Cooking water composition

Abstract

The discovery of Aquafaba as egg replacer has generated wide interested in the application of legume wastewater as food ingredient. Therefore, the cooking water from boiling and canning of chickpeas and other legumes have been analysed. The dry matter accounted for 3–6 g/100 g of the liquids, mainly consisting of carbohydrates: sugars, soluble and insoluble fibre. Proteins and minerals represented 10–30% of the dry matter. High levels of iron, potassium, magnesium, molybdenum and other minerals were found. Similarly, nutritionally relevant levels of saponins (5–15 mg/g) and phenolic compounds (0.2–0.7 mg/g) leached in the cooking water. A 100 ml serve of these ingredients could provide the recommended daily intake of numerous nutrients. Interestingly, the levels of antinutritive phytic acid and trypsin inhibitors were low, possibly due to thermal degradation. Fascinatingly, it was observed that the nutritional profile of the cooking water did not correlate with legumes composition. Instead, seeds geometry determined cooking water profiles. For example, chickpeas irregular shape allowed the outer shell to break upon boiling, thus releasing more insoluble fibre than other legumes. Seed conformation, size and thickness affects solid release in the processing water, making it a new nutritionally interesting food ingredient.