Browsing by Author "Kephas Nowakunda"

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Allometric relationships and carbon content for biomass-carbon estimation of East African Highland Bananas (Musa spp. AAA-EAHB) cv. Kibuzi, Nakitembe, Enyeru and Nakinyika
(Afr. J. Agric. Res., 2017-05-03) Daphine Kamusingize; Jackson Mwanjalolo Majaliwa; Everline Komutunga; Susan Tumwebaze; Kephas Nowakunda; Priver Namanya; Jerome Kubiriba
Globally, interests to increase carbon stocks have gained momentum in both woody and non-woody ecosystems. Despite efforts made to generate appropriate methods to estimate these stocks, most equations developed do not cater for intraspecific variabilities across e.g. species, regions or growth stages; especially in the case of bananas. Therefore, there is need to develop more robust equations to improve on the precision of biomass-carbon prediction especially at local scales to facilitate estimation of specific carbon stocks often lost in global assessments. This study aimed at developing cultivar- specific biomass estimation relationships and determining carbon content of EAHB cultivars at two growth stages. Plant data were collected purposively using destructive sampling techniques on farmers’ plots for 4 cultivars (Kibuzi, Nakitembe, Enyeru and Nakinyika) in two agro-ecological zones: the L. Victoria crescent and the South-western farmlands in the districts of Lwengo and Mbarara respectively. Results show that biomass differed across cultivars (P<0.001); hence four equations (Enyeru, Nakinyika, Kibuzi_Nakitembe and Generic) were developed following an exponential function, y=Aexp(ax), using diameter at breast height (DBH) as the predictor variable with an R2 range of 82-94%. EAHB mean carbon content varied significantly with growth stage (P<0.05) (47.6% for maiden plants before flowering and 48.8% for mature plants with a developed bunch). This study concludes that it is important to develop cultivar-specific equations for biomass-carbon estimation of EAHB cultivars to help assess their contribution to the carbon cycle especially in future studies.
Analysis of association of sensory and laboratory assessments for quality and consumer acceptability of steamed East Africa highland bananas
(Journal of The Science of Food and Agriculture, 2023-10-09) Kenneth Akankwasa; Pricilla Marimo; Alexandre Bouniol; Robooni Tumuhimbise; Moreen Asasira; Sarah Kisakye; Elizabeth Khakasa; Edgar Tinyiro; Yusuf Mukasa; Living Tukashaba; Mary G. Namuddu; Peter B. Ssenyonga; Dominique Dufour; Wilberforce Tushemereirwe; Kephas Nowakunda
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.
Combined use of sensory methods for the selection of root, tuber and banana varieties acceptable to end-users
(Journal of the Science of Food and Agriculture, 2023-06-13) Aurélie Bechoff; Laurent Adinsi; Gérard Ngoh Newilah; Mariam Nakitto; Zoé Deuscher; Reuben Ssali; Ugo Chijioke; Elizabeth Khakasa; Kephas Nowakunda; Alexandre Bouniol; Dominique Dufour; Christophe Bugaud
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.
East African highland cooking banana: towards an efficient selection of hybrids with user-preferred food quality traits
(Journal of The Science of Food and Agriculture, 2023-10-24) Kephas Nowakunda; Elizabeth Khakasa; Hernan Ceballos; Akankwasa Kenneth; Robooni Tumuhimbise; Christophe Bugaud; Moreen Asasira; Brigitte Uwimana; Alexandre Bouniol; Ephraim Nuwamanya; Lora Forsythe; Pricilla Marimo; Dominique Dufour; Wilberforce Tushemereirwe
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.
East African highland cooking banana: towards an efficient selection of hybrids with user-preferred food quality traits
(Journal of The Science of Food and Agriculture, 2023-11-13) Kephas Nowakunda; Elizabeth Khakasa; Hernan Ceballos; Akankwasa Kenneth; Robooni Tumuhimbise; Christophe Bugaud; Moreen Asasira; Brigitte Uwimana; Alexandre Bouniol; Ephraim Nuwamanya; Lora Forsythe; Pricilla Marimo; Dominique Dufour; Wilberforce Tushemereirwe
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.
Evaluation of a low-resource soy protein production method and its products
(Frontiers in Nutrition, 2023-04-20) Ece Gulkirpik; Annette Donnelly; Kephas Nowakunda; Keshun Liu; Juan E. Andrade Laborde
Introduction: One key approach to achieve zero hunger in Sub-Saharan Africa (SSA) is to develop sustainable, affordable, and green technologies to process nutritious food products from locally available sources. Soybeans are an inexpensive source of high-quality protein that may help reduce undernutrition, but it is underutilized for human consumption. This research evaluated the feasibility of a low-cost method developed initially at the United States Department of Agriculture to produce soy protein concentrate (SPC) from mechanically pressed soy cake and thus create a more valuable ingredient to improve protein intake in SSA. Methods: The method was initially tested in the bench scale to assess process parameters. Raw ingredients comprised defatted soy flour (DSF), defatted toasted soy our (DTSF), low-fat soy our 1 (LFSF1; 8% oil), and LFSF2 (13% oil). Flours were mixed with water (1:10 w/v) at two temperatures (22 or 60°C) for two durations (30 or 60 min). After centrifugation, supernatants were decanted, and pellets were dried at 60°C for 2.5 h. Larger batches (350 g) of LFSF1 were used to examine the scalability of this method. At this level, protein, oil, crude fiber, ash, and phytic acid contents were measured. Thiobarbituric acid reactive substances (TBARS), hexanal concentration and peroxide value were measured in SPC and oil to evaluate oxidative status. Amino acid profiles, in vitro protein digestibility, and protein digestibility corrected amino acid score (PDCAAS) were determined to assess protein quality. Results: Bench scale results showed accumulation of protein (1.5-fold higher) and reduction of oxidative markers and phytic acid to almost half their initial values. Similarly, the large-scale production trials showed high batch-to-batch replicability and 1.3-fold protein increase from initial material (48%). The SPC also showed reductions in peroxide value (53%), TBARS (75%), and hexanal (32%) from the starting material. SPC’s in vitro protein digestibility was higher than the starting material. Conclusion: The proposed low-resource method results in an SPC with improved nutritional quality, higher oxidative stability, and lower antinutrient content, which enhances its use in food-to-food fortification for human consumption and is thus amenable to address protein quantity and quality gaps among vulnerable populations in SSA.
Female Reproductive Potential and 3x by 2x Breeding Approach for Hybrid Seeds Development in Sukali Ndizi Genotype (Musa genome AAB)
(European Journal of Agriculture and Food Sciences, 2023-05-15) Henry Buregyeya; Naboth Oyesigye; Doreen Amumpiare; Priver B. Namanya; Kephas Nowakunda; Wilberforce K. Tushemereirwe; Eldad Karamura; Patrick Rubaihayo
Sukali Ndizi is one of the most popular local desert banana cultivars in Uganda. The crop is affected by a number of diseases and pests. Genetic improvement of the crop by hybridization may be hindered by very low seed set and poor seed germination. The main characteristics for assessing the female reproductive potential (seed set, seed quality and embryo germination of hybrid seeds) and 3x by 2x breeding approach were assessed in crosses of eleven different male diploid parents either wild or improved diploids with Sukali Ndizi landrace as the female parent for a period of 5 consecutive years planted in pollination blocks at National Agricultural Research Laboratories Kawanda (NARL). The month of pollination did not show any pattern throughout the pollination period but the crosses showed considerable variability in seed set, seed quality, and seed germination for different male diploids used. The water gravity test which differentiated the extracted seeds as sunken/viable and floating/nonviable seeds showed that a substantial amount of seed was floating and the sunken externally characterized by black hard integuments was only 39% with a range = 24%– 60% which contained embryos, of which 22% (range = 0–37%) germinated. The increase in non-viable seed suggested that ovule abortion in Sukali Ndizi which mainly involved embryo and endosperm abortions was the cause of limited seed germination and the paternity of the zygotes was a major factor underlying abortions. Flow cytometric analysis of nuclear DNA content was used to estimate ploidy levels of the progenies with results showing that using 3x by 2x breeding approach differing levels of ploidy were achieved [3x (288), 4x (61), 5x (14) and 2x (2)] signifying the predominance of 3x progenies and the presence of 5x and 4x conforming to the possibility of sexual polyploids. Although pollination of Sukali Ndizi can be done all around the year, the seed set both quantity and quality and germination were very poor, necessitating the development of an efficient regeneration protocol for zygotic embryos at varying maturity stages to increase the recovery of hybrids.
Review of instrumental texture measurements as phenotypic tool to assess textural diversity of root, tuber and banana food products
(Journal of The Science of Food and Agriculture, 2023-11-29) Oluwatoyin Ayetigbo; Santiago Arufe; Antonin Kouassi; Laurent Adinsi; Michael Adesokan; Andres Escobar; Luis Fernando Delgado; Abiola Tanimola; Oluyinka Oroniran; Cédric Kendine Vepowo; Mariam Nakitto; Elizabeth Khakasa; Ugo Chijioke; Kephas Nowakunda; Gérard Ngoh Newilah; Bolanle Otegbayo; Noel Akissoe; Mathieu Lechaudel; Thierry Tran; Emmanuel Oladeji Alamu; Busie Maziya-Dixon; Christian Mestres; Dominique Dufour
Roots, tubers and bananas (RTBs) contribute immensely to food security and livelihoods in sub-Saharan Africa, Asia and Latin America. The adoption of RTB genotypes in these regions relies on the interplay among agronomic traits, ease of processing and consumer preference. In breeding RTBs, until recently little attention was accorded key textural traits preferred by consumers. Moreover, a lack of standard, discriminant, repeatable protocols that can be used to measure the textural traits deter linkages between breeding better RTB genotypes and end user/consumer preferences. RTB products texture – that is, behaviour of RTB food products under unique deformations, such as disintegration and the flow of a food under force – is a critical component of these preferences. The preferences consumers have for certain product texture can be evaluated from expert sensory panel and consumer surveys, which are useful tools in setting thresholds for textural traits, and inform breeders on what to improve in the quality of RTBs. Textural characterization of RTBs under standard operating procedures (SOPs) is important in ensuring the standardization of texture measurement conditions, predictability of textural quality of RTBs, and ultimately definition of RTB food product profiles. This paper reviews current SOPs for the textural characterization of RTBs, including their various associated methods, parameters, challenges and merits. Case studies of texture characterized during development of SOPs and evaluation of texture of RTB populations are discussed, together with insights into key textural attributes and correlations between instrumental, sensory and consumer assessment of texture unique to various RTB food products. Hardness was considered a universal key textural attribute to discriminate RTBs. The review should provide adequate insight into texture of RTB food products and critical factors in their measurement. It aims to promote inclusion of texture in breeding pipelines by investigating which textural traits are prioritized by consumers, particularly since the inclusion of textural traits has recently gained prominence by breeders in improving RTBs.
Sensory characterization of the perceived quality of East African highland cooking bananas (matooke)
(Journal of The Science of Food and Agriculture, 2023-04-08) Elizabeth Khakasa; Charles Muyanja; Robert Mugabi; Christophe Bugaud; Nelly Forestier-Chiron; Brigitte Uwimana; Ivan Kabiita Arinaitwe; Kephas Nowakunda
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.
TARIBAN1, TARIBAN2, TARIBAN3, and TARIBAN4 ‘Matooke’ Cooking Banana Cultivars for the Great Lakes Region of Africa
(HortScience, 2022-11-23) Noel A. Madalla; Cornel Massawe; Mpoki Shimwela; Daud Mbongo; Grace Kindimba; Jerome Kubiriba; Ivan Arinaitwe; Kephas Nowakunda; Priver Namanya; Robooni Tumuhimbise; Asher W. Okurut; Adolf Saria; Munguatosha Ngomuo; Rony Swennen; Allan F. Brown; Michael Batte; Sebastien Carpentier; Inge Van den Bergh; Rhiannon Crichton; Pricilla Marimo; Eva Weltzien; Rodomiro Ortiz
Bananas and plantains (Musa sp.) are important staple and income-generating fruit crops for millions of people worldwide (Robinson and Sauco 2010; Ssebuliba et al. 2005). They are edible and vegetatively propagated parthenocarpic species (Ortiz 1997; Simmonds 1962). East African highland bananas (EAHBs) are a dis- tinct group of cultivars found only in the highland of African Great Lakes region, where the “greatest mass of bananas in the world” are found (Simmonds 1966). Bananas are important in the food economy of millions of people in this region, with annual per capita consumption estimated to be between 250 and 600 kg (Karamura et al. 2012). These triploid (2n 5 3x 5 33 chromosomes) cultivars are known locally as Matooke. When fully ripe, they can be eaten raw like dessert bananas; however, be- cause their pulp is insipid, they are mostly eaten after cooking. Shepherd (1957) referred to them as the ‘Lujugira-Mutika’ subgroup of the AAA genome group. They are also known by its acronym (EAHBs) because they thrive on the East African plateau at altitudes ranging from 900 to 1800 m above sea level (Davies 1995). A small group of these EAHBs are processed into a beverage, and called beer or ‘Mbidde’ bananas.