Major social, economic, and cultural changes that have affected humanity in recent years have also impacted the agri-food sector. In particular, the attention towards “healthy eating”, awareness of issues such as intolerances, the substitution of animal products with plant-based ones, and last but not least, environmental sustainability have driven major changes in industrial production, in companies’ market approaches, but especially in consumer eating habits.
In this context, food waste is gaining increasing interest, and among the products attracting the most attention is aquafaba.
Aquafaba
Aquafaba is defined as the cooking water of legumes, especially chickpeas and beans, which collects all the molecules released during the soaking and cooking of the legume itself; its name derives from two Latin terms “aqua”, meaning water, and “faba”, meaning bean.
The nutritional composition of aquafaba gives it several useful rheological properties.
It indeed has emulsifying, gelling, thickening, and foaming capacities that mainly derive from its content of proteins, soluble and insoluble carbohydrates, protein-carbohydrate complexes, saponins, and phenolic compounds. For this reason, it is increasingly used in cooking.
Indeed, aquafaba is a true strategic food used to replace animal-derived ingredients such as eggs, for example, in dessert preparation, or as an ingredient in low-protein foods (aquafaba’s protein content is about 10 times lower than that of eggs). This is essential for people suffering from intolerances or following vegan or vegetarian diets.
Preparation of Aquafaba
The preparation of aquafaba is similar to the canning process of legumes, starting with a soaking phase, soaking legumes in water to extract anti-nutrients, hydrate the seed, and reduce cooking times, then boiling or pressure cooking them.
It is, however, possible to obtain aquafaba in two different ways: either using the cooking water of already cooked chickpeas or beans in jars or cans, or using dried legumes soaking and cooking them at home. The more concentrated and practical solutions are the first, for legumes in glass or brick packaging, making sure the composition is legumes and water, at most salt, and no additives, preservatives, or stabilizers.
Properties and Developments of Aquafaba
Several studies have been conducted to optimize the seed-to-water ratio and cooking time to maximize yield and functionality of aquafaba.
Another aspect to consider is its rheological properties linked to pH. At slightly acidic pH values, the emulsifying and foaming properties of aquafaba increase.
There are also several technologies that can be used to improve its qualities, enhancing its nutritional and functional properties. For example, it has been confirmed that treatment of aquafaba with high-frequency ultrasound favors the improvement of its foaming and emulsifying properties. Another technology used to valorize aquafaba as well as other food waste is fermentation, which improves some rheological properties but above all enriches products with bioactive compounds, enhancing functional properties.
Conclusions
The reuse and valorization of waste, such as aquafaba, is highly topical and of particular interest to the industrial world both for economic reasons (cost reduction and development of new marketable products) and for environmental sustainability. All this fits within a business model called “circular economy” that combines environmental protection, efficiency, and new production opportunities.
Bibliography
Yue He, Venkatesh Meda, Martin J.T. Reaney, Rana Mustafa. Aquafaba, a new plant-based rheological additive for food applications. February 2021. Trends in Food Science & Technology 111(SUPPL. 2). DOI:10.1016/j.tifs.2021.02.035.
Mariana Cassel Meurera, Daiana de Souza, Ligia Damasceno Ferreira Marczaka. Effects of ultrasound on technological properties of chickpea cooking water (aquafaba). January 2021. Journal of Food Engineering 265. https://doi.org/10.1016/j.jfoodeng.2019.109688.
MUSTAFA Rana, Yue He, Youn Young Shim, Martin J.T. Reaney. Aquafaba, wastewater from chickpea canning, functions as an egg replacer in sponge cake. May 2018. International Journal of Food Science & Technology 53(e56305). DOI:10.1111/ijfs.13813.
Serventi Luca. Upcycling legume water: From wastewater to food ingredients. Switzerland: Springer Nature, (2020).
Yue He, Youn Young Shim, Rana Mustafa, Venkatesh Meda, Martin J.T. Reaney. Chickpea Cultivar Selection to Produce Aquafaba with Superior Emulsion Properties. Dec 2019 15;8(12):685. Foods. doi: 10.3390/foods8120685.
