Location: Commodity Utilization ResearchTitle: Improvement of the solubility of glandless cottonseed protein isolate for fortified beverage applications
Submitted to: Proceedings of American Chemical Society National Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/17/2023
Publication Date: N/A
Technical Abstract: Cottonseed is classified as glanded or glandless depending on gossypol glands. The presence of toxic gossypol in glanded seed limits this vast protein resource to use primarily for feeding ruminants. Glandless cottonseed present only trace levels of gossypol. may be useful as human food and non-ruminant animalsfeed sources. However, low solubility of seed protein is a major factor affecting its beverage applications. The objective of this study was to improve the aqueous solubility of glandless cottonseed protein isolate (CSPI) by pH adjustment and active additives. CSPI was purified from glandless cottonseed by NaOH solubilization and HCl neutralization. The CSPI (91.71 ± 0.13% of protein) was treated with various buffers with pH 2-10.6, a range of NaOH concentrations and different types of detergents. CSPI showed the highest solubility at pH 2.0 and pH 10-10.6, and the lowest solubility at pH 6. Temperature change from 25 to 37°C significantly increased cottonseed protein solubility. Protein solubility was maximal under 0.1 N NaOH and reduced to half by 1N NaOH. Most of the detergents increased the solubility of the protein isolate but anionic detergents decreased the solubility. The order of solubility was CTAB > BRIJ 35 > Triton X-100 > NP40 > Chaps > Tween-20 > Tween-80 > Water = DMSO > deoxycholic acid > SDS. The protein solubility was only significantly increased by size reduction of protein particles under Brij 35 treatment. UV absorbance at 280 nm and Lowry methods gave higher concentration of the protein than those of BCA and Bradford methods. Cottonseed peptides after trypsin digestion significantly inhibited the viability of mouse macrophages after treatment with 40-80 µg/mL for 24 h. The results provided useful information for increasing the solubility of glandless cottonseed protein for developing protein-fortified acidic juices and drinks.