Effect of pH and defatting on the functional attributes of safflower, sunflower, canola, and hemp protein concentrates

Abstract

Background and objectives The effect of defatting four oilseed protein concentrates (safflower, sunflower, canola, and hemp) on the surface and functional properties of the proteins was investigated as a function of pH (pH 3, 5, 7). The functionality of commercial protein concentrates (soy, faba bean, lentil, pea, northern great bean, whey) already in the marketplace was also tested for comparative purposes. Findings Defatting with hexane increased the protein content from 77.3% to 92.9% for safflower, 67.5 to 75.5% for sunflower, 58.0–66.0% for canola, and 71.0–83.2% for hemp. The approximate isoelectric point (pI) of safflower increased with defatting (5.4–5.8), whereas for canola the pI decreased with defatting (4.7–4.3), and sunflower and hemp protein concentrates had similar pI for defatted or full fat. Certain functional properties were improved with defatting, whereas others showed the opposite trend; this was highly dependent on protein type and pH. Conclusions The oilseed concentrates were comparable to the concentrates in the marketplace with canola and sunflower proteins having the greatest oil‐holding capacity and defatted safflower having the highest foaming capacity of all the proteins tested. Significance and novelty Based on their functionality, the oilseed protein concentrates have potential to be used by the food ingredient industry.

Techno‐functional and nutritional properties of full‐bran and low‐bran canaryseed flour, and the effect of solvent‐de‐oiling on the proteins of low‐bran flour and isolates

“…Subtle improvement of the color with ethanol de-oiled flours and isolates was observed in comparison to hexane (Table 1). Improvement of protein color due to solvent de-oiling was also reported elsewhere (Galves et al, 2019;Teh et al, 2014) De-oiling of canaryseed flour improved its water holding capacity (Table 3), regardless of the type of solvent used. The same trend was observed for non-de-oiled and de-oiled canaryseed isolates.…”

“…Improvement of WHC due to solvent-de-oiling was also reported for safflower and hemp protein (Galves et al, 2019). On the other hand, lower WHC due to de-oiling was reported for sunflower protein (Galves et al, 2019), hemp, canola, and flax flour (Teh et al, 2014) or remain unchanged as for soy protein (L'Hocine et al, 2006). The two de-oiled isolates, that is, HDI and EDI, showed similar WHC as C-WGI whereas, it is significantly lower in NDI.…”

“…The WHC reported in the literature is lower than the EDI of this study, presumably due to changes of the process and conditions used in these two studies and differences in the analytical method used. Improvement of WHC due to solvent-de-oiling was also reported for safflower and hemp protein (Galves et al, 2019). On the other hand, lower WHC due to de-oiling was reported for sunflower protein (Galves et al, 2019), hemp, canola, and flax flour (Teh et al, 2014) or remain unchanged as for soy protein (L'Hocine et al, 2006).…”

“…Protein denaturation could improve accessibility to digestive enzymes to improve digestibility and also potentially lower allergenicity if the allergy is caused by a conformational epitope (EFSA & European Food Safety Authority, 2014). Moreover, it could improve some functional properties, such as emulsification and foaming due to increase hydrophobicity because of structural unfolding/denaturation (Galves et al, 2019). Therefore, as an emerging protein source, it would be important to understand the effect of solvent-de-oiling on canaryseed protein and its compositional, structural, functional, and nutritional properties.…”

Effects of Hexane on Protein Profile, Solubility and Foaming Properties of Defatted Proteins Extracted from Tenebrio molitor Larvae

“…Interestingly, this phenomenon was observed at pH 5 since HDSP solubility was lower than that of NDSP. This could be related to a change in the average pI value due to the variation in protein molecular structure and protein content caused by the defatting process [ 48 ], evidenced by the profile differences observed in Figure 2 . Overall, these results suggest that little protein denaturation occurred during the defatting process, as very few differences were observed, especially at neutral pH, between whole protein meals (TMI and TMD) and soluble protein extracts (NDSP and HDSP), respectively [ 49 ].…”