Texturized pinto bean protein fortification in straight dough bread formulation.

Area of Science:

• Food Science
• Nutritional Biochemistry
• Cereal Science

Background:

• Pinto bean protein fractions can be utilized to enhance the nutritional profile of wheat-based products.
• Processing methods like air-classification and extrusion influence the functional properties and nutrient recovery of protein isolates.

Purpose of the Study:

• To evaluate the impact of incorporating texturized high protein fraction (THPF) from pinto beans into wheat flour on bread quality and nutritional content.
• To determine the optimal level of THPF addition for enhancing lysine content in white pan bread.

Main Methods:

• Pinto beans were processed into a raw high protein fraction (RHPF) via air-classification, followed by extrusion to create texturized high protein fraction (THPF).
• THPF was milled and blended with wheat flour at 5%, 10%, and 15% levels to produce composite flours for bread making.
• Dough properties (mixing tolerance index, stability, departure time) and bread characteristics (loaf volume, weight, quality) were analyzed.

Main Results:

• THPF addition significantly increased total protein and lysine content in composite flours, with 5% THPF yielding 48% more lysine than control bread.
• Extrusion processing reduced phytic acid and lipids in THPF, though binding effects may influence recovery.
• Dough strength was maintained at 5% THPF, but loaf volume decreased significantly at levels above 5%.
• Bread quality deteriorated at 10% and 15% THPF, while 5% THPF bread quality was comparable to the control.

Conclusions:

• Incorporating 5% THPF into white pan bread is an effective strategy to enhance lysine content without compromising overall loaf quality.
• Higher concentrations of THPF negatively impact bread volume and quality, suggesting a limit for optimal utilization.