Molecular and Functional Properties of Protein Fractions and Isolate from Cashew Nut (Anacardium occidentale L.).

Some molecular and functional properties of albumin (83.6% protein), globulin (95.5% protein), glutelin (81.3% protein) as well as protein isolate (80.7% protein) from cashew nut were investigated. These proteins were subjected to molecular (circular dichroism, gel electrophoresis, scanning electron microscopy) and functional (solubility, emulsification, foaming, water/oil holding capacity) tests. Cashew nut proteins represent an abundant nutrient with well-balanced amino acid composition and could meet the requirements recommended by FAO/WHO. SDS-PAGE pattern indicated cashew nut proteins were mainly composed of a polypeptide with molecular weight (MW) of 53 kDa, which presented two bands with MW of 32 and 21 kDa under reducing conditions. The far-UV CD spectra indicated that cashew proteins were rich in ß-sheets. The surface hydrophobicity of the protein isolate was higher than that of the protein fractions. In pH 7.0, the solubility of protein fractions was above 70%, which was higher than protein isolate at any pH. Glutelin had the highest water/oil holding capacity and foaming properties. Protein isolate displayed better emulsifying properties than protein fractions. In summary, cashew nut kernel proteins have potential as valuable nutrition sources and could be used effectively in the food industry.

Effects of micronized okara dietary fiber on cecal microbiota, serum cholesterol and lipid levels in BALB/c mice.

Micronized by a dry grinding method (D-ODF) or a wet granulating method (W-ODF), okara dietary fiber (ODF), was fed to BALB/c mice for 28 d. The water holding capacity of D-ODF and W-ODF was significantly enhanced after micronization. W-ODF had a larger swell capacity and a higher content of soluble dietary fiber than crude ODF and D-ODF. After feeding for 28 d, the populations of Escherichia coli and Lactobacilli in the cecum were significantly lower and higher in the W-ODF group than other groups, respectively, while the population of Bifidobacterium increased in all groups. The effect of each diet on the population of E. coli. Lactobacilli and Bifidobacterium was all maintained for a short period of time except that the effectiveness of W-ODF diet on the Bifidobacterium population lasted slightly longer than other diets. At the end of the feeding period, serum total cholesterol (TC) and triglyceride in D-ODF and W-ODF diets were significantly lower and HDL-C/TC ratio was significantly higher than those in crude ODF.

Relationship between functional properties and aggregation changes of whey protein induced by high pressure microfluidization.

Aggregation changes of whey protein induced by high-pressure microfluidization (HPM) treatment have been investigated in relation with their functional properties. Whey protein was treated with HPM under pressure from 40 to 160 MPa. Functional properties (solubility, foaming, and emulsifying properties) of whey protein concentrate (WPC) ultrafiltered from fluid whey were evaluated. The results showed significant modifications in the solubility (30% to 59%) and foaming properties (20% to 65%) of WPC with increasing pressure. However, emulsifying property of WPC treated at different pressures was significantly worse than untreated sample. To better understand the mechanism of the modification by HPM, the HPM-induced aggregation changes were examined using particle size distribution, scanning electron microscopy, and hydrophobicity. It was indicated that HPM induced 2 kinds of aggregation changes on WPC: deaggregation and reaggregation of WPC, which resulted in the changes of functional properties of WPC modified by HPM.