Processing strategies to enhance the functionality of a legume by-product and its application in vegan muffins

Global concerns regarding the consumption of animal products have increased the consumption of plant-based alternatives [1], also containing legumes [2]. To be edible, dry legumes need to be cooked, generating a large waste of cooking water. Chickpea cooking water (CCW), known as aquafaba, has gained attention as a plant-based alternative to egg-white (EW) in food applications [3; 4]. However, limited information on how different treatments affect CCW technological properties are available. Thus, this study investigates the foaming and emulsifying properties of CCW as affected by two treatments: the acidification with lactic acid (LA) and the clarification process (S). CCW was drained from canned chickpeas. Foaming capacity (e.g., overrun, foams air bubble distribution and foam stability) and emulsifying properties of CCW subjected to different treatments were characterized. Aerated baked products containing CCW were developed and characterized both fresh and after storage in paper bags for up to 6 days at 20°C and 60% RH. An EW-based muffin was produced as reference. The treatments applied significantly (p<0.05) affected CCW-overrun, which varies from 1353% (CCW) to 2112% (CCWSA). LA addition resulted in a finer foam structure (i.e., higher number of small air bubbles) and a more stable foam (88-93%), while clarification reduced foam stability. The emulsion ability was not affected by the different treatments. Compared to EW, all CCWs foams had higher overrun (>30%) and emulsion ability (>15%); however, only CCWS-dough showed a baking development higher than EW-sample (151% vs. 146%). Acidification significantly (p<0.05) decreased muffin volume (11-21%), suggesting that the interaction within the complex matrix and baking process may interfere with foaming capacity. Regardless of treatment, CCW-muffins were 31-64% softer than EW-muffin, even if they had similar crumb moisture. All samples showed a significant (p<0.05) moisture decrease (>25%) and hardness increased (84-90%) after 6 days of storage. This study demonstrates that acidification is a promising strategy to enhance foaming properties, while clarification has limited effects. Furthermore, CCW resulted a valuable alternative foaming and emulsifying agent for sustainable, plant-based and aerated food applications of interest for target consumers (e.g., eggs-allergic and vegans). The study outcomes contribute to valorizing legume by-products, and they align with current trends, such as circular food processing and innovation in plant-based productions. [1] Tso R, Forde CG (2021). Unintended consequences: nutritional impact and potential pitfalls of switching from animal-to plant-based foods. Nutrients. 13.8. 2527. [2] Henn K, Olsen SB, Goddyn H, Bredie WL (2022). Willingness to replace animal-based products with pulses among consumers in different European countries. Food Research International. 157: 111403. [3] Tufaro, D., & Cappa, C. (2023). Chickpea cooking water (Aquafaba): Technological properties and application in a model confectionery product. Food Hydrocolloids, 136, 108231. [4] Serventi L (2020). Upcycling Legume Water: from wastewater to food ingredients, 1st ed, Christchurch (New Zealand), Springer International Publishing.