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Comparative study of the functional properties of lupin, green pea, fava bean, hemp, and buckwheat flours as affected by pH.

Raikos V, Neacsu M, Russell W, Duthie G - Food Sci Nutr (2014)

Bottom Line: In this study, the effect of pH on the functional properties of lupin, green pea, fava bean, hemp, and buckwheat flours was investigated and compared with wheat flour.Wheat, green pea, buckwheat, and fava bean were more capable of forming firm gels compared with lupin and hemp, as indicated by least gelling concentrations (LGCs).Depending on the application, flour functionality may be effectively tailored by pH adjustment.

View Article: PubMed Central - PubMed

Affiliation: Natural Products Group, Rowett Institute of Nutrition and Health, University of Aberdeen AB21 9SB, Scotland, UK.

ABSTRACT
The demand for products of high nutritional value from sustainable sources is growing rapidly in the global food market. In this study, the effect of pH on the functional properties of lupin, green pea, fava bean, hemp, and buckwheat flours was investigated and compared with wheat flour. Functional properties included solubility, emulsifying and foaming properties, gelling ability, and water holding capacity (WHC). All flours had minimal solubility at pH 4 and their corresponding values increased with increasing pH. Emulsifying properties were improved at pH 10 for all samples and emulsion stability showed a similar trend. Increasing pH in the range 4-10 enhanced the foaming properties of the flours, particularly buckwheat and hemp. Wheat, green pea, buckwheat, and fava bean were more capable of forming firm gels compared with lupin and hemp, as indicated by least gelling concentrations (LGCs). The ranking of the water binding properties of the different types of flours were lupin>hemp>fava bean>buckwheat>green pea>wheat. Results indicate that underutilized flours from sustainable plant sources could be exploited by the food industry as functional food ingredients or as replacements of wheat flour for various food applications. Depending on the application, flour functionality may be effectively tailored by pH adjustment.

No MeSH data available.


Effect of pH on whipping ability and foam stability of flours. Results are presented as mean ± SE for triplicate analyses.
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fig04: Effect of pH on whipping ability and foam stability of flours. Results are presented as mean ± SE for triplicate analyses.

Mentions: The capacity of flours to form foams is widely exploited by the food industry for bakery and confectionery applications such as mousses, meringue cakes, and whipped toppings. Foaming capacity depends on the ability of proteins to adsorb quickly at the air–water interface during whipping, whereas foam stability is determined by the properties of the multilayer, cohesive film which surrounds the air bubbles and offers resistance against liquid drainage and droplet coalescence (Sreerama et al. 2012). The foaming properties of the flour samples differed significantly (Fig.4) possibly reflecting the influence of protein type and concentration on foaming capacity and foam stability (Kinsella 1979). Increasing pH in the range 4–10 enhanced the foaming properties of the flours, particularly for buckwheat and hemp. Olawuni et al. (2013) reported the improvement of foaming capacity for full fat and defatted Asparagus beans flours with increasing pH (4–12). This may be attributed to the increased solubility within the specified pH range, because foaming capacity requires rapid adsorption of protein at the air–water interface during whipping, penetration into the surface layer, and structural reorganization at the interface (Were et al. 1997). Furthermore, the improved ability to trap air particles at a pH far from the isoelectric point could be due to the increased flexibility and surface activity of the highly charged protein molecules (Aluko and Yada 1995). However, not all samples showed the same pH-dependent pattern of foaming properties. Green pea produced relatively thick, voluminous foams which were stable even at pH 4 (65%). In addition, the foaming capacity of wheat flour deviated from the theoretical expectation that solubility is positively correlated with whipping ability (Nakai 1983). Wheat proteins had maximum foaming ability at pH 4 (78.7%) followed by a decline in pH 7 (44.7%) and pH 10 (36.7%). Furthermore, despite high foaming abilities of wheat flour and fava bean flour at pH 4 and 10, respectively, stability was poor (5.7% and 2.7%, respectively). Foam stability is an important property because the usefulness of whipping agents depends on their ability to maintain the whip for as long as possible (Lin et al. 1974). In these cases, molecular flexibility appeared adequate to facilitate foam formation, but stability was compromised by intermolecular interactions at the interface.


Comparative study of the functional properties of lupin, green pea, fava bean, hemp, and buckwheat flours as affected by pH.

Raikos V, Neacsu M, Russell W, Duthie G - Food Sci Nutr (2014)

Effect of pH on whipping ability and foam stability of flours. Results are presented as mean ± SE for triplicate analyses.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4256586&req=5

fig04: Effect of pH on whipping ability and foam stability of flours. Results are presented as mean ± SE for triplicate analyses.
Mentions: The capacity of flours to form foams is widely exploited by the food industry for bakery and confectionery applications such as mousses, meringue cakes, and whipped toppings. Foaming capacity depends on the ability of proteins to adsorb quickly at the air–water interface during whipping, whereas foam stability is determined by the properties of the multilayer, cohesive film which surrounds the air bubbles and offers resistance against liquid drainage and droplet coalescence (Sreerama et al. 2012). The foaming properties of the flour samples differed significantly (Fig.4) possibly reflecting the influence of protein type and concentration on foaming capacity and foam stability (Kinsella 1979). Increasing pH in the range 4–10 enhanced the foaming properties of the flours, particularly for buckwheat and hemp. Olawuni et al. (2013) reported the improvement of foaming capacity for full fat and defatted Asparagus beans flours with increasing pH (4–12). This may be attributed to the increased solubility within the specified pH range, because foaming capacity requires rapid adsorption of protein at the air–water interface during whipping, penetration into the surface layer, and structural reorganization at the interface (Were et al. 1997). Furthermore, the improved ability to trap air particles at a pH far from the isoelectric point could be due to the increased flexibility and surface activity of the highly charged protein molecules (Aluko and Yada 1995). However, not all samples showed the same pH-dependent pattern of foaming properties. Green pea produced relatively thick, voluminous foams which were stable even at pH 4 (65%). In addition, the foaming capacity of wheat flour deviated from the theoretical expectation that solubility is positively correlated with whipping ability (Nakai 1983). Wheat proteins had maximum foaming ability at pH 4 (78.7%) followed by a decline in pH 7 (44.7%) and pH 10 (36.7%). Furthermore, despite high foaming abilities of wheat flour and fava bean flour at pH 4 and 10, respectively, stability was poor (5.7% and 2.7%, respectively). Foam stability is an important property because the usefulness of whipping agents depends on their ability to maintain the whip for as long as possible (Lin et al. 1974). In these cases, molecular flexibility appeared adequate to facilitate foam formation, but stability was compromised by intermolecular interactions at the interface.

Bottom Line: In this study, the effect of pH on the functional properties of lupin, green pea, fava bean, hemp, and buckwheat flours was investigated and compared with wheat flour.Wheat, green pea, buckwheat, and fava bean were more capable of forming firm gels compared with lupin and hemp, as indicated by least gelling concentrations (LGCs).Depending on the application, flour functionality may be effectively tailored by pH adjustment.

View Article: PubMed Central - PubMed

Affiliation: Natural Products Group, Rowett Institute of Nutrition and Health, University of Aberdeen AB21 9SB, Scotland, UK.

ABSTRACT
The demand for products of high nutritional value from sustainable sources is growing rapidly in the global food market. In this study, the effect of pH on the functional properties of lupin, green pea, fava bean, hemp, and buckwheat flours was investigated and compared with wheat flour. Functional properties included solubility, emulsifying and foaming properties, gelling ability, and water holding capacity (WHC). All flours had minimal solubility at pH 4 and their corresponding values increased with increasing pH. Emulsifying properties were improved at pH 10 for all samples and emulsion stability showed a similar trend. Increasing pH in the range 4-10 enhanced the foaming properties of the flours, particularly buckwheat and hemp. Wheat, green pea, buckwheat, and fava bean were more capable of forming firm gels compared with lupin and hemp, as indicated by least gelling concentrations (LGCs). The ranking of the water binding properties of the different types of flours were lupin>hemp>fava bean>buckwheat>green pea>wheat. Results indicate that underutilized flours from sustainable plant sources could be exploited by the food industry as functional food ingredients or as replacements of wheat flour for various food applications. Depending on the application, flour functionality may be effectively tailored by pH adjustment.

No MeSH data available.