# Assessment of end user traits and physicochemical qualities of cassava flour: A case of Zombo district, Uganda

Ann Ritah Nanyonjo, Robert Sezi Kawuki, Florence Kyazze, Williams Esuma, Enoch Wembabazi, Dominique Dufour, Ephraim Nuwamanya, Hale Tufan

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Ann Ritah Nanyonjo, Robert Sezi Kawuki, Florence Kyazze, Williams Esuma, Enoch Wembabazi, et al. Assessment of end user traits and physicochemical qualities of cassava flour: A case of Zombo district, Uganda. International Journal of Food Science and Technology, 2021, 56 (3), pp.1289-1297. 10.1111/ijfs.14940 . hal-05176990

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Original article

# Assessment of end user traits and physicochemical qualities of cassava flour: a case of Zombo district, Uganda

Ann Ritah Nanyonjo,<fnref n="1" />* ID Robert Sezi Kawuki,<fnref n="1" /> Florence Kyazze,<fnref n="2" /> Williams Esuma,<fnref n="1" /> Enoch Wembabazi,<fnref n="1" /> Dominique Dufour,<fnref n="3" />,<fnref n="4" /> ID Ephraim Nuwamanya<fnref n="1" /> & Hale Tufan<fnref n="5" />

*(Received 16 October 2020; Accepted in revised form 11 December 2020)*

**Summary** Cassava breeding programmes in Uganda do not currently select materials based on flour making quality, explaining in part the low adoption rates of many released varieties. In this study, we describe end user trait preferences, processing qualities and physicochemical properties of cassava flour. We found that higher proportion of women than men showed preference for most attributes of cassava flour quality evaluated in this study. Preference for colour was 66% and 52% among women and men, respectively, while that for stickiness of *Kwon* was 26% (women) and 15% (men). Ease of peeling and stickiness of *Kwon* were key processing traits. Heap fermented flour had higher pasting temperatures, but lower viscosities than sun-dried flour, and had lower amylose content compared to fresh root starch. The results demonstrate the importance of gender sensitive participatory evaluation of breeding materials, in tandem with physicochemical evaluation during selection of best possible candidate breeding lines.

**Keywords** Cassava, fermentation, men, physicochemical properties, women.

Introduction

Cassava (*Manihot esculenta* Crantz) is a major root
crop grown and consumed in the tropical and sub-
tropical regions of the world (Burns *et al.*, 2010). Cas-
sava is mainly cultivated for its starchy roots (Sánchez
*et al.*, 2009), although its leaves are also eaten as a
vegetable (Aduni *et al.*, 2005). Cassava roots are bulky
and highly perishable, and therefore need to be pro-
cessed into longer lasting forms such as flour (Brad-
bury & Denton, 2010; Akama., 2013). Processing also
reduces levels of hydrogen cyanide (HCN) (Guédé
*et al.*, 2013), thus rendering roots of cultivars with
high levels of HCN safe for human consumption (Car-
doso *et al.*, 2005; Lambri *et al.*, 2013). In sub-Saharan
Africa, traditional cassava processing methods are
highly variable and differentiated geographically. Sub-
merged root fermentation is common practice in Nige-
ria to produce cassava products such as gari, fufu and
papuru (Egwim *et al.*, 2016), while heap fermentation
is common in Uganda and Mozambique (Alexander
*et al.*, 1995; Tivana *et al.*, 2007).

Cassava breeding efforts have led to identification
and deployment of varieties with low HCN content,
which are safe for fresh consumption. In Uganda, vari-
etal selection is largely based on defensive and selected
agronomic root traits (Kawuki et al., 2016). Ideally,
roots of such varieties can be processed into flour
without undergoing fermentation. However, some
communities typically consume cassava products aris-
ing from flour processed through fermentation (Car-
doso et al., 2005; Lambri et al., 2013). This narration
highlights a major drawback in current cassava breed-
ing operations that are implemented with limited and/
or poor understanding of traits that define quality of
processed root products.

This challenge is aggravated by commonly used out-
reach approaches like participatory variety selection
that only engage men and women towards the end of
variety development process, at which point variability
for product quality traits may have been significantly
lost or reduced. Consequently, these factors singly
and/or in combination have created a situation where
genetic gains in cassava for disease resistance, yield
and adaptability are high, and on the contrary no and

<footnote n="1">1 National Crops Resources Research Institute (NaCRRI), 9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala, Uganda</footnote>

<footnote n="2">2 Makerere University, P.O Box 7062, Kampala, Uganda</footnote>

<footnote n="3">3 CIRAD, UMR Qualisud, Montpellier F-34398, France</footnote>

<footnote n="4">4 Qualisud, CIRAD, Institut Agro, Univ Montpellier, Avignon Université, Université de La Région, Montpellier, France</footnote>

<footnote n="5">5 Cornell University, Ithaca NY, 14850, USA</footnote>

<footnote>*Correspondent: E-mail: nanyonjoaritah@gmail.com</footnote>
or minimal gains for product traits (Teeken et al., 2018).

Essentially, cassava breeding should generate tech-
nologies that meet aspirations of men, women, boys
and girls; these technologies should also be mindful of
their different needs, constraints, roles and responsibil-
ities (Farnworth & Jiggins, 2003). Women perform a
bulk of the roles involved in cassava production, pro-
cessing and marketing (Esuma et al., 2019) and thus
should be actively involved in technology development,
verification and/or dissemination.

For example, Linley *et al.* (2002) found that women continue to grow bitter cassava landraces and not elite varieties owing to the quality superiority of their end products; this has persistent despite the yield and disease susceptibility penalties the landraces experience (Ribeiro *et al.*, 2012). It is thus imperative that cassava breeding programmes refocus their breeding strategies to ensure that varieties to be released combine both disease resistance and desirable product quality traits defined by men and women.

Ideally, selection for such traits requires their trans-
lation into objectively measureable parameters. Root
profiling to quantify starch functional and biophysical
properties has been proposed as a suitable strategy to
quantify traits of cassava roots (Nuwamanya et al.,
2010). Indeed, related studies have established that
root quality can be assessed by evaluating starch prop-
erties and correlating them to amylose content (Nuwa-
manya et al., 2010; Osungbaro et al., 2012). Therefore,
it is logical to propose that once measurable traits
associated with product quality are identified, they can
then be used routinely to guide selection. Accordingly,
this study was aimed at (i) identifying flour qualities
preferred by men and women consumers, (ii) conduct-
ing participatory cassava root processing and (iii) eval-
uating physicochemical properties of elite genotypes
and landraces related to cassava flour quality.

**Materials and methods**

Location

This research was conducted in Zombo district, North
Western Uganda between 2°30′48″N and 30°54′32″E.
Zombo district was chosen because of the unique pro-
cessing method specific to this area, where cassava
roots are initially heap fermented and thereafter pro-
cessed into flour. In addition, Zombo is a highland
area and the cassava breeding programme was target-
ing to develop varieties suited for such environments.

Men and women preference of cassava root quality traits

Eight focus group discussions (FGDs) led by a facilita-
tor and guided by preset questions were used to collect

qualitative data. Moreover, questionnaires (n = 128) were used to collect quantitative data from Sixty-two men and Sixty-six women engaged in cassava production. Purposive sampling ensured respondents were from a range of ages, as well as balancing the number of women and men consulted.

Sources and genotypes of cassava used

The genetic materials used for processing evaluation comprised of 20 elite cassava genotypes sourced from an advanced yield trial and 16 landraces locally grown by men and women in Zombo. The elite genotypes were selected from a highland trial previously conducted in Zombo district in 2016. All agronomic data associated with the highland trial can be accessed at www.cassavabase.org/breeders/trials. An experimental trial was laid in a randomised complete block design with two replicates. Each clone was represented by ten plants per row at a spacing of 1 m × 1 m.

Processing of cassava roots

Eighteen women from the community were each sup-
plied with cassava roots harvested from four geno-
types, to process flour at their homes using the
traditional heap fermentation practice with nine
women processing roots from one replicate. In each
woman's home, cassava roots were peeled and spread
on tarpaulin under the sun. Cassava roots were left
under the sun for four to six hours to reduce the moist-
ture content of the roots without complete drying of
the roots. Thereafter, whole partially dry roots were
heaped in a corner inside the house and covered with
polythene sacs. The roots were placed on bare ground
in heaps to ferment. Fermentation ended within two
to three days, when roots were soft and covered with
black moulds. The fermented roots were cleaned with
knives to remove black moulds. Clean roots were bro-
ken into small pieces by pounding them in a local
motor with a local pounding pestle called Konyu. Cas-
sava flakes were spread on tarpaulin under the sun
until they dried. Dry cassava flakes were pounded with
in a local motor with Konyu into fine flour. A sieve
was used to separate large flakes from fine flour for
further pounding. The cassava product Kwon was pre-
pared using cassava flour generated following heap fer-
mentation. Briefly, 100 g of cassava flour was mixed
with 250 mL of boiling water until a thick paste (re-
ferred to as Kwon) was formed.

Evaluation of the processing quality of cassava genotypes

The eighteen women who processed cassava roots
evaluated genotypes on attributes related to processing
of heap fermented flour and the product *Kwon* (thick
paste processed from heap fermented cassava flour). Consequently, a structured questionnaire with questions rated by a scale customised to the Likert scale (Likert, 1932) was used to assess cassava genotypes. Focus was given to attributes, namely (i) ease of peeling assessed by how easily the peel detached from the cortex during peeling; (ii) days to fermentation assessed by the number of days a genotype took to complete the fermentation process; (iii) texture after fermentation assessed by the softness or hardness of the roots after fermentation; (iv) ease of mixing flour with water assessed by how easily the stick moved during mixing cassava flour with boiling water; and (v) quality of cassava *Kwon* evaluated by ability of flour to make a paste that sticks together even when it is left to cool for ten minutes.

<table><caption>**Table 1** Cassava varieties commonly processed into flour by men and women</caption><thead><tr><th rowspan="2">Variety</th><th colspan="2">Percentage of men and women who process the variety</th><th rowspan="2">Type of variety</th></tr><tr><th>% men (n = 62)</th><th>%women (n = 66)</th></tr></thead><tbody><tr><td>Longe</td><td>11.3</td><td>8.7</td><td>Sweet</td></tr><tr><td>Nyacharitas</td><td>16.3</td><td>12.7</td><td>Sweet</td></tr><tr><td>Nyamatia</td><td>11.8</td><td>9.2</td><td>Bitter</td></tr><tr><td>Nyapalei</td><td>13.5</td><td>10.5</td><td>Bitter</td></tr><tr><td>Nyapamitu</td><td>56.2</td><td>43.4</td><td>Bitter</td></tr><tr><td>Nyapopoga</td><td>15.0</td><td>12.7</td><td>Bitter</td></tr><tr><td>Nyaronega</td><td>30.4</td><td>23.6</td><td>Bitter</td></tr><tr><td>Nyarudota</td><td>48.5</td><td>51.5</td><td>Bitter</td></tr></tbody></table>

Chi-square ($\chi^2$ = 9.71, P = 0.78, df = 14).

<caption>**Figure 1** Preferred flour quality attributes of men and women in Zombo district. SCP/B = sweet cassava paste/ flour, GWHC = good water holding capacity, HDM = high dry matter, LQF = large quantities of flour, GSC = good swelling capacity. % is a symbol for percentage. [Colour figure can be viewed at wileyonlinelibrary.com]</caption>

## Physical chemical evaluation

Remnant flour from processing evaluation of selected cassava genotypes was used for physicochemical evaluation. Selection of genotypes for physicochemical analyses was based on quality of cassava fermentation (days to fermentation and texture after fermentation) and stickiness of cassava *Kwon*. Quality of fermentation was considered because it is a step in production of cassava flour that influences the characteristics of flour (González & Johnson, 2009). Quality of *Kwon* was considered because the study to determine trait preferences of men and women showed that it was a quality attribute of flour. Therefore, flour from six elite cassava genotypes and six landraces was stored in well labelled air tight containers prior to being subjected to physicochemical evaluation.

Physicochemical analyses were done for heap fermented, sun-dried and fresh root starch samples. Fresh root starch was prepared following a method described by (Nuwamanya *et al.*, 2010). To generate sun-dried flour, cassava roots were peeled, grated, sun-dried and pounded with a local motor and pestle. Fresh root starch and sun-dried samples were packaged in well labelled air tight containers. The samples were evaluated for amylose content, pasting properties, swelling power and solubility. Amylose content of the heap fermented cassava flour and fresh root starch was measured using the method described by (Afoakwa, 2011). Pasting properties of sun-dried and heap fermented samples were evaluated for using the rapid visco analyser (RVA) profiling procedure described by (Sánchez *et al.*, 2010). Swelling power and solubility were determined for fresh root starch using a method described by (Ceballos *et al.*, 2007).

<figure><img src="image_4.png" /></figure>
<table><caption>**Table 2** Analysis of variance for processing evaluation traits</caption><thead><tr><th>Variation</th><th>df</th><th>EoP</th><th>DtF</th><th>TaF</th><th>EoM</th><th>SoK</th></tr></thead><tbody><tr><td>Replicate</td><td>1</td><td>0.09</td><td>2.02</td><td>5.40</td><td>0.49</td><td>0.31</td></tr><tr><td>Genotype</td><td>35</td><td>2.15*</td><td>0.39</td><td>1.30</td><td>1.88</td><td>1.69**</td></tr><tr><td>Error</td><td>36</td><td>32.00</td><td>30.00</td><td>30.00</td><td>2.67</td><td>0.55</td></tr></tbody></table>

df, degrees of freedom; DtF, days to fermentation; EoM, Ease of mixing; EoP, ease of peeling; SoK, stickiness of Kwon.

* significant at <0.05.

** significant at < 0.01.

## Data analysis

Content analysis described by Elo & Kyngäs (2008) was used to analyse data from FGDs. Briefly, data were examined to generate themes which were used to define cassava product traits. Meanwhile, descriptive statistics were generated from quantitative data using the statistical package for social sciences (SPSS) version 21.0 (2013 release, IBM Corp., Armonk, NY, USA). Summary statistics from evaluation for traits related to processing and the product Kwon were obtained using R software version 3.41 (R Core Team, 2020). Similarly, summary statistics from evaluation of physicochemical properties were generated using the same software.

## Results and discussion

### Preference profiles for cassava flour among men and women

This study sought to understand attributes that define the quality of cassava flour processed through heap fermentation, and how preference for such qualities varies among men, women in Zombo district, a high-land community in North Western Uganda.

The study showed that most popular cassava landraces processed by both men and women in Zombo are Nyapamitu, Nyarodota and Nyaronega, all of which are bitter (Table 1). Fermentation of cassava roots is not uncommon in communities that cultivate bitter cassava landraces (Linley et al., 2007). This means that preference for bitter varieties by men and women in the study may be linked to other attributes such as quality of flour, and not necessarily bitterness. Indeed, the chi-square test ($\chi^2$ = 9.71, P = 0.78, df = 14) indicated that gender and variety processed were independent implying that selection of a variety was largely influenced by its inherent attributes.

<table><caption>**Table 3** Mean performance of genotypes for sticky cassava Kwon and ease of peeling</caption><thead><tr><th>Genotype</th><th>Sticky cassava Kwon</th><th>Ease of peeling</th></tr></thead><tbody><tr><td>Elite</td><td></td><td></td></tr><tr><td>UGH150022</td><td>5.0a</td><td>3.0bc</td></tr><tr><td>UGH150024</td><td>5.0a</td><td>4.0ab</td></tr><tr><td>UGH150031</td><td>5.0a</td><td>2.5c</td></tr><tr><td>UGH150040</td><td>5.0a</td><td>1.0c</td></tr><tr><td>UGH150085</td><td>5.0a</td><td>4.0ab</td></tr><tr><td>UGH150091</td><td>5.0a</td><td>3.5bc</td></tr><tr><td>UGH150094</td><td>5.0a</td><td>2.0c</td></tr><tr><td>UGH150105</td><td>5.0a</td><td>3.0bc</td></tr><tr><td>UGH150461</td><td>5.0a</td><td>5.0a</td></tr><tr><td>UGH150067</td><td>4.5ab</td><td>3.0bc</td></tr><tr><td>UGH150073</td><td>4.5ab</td><td>5.0a</td></tr><tr><td>UGH150014</td><td>4.0ab</td><td>2.5c</td></tr><tr><td>UGH150059</td><td>4.0ab</td><td>2.0c</td></tr><tr><td>UGH150053</td><td>3.5bc</td><td>2.0c</td></tr><tr><td>UGH150155</td><td>3.5bc</td><td>2.5c</td></tr><tr><td>UGH150023</td><td>3.0bc</td><td>5.0a</td></tr><tr><td>UGH150058</td><td>3.0bc</td><td>3.5bc</td></tr><tr><td>UGH150089</td><td>2.5c</td><td>3.0bc</td></tr><tr><td>UGH150121</td><td>2.0c</td><td>1.5c</td></tr><tr><td>Average of elite</td><td>4.2</td><td>3.1</td></tr><tr><td>Local varieties</td><td></td><td></td></tr><tr><td>Longe</td><td>5.0a</td><td>4.5ab</td></tr><tr><td>Nyamatia</td><td>5.0a</td><td>5.0a</td></tr><tr><td>Nyamukalasa</td><td>5.0a</td><td>4.5ab</td></tr><tr><td>Nyamukele</td><td>5.0a</td><td>2.0c</td></tr><tr><td>Nyapalei</td><td>5.0a</td><td>3.5bc</td></tr><tr><td>Nyarodota</td><td>5.0a</td><td>3.5bc</td></tr><tr><td>Tme 14</td><td>5.0a</td><td>3.5bc</td></tr><tr><td>Nyacharitas</td><td>4.5ab</td><td>5.0a</td></tr><tr><td>Nyalusi</td><td>4.5ab</td><td>4.5ab</td></tr><tr><td>Nyamateo</td><td>4.5ab</td><td>3.5bc</td></tr><tr><td>Akena</td><td>4.0ab</td><td>4.0ab</td></tr><tr><td>Nyamukelele</td><td>4.0ab</td><td>4.0ab</td></tr><tr><td>Nyapopoga</td><td>4.0ab</td><td>4.0ab</td></tr><tr><td>Nyaronega</td><td>4.0ab</td><td>3.5bc</td></tr><tr><td>Nyagota</td><td>2.5c</td><td>3.0bc</td></tr><tr><td>Telengule</td><td>2.0c</td><td>3.5bc</td></tr><tr><td>Nyapamitu</td><td>4.5ab</td><td>4.0ab</td></tr><tr><td>Average of local varieties</td><td>4.3</td><td>3.9</td></tr><tr><td>LSD (5%)</td><td>2.05</td><td>2.40</td></tr></tbody></table>

Note: Alphabetical letters show grouping of clones after mean separation using Fisher's protected least significant difference (LSD) test at 5%.

Cassava roots are commonly processed into flour following a stepwise procedure. In Zombo, the procedure of processing roots into flour was by heap fermentation. Apart from reducing levels of HCN, heap fermentation was purported to improve organoleptic attributes of cassava flour.

...fermenting removes bitterness, it gives cassava flour a nice smell and the ability to make sticky food... (Woman, Zeu sub-county FGD)
<figure><img src="image_5.png" /><figcaption>**Figure 2** Paste profile of selected cassava genotypes: (a) heap fermented cassava flour; (b) sun-dried cassava flour. Heap fermented samples maintain paste stability at high temperature. [Colour figure can be viewed at wileyonlinelibrary.com]</figcaption></figure>

According to Putri *et al*. (2011), heap fermentation improves the odour and taste of cassava flour.

A range of attributes were mentioned by men and women in describing their perception of high quality cassava flour (Fig. 1). Considering a cut-off of 20%, some attributes were preferred more by women than by men. Notable of these were white flour (66% women verses 52% men), fine texture (22% women verses 16% men), ease of mixing (22% women verses 10% men), good water holding capacity (24% women verses 16% men) and sticky *Kwon* (26% women verses 15% men), respectively. Despite this, heavy flour and high dry matter content were preferred by more men than women, although they did not meet the cut-off point. These flour quality attributes preferred by women and men are linked to cassava *Kwon*. This finding highlights both the importance of *Kwon* to the Zombo community and need for participatory product-based evaluation and selection.

## Processing and physicochemical properties of elite cassava genotypes and landraces

Cassava genotypes used in this study were evaluated for major aspects of the processing procedure. We noted significant genotypic differences (*P* < 0.05) for ease of peeling and stickiness of *Kwon* (Table 2). Elite genotypes had an average of 3.1 for ease of peeling while land races had 3.9 clearly illustrating that landraces scored highly for ease of peeling (Table 3). According to González & Johnson (2009), ease of peeling was one of the quality attributes that consumers considered when selecting cassava roots to purchase.

Furthermore, sticky *Kwon* ranged from 2.0 up to 5.0 (Table 3). It suffices to note that landraces had a slightly higher (4.3) average for sticky *Kwon* than elite genotypes (4.2). The ability of cassava flour to form a ‘thick paste’ referred to as ‘stickiness’ is a critical
starch pasting property whose differences are reported to be genotype dependant (Asaoka *et al.*, 1992). These differences in starch pasting properties provide breeders an opportunity to make selections (Nuwamanya *et al.*, 2010). Starch pasting properties which occur during heating are well illustrated through RVA profiling (Osungbaro *et al.*, 2012). Accordingly, we obtained RVA profiles for heap fermented and sun-dried cassava flour samples (Fig. 2).

Heap fermented flour samples had lower values for peak, final and breakdown viscosities than the sun-dried flour samples. On the other hand, heap fermented flour samples had higher pasting temperatures and trough viscosity as compared to the sun-dried flour samples. While sun-dried flour samples had a characteristic pasting profile with a visible break down, most heap fermented flour samples had unique profiles with no visible break down (Fig. 2). Indeed Gomes *et al.* (2005) found similar observations on fermented cassava starch which was modified by annealing. The authors attributed reduced peak viscosity to decreased amylose leaching.

Annealing is a process that modifies starch by rearranging starch granules without destroying the their structure (Alcázar-Alay & Meireles, 2015). According to Corke (2007), such modifications result into starch following the type C pasting profile (has no visible pasting peak and breakdown) as were observed from RVA profiles of heap fermented samples in this study. Having no visible breakdown on the pasting profile indicates low extent of breakdown of the paste and thus paste stability at high temperatures (Eriksson, 2013). This attribute has positive implications on the ability of cassava flour to form *Kwon* at high temperature since the paste will remain viscous even at high temperature.

Nyacharitas had the highest peak, trough and end viscosities for sun-dried flour (Fig. 2b). In addition, Nyacharitast had the highest peak, trough and end viscosities for heap fermented flour (Fig. 2a). It suffices to note that, Nyacharitas had high ability to make sticky cassava *Kwon* (4.5) (Table 3). This finding suggests that high peak viscosities are associated to stickiness, a pre-condition that has to be examined further with more diverse cassava genotypes. Nyamukalasa (85.35 °C) and UGH150094 (85.35 °C) had the highest pasting temperature for heap fermented flour, while UGH150094 (78.95 °C) had the highest for sun-dried flour (Table 4). It is likely that high pasting temperature could be due to high amylose content (Ekwu *et al.*, 2011).

Results for amylose content are presented in Table 5. Genotype UGH150121 had the highest amylose content (30.76) among the fresh starch samples, while UGH150105 had the least amylose (22.1%). With regard to the heap fermented flour samples,

<table><caption>**Table 4** Mean genotype performance for pasting temperature</caption><thead><tr><th>Genotype</th><th>PT (°C)</th></tr></thead><tbody><tr><td>Fermented UGH150059</td><td>82.55 ± 0.60</td></tr><tr><td>Sun-dried UGH150059</td><td>65.65 ± 0.00</td></tr><tr><td>Fermented UGH150067</td><td>84.15 ± 0.03</td></tr><tr><td>Sun-dried UGH150067</td><td>67.70 ± 0.00</td></tr><tr><td>Fermented UGH150094</td><td>85.35 ± 0.00</td></tr><tr><td>Sun-dried UGH150094</td><td>78.95 ± 1.13</td></tr><tr><td>Fermented UGH150105</td><td>67.3 ± 0.21</td></tr><tr><td>Sun-dried UGH150105</td><td>65.83 ± 0.24</td></tr><tr><td>Fermented UGH150121</td><td>78.45 ± 1.94</td></tr><tr><td>Sun-dried UGH150121</td><td>66.05 ± 0.07</td></tr><tr><td>Fermented Nyacharitas</td><td>78.95 ± 0.03</td></tr><tr><td>Sun-dried Nyacharitas</td><td>64.76 ± 0.11</td></tr><tr><td>Fermented Nyamateo</td><td>80.95 ± 0.56</td></tr><tr><td>Sun-dried Nyamateo</td><td>66.03 ± 0.11</td></tr><tr><td>Fermented Nyamukalasa</td><td>85.35 ± 0.00</td></tr><tr><td>Sun-dried Nyamukalasa</td><td>65.28 ± 1.09</td></tr><tr><td>Fermented Nyapaleyi</td><td>83.8 ± 0.28</td></tr><tr><td>Sun-dried Nyapaleyi</td><td>64.02 ± 0.04</td></tr><tr><td>Fermented Telengule</td><td>68.45 ± 0.03</td></tr><tr><td>Sun-dried Telengule</td><td>68.05 ± 0.07</td></tr><tr><td>LSD fermented</td><td>11.55</td></tr><tr><td>LSD sun-dried</td><td>2.26</td></tr></tbody></table>

<table><caption>**Table 5** Amylose content of fresh root starch and heap fermented flour</caption><thead><tr><th rowspan="2">Genotype</th><th colspan="2">Amylose content (%)</th></tr><tr><th>Fresh roots starch</th><th>Heap fermented flour</th></tr></thead><tbody><tr><td>UGH150121</td><td>30.76<sup>a</sup> ± 2.51</td><td>21.72<sup>a</sup> ± 0.82</td></tr><tr><td>UGH150059</td><td>26.94<sup>a</sup> ± 0.48</td><td>20.53<sup>a</sup> ± 0.46</td></tr><tr><td>UGH150067</td><td>22.35<sup>a</sup> ± 0.67</td><td>21.12<sup>a</sup> ± 4.23</td></tr><tr><td>UGH150089</td><td>25.49<sup>a</sup> ± 2.47</td><td>19.32<sup>a</sup> ± 2.06</td></tr><tr><td>UGH150105</td><td>22.05<sup>a</sup> ± 5.18</td><td>20.63<sup>a</sup> ± 1.17</td></tr><tr><td>UGH150094</td><td>28.70<sup>a</sup> ± 0.71</td><td>21.96<sup>a</sup> ± 0.30</td></tr><tr><td>Nyapamitu</td><td>23.01<sup>a</sup> ± 0.89</td><td>24.32<sup>a</sup> ± 0.66</td></tr><tr><td>Telengule</td><td>23.32<sup>a</sup> ± 0.08</td><td>21.18<sup>a</sup> ± 1.54</td></tr><tr><td>Nyamukalasa</td><td>26.01<sup>a</sup> ± 4.92</td><td>22.54<sup>a</sup> ± 2.17</td></tr><tr><td>Nyapalei</td><td>23.31<sup>a</sup> ± 3.36</td><td>22.25<sup>a</sup> ± 1.89</td></tr><tr><td>Nyacharitas</td><td>23.45<sup>a</sup> ± 0.61</td><td>17.02<sup>a</sup> ± 5.09</td></tr><tr><td>Nyamateo</td><td>29.14<sup>a</sup> ± 2.88</td><td>18.91<sup>a</sup> ± 0.93</td></tr><tr><td>Mean</td><td>25.38</td><td>20.95</td></tr><tr><td>LSD at 5%</td><td>24.66</td><td>12.10</td></tr><tr><td>CV (%)</td><td>5.07</td><td>4.57</td></tr></tbody></table>

CV, coefficient of variation; LSD, least significant difference.

Note: Letters show grouping of clones after mean separation using Fisher's protected least significant difference (LSD) test at 5 %

Alphabetical letters show grouping of clones after mean separation using Fisher's protected least significant difference (LSD) test at 5%.

Nyamukalasa had the highest amount amylose (22.5%), while Nyacharitas had the lowest (17.0%). Amylose content was higher in fresh root starch samples (with average 25.38) compared to heap fermented
<figure><img src="image_6.png" /><figcaption>**Figure 3** Swelling power and solubility of fresh root cassava starch.

Units = swelling power (g of water/ g of starch) and solubility (%). [Colour figure can be viewed at wileyonlinelibrary.com]</figcaption></figure>

flour (with average 20.95). Such differences could be
due to amylose degradation by lactic acid bacteria
(Lactobacillus fermentum) which is a key organism
involved in fermentation (Tivana *et al*., 2007). Indeed,
amylose content could have implications on pasting
properties because it is a non-branched polymer of
starch that is not easily hydrolysed (BeMiller & Whis-
tler, 2009). Consequently, when exposed to heat, cas-
sava flour from Nyamukalasa would require higher
temperature to gelatinise and form a thick paste
(Kwon) than that from Nyacharitas. The relationship
between amylose content, pasting properties and sticki-
ness of cassava Kwon, if further investigated, could be
key in evaluating genotypes for the important attribute
– stickiness of cassava Kwon.

Meanwhile, swelling power of cassava starch ranged
from 30 to 40 g of water/g of starch. Nyapamitu had
the highest ability to swell (40. 66 g of water/ g of
starch) while Nyacharitas had the lowest swellability
of 30.20 g of water/g of starch (Fig. 3). Solubility of
fresh root cassava starch ranged from 10 to 18%.
Telengule (18.48%) had the highest solubility while
UGH150105 (10.30%) had the lowest solubility.
According to Nuwamanya et al. (2010), swelling abil-
ity is inversely related to its amylose content. Indeed,
UGH150105 which had the lowest amylose content
(22.05%) (Table 5) had high ability to swell (39.25 g
of water/ g of starch, Fig. 3). Performance of
UGH150105 for swelling power and solubility corrob-
orated the findings by Ceballos et al. (2007) on mutant

cassava. According to the authors, the mutant geno-
type had lower solubility but higher swelling ability
and they related it to its low amylose content.

Conclusion

Data sets presented in this study highlight three
major findings. First, men and women differ in their
cassava flour preferences, strengthening the argument
for considering gender related traits during selection,
and including women and men to participate in the
variety development process. Second, landraces pos-
sessed better processing qualities compared to elite
genotypes. Thus, land races with superior processing
qualities can be used as progenitors and/or checks
when under taking root quality assessment. Third,
physicochemical properties notably paste properties
exhibited strong association with Kwon product
thickness, a key quality attribute. This information
could guide development of protocols for making
selections for quality cassava flour. We postulate
that this will contribute to development of improved
varieties that exhibit critical quality traits preferred
by men and women, for increasing adoption of
released varieties.

Acknowledgements

The authors are grateful to the technical staff of
NaCRRI who collected survey and cassava processing
evaluation data. We acknowledge the Next Generation Cassava Breeding project (www.nextgencassava.org) which funded this research.

## Conflict of interest

The authors declare that they have no conflict of interests.

## Author contribution

**Ritah Ann Nanyonjo:** Conceptualization (supporting); Data curation (lead); Formal analysis (lead); Investigation (lead); Methodology (equal); Writing-original draft (lead); Writing-review & editing (lead). **RoberT Sezi Kawuki:** Conceptualization (equal); Formal analysis (supporting); Funding acquisition (supporting); Investigation (supporting); Methodology (equal); Project administration (lead); Resources (supporting); Supervision (lead); Writing-review & editing (equal). **Florence Birungi Kyazze:** Data curation (supporting); Formal analysis (supporting); Investigation (supporting); Methodology (equal); Supervision (equal); Writing-review & editing (equal). **Williams Esuma:** Data curation (supporting); Formal analysis (equal); Methodology (supporting); Writing-original draft (supporting); Writing-review & editing (equal). **Enoch Wembabazi:** Data curation (equal); Formal analysis (equal); Investigation (supporting); Writing-review & editing (equal). **Dominique Dufour:** Conceptualization (equal); Formal analysis (equal); Investigation (supporting); Methodology (equal); Supervision (equal); Writing-review & editing (equal). **Ephraim Nuwamanya:** Conceptualization (supporting); Data curation (supporting); Formal analysis (equal); Investigation (supporting); Methodology (equal); Supervision (equal); Writing-review & editing (equal). **Hale Tufan:** Conceptualization (lead); Formal analysis (supporting); Funding acquisition (lead); Investigation (supporting); Methodology (lead); Project administration (supporting); Resources (lead); Writing-original draft (supporting); Writing-review & editing (equal).

## Ethical approval

Men and women were asked for their consent to participate and were assured of the anonymity of the information they gave. In addition, introduction of the study and its purpose was made. Indeed, respondents were free to cancel the interview any time if they lost interest to participate.

## Peer review

The peer review history for this article is available at https://publons.com/publon/10.1111/ijfs.14940.

## Data availability statement

Data that support the findings of this study are available from the corresponding author upon reasonable request.

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