI: 44.34%) and represents a viable natural alternative for diabetes management.</p><p> The performance comparison between acarbose and aerogels containing CNF, lignin, and phenolic compounds derived from olive pomace is examined here for the first time. Furthermore, the production of aerogels from olive pomace—a waste product of the olive industry—and their application in bakery products to lower GI values serves as a significant example of industrial symbiosis across sectors.</p>