Enzymatic Hydrolysis and Fermentation of Pea Protein Isolate and Its Effects on Antigenic Proteins, Functional Properties, and Sensory Profile

Combinations of enzymatic hydrolysis using different proteolytic enzymes (papain, Esperase®, trypsin) and lactic fermentation with Lactobacillus plantarum were used to alter potential pea allergens, the functional properties and sensory profile of pea protein isolate (PPI). The order in which the treatments were performed had a major impact on the changes in the properties of the pea protein isolate; the highest changes were seen with the combination of fermentation followed by enzymatic hydrolysis. SDS-PAGE, gel filtration, and ELISA results showed changes in the protein molecular weight and a reduced immunogenicity of treated samples. Treated samples showed significantly increased protein solubility at pH 4.5 (31.19–66.55%) and at pH 7.0 (47.37–74.95%), compared to the untreated PPI (6.98% and 40.26%, respectively). The foaming capacity was significantly increased (1190–2575%) compared to the untreated PPI (840%). The treated PPI showed reduced pea characteristic off-flavors, where only the treatment with Esperase® significantly increased the bitterness. The results from this study suggest that the combination of enzymatic hydrolysis and lactic fermentation is a promising method to be used in the food industry to produce pea protein ingredients with higher functionality and a highly neutral taste. A reduced detection signal of polyclonal rabbit anti-pea-antibodies against the processed protein preparations in ELISA furthermore might indicate a decreased immunological reaction after consumption.

Effect of lactic fermentation, microwave, and ultrasonic extraction on the bioactive compounds from Anoectochilus formosanus Hayata

Anoectochilus formosanus (family Orchidaceae) is a perennial herb that contains many bioactive valuable. In this study, the extract efficiency of bioactive compounds from Anoectochilus formosanus Hayata by microwave-assisted extraction (MAE), ultrasonicassisted extraction (UAE) treatments, and lactic fermentation in individual and combined impacts were evaluated through the total phenolic content, total polysaccharide content, and antioxidant activity. The results showed that MAE and UAE treatments and lactic fermentation enhanced the effective extraction of bioactive compounds compared to the control samples. The bioactive compound contents from A. formosanus fluid trend differences in individual treatment factors. However, there was no significant difference between these treatment factors in which the fermentation process requires more time to reach the expected extraction efficiency. The ultrasonic pretreatment combined lactic fermentation process would bring many benefits; first, no need for more the MAE treatment; second, reduce fermentation time; third, bring a probiotic source as well as valuable metabolic products from the lactic fermentation process.

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

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.