Pea Protein Extraction Assisted by Lactic Fermentation: Impact on Protein Profile and Thermal Properties

Abstract

Although pea protein has been widely explored, its consumption is still limited by undesirable sensory characteristics and low solubility. All these properties can be modified during protein extraction process. Besides, previous studies showed that lactic acid bacteria (LAB) have a positive effect on legume protein ingredients in terms of flavor and functional properties. Hence, the objective of this work was to explore an alternative extraction method based on alkaline extraction/isoelectric precipitation (AEIEP) resulting in globulin-rich and residual albumin-rich fractions. Here, the decrease in pH was achieved by lactic fermentation instead of mineral acid addition. Different bacteria strains (Streptococcus thermophilus, Lactobacillus acidophilus and Bifidobacterium lactis) have been used alone or in co-culture, and the results were compared with the usual acidification. The extraction assisted by fermentation led to the increase by 20–30% in protein content/yield of the albumin fraction, meaning that the solubility of the extracted pea protein was increased. This result could be explained by the proteolytic activity of bacteria during lactic fermentation. Therefore, the thermal denaturation properties of the isolated protein fractions measured by differential scanning calorimetry could be mainly ascribed to differences in their polypeptide compositions. In particular, higher denaturation enthalpy in globulin fractions after fermentation compared to AEIEP (~15 J/g protein vs. ~13 J/g protein) revealed the relative enrichment of this fraction in pea legumins; a higher part of 7S globulins seemed to be consumed by lactic acid bacteria.

Antioxidant activities of solid‐state fermentation derived proteins and peptides from heat‐stabilized defatted rice bran

“…In another study, the combination of different lactic acid bacteria ( Lactobacillus acidophilus , Streptococcus thermophilus , and Bifidobacterium lactis ) was used to study the effect of fermentation on pea protein extraction. The results showed that due to the fermentation, the protein content and yield of albumin rich fraction were increased about 20% and 30%, respectively (Emkani et al, 2021). This is the first time that SSF of HDRB with the highest amount of soluble protein is reported.…”

Prebiotic activity of paramylon isolated from heterotrophically grown Euglena gracilis

“…It is not completely clear how whole Euglnea cell powder was able to elicit the Lactobacillus growth. Lactic acid bacteria are known to be proteolytic ( Emkani et al., 2021 ), responsible for protein aggregation ( Berterame et al., 2016 ) and thus act as a permeabilizer and outer membrane-disintegrating agent ( Alakomi et al., 2000 ) due to lactic acid production. Therefore, it can be hypothesized that Euglena which only has a proteinaceous pellicle membrane as outer covering might be more susceptible to leakage leading to paramylon and other cellular components release which might have aided in the Lactobacilus growth.…”

Plant Proteins for Future Foods: A Roadmap

“…More work is needed to integrate these findings into commercial processes. Some other new ideas involve using fermentation to assist protein extraction [68] or redesigning the wet fractionation process to be milder [69]. Some authors even suggest to selectively extract the albumin fraction (under acidic conditions) to obtain a functional protein isolate while using the residual proteins for feed [70].…”