*3.6. Correlation Analysis*

The overall interrelationships among chickpea physical, proximate composition (protein, fat, carbohydrate, fibre and ash), hydration characteristics, and AQ yield, emulsion capacity and stability are shown in Table 3.



AQ yield was inversely correlated to both *ES* (*r* = −0.94\*) and ash content (*r* = −0.92\*). Emulsion stability was also negatively correlated to AQ moisture content (*r* = −0.91\*), suggesting that AQ with higher dry matter contents have better emulsion properties. Seed coat incidence, *SSA* and *WSA* were not related to seed dimension, but *SSA* was found to have the highest negative correlation with seed weight (*r* = −0.97\*\*). *HSW* was also positively correlated to *ED* (*r* = 0.97\*\*), indicating that heavier and larger chickpea seeds develop a smaller surface area per unit mass. Fibre was closely correlated to *SCI* (*r* = 0.95\*) and seed coat thickness (*WSA*: *r* = 0.90\*). Therefore, a chickpea cultivar with low *SCI* and *WSA* will have low fibre content in the seed coat [43]. These results were observed for CDC Leader, which had the lowest *SCI* and produced AQ with superior emulsion formation and stabilization properties.

Fat content was negatively correlated with *SSA* (*r* = −0.96\*) and *WSA* (*r* = −0.90\*), complementary to Gil et al. (1996) who observed a similar relationship in Desi and Kabuli chickpea [44]. In their study, fat content was also positively, and significantly, correlated to *HSW* for both chickpea classes. However, in this study, correlation between chickpea fat content and *HSW* (*r* = 0.87) was insignificant. This study supported observations made by Khattak et al. (2006), who revealed a strong, positive correlation between seed size and seed weight [42]. Moreover, they found that seed size was positively correlated with chickpea hydration capacity and protein content, as well as moisture content. However, no similar correlation was observed in this study.

Chickpea emulsion properties have often been linked to carbohydrate content, protein content [45,46] and some phytochemicals, such as phenolics [47] and saponins [48,49]. Shim et al. [10] investigated AQ compositions recovered from commercially canned chickpea products and identified proteins present in AQ. They demonstrated that most proteins in AQ are mostly of small molecular weight (≤16.7 kDa) and many belong to the groups that include late embryogenesis abundant proteins (LEAP), dehydrins and defensin. Main carbohydrate types in AQ are simple sugars (such as sucrose and glucose), soluble and insoluble fiber including cellulose and pectin [11,12]. Importantly, the contribution of hydrophobic polysaccharides and amphiphilic phytochemicals to emulsification activity cannot be neglected. Improved rheological properties of hydrophilic polysaccharides induced steric and mechanical stabilization e ffects, which slowed or even prevented emulsion droplet aggregation by forming thick charged layers [50].

AQ also contains saponins, which are regarded as surfactants and emulsifiers due to their amphiphilic structure [11,49]. Chung et al. (2017) presumed that saponins could pack tightly together at the oil water interface, and thereby, e ffectively avoid unfavourable molecular interactions between the phases [51]. This could lower the interfacial tension to generate smaller droplets during homogenization and lead to higher emulsion stability [51].

Chickpea seed physicochemical properties and hydration characteristics did not correlate with AQ emulsion capacity and stability. This could be due to other factors that control the dispersal of chemical substances into AQ during cooking and the interaction between these components during cooking and storage.
