Functional Peptides from Yak Milk Casein: Biological Activities and Structural Characteristics.

The average content of casein in yak milk is 40.2 g/L. Casein can be degraded by enzymatic digestion or food processing to produce abundant degradation peptides.

Enzymatic Hydrolysis Optimization of Yak Whey Protein Concentrates and Bioactivity Evaluation of the Ultrafiltered Peptide Fractions.

Yak whey protein concentrates (YWPCs) have good functional properties, but there is still a gap in the study of their peptides. In this study, peptides were obtained by enzymatic hydrolysis, and the bioactivity of each ultrafiltration fraction was evaluated using an optimal process. YWPCs were isolated and purified from yak milk as the raw material.

Effect of Hydrothermal Treatment on the Structure and Functional Properties of Quinoa Protein Isolate.

The aim of this study was to investigate the effects of hydrothermal treatment at different temperatures and times on the structure and functional properties of quinoa protein isolate (QPI). The structure of QPI was investigated by analyzing changes in the intrinsic fluorescence spectrum, ultra-violet (UV) spectrum, and Fourier transform infrared spectrum. The solubility, water/oil-holding capacity, emulsifying activity, and emulsion stability of QPI were studied, as were the particle size and the thermogravimetric properties of QPI.

Ultrasonic Assisted Extraction of Quinoa ( Willd.) Protein and Effect of Heat Treatment on Its In Vitro Digestion Characteristics.

To extract and utilise the protein in quinoa efficiently, we investigated the effect of rate of quinoa protein isolate (QPI) extraction by ultrasound-assisted alkaline extraction and traditional alkaline extraction methods using single-factor experiments and Box-Behnken design. The effect of different heat treatment temperature and time on QPI functional properties and in vitro digestion characteristics were also investigated. The results showed that the optimal conditions of ultrasound- assisted alkaline extraction process were: ultrasonic time 99 min, solid-liquid ratio 1:20 , ultrasonic temperature 47 °C, and pH 10, and its extraction rate and purity were 74.

Effects of Fermentation on the Chemical Structure and Antioxidant Activity of Polysaccharides from Bulbs of Lanzhou Lily.

Recently, Lanzhou lily has attracted more attention because of its bioactive components specifically polysaccharides. We studied in vitro the effects of fermentation on the physicochemical properties, chemical structure, and antioxidant activity of the Lanzhou lily polysaccharide. The results showed that compared with the unfermented Lanzhou lily polysaccharide (LP-W), the molecular weight ( ) of the fermented Lanzhou lily polysaccharide (LPF-W) decreased from 4334 to 1684 kDa, the particle size decreased from 300.

A freeze-thawing method applied to the fabrication of 3-d curdlan/polyvinyl alcohol hydrogels as scaffolds for cell culture.

In this work, an innovative composite hydrogel composed of curdlan (CD)/polyvinyl alcohol (PVA) hydrogels with a 3-d network structure was successfully prepared by freeze-thaw processing. The presence of interactions, changes in crystallinity, and thermal behaviour were investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetry (TGA and DTG), respectively. The morphology of the hydrogels was investigated by scanning electron microscopy (SEM).

Isolation of antioxidant peptides from yak casein hydrolysate.

Enzymatic hydrolysis of protein is a principal method to obtain antioxidant peptides. A yak casein hydrolysate (YCH) was prepared by alcalase and trypsin digestion. An ultrafiltration membrane system was used to divide the hydrolysate into four molecular weight fractions; YCH-4 (<3 kDa) had the highest antioxidant activity.

Purification, structure and anti-oxidation of polysaccharides from the fruit of Bobr.

In this paper, polysaccharides were extracted from the fruits of Bobr. (NTWP) using a hot water extraction method and extraction conditions were optimized by RSM. The optimal conditions were determined as follows: extraction time 7 h, extraction temperature 60 °C, ratio of water to raw material 15 : 1, and with these conditions, the yield was 14.

Ultrasound-assisted extraction of polysaccharides from Rhododendron aganniphum: Antioxidant activity and rheological properties.

In this study, we aimed to optimize the extraction of polysaccharides from the leaves of Rhododendron aganniphum and investigate its rheological properties and antioxidant activity. After optimizing the operating parameters using a Box-Behnken design (BBD), the results showed that the optimal ultrasound-assisted extraction conditions were as follows: extraction temperature, 55°C; liquid-solid ratio, 25:1; extraction time, 2.2h; and ultrasound treatment power, 200W.

Catalytic synthesis of sulfated polysaccharides. II: comparative studies of solution conformation and antioxidant activities.

Sulfated derivatives of Artemisia sphaerocephala polysaccharide (ASP) with high degree of substitution (DS) were synthesized using 4-dimethylaminopyridine (DMAP)/dimethylcyclohexylcarbodiimide (DCC) as catalyst. Size exclusion chromatography combined with multi-angle laser light scattering (SEC-LLS) results showed a decrease in fractal dimension (df) values of sulfated ASP (SASP). Compared to ASP and SASP with low DS (0.

Regioselective synthesis of sulfated guar gum: comparative studies of structure and antioxidant activities.

We reported here a new synthesis of C-2 and C-3 sulfated guar gum (SRSGG) with low degree of substitution (DSS) of 0.58, employing triphenylchloromethane (TrCl) as a protected precursor. The yield and DSTr (calculated from the weight of triphenylmethanol) of triphenylmethylated GG (GGTr) was 165.

Selenylation modification can enhance antioxidant activity of Potentilla anserina L. polysaccharide.

Potentilla anserina L. polysaccharide had been selenizingly modified by nitric acid-selenious acid method with microwave-assistant. The optimal reaction parameters on selenylation modification were time 116 min, temperature 63°C, microwave power 190 W and the actual value of selenium content was 2690.

Synthesis of selenium-containing polysaccharides and evaluation of antioxidant activity in vitro.

Selenium (Se) is an essential trace element for human beings and many other forms of life. Organic Se from natural foods has higher bioavailability and is safer than inorganic Se species. In the present study, selenium-containing derivatives of Artemisia sphaerocephala polysaccharide with the highest Se content of 1703 μg/g were synthesized using H(2)SeO(3)/HNO(3) and BaCl(2) as a catalyst.

Structure and antioxidant activities of sulfated guar gum: homogeneous reaction using DMAP/DCC catalyst.

It was essential to understand the chemical structure of polysaccharides for further research and biochemical or medical application of this natural biopolymer. In the present study, sulfated derivatives of guar gum with high degree of sulfation (DS) were synthesized using 4-dimethylaminopyridine (DMAP)/dimethylcyclohexylcarbodiimide (DCC) as catalyst in homogeneous conditions. The effects of the ratio of chlorosulfuric acid to pyridine, the content of catalyst and reaction temperature were investigated.

Structure-antioxidant relationships of sulfated galactomannan from guar gum.

Sulfated polysaccharides exerted potential biological property which was relative to degree of sulfation (DS), M(w), substitution position and chain conformation. In the present study, commercial guar gum was purified and its sulfated derivates with different DS and M(w) were synthesized. FT-IR and 13C NMR analysis indicated that C-6 substitution was predominant in sulfated samples compared with other positions.

A comparison study on microwave-assisted extraction of Artemisia sphaerocephala polysaccharides with conventional method: Molecule structure and antioxidant activities evaluation.

The conventional extraction methods for polysaccharides were time-consuming, laborious and energy-consuming. Microwave-assisted extraction (MAE) technique was employed for the extraction of Artemisia sphaerocephala polysaccharides (ASP), which is a traditional Chinese food. The extracting parameters were optimized by Box-Behnken design.