Optimizing the Integration of Microwave Processing and Enzymatic Extraction to Produce Polyphenol-Rich Extracts from Olive Pomace.

The integration of green technologies such as microwave- and enzyme-assisted extraction (MEAE) has been shown to improve the extraction efficiency of bioactive compounds while reducing processing time and costs. MEAE using tannase alone (MEAE-Tan), or in combination with cellulase and pectinase (MEAE-Tan-Cel-Pec), was optimized to produce enriched phenolic and antioxidant extracts from olive pomace. The individual and integrated impact of enzyme concentration, temperature, and pomace/water ratio were determined using a central composite rotatable design. Optimal extraction conditions for MEAE-Tan (60 °C, 15 min, 2.34% of enzyme (w/w), and 1:15 pomace/water ratio) and MEAE-Tan-Cel-Pec (46 °C, 15 min, 2% of enzymes (w/w), in the proportion of 1:1:1, and 1:20 pomace/water ratio) resulted in extracts containing 7110.6 and 2938.25 mg GAE/kg, respectively. The antioxidant activity of the extracts was correlated with phenolic acid release, which was enzyme-dependent, as determined with HPLC-DAD analysis. Enzyme selection had a significant impact on the phenolic profile of extracts, with tannase releasing high concentrations of chlorogenic acid and the combined use of enzymes releasing high concentrations of hydroxytyrosol and chlorogenic and ferulic acids. The novelty of this study relies on the integration and optimization of two green technologies (microwave- and enzyme-assisted extraction) to improve the extraction efficiency of bioactive phenolics from olive pomace while reducing processing time and costs. While these techniques have been evaluated isolated, the benefits of using both processing strategies simultaneously remain largely unexplored. This study demonstrates the effectiveness of the integration and processing optimization of two environmentally friendly technologies as a promising alternative to treat agro-industrial byproducts.

Anti-glycation effect and the α-amylase, lipase, and α-glycosidase inhibition properties of a polyphenolic fraction derived from citrus wastes.

The advanced glycation end products (AGEs) constitute a wide variety of substances synthesized from interactions between amino groups of proteins and reducing sugars, which excess induces pathogenesis of chronic diseases. Brazil is the major producer of citrus, a low-cost source of hesperidin, which is a polyphenol recognized for its capacity to inhibit AGEs formation. This is the first work to evaluate the effects of a polyphenolic fraction derived from citrus wastes on the antiglycation and on the inhibition properties of digestive enzymes on the possibility to process these wastes in high value-added products. At concentrations of 10, 15 and 20 mg/mL inhibition of AGEs was higher than 60%. The extracts were able to inhibit by 76% the activity of pancreatic lipase and by 98% the activity of α-glucosidase. For the α-amylase the inhibition capacity was lower than 50%. Strong correlation was obtained among anti-glycation with polyphenolic content and antioxidant capacity.

Bioconversion of Isoflavones into Bioactive Equol: State of the Art.

BACKGROUND: Soy isoflavones, an important class of phytoestrogens, are suggested to be responsible for a number of biological activities associated with health benefits, including defense against various chronic diseases, including breast and prostate cancer, cardiovascular disorders, and osteoporosis, and they may alleviate the symptoms of menopause. METHODS: However, current researches (including patents) have shown that the clinical efficacy of these phenolic compounds is related to the ability of an individual to biotransform isoflavones into equol, which is a metabolite of daidzein formed exclusively by the intestinal microbiota. RESULTS: This biologically active metabolite presents greater effects than other isoflavones; however, only about 30-50 % of people have a microbiota that is able to produce equol from dietary daidzein. Concern has recently grown about applications to improve the production of this metabolite. CONCLUSION: This paper summarizes the metabolism of equol, its production, and clinical implications.

Enzymatic biotransformation of polyphenolics increases antioxidant activity of red and white grape pomace.

Grape pomace (GP) is a polyphenolic-rich byproduct of wine production. As most polyphenolics are either bound to cellular matrices or present as free polymeric forms, treatment with hydrolytic enzymes may act to increase GP functionalities. The aim of this study was to examine the impact of tannase alone (T), pectinase plus cellulase (PC) or a mixture of them (TPC) on the hydrolysis of polyphenolics in red GP (RGP), white GP (WGP), and mixed GP (MGP) from Brazilian wine production, as well as antioxidant activity of the products. T was the most potent in increasing total polyphenols in GP by liberating gallic acid, caffeic acid, quercetin, and trans-resveratrol. PC increased the catechin content in RGP and TPC increased the procyanidin B2 in WGP. T treatment of GP was most effective in increasing antioxidant activity. In conclusion, the enzymatic treatment, particularly with T, increases the polyphenolic content and antioxidant activity of GP.

Simultaneous extraction of oil and antioxidant compounds from oil palm fruit (Elaeis guineensis) by an aqueous enzymatic process.

Oil palm (Elaeis guineensis) fruit was treated with enzymes to facilitate simultaneous recovery of oil and bioactive compounds. Tannase from Paecilomyces variotii, cellulase and pectinase were evaluated for their influence on oil recovery and antioxidant capacity (DPPH), oxidative stability (Rancimat), fatty acid profile, total phenols, total carotenoids and tocols of the oil. Maximum oil recovery (90-93% total oil) was obtained with central composite design using 4% of enzyme preparation (w/w) as 80 U of tannase, 240 U of cellulase and 178 U of pectinase, pH 4, ratio of solution to pulp of 2:1 and 30 min of incubation at 50 °C. Tannase improved the phenolic compounds extraction by 51% and pectinase plus cellulase improved carotene extraction by 153%. Samples treated with tannase showed a 27% and 53% higher antioxidant capacity for the lipophilic and hydrophilic fractions.

Effects of temperature, pH and additives on the activity of tannase produced by Paecilomyces variotii

A biochemical characterization of the tannase from a Paecilomyces variotii strain isolated in Sao Paulo, Brazil was carried out. Paecilomyces variotii is a strain obtained from the screening of five hundred fungi that were tested for their production of tannase. The enzyme produced was partially purified using ammonium sulfate precipitation followed by ion exchange chromatography, diethylaminoethyl (DEAE)-Sepharose. Effects of temperature and pH on the activity of crude tannase crude and purified tannase was studied. Km was found to be 0.61 ‘mol and Vmax = 0.55 U/mL. Temperature of 40 to 65øC and pH 4.5 to 6.5 were optimum for tannase activity and stability; it could find potential use in the food-processing industry. The effects of different inhibitors, surfactants and chelators on the enzyme activity were also studied