Near-infrared spectroscopy applications for high-throughput phenotyping for cassava and yam: a review

Open Access Article; Published online: 12 Aug 2020The review aimed to identify the different high‐throughput phenotyping (HTP) techniques that used for quality evaluation in cassava and yam breeding programmes, and this has provided insights towards the development of metrics and their application in cassava and yam improvements. A systematic review of the published research articles involved the use of NIRS in analysing the quality traits of cassava and yam was carried out, and Scopus, Science Direct, Web of Sciences and Google Scholar were searched. The results of the review established that NIRS could be used in understanding the chemical constituents (carbohydrate, protein, vitamins, minerals, carotenoids, moisture, starch, etc.) for high‐throughput phenotyping. This study provides preliminary evidence of the application of NIRS as an efficient and affordable procedure for HTP. However, the feasibility of using mid‐infrared spectroscopy (MIRS) and hyperspectral imaging (HSI) in combination with the NIRS could be further studied for quality traits phenotyping

Crystalline and pasting properties of cassava starch are influenced by its molecular properties

This study was undertaken to detail starch characteristics among cassava varieties and compare them to their improved progenies. Cassava starch was extracted from roots of both the parents and progenies of two popular Ugandan local varieties (Bamunanika and Nyaraboke) and three popular elite varieties (NASE 10, TME 14 and 95/SE/00036) and their properties compared. The pasting and rheological properties showed a unique pasting curve in the progenies compared to the parents with significantly low peak viscosities among the progenies. Percentage crystallinity as determined by X-ray crystallography was on average four points higher in parents compared to progenies. There were no significant differences in the average amylose contents (17 - 20%) and starch contents (about 81%) in both the progenies and their parents. Significant relationships were observed between crystalline and pasting properties of the starch among the clones and parents. The above differences suggest possible variations in the amylopectin chain structure and starch molecular properties attributable to differences in the starch branching enzyme among the progenies and their parents.This work was supported under the BIO-EARN program, with a grant from the Swedish International Cooperation Agency/Department for Research Cooperation (Sida/ SAREC)

Starch quality traits of improved provitamin A cassava (Manihot esculenta Crantz)

Provitamin A cassava clones were analysed for starch yield and critical starch quality attributes, to understand possible applications in the food industry. Total carotenoids content in the test clones ranged from 0.03-11.94 μg g-1 of fresh root. Starch yield ranged from 8.4-33.2 % and correlated negatively (r = -0.588, P < 0.001) with carotenoids content. Amylose content (16.4–22.1%) didn't differ significantly (P ≤ 0.05) among the cassava clones. Meanwhile, total carotenoid content had significant negative correlations (P ≤ 0.05) with starch pasting temperature, peak time, setback viscosities and peak area. The reduced peak time and pasting temperatures in high-carotenoid cassava signifies reduction in energy requirements in yellow-fleshed roots when compared to white-fleshed cassava. This attribute is desirable for the food industry as it would reduce the overall cost of processing the cassava. Furthermore, final viscosities of starch from carotenoid-rich cassava were lower than those of white-fleshed roots, making provitamin A cassava suitable for soft food processing

Early detection of plant diseases using spectral data

Early detection of crop disease is an essential step in food security. Usually, the detection becomes possible in a stage where disease symptoms are already visible on the aerial part of the plant. However, once the disease has manifested in different parts of the plant, little can be done to salvage the situation. Here, we suggest that the use of visible and near infrared spectral information facilitates disease detection in cassava crops before symptoms can be seen by the human eye. To test this hypothesis, we grow cassava plants in a screen house where they are inoculated with disease viruses. We monitor the plants over time collecting both spectra and plant tissue for wet chemistry analysis. Our results demonstrate that suitably trained classifiers are indeed able to detect cassava diseases. Specifically, we consider Generalized Matrix Relevance Learning Vector Quantization (GMLVQ) applied to original spectra and, alternatively, in combination with dimension reduction by Principal Component Analysis (PCA). We show that successful detection is possible shortly after the infection can be confirmed by wet lab chemistry, several weeks before symptoms manifest on the plants

Gendered Matooke product profile in Uganda

The WP1 Gendered Food Product Profile for Matooke in Uganda reflects the final step ( step 5) of an interdisciplinary five-step methodology developed to identify demand for quality characteristics among diverse user groups along the food chain ( Forsythe et al., 2022). This methodology includes: step 1) interdisciplinary state of knowledge of the product ; step 2) gendered food mapping, which includes participatory research with men and women in rural communities regarding their product preferences and priorities; step 3) participatory processing diagnosis and quality characteristics ; and step 4) consumer testing studies in rural and urban areas of the product using contrasted RTB varieties. Results from step 1 and 2 have been published in Kenneth Akankwasa, Pricilla Marimo, Robooni Tumuhimbise, Moreen Asasira, Elizabeth Khakasa, Innocent Mpirirwe, Uli Kleih, Lora Forsythe, Geneviève Fliedel, Dominique Dufour & Kephas Nowakunda (2021). The East African highland cooking bananas ‘Matooke’ preferences of farmers and traders: Implications for variety development. International Journal of Food science and Technology, 56(3), 1124-1134. https://doi.org/10.1111/ijfs.14813. The WP1 Gendered Food Product Profile for Matooke in Uganda has been agreed by a multidisciplinary team based on the evidence collected on preferred quality characteristics at each step and assessed for their potential harm and benefit for women, based on an adapted G+ tool (publication pending by Forsythe et al.). ‘Matooke’ is a staple food made from highland cooking bananas in the Great Lakes region of East Africa. Improvement of bananas for resistance to pests and diseases has been a major breeding objective of the national breeding programme. This product profile for matooke presents the quality characteristics among different user groups in Uganda basing on a participatory and interdisciplinary method. The Matooke Food Product Profile is essentially a description of a high-quality food product from an evolving list of sensory, processing and agronomic characteristics that reflects different preferences among users from a gender perspective. This involved aggregating evidence on preferences with farmers, traders, processors and consumers, where important characteristics and their indicators were identified and prioritised, and finally, agreed by a multidisciplinary team together with a gendered livelihoods assessment. Key raw material characteristics identified include: big fingers for they ease the preparation process (easy to peel, high peel yield and less time used), big bunch (high market value, food for home use). Creamy pulp colour, shiny green finger colour and disease free are other important characteristics. The gender analysis of the final list of characteristics, which used an adapted G+ tool, resulted in big bunch being de-prioritised. Although this characteristic was noted as essentially important, it can place a labour burden especially on women in cases of harvesting, carrying to their homes for preparation for example, if women carry for long distances from farms for home consumption/paying to carry on bicycle, need for technology promotional adjustments (need to prioritise an attainable and acceptable threshold. At processing, the creamy pulp colour, easy to peel, big fingers, soft peel, straight fingers and relatively low sap were preferred. Low sap saves both time and money in terms of washing the pulp, soap to clean the sticky sappy hands and utensils, and too much sap would alter the colour of both pulp and mashed food. However, some sap is important and most varieties in the market have varying sap content. Therefore prioritising breeding more for this this trait might result in undesired amount of sap undesired by users. At the end product stage, soft texture, good smell, yellow colour, good matooke taste and holding together when mashed were the most important end product characteristics. Through the gender assessment, it was learned that a yellow colour might be attained at first boiling/steaming, it may require additional time and fuel (simmering) for some varieties, which may seem costly in terms of time and money. (2021-09-01