Novel Pickering emulsion gels stabilized solely by phenylalanine amidated pectin: Characterization, stability and curcumin bioaccessibility.

Pickering emulsion gels represent a novel class of non-toxic and biocompatible emulsions, offering extensive applications in the pharmaceutical and food additive sectors. This study delineates the synthesis of Pickering emulsion gels utilizing native and amidated pectin samples. Phenylalanine amidated pectin (AP) was procured via an ultra-low temperature enzyme method, while the control group (LP) adhered to an identical procedure without papain catalysis. Experimental outcomes revealed that the AP Pickering emulsion gel manifested superior stability compared to pectin emulsion samples (PE and LP). The Pickering emulsion gel from 5 % amidated pectin (5AP) retained stability throughout a 14-day emulsion stability assessment. Furthermore, all emulsion samples were evaluated for their capacity to deliver and sustain curcumin within an in vitro digestion simulation. Rheological properties and oil droplet size results indicated that the 5AP Pickering emulsion gel exhibited optimal cream index and emulsion stability, effectively inhibiting premature water-oil stratification within the emulsion and augmenting curcumin bioaccessibility. Within the in vitro digestion simulation, the 5AP Pickering emulsion gel demonstrated the highest curcumin bioaccessibility, measured at 17.96 %.

Preparation of amidated pectins through enzymatic method: Structures, hydrogel properties and its application potential in fat substitutes.

In this paper, α-alanine and ß-alanine were used as modifiers to prepare α-alanine amidated pectin (α-AP) and ß-alanine amidated pectin (ß-AP) through enzymatic method. The effects of alanine and its isomer on the amidation degree and physicochemical properties of pectin were studied. Fourier transform infrared spectrum, proton nuclear magnetic resonance analysis, X-ray photoelectron spectrum and elemental analysis indicated that the amino groups from α-C and ß-C could be aminated with the carboxyl group of pectin to form the corresponding aminated pectin. The alanine grafting ratio of α-AP and ß-AP were 21.99% and 18.92%, respectively. The results showed that the dynamic viscosity of ß-AP was significantly higher than that of α-AP due to the influence of amino acid side chain. However, due to the higher alanine grafting ratio of α-AP, the strength of hydrogel prepared by α-AP was higher than that of ß-AP, and it also has the highest elastic modulus and swelling capacity. In addition, pectin, as a carbohydrate-based fat substitute, has been widely used in the field of food to simulate the smooth and delicate taste of fat. Compared with High methoxy pectin (HMP) and ß-AP, α-AP had better colloid stability and smaller hydrogel particles in the composite system. The results provide references for the application of amidated pectin in low-fat food.

Fabrication of phenylalanine amidated pectin using ultra-low temperature enzymatic method and its hydrogel properties in drug sustained release application.

In this study, pectin was modified with phenylalanine by ultra-low temperature enzymatic method to improve its gel properties. The grafting ratio of phenylalanine amidated pectin was studied under different reaction conditions. The highest value (29.21 %) was reached a reaction temperature of -5 °C and time of 12 h. Further analysis indicated that phenylalanine and high methoxyl pectin combined at the solid-liquid two phase interface under the catalysis of papain to form phenylalanine amidated pectin. Moreover, the physicochemical properties of pectin hydrogel and its feasibility as a sustained-release drug carrier were discussed. The results showed that phenylalanine amidated pectin can form hydrogel with a certain strength under acidic conditions, and there is no need to add a lot of soluble solids and divalent cations. Besides, the phenylalanine amidated pectin hydrogel as a sustained release carrier of drugs showed more sustained and complete drug release.

Development and Validation of an Enzymatic Method To Determine Stevioside Content from Stevia rebaudiana.

An enzymatic method for specific determination of stevioside content was established. Recombinant ß-glucosidase BT_3567 (rBT_3567) from Bacteroides thetaiotaomicron HB-13 exhibited selective hydrolysis of stevioside at ß-1,2-glycosidic bond to yield rubusoside and glucose. Coupling of this enzyme with glucose oxidase and peroxidase allowed for quantitation of stevioside content in Stevia samples by using a colorimetric-based approach. The series of reactions for stevioside determination can be completed within 1 h at 37 °C. Stevioside determination using the enzymatic assay strongly correlated with results obtained from HPLC quantitation (r2 = 0.9629, n = 16). The percentages of coefficient variation (CV) of within day (n = 12) and between days (n = 12) assays were lower than 5%, and accuracy ranges were 95-105%. This analysis demonstrates that the enzymatic method developed in this study is specific, easy to perform, accurate, and yields reproducible results.

Research progress in molecular modification and pharmacological activity of Chinese materia medica polysaccharides / 中草药

Molecular modification of Chinese materia medica polysaccharides (CMMP) is considered as the technology of modification on some special structure or functional group in the main chain or the side chain of polysaccharides on the purpose of changing certain physicochemical properties and the spatial structure of polysaccharides by using physical, chemical and biological methods which can enhance the biological activity. Physical methods mainly include ultrasonic method and irradiation technology. Chemical methods refer to sulfation, phosphorylation, acetylation, carboxymethylation, alkylation, sulfonylation, selenylation, and so on. Biological method is also called the enzymatic modification containing enzyme degradation and enzymatic synthesis. In recent years, it has been shown that the physicochemical properties and spatial structure of CMMP could be changed after modification, which could make their immunopharmacology activity, such as immune adjustment, antivirus, antitumor, and antioxidant, enhanced obviously. The main modification methods of CMMP and the related pharmacological activity of its products after modification are summarized in this paper.