Recovery of Yam Soluble Protein from Yam Starch Processing Wastewater.

Over the past two decades, many studies have shown that the yam storage protein dioscorin, which is abundant in the wastewater of starch processing, exhibits many biological activities both in vitro and in vivo. In the present study, the acid-precipitation method was optimized using Box-Behnken design (BBD) combined with response surface methodology (RSM) for the recovery of yam soluble protein (YSP) from wastewater. The experimental yield of YSP reached 57.7%. According to relative quantitative proteomics (LC-MS/MS), the crude YSP was mainly composed of 15 dioscorin isoforms, which was further verified by anion-exchange and size-exclusion chromatography. YSP was found to be rich in glutamic acid and aspartic acid, and the eight essential acids made up approximately 33.7% of the YSP. Moreover, the YSP demonstrated antioxidant activity, including scavenging DPPH, hydroxyl and superoxide anion radicals, and the possible structure-activity relationships were discussed. These results indicated that YSP produced by acid precipitation may be used as a protein source with antioxidant properties.

Foliar application is an effective method for incorporating selenium into peanut leaf proteins with antioxidant activities.

Proteins were extracted from Se-enriched peanut leaves, an agro-byproduct, and the foliar application of sodium selenite was indicated to be an effective method to incorporate Se into leaf selenoproteins with 75-80% incorporation rates. After trypsin digestion, the most abundant proteins from Se-enriched peanut leaf (PSPL) were identified as pathogenesis-related class 10 proteins, Ara h 8 allergen and its isoforms, using LC-MS/MS. The Se species in both the low Se PSPL and high Se PSPL were determined to be selenomethionine (SeMet), methylselenocysteine (MeSeCys) and selenocystine (SeCys2) with SeMet (15.6 mg/g) dominated the high Se PSPL. Their antioxidant activities were also evaluated using free radical scavenging assay, reducing power assay and ferric thiocyanate (FTC) test. As results, the PSPL exhibited potent DPPH radical (96.2%) and superoxide anion radical (98.4%) scavenging activities and showed strong reducing power in a Se-concentration-dependent manner, indicating that PSPL can be used as antioxidants and Se sources to improve health.

[Sulfated modification and anticoagulant activity in vitro of sulfated glucan isolated from the aqueous extract of Hedysarum polybotrys].

SHG was sulfated by chlorosulfonic acid-pyridine method, and six samples which we got were prepared in different reaction conditions. There is a characteristic absorption peak near 260 nm in UV spectra and there are two characteristic absorption peaks near 1240 cm(-1) and 810 cm(-1) in the FT-IR. Degree of sulfation (DS) was calculated by elemental analysis and turbidimetry. Under the same conditions the absorption peaks become strong with the DS increase. The anticoagulant activity of SHG and sulfated modification samples was evaluated by the classic coagulant assays of prothrombin time (PT), activated partial thrombin time (APTT) live enzymes, and plasma thrombin time (TT). Results show that sulfated SHG has a good anticoagulant activity in vitro, and DS increased activity within a certain range.