## 1 Introduction  
Fermentation makes a valuable contribution to the development of the flavour, texture, and overall acceptability of fermented products. The concentration and composition of volatile flavour compounds can be key to consumer acceptability and preference [1]. Fermentation by microorganisms could also result in a significant increase in the quality of protein, vitamins and other essential nutrients [2]. Unlike other preservation methods focusing mainly on inhibiting the growth of microbes in food or at least reducing their numbers, fermentation encourages the growth of desired organisms whose metabolic activities improve the sensory and physical attributes of the product, in addition to extending shelf life [3, 4].  
Lafun is a cassava product traditionally prepared by steeping peeled cassava root pieces in water followed by fermentation for 2-5 days. The fermented roots are sun-dried on surfaces such as cement floors, tarred roads, and rocks and subsequently milled into powder [5]. Drying can take days or weeks, depending on the weather [6]. The coarse flour obtained is sieved and made into a gruel in boiling water and consumed with a stew of vegetables and a protein source. If properly stored, the shelf life of the cassava flour can be 6 months or more. Rheological analysis can reveal some of the flour qualities by estimating the degree of viscosity and deformability. A relatively high degree of viscosity and deformability of latun gruel indicates good quality.  
Rheological evaluation of food is an important tool for the assessment of product quality. Rheological measurement investigates how food materials respond to an external (applied) force (stress) and deformation (strain) as a function of time [7]. Oscillatory rheology, in which a small strain is applied, is well suited to the evaluation of the physical properties of food products, such as hydrated latfun, that are viscoelastic [8]. How a food material deforms during handling or consumption is typically a function of both the texture and rheology of that food [9]. Rheological analysis is important to monitor the effects of compositional and processing parameters that are needed in developing latfun with the desired rheological behaviour.  
Since latfun is a product of spontaneous fermentation, the microbiological composition is of a mixed culture that includes _Saccharomyces cerevisiae_, _Kluyveromyces marxiamus_, _Pichia scutulata_, _Lactobacillus fermentum_, _Lactiplantibacillus plantarum_, and _Bacillus cereus_[10; 11].  
Spontaneous fermentation can result in variable product quality and potentially the presence of microorganisms that could be detrimental to human health. Utilising food grade starter cultures in a controlled way would overcome this challenge. Previous work has been carried out to understand the predominant microorganisms in the fermentation of cassava to produce latfun and their role in the process [12; 13]. [PERSON] et al. [5], in their work, showed the effect of combining yeast and LAB as a mixed starter culture to produce latfun.  
LAB strains vary in their metabolic characteristics, impacting their capacity to degrade components in cassava and synthesise new substances, which can impact the composition, rheological properties, and volatile flavour profile of latfun. Additionally, the composition of different cassava varieties varies. Therefore, substrate variability also results in the variability of latfun composition, impacting stability, rheological characteristics, and flavour profile.  
Still, there is little or no information on the impact of LAB strains and cassava varieties on the rheological properties, proximate composition, and volatile compounds of latfun. Therefore, the present study determines the impact of selected LAB strains as monoculture or co-culture on the physical properties and aroma profile of latfun produced using three varieties of cassava: bitter (B), sweet (S), and vitamin A fortified (F), in order to assess their potential as starter cultures for latfun production.