**3. Methods of reducing cooking time in AYB**

Several studies have reported a significant decrease in cooking time after seeds were subjected to processing methods like presoaking, dehulling, frying, steaming, and blanching [43, 71, 111, 112].

#### **3.1 Presoaking of seeds**

Presoaking is a long-age traditional practice used in homes to reduce cooking time, especially in grain legumes. The approach is flexible, simple, and common both at the domestic and industrial levels. The process involves the imbibition of water through the outer cuticle, the seed coat, and then into the cotyledons; [69, 113]. The first step in imbibition is the penetration of water by the seed, and the process can be through the seed coats since the seed coat has high fiber content and thus high-water holding capacity. Water inhibition can also occur through the micropyle or hilum; when the water reaches the cotyledons, the seed starts to absorb water and swell until the seeds attain their maximum water uptake capacity. Presoaking of seed before cooking enables the easy identification of unhydrated seeds, which can be discarded to achieve uniform cooking time. The procedure reduces cooking time because the hydrated seeds acquire a soft texture and thereby speeding up the cooking process and shortening the cooking time [114]. Also, soaking aid the easy identification of hydratable seeds and improves the nutrient quality of foods since the soaked content is usually discarded. Soaking grains before cooking is a good practice used traditionally in increasing food safety especially in situations when consumers have no idea of the storage preservatives used for the target grain.

The effect of presoaking in shortening the cooking time of AYB's seed was reported by several authors. Presoaking AYB seeds in distilled water over a varying time of 6, 12, 18, and 24 hours reduced cooking time by 50%. The process also reduced the level of tannin and phytate, in addition to improving in-vitro protein digestibility. Soaking for 12 hours was the most effective in reducing cooking time, tannin, phytate, and in-vitro protein digestibility; however, soaking for 24 hours before dehulling was observed to significantly increase crude protein level by 16% [43]. In a similar study, AYB seeds were presoaked each in 0.20%, 0.40%, 0.60%, 0.80% and 1.00% of akanwu (sodium sesquicarbonate), and common salt (sodium chloride) and water for a duration of 6, 12, 18, 24, 30, 36 hours. Seeds soaked for 6 hours in 0.060% akanwu and 1.00% common salt showed a 50% decrease in cooking time, while seeds soaked in tap water achieved a 50% reduction in cooking time after 24 hours of presoaking. Meanwhile, seeds presoaked in tap water took about 180 minutes to get tender [112]. According to a study, a 50% reduction in cooking time was achieved when seeds were presoaked for 12 hours in either 1% potash or 4% common salt. Seeds soaked for 12 hours in 4% common salt reached tenderness after 45 minutes of cooking however seeds that were not soaked remained hard even after 60 minutes of cooking [111]. In a similar experiment,

presoaking seeds in a different medium (water, alkali, brine, alkaline-brine) reduced the cooking time to a considerable level; the most effective medium was alkaline-brine, with a maximum cooking time of 100 minutes as against 210 minutes reported for cooking dry raw seeds [115]. In a separate study, AYB grains soaked overnight reached tenderness after 60 minutes of cooking [71]. Notably, aside from reducing cooking time, presoaking is also effective in investigating nutrient and anti-nutrient content [15, 43, 116–119].
