Comparison of Protein Extraction Solutions for Rice Starch Isolation and Effects of Residual Protein Content on Starch Pasting Properties

The nutrient composition and the acceptability of biscuit from composite flours of wheat, Bambara groundnut (Vigna subterranea), Ground bean seed (Macrotyloma) and Moringa seed (Moringa oleifera) were evaluated. Bambara groundnut (Vigna subterranea), Ground bean seed (Macrotyloma) and Moringa seed (Moringa oleifera) were dried, and processed into flour. The flour blends developed was used as a substitute for wheat flour as composite flour. The resulting mixtures were then used to produce biscuits at different ratios of wheat flour to flour blends; 100:0, 90:10, 80:20 and 70:30 level of the flour blends. The pasting properties, proximate composition, minerals, physical (spread ratio, weight, thickness and colour) and sensory properties of the composite biscuit were evaluated. The pasting properties of the flours showed that pasting temperature ranged from 68.50°C - 70.0°C and the peak viscousity range from 101.17 RVU – 207.17 RVU, while Break down (43.0 RVU) was highest in 90% wheat: 10% (Bambara- groundnut-ground bean seed- moringa seed flour) (WFF1). The protein content increased from 12.50% in the control (100% wheat flour) to a range of 14.40% - 16.19% in the biscuits; crude fibre decreased from 2.83 to 2.40 - 1.84%, ash content increased from 1.26% to a range of 1.53 - 2.01%, while carbohydrate and energy value reduced from 69.20 to 65.54 - 63.36% and 384.04 Kcal/100 g to 391.34 - 391.55 Kcal/100 g respectively. As the ratio of blends level increase, the thickness, diameter and weight increased but the spread ratio decreased. In conclusion incorporation of bambara groundnut, ground bean seed and moringa seed flour blends played important role in enhancing the nutritional properties of biscuits through improving their protein content, energy value and mineral elements especially calcium and potassium.

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Effects of preservation on protein extraction in four seaweed species

Journal of Applied Phycology ◽

10.1007/s10811-020-02197-y ◽

2020 ◽

Vol 32 (5) ◽

pp. 3401-3409

Author(s):

Tom Wijers ◽

Alwin Hylkema ◽

Tsjippie Visser ◽

Klaas Timmermans

Keyword(s):

Protein Content ◽

Protein Extraction ◽

Saccharina Latissima ◽

Chondrus Crispus ◽

Seaweed Species ◽

Preservation Method ◽

Freeze Dried ◽

The Right ◽

Kjeldahl Nitrogen ◽

Protein Extractability

Abstract Using either freshly pulped or preserved seaweed biomass for the extraction of protein can have a great effect on the amount of protein that can be extracted. In this study, the effect of four preservation techniques (frozen, freeze-dried, and air-dried at 40 and 70 °C) on the protein extractability, measured as Kjeldahl nitrogen, of four seaweed species, Chondrus crispus (Rhodophyceae), Ascophyllum nodosum, Saccharina latissima (both Phaeophyceae) and Ulva lactuca (Chlorophyceae), was tested and compared with extracting freshly pulped biomass. The effect of preservation is species dependent: in all four seaweed species, a different treatment resulted in the highest protein extractability. The pellet (i.e., the non-dissolved biomass after extraction) was also analyzed as in most cases the largest part of the initial protein ended up in the pellet and not in the supernatant. Of the four species tested, freeze-dried A. nodosum yielded the highest overall protein extractability of 59.6% with a significantly increased protein content compared with the sample before extraction. For C. crispus extracting biomass air-dried at 40 °C gave the best results with a protein extractability of 50.4%. Preservation had little effect on the protein extraction for S. latissima; only air-drying at 70 °C decreased the yield significantly. Over 70% of the initial protein ended up in the pellet for all U. lactuca extractions while increasing the protein content significantly. Extracting freshly pulped U. lactuca resulted in a 78% increase in protein content in the pellet while still containing 84.5% of the total initial total protein. These results show the importance of the right choice when selecting a preservation method and seaweed species for protein extraction. Besides the extracted protein fraction, the remaining pellet also has the potential as a source with an increased protein content.

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