L.U. Thompson

Isolation of Rapeseed Protein Using Sodium Hexametaphosphate

Abstract The suitable conditions for the extraction and precipitation of proteins from rapeseed flour (RF) using sodium hexametaphosphate (SHMP) were determined. Rapeseed protein isolate (RI) was then prepared and analyzed for chemical composition, biological value, color and yield. The highest nitrogen yield was obtained when RF was double extracted with 2% SHMP at pH 7.0, first with a RF to solvent ratio of 1: 10 and second with a ratio of 1:6 at 25°C for 30 min. The maximum precipitation of the extracted nitrogen was observed in the extract diluted with an equal volume of distilled water and adjusted to pH 2.5. The RI contained on dry basis, 72.6% protein (N × 6.25), 12.2% ash, 0.7% crude fiber, 7.6% nitrogen free extract, 3.21% phosphorus, trace amounts of glucosinolate and no myrosinase activity. Its PER was equal to that of cheese whey protein concentrate and greater than that of casein. RI was yellow at pH 2.5 and tan at pH 7.0. Ether extraction lightened the color of the neutralized RI. Thirty-four percent total solids yield and 53% protein yield were observed in the preparation of RI.

Preparation of Mung Bean Flour and its Application in Bread Making

Abstract Mung beans (Phaseolus aureus) were steam conditioned and dehulled in the Palyi decorticating pressure plate huller with 87% recovery. Dehulled beans were further processed into flour in two different experimental mills, Allis Chalmers Mill and Buhler Experimental Mill MLU 202, with the straight grade flour yield of 72% and 75.7%, respectively. Dehulling improved the food value of the flour which was found a suitable protein supplement in bread formulas up to 15% concentration (with 0.5% SSL). At this concentration, an approximately 10% increase in protein and an average 41–42% increase in lysine (before baking) may be expected.

Yield and Properties of Cottonseed-Cheese whey Protein Coprecipitate Prepared Using Sodium Hexametaphosphate

Abstract The best yield conditions for the preparation of cottonseed-cheese whey protein coprecipitate using sodium hexametaphosphate were determined. The coprecipitate was then prepared under these conditions and evaluated for nitrogen yield, acidulant requirement, and properties in comparison with separately precipitated cottonseed and cheese whey proteins. The coprecipitation resulted in an acidulant saving but slightly less nitrogen yield than the separate precipitation of cottonseed and cheese whey proteins. The low nitrogen yield maybe improved by reducing the concentration of cations in cheese whey which competes with protein for phosphate ions. The coprecipitate had a higher protein score and protein efficiency ratio than the cottonseed isolate and the cottonseed isolate-cheese whey mixture, suggesting the nutritional advantage of the coprecipitation process over separate precipitation of cottonseed and cheese whey proteins. Although the coprecipitate had better functional properties than the cotton seed isolate, it did not differ very much from the cottonseed-cheese whey isolate mixture.