Prediction of functional characteristics of gari (cassava flakes) using near-infrared reflectance spectrometry.

Open Access JournalGari is a creamy, granular flour obtained from roasting fermented cassava mash. Its preparation involves several unit operations, including fermentation, which is essential in gari production. Fermentation brings about specific biochemical changes in cassava starch due to the actions of lactic acid bacteria. Consequently, it gives rise to organic acids and a significant reduction in the pH. Consumer preferences for gari are influenced by these changes and impact specific functional characteristics, which are often linked to cassava genotypes. Measurement of these functional characteristics is time-consuming and expensive. Therefore, this study aimed to develop high-throughput and less expensive prediction models for water absorption capacity, swelling power, bulk density, and dispersibility using Near-Infrared Reflectance Spectroscopy (NIRS). Gari was produced from 63 cassava genotypes using the standard method developed in the RTB foods project. The prediction model was developed by dividing the gari samples into two sets of 48 samples for calibration and 15 samples as the validation set. The gari samples were transferred into a ring cell cup and scanned on the NIRS machine within the Vis-NIR range of 400–2,498 nm wavelength, though only the NIR range of 800–2,400 nm was used to build the model. Calibration models were developed using partial least regression algorithms after spectra preprocessing. Also, the gari samples were analysed in the laboratory for their functional properties to generate reference data. Results showed an excellent coefficient of determination in calibrations (R2 Cal) of 0.99, 0.97, 0.97, and 0.89 for bulk density, swelling power, dispersibility, and water absorption capacity, respectively. Also, the performances of the prediction models were tested using an independent set of 15 gari samples. A good prediction coefficient (R2 pred) and low standard error of prediction (SEP) was obtained as follows: Bulk density (0.98), Swelling power (0.93), WAC (0.68), Dispersibility (0.65), and solubility index (0.62), respectively. Therefore, NIRS prediction models in this study could provide a rapid screening tool for cassava breeding programs and food scientists to determine the food quality of cassava granular products (Gari)

Understanding cassava varietal preferences through pairwise ranking of gari-eba and fufu prepared by local farmer-processors

Within communities in Osun and Imo States of Nigeria, farmer‐processors grew and processed a diverse set of improved and landrace cassava varieties into the locally popular foods, gari, eba and fufu. Local and 15 main varieties were grown in a 'mother and baby trials' design in each state. Mother trials with three replications were processed by farmer‐processors renown in their community for their processing skills. Baby trials were managed and processed by other farmer‐processors. The objective was to identify food quality criteria to inform demand‐led breeding to benefit users, especially women, given their key roles in processing. Farmer‐processors evaluated the overall quality of fresh roots and derived food products through pairwise comparisons. Improved varieties had higher fresh and dry root yield. Overall, landraces ranked first for quality of gari and eba, but several improved varieties were also appreciated for good quality. Landraces in Osun had higher gari yield and a higher swelling power compared to improved varieties. Colour (browning), bulk density, swelling power, solubility and water absorption capacity were the criteria most related to food product ranking by farmer‐processors. Evaluation of varieties under farmer‐processors' conditions is crucial for providing guidance to breeders on critical selection criteria

Drivers of consumer acceptability of cassava gari-eba food products across cultural and environmental settings using the Triadic Comparison of Technologies approach (tricot)

BACKGROUND: Nigeria and Cameroon are multi-ethnic countries with diverse preferences for food characteristics. The present study aimed to inform cassava breeders on consumer-prioritized eba quality traits. Consumer testing was carried out using the triadic compar ison of technologies (tricot). Diverse consumers in villages, towns and cities evaluated the overall acceptability of eba made from differ ent cassava genotypes. Data from both countries were combined and linked to laboratory analyses of eba and the gari used to make it. RESULTS: There is a strong preference for eba with higher cohesiveness and eba from gari with higher brightness and especially in Cameroon, with lower redness and yellowness. Relatively higher eba hardness and springiness values are preferred in the Nigerian locations, whereas lower values are preferred in Cameroon. Trends for solubility and swelling power of the gari differ between the two countries. The study also reveals that the older improved cassava genotype TMS30572 is a benchmark geno type with superior eba characteristics across different regions in Nigeria, whereas the recently released variety Game changer performs very well in Cameroon. In both locations, the recently released genotypes Obansanjo-2 and improved variety TM14F1278P0003 have good stability and overall acceptability for eba characteristics. CONCLUSION: The wide acceptance of a single genotype across diverse geographical and cultural conditions in Nigeria, as well as three acceptable new improved varieties in both locations, indicates that consumers' preferences are surprisingly homogeneous for eba. This would enhance breeding efforts to develop varieties with wider acceptability and expand potential target areas for released varieties

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

Soil Pollution by Toxic Metals near E-waste Recycling Operations in Ibadan, Nigeria

Background. Unsound recycling of e-waste releases toxic metals into environmental media and has deleterious health consequences to humans as the metals transfer to humans through the food chain, direct contact and inhalation. Objectives. This study assessed soil contamination with lead (Pb), copper (Cu), chromium (Cr), nickel (Ni) and cadmium (Cd) arising from crude e-waste recycling. Methods. Forty-eight soil samples were collected from the vicinity of high-, medium- and low-activity recycling operations in Ogunpa in Ibadan, Nigeria as well as from the botanical garden of the University of Ibadan for background samples. Total extractable metals were leached with aqua regia and the leachates were analyzed using flame atomic absorption spectrometry. Speciation analysis was also conducted on soil samples that showed high concentrations of metals to determine the distributions in various phases. Results. All soil samples were determined to be sandy loam in composition with pH and organic matter ranging from 7.1–7.9 and 1.56–1.81%, respectively. Metal concentrations (mg/kg) for soils from the study area ranged as follows: Pb, 269 – 5650; Cu, 203 – 3483; Cr, 3.30 –42.4; Ni, 0.14 – 24.0; and Cd, below detection limit – 2.50. The results indicated enrichment in soil by all metals, especially Pb and Cu, which were many times higher compared with background concentrations. Additionally, average Pb and Cu concentrations were higher than regulatory limits for soil set by selected countries across the globe. Speciation studies indicated that about 65% and 88% of Pb and Cu, respectively, were liable to potential mobility with slight changes in natural conditions. Other metal concentrations, although with higher concentrations compared with background levels, were within the permissible limits in soils accepted by many countries across the globe. There were significant correlations between all metals, suggesting that they may have been released from a common source. Conclusions. Soils from the study area require urgent clean-up, especially for Pb and Cu, to safeguard human health and the environment. Competing Interests. The authors declare no competing financial interests

Effect of Sample Preparation Methods on the Prediction Performances of Near Infrared Reflectance Spectroscopy for Quality Traits of Fresh Yam (Dioscorea spp.)

High throughput techniques for phenotyping quality traits in root and tuber crops are useful in breeding programs where thousands of genotypes are screened at the early stages. This study assessed the effects of sample preparation on the prediction accuracies of dry matter, protein, and starch content in fresh yam using Near-Infrared Reflectance Spectroscopy (NIRS). Fresh tubers of Dioscorearotundata (D. rotundata) and Dioscoreaalata (D. alata) were prepared using different sampling techniques—blending, chopping, and grating. Spectra of each sample and reference data were used to develop calibration models using Modified Partial Least Square (MPLS). The performance of the model developed from the blended yam samples was tested using a new set of yam samples (N = 50) by comparing their wet laboratory results with the predicted values from NIRS. Blended samples had the highest coefficient of prediction (R2pre) for dry matter (0.95) and starch (0.83), though very low for protein (0.26), while grated samples had the lowest R2pre of 0.87 for dry matter and 0.50 for starch. Results showed that blended samples gave a better prediction compared with other methods. The feasibility of NIRS for the prediction of dry matter and starch content in fresh yam was highlighted

A Review of the Use of Near-Infrared Hyperspectral Imaging (NIR-HSI) Techniques for the Non-Destructive Quality Assessment of Root and Tuber Crops

Hyperspectral imaging (HSI) is one of the most often used techniques for rapid quality evaluation for various applications. It is a non-destructive technique that effectively evaluates the quality attributes of root and tuber crops, including yam and cassava, and their food products. Hyperspectral imaging technology, which combines spectroscopy and imaging principles, has an advantage over conventional spectroscopy due to its ability to simultaneously evaluate the physical characteristics and chemical components of various food products and specify their spatial distributions. HSI has demonstrated significant potential for obtaining quick information regarding the chemical composition of the root and tuber, such as starch, protein, dry matter, amylose, and soluble sugars, as well as physical characteristics such as textural properties and water binding capacity. This review highlights the principles of near-infrared hyperspectral imaging (NIR-HSI) techniques combined with relevant image processing tools. It then provides cases of its application in determining crucial biochemical quality traits and textural attributes of roots and tuber crops, focusing on cassava and yam. The need for more information on using NIR-HSI in the quality evaluation of yam and cassava was underscored. It also presents the challenges and prospects of this technology

Correlate the cyanogenic potential and dry matter content of cassava roots and leaves grown in different environments

Abstract Cassava (Manihot esculenta Crantz) is an essential stable food crop in Sub-Saharan Africa commonly consumed amongst the low-income communities in Africa. Though cassava roots and leaf have vast economic and commercial benefits, it produces cyanogenic glycosides, which are toxic and most often responsible for the bitter taste of some cassava cultivars. The study evaluates the cassava roots and leaves’ cyanogenic potential and dry matter content of the Genetic Gain Assessment trial grown in a different environment. It establishes the association between the cyanogenic potential (CNP) and the roots and leaves dry matter (DM). Genetic Gain Assessment (GGA) cassava genotypes (N = 400) selected for the Uniform Yield Trial (UYT) breeding stage were planted under IVS (Dry season in Inland Valley Hydromorphic area) and Upland (rain-fed conditions) in two locations of IITA Research Farms, namely; Ibadan (IVS and Upland) and Mokwa (Upland) in Nigeria. The CNP content of cassava leaves in IVS, Mokwa, and Upland ranged from 3.39 to 272.16 mg/100 g, 4.28 to 228.72 mg/100 g, and 13.13 to 127.39 mg/100 g, respectively. However, the respective CNP range in root samples across IVS, Mokwa, and Upland was 0.76–76.31 mg/100 g, 0.94–136.53 mg/100 g, and 2.37–47.11 mg/100 g. Also, the mean ± SD of DM content of leaves were 27.97 ± 3.01%, 28.81 ± 4.01%, and 13.65 ± 3.69%, respectively, in IVS, Mokwa, and Upland, while the root samples had mean ± SD of DM content of 38.09 ± 4.80%, 32.69 ± ,5.93% and 24.63 ± 5.07% respectively. Furthermore, location and genotype had a highly significant effect (p < 0.001) on the CNP and DM of roots and leaves. Also, linear regressions were established between CNP and DM of root and leaf with regression equation; DM-Root = 1.1999*DM-Leaf (r = 0.956) and CNP-Root = 0.29006*CNP-Leaf (r = 0.54). The relationship between the DM (root and leaf) and CNP (root and leaf) could serve as a valuable “inter-prediction” tool for these parameters

Assessment of biochemical, cooking, sensory and textural properties of the boiled food product of white yam (D. rotundata) genotypes grown at different locations

Specific biochemical properties and textural attributes determine the final quality and acceptability of yam food products. This study assessed the flour and cooking qualities (boiled yam) of sixteen elite white yam genotypes (D. rotundata) grown in three locations. Fresh yam samples were cut into regular-shaped pieces and boiled using the standard procedure. Sub-samples were oven-dried at 65 °C for 72 h and milled to flour. The biochemical profiling for the yam flour showed, on average, 61.35 ± 5.15% starch, 5.35 ± 0.15% sugar, 1.55 ± 0.24% crude fiber, 1.91 ± 0.31% ash, 5.65 ± 0.66% protein, 0.33 ± 0.02% fat and 34.87 ± 1.94% amylose content. The boiled yam's water absorption and cooking time ranged from 0.35 to 5.17% and 7.00–18 min, with an average of 2.74% and 10.64 min, respectively. The hardness of boiled yam from the sensory assay correlated positively with the hardness of instrumental texture analysis (p < 0.001, r = 0.47). In contrast, the hardness of instrumental texture had a significant negative correlation with the chewiness of sensory profile analysis (p < 0.05, r = 0.37). Likewise, water absorption correlated positively and significantly (p < 0.05, r = 0.43) with the chewiness of the sensory analysis. The study shows that the sensory attributes that determine the acceptability of boiled yam could be determined using instrumental measurements to save time and cost