**5. Textural attributes of cooked fufu and possible influence of pectin**

Fufu is a traditional fermented food product consumed in the southern, western, and eastern parts of Nigeria and some other West African countries [24]. The variations in processing methods and differences in the biophysical traits of the varieties may change the textural properties of the cooked fufu [25]. For instance, Awoyale et al. [25] reported that the cooked fufu dough prepared from TMEB419 flour (45.34 N/m2 ) was significantly (p<0.05) harder than that prepared from TMS13F1153P0001 flour (19.37 N/m2 ) (**Table 2**). The high pectin content in the cooked fufu dough prepared from the TMS13F1153P0001 flour might have contributed to the softer texture during cooking and cooling [22]. In addition, the high water binding and holding capacity of pectin may keep the cooked fufu dough matrix moist, thus maintaining starch in a


*\*\*p<0.05.*

*NS: not significant.*

*Means with the same letters within the same column are not significantly different (p > 0.05). Source: Awoyale et al. [25].*

#### **Table 2.**

*Instrumental texture profiling of cooked fufu dough produced from different cassava varieties.*

#### *Cassava Pectin and Textural Attributes of Cooked gari (*eba*) and fufu Dough DOI: http://dx.doi.org/10.5772/intechopen.109580*

gelatinized state, hence making the fufu dough relatively soft in the cooled form [23]. Awoyale et al. [25] added that the hardness of the fufu dough has a positive correlation with most of the functional properties of the flour (except for dispersibility) and a negative correlation with pasting properties (except for breakdown viscosity and pasting temperature). Although this observation was not supported by the findings of Zhai et al. [22] who stated that as pectin content increased in the waxy rice starch and pectin blends, the peak and final viscosity of the products gradually increased. This may be due to differences in their starch and pectin composition.

Adhesiveness is the degree to which the cooked dough sticks to the hand, mouth surface, or teeth [25]. The adhesiveness of the fufu dough ranged from −54.64 to −30.61 N/m<sup>2</sup> , with the product from TMS13F1020P0001 flour having the highest value (p<0.05) and that from NR14B-218 flour having the lowest (**Table 2**). The low adhesiveness of the cooked fufu from NR14B-218 may be attributed to the lower hydrophobic interaction that may have led to inhomogeneity and instability in the network structure of the fufu dough, thus reducing the textural characteristics [22]. The adhesiveness of the cooked fufu dough had a positive correlation with all the functional properties (except for the water absorption capacity and solubility index), pasting properties, and chemical composition (except for sugar and starch, ash content, and pH value) of the flour [25]. Since high water-holding capacity is a characteristic of pectins, the negative correlation that exists between the adhesiveness of the cooked fufu dough and the water absorption capacity of the fufu flour might be a sign that the fufu flour from the NR14B-218 variety may have low pectin content [16].

Cohesiveness and moldability define how well the cooked fufu dough withstands a second deformation relative to its resistance to the first time. It is calculated as the work area during the second compression divided by the work area during the first [26]. Usually, the cooked fufu dough is squeezed manually, during which the mechanical and geometrical characteristics are assessed, molded into balls with the hand, then dipped into the soup, and swallowed [25]. The moldability of the fufu dough ranged from 0.92 in TMS13F1020P0001 flour to 0.99 in TMS13F1153P0001 flour (**Table 2**). The high cohesiveness of the cooked fufu dough from TMS13F1153P0001 flour may be linked with increased pectin concentration upon cooking and cooling, which may be due to the retrogradation of starch [16]. The moldability of the fufu dough was positively correlated with all the functional properties of the flour (except for water-absorption capacity, swelling power, and dispersibility), the pasting properties (except for peak and breakdown viscosities and pasting temperature), and the chemical composition (except for amylose content) [25]. The positive correlation between the cooked fufu dough moldability and the final viscosity may be evidence that the TMS13F1153P0001 fufu flour is high in pectin content [22]. Also, the possible interaction between the starch molecules and pectin during the gelatinization process may have increased the final viscosity of the dough and then responsible for the high moldability of the cooked fufu dough from TMS13F1153P0001 flour [27].

Stretchability or elasticity is the degree to which the cooked fufu dough returns to its original shape after compression between the teeth [25, 26]. The stretchability was lower in the product from TMS13F1020P0001 flour (0.75) and higher in that from TMEB419 flour (1.06) (**Table 2**). The stretchability of the dough also had a positive correlation with all the functional properties of the flour (except for solubility index and dispersibility), pasting properties (except for setback viscosity, peak time, and pasting temperature), and chemical composition (except for starch and amylose contents) [25].

The energy required to disintegrate a semi-solid food until it can be swallowed is known as gumminess. It is calculated as cohesiveness multiplied by hardness [25, 26]. The gumminess of the product from TMEB419 flour (42.38 N/m2 ) was significantly (p<0.05) more than that in the product from TMS13F1153P0001 (19.27 N/m2 ) (**Table 2**). The low gumminess of the cooked fufu dough prepared from TMEB419 flour may be due to the low hydrophobic interaction that might have led to inhomogeneity and instability in the network structure of the dough, thus reducing the textural characteristics [22]. Awoyale et al. [25] added that the gumminess of the fufu dough has a positive correlation with the functional properties of the flour (except for dispersibility), a negative correlation with the pasting properties (except for breakdown viscosity and pasting temperature), and a negative correlation with the chemical composition (except for amylose content). The positive correlation between the gumminess of the fufu dough and the breakdown viscosity implies that the TMS13F1153P0001 cooked fufu dough with low gumminess may be high pectin content. This is because Luo et al. [27] reported that the addition of pectin gradually decreased the breakdown value of the waxy rice starch and pectin blends. The authors added that the decrease in breakdown values might be due to the pectin being able to cover the starch granules step by step with the increasing concentration of pectin so that the stability of the waxy rice starch and pectin mixture was enhanced. Also, the negative correlation between the gumminess of the fufu dough and the setback viscosity of the fufu flour may be evidence that TMS13F1153P0001 cooked fufu dough with low gumminess maybe high in pectin content. This is because Zhai et al. [22] reported that the addition of pectin significantly reduced the setback viscosity of the waxy rice starch and pectin mixture, implying that pectin inhibited the retrogradation of gelatinized starch.
