Proteins from pseudocereal seeds: solubility, extraction, and modifications of the physicochemical and techno-functional properties

Pseudocereals (amaranth, buckwheat and quinoa) are emerging as popular gluten-free crops. This may be attributed to their wide-ranging health benefits, including antioxidant, hypoglycemic and serum-cholesterol reducing properties. Proteins of these crops have a high nutritional quality as a result of the presence of essential amino acids. Additionally, amaranth, buckwheat and quinoa proteins (AP, BP and QP, respectively) have physicochemical properties that are useful for the manufacture of different types of food. However, native pseudocereal proteins demonstrate a low solubility in water, mainly because of their composition. The major components of these proteins are albumins (water-soluble) and globulins (salt-soluble), although some proportions of glutelin (alkali-soluble) and prolamins (alcohol-soluble) are also found. The most commonly used method for extracting pseudocereal proteins is the alkaline extraction method, which may contribute to the low solubility of pseudocereal protein. Fortunately, different methods for modifying physicochemical (or techno-functional) properties have been proposed to extend their industrial application. For example, high-intensity ultrasound (HIUS) proved useful for improving the solubility of API and QP. Heating can allow for the formation of soluble aggregates of QP. The combination of heating and HIUS can improve the digestibility, solubility and foam properties of AP. Conjugation through the Maillard reaction can improve BPI and QP interfacial properties. Thus, present study provides a review of the solubility, extraction and modification of the techno-functional properties of AP, BP and QP. © 2022 Society of Chemical Industry.

Effect of high hydrostatic pressure on the edible quality, health and safety attributes of plant-based foods represented by cereals and legumes: a review

Consumers today are increasingly willing to reduce their meat consumption and adopt plant-based alternatives in their diet. As a main source of plant-based foods, cereals and legumes (CLs) together could make up for all the essential nutrients that humans consume daily. However, the consumption of CLs and their derivatives is facing many challenges, such as the poor palatability of coarse grains and vegetarian meat, the presence of anti-nutritional factors, and allergenic proteins in CLs, and the vulnerability of plant-based foods to microbial contamination. Recently, high hydrostatic pressure (HHP) technology has been used to tailor the techno-functionality of plant proteins and induce cold gelatinization of starch in CLs to improve the edible quality of plant-based products. The nutritional value (e.g., the bioavailability of vitamins and minerals, reduction of anti-nutritional factors of legume proteins) and bio-functional properties (e.g., production of bioactive peptides, increasing the content of γ-aminobutyric acid) of CLs were significantly improved as affected by HHP. Moreover, the food safety of plant-based products could be significantly improved as well. HHP lowered the risk of microbial contamination through the inactivation of numerous microorganisms, spores, and enzymes in CLs and alleviated the allergy symptoms from consumption of plant-based foods.

Enzyme-assisted development of biofunctional polyphenol-enriched buckwheat protein: physicochemical properties, in vitro digestibility, and antioxidant activity

BACKGROUND

During the last decade buckwheat was reported to have positive health effects. The present study investigated a high-polyphenol buckwheat protein (Fagopyrum esculentum Moench) prepared by enzyme-assisted processing, together with its physicochemical properties, in vitro digestibility, and antioxidant activity.

RESULTS

Buckwheat protein prepared from the synergistic enzymatic action of α-amylase and amyloglucosidase (E-BWP) had much higher polyphenol content than buckwheat protein prepared by isoelectric precipitation (I-BWP) or salt extraction (S-BWP). Rutin degraded during the process, giving quercetin. The protein constituents and amino acid composition of E-BWP were very similar to those of native buckwheat and were able to meet the WHO/FAO requirements for both children and adults. During in vitro digestion, E-BWP showed anti-digestive behavior with a nitrogen release that was lower than that of I-BWP or S-BWP. The positive effect of the polyphenol content of E-BWP resulted in a higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) content and greater reducing activity.

CONCLUSION

Buckwheat protein with high polyphenol content was successfully developed by enzyme-assisted processing. It had a well-balanced amino acid profile, antidigestive behavior, and high antioxidant activities. The results suggest that enzyme-assisted processing is promising in the production of polyphenol-enriched cereal protein, contributing higher functionality with good nutritional and antioxidant properties. © 2018 Society of Chemical Industry.