The East African highland cooking bananas 'Matooke' preferences of farmers and traders: Implications for variety development

Combined use of sensory methods for the selection of root, tuber and banana varieties acceptable to end-users

BACKGROUND

The assessment of user acceptability in relation to crop quality traits should be a full part of breeding selection programs. Our methodology is based on a combination of sensory approaches aiming to evaluate the sensory characteristics and user acceptability of root, tuber and banana (RTB) varieties.

RESULTS

The four-stepped approach links sensory characteristics to physicochemical properties and end-user acceptance. It starts with the development of key quality traits using qualitative approaches (surveys and ranking) and it applies a range of sensory tests such as Quantitative Descriptive Analysis with a trained panel, Check-All-That-apply, nine-point hedonic scale and Just-About-Right with consumers. Results obtained on the same samples from the consumer acceptance, sensory testing and physicochemical testing are combined to explore correlations and develop acceptability thresholds.

CONCLUSION

A combined qualitative and quantitative approach involving different sensory techniques is necessary to capture sensory acceptance of products from new RTB clones. Some sensory traits can be correlated with physicochemical characteristics and could be evaluated using laboratory instruments (e.g. texture). Other traits (e.g. aroma and mealiness) are more difficult to predict, and the use of a sensory panel is still necessary. For these latter traits, more advanced physicochemical methods that could accelerate the breeding selection through high throughput phenotyping are still to be developed. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

East African highland cooking banana: towards an efficient selection of hybrids with user-preferred food quality traits

BACKGROUND

Determinants of culinary qualities of East African highland cooking bananas (EAHCB) are not well known. This constrains the inclusion of user-preferred traits in breeding. The present study aimed to quantify key indicators of user-preferred characteristics to enable selection of acceptable hybrids.

RESULTS

Qualitative characteristics that drive preference were big bunches (15-34 kg), long straight/slightly curved fingers (12-23 cm), yellowness and soft texture. Descriptive sensory analysis of the intensity of colour and texture the 23 genotypes revealed that landraces Kibuzi, Mbwazirume, Nakitembe and Mpologoma had higher intensity of yellowness and lower intensity of hardness (softer) and a low score (≤ 1.0) of astringency taste. A preference test showed that they had higher acceptability scores. Biochemical, instrumental and sensory data revealed correlations between sensory firmness and instrumental hardness (r = 0.5), sensory firmness and amylopectin (r = -0.54), suggesting that qualitative descriptions can be predicted by instrumental and biochemical indicators. Significant (P < 0.05) variations in amylose and total starch content were observed in different varieties. Moderate correlations between instrumental hardness and firmness in mouth (r = 0.55), cohesiveness and firmness in the mouth (r = 0.57), and adhesiveness and firmness in the mouth (r = 0.64) were observed. Surprisingly, carotenoids content was not correlated with yellowness in cooked matooke. However, positive correlations were observed between chroma (b*) parameters of raw matooke and sensorial assessed color on cooked samples.

CONCLUSION

Qualitative characteristis; the bunch, pulp colour and texture; that drive users-preference in the EAHCB were quantified, paving way for breeders to use them to select genotypes with these attributes early in the breeding process. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Sensory characterization of the perceived quality of East African highland cooking bananas (matooke)

BACKGROUND

It has recently become increasingly evident that banana projects in Uganda need to consider consumer preferences as part of the breeding process to increase the acceptability of new cultivars. A trained panel used quantitative descriptive analysis (QDA) as a tool to assess the sensory characteristics of 32 cooking bananas (matooke). The aim was to investigate which sensory characteristics best describe matooke.

RESULTS

Fourteen descriptors were generated. The preferred attributes of matooke were high-intensity yellow color, homogeneous distribution of yellow color, good matooke aroma, highly moldable by touch, moist and smooth in the mouth. Analysis of variance revealed significant differences in the yellowness, homogeneity of color, firmness, moistness, smoothness, matooke aroma, hardness, and moldability across the genotypes (P < 0.05). Principal component analysis (PCA) showed strong positive correlations between yellowness and homogeneity of the color (R = 0.92). Smoothness in the mouth and moldability by touch were strongly and positively correlated (R = 0.88). Firmness in the mouth was well predicted by hardness to touch (R2 = 0.85). The matooke samples were ranked into two sensory clusters by agglomerative hierarchical clustering (AHC).

CONCLUSION

The study showed attribute terms that could be used to describe matooke and also revealed that QDA may be used as a tool during the assessment and selection of new cooking banana hybrids to identify relevant sensory attributes because of its ability to discriminate among the banana hybrids. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Analysis of association of sensory and laboratory assessments for quality and consumer acceptability of steamed East Africa highland bananas

BACKGROUND

The relevance of several characteristics for the acceptability of steamed East Africa bananas (matooke) was assessed using consumer-preferred characteristics, the overall liking scores, check-all-that-apply (CATA) and the Just About Right scale. The study was conducted in rural and urban locations in three banana growing regions of Uganda. Two landraces and two hybrids were processed into matooke. Twelve trained panellists evaluated color, taste and texture sensory characteristics.

RESULTS

Consumers scored matooke from landraces as the most liked. The CATA test showed that the most important characteristics were: smooth mouthfeel, soft to the touch, not sticky, moldable, deep yellow color, attractive, good matooke taste and smell. Principal component analysis confirmed that most of the preferred sensory characteristics were associated with the local genotypes, whereas the less preferred characteristics were associated with hybrids. Correlation analysis revealed strong positive correlations between the consumer assessed characteristics, hardness by touch, softness to touch and yellowness, as well as quantitative laboratory characteristics (moldable, hardness by touch, softness and yellowness) of the steamed matooke. Color assessed by consumers was strongly correlated with the laboratory-assessed color indicators.

CONCLUSION

The strong associations observed between laboratory-assessed and consumer-based characteristics (moldable by touch and yellowness) suggest the possibility of predicting consumer characteristics using quantitative laboratory sensory assessments. Matooke taste as assessed by consumer panel is strongly associated with smooth texture and deep yellow color, which were the characteristics associated with landraces in the laboratory sensory assessment. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Genetic diversity of the banana Fusarium wilt pathogen in Cuba and across Latin America and the Caribbean

Fusarium wilt of bananas (FWB) is a severe plant disease that leads to substantial losses in banana production worldwide. It remains a major concern for Cuban banana cultivation. The disease is caused by members of the soil-borne Fusarium oxysporum species complex. However, the genetic diversity among Fusarium species infecting bananas in Cuba has remained largely unexplored. In our comprehensive survey, we examined symptomatic banana plants across all production zones in the country, collecting 170 Fusarium isolates. Leveraging genotyping-by-sequencing and whole-genome comparisons, we investigated the genetic diversity within these isolates and compared it with a global Fusarium panel. Notably, typical FWB symptoms were observed in Bluggoe cooking bananas and Pisang Awak subgroups across 14 provinces. Our phylogenetic analysis revealed that F. purpurascens, F. phialophorum, and F. tardichlamydosporum are responsible for FWB in Cuba, with F. tardichlamydosporum dominating the population. Furthermore, we identified between five and seven distinct genetic clusters, with F. tardichlamydosporum isolates forming at least two subgroups. This finding underscores the high genetic diversity of Fusarium spp. contributing to FWB in the Americas. Our study sheds light on the population genetic structure and diversity of the FWB pathogen in Cuba and the broader Latin American and Caribbean regions.

Evidence for metabolite composition underlying consumer preference in Sub-Saharan African Musa spp

Breeding programs for disease resistant bananas in Sub-Saharan Africa generated resistant bananas, which did not meet fruit quality characteristics preferred by consumers. The present study aimed to establish chemotypes underlying preferred cooking bananas of Matooke, Mchare and plantain and less preferred Mbidde bananas, used for beer brewing. The metabolite data of Mbidde showed higher levels of metabolites associated with sour, sweet, and astringent taste; as well as different textural properties associated with cell wall composition and lignin content. Significant differences in the majority of specialised and primary metabolites were observed in the pulp of cooking banana groups. Analysis of peel tissue indicated similar metabolic differences in the protective layer surrounding the pulp and suggested a distinct genetic regulation of phenylpropanoid and flavonoid pathways between the genome groups. In summary, the present data can be used to establish metabolic traits associated with consumer preference, which can augment modern breeding programs.

Internal Quality Assessment of East African Highland Cooking Banana (Musa spp.) Flour: Significance for Breeding and Industrial Applications

This study assessed the internal quality traits of East African Highland cooking banana flours, exploring their significance for breeding and potential industrial applications. Twenty cultivars (nine hybrids and eleven landraces) were used. Swelling power capacity, water solubility, water absorption capacity, water absorption index, freeze-thawing stability, and pasting characteristics of banana flour were assessed using standard methods. The results showed that cultivars with high swelling power also exhibited a high water absorption capacity and water absorption index, thus making them suitable for bakery industries. The water absorption capacity ranged between 5.66% (N2) and 11.68% (N11). Landraces KBZ (9.01) and NKYK (8.05), and hybrids N11 (11.68) and N9 (8.48) are suitable as thickeners due to high WAC. Hybrids (N7, 27.83%, and N9, 22.59%) and landraces (NMZ, 32.69%, and NFK, 34.24%) had low freeze-thawing stability, hence it is applicable as a food stabilizer. Landrace NKT (19.14%) and hybrid N9 (16.95%) had the highest solubility, and landrace KBZ (6.93%) and hybrid N3 (6.66%) had the lowest solubility. Landraces MSK (6265), NKY (3980), and NFK (3957), and hybrids N6 (3608), N7 (3505), and N9 (3281 RVU) had high peak viscosity. The trough viscosity, final viscosity, and breakdown viscosity of cultivars varied from 422.5 to 5004 RVU. The landraces MSK (5021 RVU) and NFK (4111 RVU) had the highest final viscosity, making them suitable for application in the food industry for thick and stable sauces. Landrace TRZ had the lowest pasting temperature (62.7 °C), making it advantageous for use where fast gelatinization is required, hence saving energy costs and cooking time. These findings suggest that the genetic attributes inherent in cultivars can be incorporated into breeding programs targeting required traits for industrial application.

Soil Sterilization Eliminates Beneficial Microbes That Provide Natural Pest Suppression Ecosystem Services Against Radopholus similis and Fusarium Oxysporum V5w2 in the Endosphere and Rhizosphere of Tissue Culture Banana Plants

Endosphere and rhizosphere microbes offer plant growth promotion and pest suppression ecosystem services in banana-based agroecosystems. Interest has been growing towards the use of such beneficial microbes in protecting vulnerable tissue culture banana plants against pathogens such as Radopholus similis and Fusarium oxysporum. A screenhouse experiment with potted tissue culture banana plants was conducted using sterile and non-sterile soil to investigate the effect of soil biota on R. similis and F. oxysporum strain V5w2. Plants grown in non-sterile soil had lower damage and R. similis density in roots and rhizosphere, while most plant growth-related parameters including root freshweight, shoot freshweight, total freshweight, plant height, and leaf size were larger compared to those from sterile soil. Shoot dryweight and Mg content were higher in plants from sterile soil, while their leaves developed discolored margins. R. similis-inoculated plants in sterile soil were smaller, had more dead roots, higher nematode density, and produced fewer and smaller leaves, than those from non-sterile soil. For all plant growth-related parameters, nematode density and root damage, no differences were recorded between controls and F. oxysporum V5w2-inoculated plants; and no differences between those inoculated with R. similis only and the ones co-inoculated with the nematode and F. oxysporum V5w2. Banana roots inoculated with F. oxysporum V5w2 were lighter in color than those without the fungus. Independent or combined inoculation of banana plants with F. oxysporum V5w2 and R. similis resulted in lower optical density of root extracts. In vitro assays indicated the presence of Fusarium spp. and other root endophytic microbes that interacted antagonistically with the inoculated strain of F. oxysporum V5w2. It is concluded that, soil sterilization eliminates beneficial microbes that provide natural pest suppression ecosystem services against R. similis and F. oxysporum in the endosphere and rhizosphere of tissue culture banana plants. I recommend the integration of microbiome conservation into tissue culture technology through the proposed “Tissue Culture Microbiome Conservation Technology.”

Soil Microbes Determine Outcomes of Pathogenic Interactions Between Radopholus similis and Fusarium oxysporum V5w2 in Tissue Culture Banana Rhizospheres Starved of Nitrogen, Phosphorus, and Potassium

The contributions of soil biota toward outcomes of pathogenic interactions between Radopholus similis and Fusarium oxysporum V5w2 in tissue culture banana plants starved of nitrogen (N), phosphorus (P), and potassium (K) were investigated. The study was based on three screenhouse factorial experiments (2 × 2 × 2) comprising of potted banana plants with or without R. similis, with or without F. oxysporum V5w2, and either grown in sterile or non-sterile soil. All plants in each of the three experiments received nutrient solutions that were deficient in N, P, or K, respectively. In all the three nutritional regimes, plants inoculated with R. similis were heavily colonized by the nematode with high percentage dead roots and necrosis, while their root biomasses were low. N-starved plants co-inoculated with R. similis and F. oxysporum V5w2 had lower percentage dead roots and tended to have numerically lower nematode density compared to those treated with R. similis only, especially in non-sterile soil. N-starved plants inoculated with R. similis had higher shoot dry weight, were taller with more leaves that were larger, compared to those not inoculated with the nematode. Plants grown in non-sterile soil had lower percentage dead roots, necrosis and R. similis density than those from sterile soil, regardless of the nutrient regime. N-starved plants from non-sterile soil were shorter with smaller leaves having decreased chlorophyll content and lower biomass, compared to those from sterile soil. By contrast, P and K starved plants from non-sterile soil were taller with larger leaves and more biomass, compared to those from sterile soil. Roots inoculated with R. similis had higher endophytic colonization by Fusarium spp., especially when co-inoculated with F. oxysporum V5w2 and grown in sterile soil among the N and K-starved plants. In conclusion, pathogenic interactions between R. similis and F. oxysporum V5w2 are predominantly suppressed by a complex of soil microbes that exert plant growth promoting effects in tissue culture banana plants through N, P, and K dependent processes. Nitrogen is the most important limiting factor in rhizosphere interactions between banana roots, beneficial microbes and the pathogens. Soil sterilization and the stringent aseptic tissue culture techniques still require the development of alternative innovative ways of conserving microbial services for sustainable agriculture.