Impact of Intercropped Legume Flours on the Nutritional and Textural Attributes of Wheat Cakes: A Sustainable Approach to Enhanced Nutrition

The plant-based diets market has grown in popularity over recent decades and is projected to reach USD 27 billion by 2030. Innovative systems such as intercropping, defined as growing two or more crop species in proximity, are promising contributors to the advancement of sustainable agriculture by improving resource efficiency, enhancing crop resilience, and cutting down the need for chemical inputs. However, legume seed lots grown under intercropping versus monocropping systems differ in composition, which, in turn, can influence seed flour quality. Furthermore, antinutritional properties of legumes, such as phytic acid, condensed tannins (CTs), and raffinose family oligosaccharides (RFOs), limit their utilisation in product formulation. Therefore, the purpose of the study was to reduce these antinutritional compounds for utilisation of the intercropped legume flour in bakery products. A harvest of intercropped peas and faba bean mix (IM) obtained from Irish farmers was soaked (S) for 8 and 16 h and germinated (G) for 24, 48, and 72 h. Non-germinated intercropped mix (IM) was used as a control. All flours were subsequently used to substitute for wheat flour and fortify wheat-based cakes. The 72 h germinated intercropped mix (pea bean; 95.5:4.5) flour showed significantly (p < 0.05) lower levels of antinutritional compounds than the non-germinated intercropped flour. Raffinose, stachyose, and verbascose contents were reduced by 43%, 38%, and 46%, respectively, while phytic acid and condensed tannins decreased by 32% and 57%, respectively. The germination process also reduced the green hue (a*) from −8.37 to −6.49 and enhanced levels of soluble dietary fibre by 2.67% of the flour, while improving their suitability for bakery applications. Wheat-based cakes fortified with germinated and non-germinated intercropped legume flours showed a significant enhancement in protein and soluble dietary fibre contents. Compared with the control cake, protein content increased from 9.52 to 12.80%, while soluble dietary fibre content increased from 0.47 to 1.99% in the fortified cakes. Cakes containing up to 40% germinated flour (G72) showed comparable specific volume values 1.84–1.86 mL/g) and slice brightness (112.50–94.23) to the control cake. Additionally, cakes formulated with 40% intercropped flour showed significantly lower condensed tannin and phytic acid contents (p < 0.05), with reductions of 38% and 31.38%, respectively. Samples containing intercropped legume flours proved suitable for bakery applications, supporting up to 40% substitution in wheat-based cakes, and the germination process was effective in reducing antinutritional properties in intercropped legume flour fortified cakes.