Search

Pectin is a complex polysaccharide found in plant cell walls and interlayers. As a food component, pectin is benefit for regulating intestinal flora. Metabolites of intestinal flora, including short-chain fatty acids (SCFAs), bile acids (BAs) and lipopolysaccharides (LPS), are involved in blood glucose regulation. SCFAs promote insulin synthesis through the intestine-GPCRs-derived pathway and hepatic adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) pathway to promote hepatic glycogen synthesis. On the one hand, BAs stimulate intestinal L cells and pancreatic α cells to secrete Glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) through receptors G protein-coupled receptor (TGR5) and farnesoid X receptor (FXR). On the other hand, BAs promote hepatic glycogen synthesis through AMPK pathway. LPS inhibits the release of inflammatory cytokines through Toll-like receptors (TLRs)-myeloid differentiation factor 88 (MYD88) pathway and mitogen-activated protein kinase (MAPK) pathway, thereby alleviating insulin resistance (IR). In brief, both SCFAs and BAs promote GLP-1 secretion through different pathways, employing strategies of increasing glucose consumption and decreasing glucose production to maintain normal glucose levels. Notably, pectin can also directly inhibit the release of inflammatory cytokines through the -TLRs-MYD88 pathway. These data provide valuable information for further elucidating the relationship between pectin-intestinal flora-glucose metabolism.

Pectin is one of high-value functional food ingredients. Better knowledge of properties of chayote pectin would help to promote the application of the chayote as a pectin source. In this study, ultrasound-assisted extraction (UAE) was used to extract chayote pectin. The extraction parameters were optimized by a Box-Behnken response surface design. The highest yield (6.19%) was obtained at a liquid/solid ratio of 50 mL/g, ultrasonic temperature of 70 °C and ultrasonic time of 40 min as optimized extraction conditions. The chemical properties, spectral information and rheological properties of pectin extracted with UAE under the optimum conditions (PEUO) were measured and the results indicated that the PEUO exhibited a low degree of esterification, high molar mass (2.47 × 10 6  g/mol) and suitable foaming capacity. The PEUO featured a stronger antioxidant capacity compared to commercially apple pectin and the PEUO solutions (1%, 2%, 3% and 5%) showed a non-Newtonian behavior. Hence, PEUO may provide beneficial characteristics to find use in food industry., (Copyright © 2020 Elsevier B.V. All rights reserved.)

In this study, the extract methods of pectin fromZanthoxylum bungeanumMaxim. seeds under atmospheric pressure and pressurized pretreatment were investigated and compared. Response surface methodology was applied to optimize the extraction conditions for obtaining the maximum yield of pectin. The optimum extraction conditions under atmospheric pressure were as follows: pH 2.5, 84.8°C, 81.0 min, and liquid-to-solid ratio 14.2:1 (ml/g). The optimum extraction conditions under pressurized pretreatment were as follows: pH 6.1, 117.7°C, and 95.4 min. In contrast, the optimal extraction yield under pressurized pretreatment was 76.52% above that of extraction under atmospheric pressure. [ABSTRACT FROM PUBLISHER]

Composite edible films of pectin (PEC) and konjac glucomannan (KGM) were incorporated with tea polyphenol (TP) to develop active food packaging. The effects of 1%–5% TP (w/w, on a dry basis of the weight of PEC and KGM) on the structural and physical properties, antioxidant and antimicrobial activity of the resultant PEC/KGM films were systematically evaluated. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) suggested the good compatibility of the components and the well-dispersion of TP in the matrix, due to the occurrence of hydrogen-bonding among them. The incorporation of TP significantly improved the antioxidant and antimicrobial activity of the films, while induced decreases in the transmittance, moisture content and elongation at break. In particular, addition of TP at appropriate levels remarkably increased the mechanical and water-resistant properties of the films. For example, the tensile strength and contact angle value of the films with 2% TP increased by 5.28 MPa and 18.93°, respectively. However, overloading of TP in the composite films might produce some aggregations and thus have negative effects on their performance. In sum, the developed PEC/KGM/TP films possessed the potential to be applied as bioactive materials in food packaging sectors. Image 103690 • Pectin (PEC) and konjac glucomannan (KGM) showed high compatibility as good film-forming substrates. • Tea polyphenol (TP) was incorporated into PEC/KGM films to develop active food packaging. • TP was well dispersed in the matrix due to the occurrence of hydrogen-bonding. • Addition of TP at appropriate levels could simultaneously enhance the physical and functional properties of PEC/KGM films. [ABSTRACT FROM AUTHOR]