Ensuring quality in nutritional pulse based pitas: Study

Navy and pinto beans are the best suited when making pita breads with pulse flours in place of wheat but substitution must be minimised to 25% if quality is to be maintained, according to new research.

A study set to be published in the Journal of the Science of Food and Agriculture looked at replacing regular wheat flour with pulse flours milled from green lentils, navy beans and pinto beans.

The objectives were to determine the most suitable pulse flour for wheat flour substitution in pita bread, to determine the optimum level of incorporation of pulse flours for acceptable quality and to evaluate the effect of particle size on product quality.

The Canadian researchers, led by Yulia Borsuk, found that “acceptable pita breads can be made using pulse flours, although the substitution level is limited to 25%.”

“Overall, navy and pinto bean flours appeared more suitable for pita bread,” due to superior texture and colour, they concluded.

When pitas were made with 25% pinto or navy bean coarse flour in substitution, sensory parameters remained as good as or better than the end products containing just wheat flour.

Pulse appeal

“Pita bread has gained wide acceptance in many parts of the world, particularly the Middle East. However, no results have been reported for high levels of pulse flour incorporation,” researchers detailed, prompting an investigation into partial and complete pulse flour inclusion in pita bread.

Pulses are high in proteins and are also fibrous and contain vitamins and minerals. When combined with cereal proteins in a diet the human body has an improved amino acid score, the study detailed.

Fortification of breads with flours milled from chickpeas, pigeon peas, faba beans and pinto and navy beans is often done for nutritional purposes.

Study details

‘Control’ pitas were made using 100% wheat flour and then pitas were substituted with 25%, 65% and 100% pulse flours (green lentils, navy, pinto).

80 panellists from the Consumer Product Testing Centre in Canada evaluated aroma, appearance, colour flavour, texture and overall acceptability using a ‘likeability’ scale. Statistical analysis was also conducted to determine the effects flour type, flour particle size and the level of substitution.

Quality assurance

The study found that flours with coarse particle sizes, such as the navy and pinto bean, have a greater ability to retain water than fine flours.

However the level of substitution also impacted moisture levels in the end product, showing that as the proportion of pulse flours was increased, the moisture content steadily decreased.

The characteristic pocket remained unchanged when replacing wheat flour with pulse flours but in some cases the diameter of the end products was altered. With fine navy bean flour, the pitas had smaller diameters.

When using significant substitution levels of pulse flours (75% and 100%) texture was impacted negatively, with drier end products and less soft crumb.

Colour was found to vary in the pita bread when pinto flour was used, but variation was less significant with navy bean flour.

Source: Onlinelibrary.Wiley

August 2012, Volume 92, Issue 10, pages 2055-2061

Incorporation of pulse flours of different particle size in relation to pita bread quality”

Authors: Y. Borsuk, S. Arntfield, O.M. Lukow, K. Swallow, L. Malcolmson