*2.1. Materials*

Four Kabuli chickpea cultivars (CDC Leader, CDC Orion, CDC Luna and Amit) and one Desi chickpea cultivar (CDC Consul) were generously provided by Dr. Bunyamin Tar'an from the University of Saskatchewan, Crop Development Centre (CDC, Saskatoon, SK, Canada). Seed was randomly selected and manually cleaned and freed of broken seed, dust and other foreign materials. Canola oil (purity 100%; ACH Food Companies, Inc., Terrace, IL, USA) and baking soda (NaHCO3; ARM & HAMMER by Church and Dwight Co., Inc., Mississauga, ON, Canada) were purchased from a local supermarket (Walmart, Saskatoon, SK, Canada). Sodium dodecyl sulfate (SDS) was purchased from GE Healthcare (Mississauga, ON, Canada). Anhydrous ether was obtained from Fisher Scientific Co. (Ottawa, ON, Canada). Sodium hydroxide (NaOH) and sodium chloride (NaCl) were purchased from Sigma-Aldrich Canada Ltd. (Oakville, ON, Canada). Concentrated sulphuric acid (H2SO4, ≥96%, *w*/*w*) and methanol were acquired from EMD Millipore Corporation (Burlington, MA, USA).

#### *2.2. Fresh AQ Preparation*

Chickpea seed (100 g) was washed and soaked in distilled water at a ratio of 1:4 (*w*/*w*), covered, and kept at 4 ◦C for 16 h [11]. Soaking water was then drained and discarded. Soaked chickpea seed (100 g) was rinsed with distilled water and then mixed with 100 mL distilled water in 250 mL sealed glass jars and cooked in a pressure cooker at 115–118 ◦C (an autogenic pressure range of 70–80 kPa) for 30 min. Subsequently, jars of cooked chickpeas were cooled by holding at room temperature for 24 h. Cooled AQ was drained from cooked chickpea seed using a stainless-steel strainer, then stored in a freezer (−18 ◦C). AQ samples from each chickpea cultivar were prepared in quadruplicate. Prior to analysis, AQ was thawed at 4 ◦C overnight then held at room temperature for 2 h. AQ moisture content was determined by oven drying at 105 ◦C overnight according to the American Association of Cereal Chemists (AACC) method 44-15.02 (AACC, 2000) [13].

#### *2.3. AQ Emulsion Properties*

#### 2.3.1. AQ Oil Emulsion Preparation

Freshly thawed AQ (6 g), produced from each cultivar, was mixed with 14 g canola oil using a kitchen hand mixer. The mixer was set at its maximum speed for 2 min. Canola oil was added dropwise to the AQ to produce emulsions. The emulsion type (O/W or W/O) was determined by a simple dilution test: A small amount of emulsion was dispersed into two beakers, one containing the oil phase (canola oil) and the other containing the aqueous phase (water). An easy dispersion occurs only in the continuous phase of the emulsion [14]. All emulsions prepared in this study dispersed easily in water, and were thereby confirmed to be O/W emulsions.

## 2.3.2. Emulsion Capacity

Each AQ oil emulsion was diluted 100-fold with 0.1% SDS ( *w*/*v*), and emulsion turbidity (500 nm) was calculated immediately after dilution. A UV-Vis spectrophotometer was used to determine transmittance at 500 nm. Emulsion turbidity value ( *T*) was calculated using Equation (1).

$$T = \frac{2.303 \times A \times V}{I},\tag{1}$$

in which *T* is the emulsion turbidity (m−1), *A* is the emulsion "absorbance" measurement at 500 nm (1/transmittance), *V* is the dilution factor and *I* is the path length (0.01 m).

AQ emulsion capacity (*EC*) was determined according to Liu et al. (2016) [15]. An emulsifying activity index (*EAI*) was used as an indicator and defined by Wang et al. (2010) and Pearce and Kinsella (1978) using Equations (2) [16] and 3 [17], respectively.

$$EAI = \frac{2T}{\mathcal{Q} \times \mathcal{C}'} \tag{2}$$

in which ∅ is the oil volume fraction of dispersed phase and *C* is the emulsifier concentration (the weight of AQ per unit volume of the aqueous phase before the emulsion is formed) [17].

$$\mathcal{Q} = \frac{\mathbb{C} - A\_1 - E(B - \mathbb{C})}{\mathbb{C} - A\_1 + \frac{(B - \mathbb{C})\{(1 + E) \cdot D\_0 - E\}}{D\_S}}.\tag{3}$$

In Equation (3), *A*1 denotes mass of beaker; *B* is mass of beaker plus emulsion; *C* is the mass of beaker plus emulsion dry matter; *D*0 is the oil density; *D*s is the protein solution density, and *E* is the solute concentration (mass per unit of solvent) [17]. All measurements were conducted in triplicate, and results expressed as mean ± standard deviation (SD).

## 2.3.3. Emulsion Stability

Emulsion stability (*ES*) value was determined at room temperature. Emulsions were transferred to sealed 15 mL centrifuge tubes, which were then centrifuged at 1860× *g* for 15 min. The weight of the original emulsion before centrifugation ( *F*0) and the emulsified layer ( *F*1) after centrifugation were measured. The emulsion stability at room temperature was determined by Equation (4) [18].

$$ES = \frac{F\_1}{F\_0} \times 100\%.\tag{4}$$

All measurements were conducted in triplicate, and results expressed as mean ± SD.

#### *2.4. Chickpea Physical Properties*

Hundred seed weight (*HSW*, g) was determined by randomly selecting and weighing 100 grains selected from each chickpea cultivar. Seed coat incidence (*SCI*, %) was determined by the method of Alova and Patanè (2010) with minor modification [19]. The seed coats of ten chickpea seeds were removed after soaking seed in distilled water at 4 ◦C for 12 h. Then the seed coat and cotyledons were dried separately at 65 ◦C for 4 h, and weighed each hour until a constant weight was recorded.

Seed dimensions were determined by randomly selecting ten chickpea seeds and then using a micrometer to record the seed dimensions in three perpendicular directions. Equation (5) was used to calculate the geometric average of the diameter of an equivalent dimension (*ED*, mm).

$$ED = \left(L \times \mathcal{W} \times T\right)^{1/3},\tag{5}$$

in which *L*, *W* and *T* were the major, minor and intermediate axes (mm), respectively [20].

The surface area per unit mass of seed (or, specific surface area, *SSA*, mm<sup>2</sup>/mg) and seed coat weight per surface area (namely seed coat thickness, *WSA*, mg/cm2) of a single seed were calculated based on the *ED* and *HSW* value by the following Equations (6) and (7), respectively.

$$
\Delta SA = \frac{\pi \times ED^2 \times 100}{HSW},
\tag{6}
$$

$$WSA = \frac{HSW}{100 \times \pi \times ED^2}.\tag{7}$$

#### *2.5. Chickpea Hydration Kinetics*

Hydration kinetic tests were performed by the method of Avola and Patanè (2010) [19] with minor modification. Chickpea seed was soaked at room temperature (20–22 ◦C) and weighed periodically to determine water uptake kinetics. Ten seeds were transferred to a 200 mL beaker, which contained 150 mL deionized water or aqueous solutions of 0.5% (*w*/*v*) NaCl or NaHCO3. Beakers were held at a constant temperature of 22 ◦C. Each hour up to the eighth hour, then at 24 h after initial imbibition, the seed was drained, and then weighed after free water was absorbed with a low-lint wiper. A clean wiper was used for each weighing to avoid contamination with solutes or water.

A two-parameter asymptotic Equation (8) was used to model water uptake kinetics (SigmaPlot 9.0; Systat Software, Inc., San Jose, CA, USA).

$$H\_t = H\_{\text{max}} \times \left(1 - e^{-kx}\right) \tag{8}$$

in which *Ht* is hydration weight (g/seed) after soaking for time t (h), *Hmax* is the asymptote of the curve (to estimate seed weight at full hydration), k is a curve parameter that is related to the initial hydration rate (estimating *Hrate*). All measurements were conducted in triplicate, and results expressed as mean ± SD.

#### *2.6. Chickpea Chemical Properties*

The moisture content of whole chickpea seed was measured by the ASAE S352.2 air oven drying method (103 ◦C, 72 h, 15 g) [21]. Selected whole chickpea seed was ground with a disc mill before proximate composition analysis. Analyses of crude protein, crude fat, ash and crude fibre were performed using Association of Official Analytical Chemists (AOAC) methods [22]. In brief, nitrogen content was analyzed by combustion (AOAC Method 990.03) [22] using a LECO (Saint Joseph, MI, USA) nitrogen analyzer. Protein content was calculated as nitrogen content multiplied by a conversion factor 6.25. Fat was extracted from ground samples according to AOAC method 920.39 [22] using anhydrous ether in a Soxhlet apparatus (Extraction system B-811, BÜCHI Labortechnik AG., Switzerland). Ground

chickpea samples were weighed (2 g) onto filter paper which was then placed in a cellulose Soxhlet extraction thimble and washed five times with 20 mL distilled H2O each time.

After drying in an oven at 102 ◦C for 2 h, oil was extracted over 5 h in a Soxhlet apparatus with anhydrous ether. Chickpea ash content was determined by the AOAC method 942.05 [22]. Samples were weighed (2 g) in separate, pre-weighed porcelain crucibles, and placed in a preheated furnace (600 ◦C) for 2 h. Crucibles were then transferred to a desiccator, cooled and reweighed. Sample weight remaining after ignition of a 2 g sample was regarded as ash content. Crude fibre content was determined by AOAC method 962.09 with minor modification [22]. Samples were digested with 1.25% ( *w*/*v*) boiling H2SO4 (30 min) followed by 1.25% ( *w*/*v*) boiling NaOH (30 min) and washed with methanol. Samples were then dried to a constant weight and the residue burned. Weight loss on ignition of the dried residue was regarded as crude fibre content. Carbohydrate content was determined by subtracting the total percentage of protein, fat, fibre and ash components from 100%. All measurements were conducted in triplicate, and results were expressed as mean ± SD.
