Sweet Potato Roots Research Articles

Produtividade e qualidade da batata-doce em função da adubação fosfatada em diferentes solos

ABSTRACT Phosphorus (P) is an essential nutrient for growth and yield of sweet potatoes; in sandy soils, sweet potato yield and quality may be limited by application of low P doses, mainly in degraded areas. The objective of this work was to evaluate the effect of P doses on yield and quality of sweet potato root tubers grown in tropical sandy soils with different initial P availabilities: 23.2 mg dm-3 (high P - crop rotation) and 3.7 mg dm-3 (low P - post degraded pasture). Two experiments were carried out in a randomized block design, with four replicates. The treatments consisted of P doses (0, 22, 44, 88, and 176 kg ha-1) applied to the planting bed. Tuber yield, number and mean weight of tubers, P concentration in leaves and tubers, exported P, as well as the percentage of starch, reducing sugars, total sugars, and sucrose in the tubers were evaluated. P concentration in the soil was evaluated at the end of the experiment. In the area with high P availability (> 20 mg dm-3 - resin), increasing P doses did not increase root tuber yield and decreased root starch concentrations. In the area with low P availability (< 3.7 mg dm-3 - resin), root tuber yield and starch concentration peaked when applying 68 and 33 kg ha-1 of P, respectively. In areas after degraded pasture, with low initial soil P concentration, P fertilization for sweet potato crops should be carried out with a P dose of 68 kg ha-1. In areas with crop rotation and adequate soil P concentration, P fertilization should be carried out to replace the amount of P exported by the harvested root tubers to avoid decreases in soil fertility.

Influence of partial feeding of orange fleshed sweet potato root meal on the blood indices of finisher broiler chickens

Abstract A six-week study was conducted to evaluate the effects of partial replacement of maize with Orange Fleshed Sweet Potato (OFSP) root meal on the haematological parameters and serum biochemistry of broiler chickens at finisher phase. One hundred and eight (108) day old broiler chicks were randomly allotted into 4 dietary treatments (T1, T2, T3 and T4) with 3 replicates each and 9 birds per replicate. The test ingredient, OFSP root meal was included in broiler finisher diets as replacement for maize at 0%, 6%, 12% and 18% in the dietary treatments respectively. The study revealed no effect on all the haematological parameters. The result of the serum biochemistry also showed no significant differences (P>0.05) on all the parameters measured with the exception of triglycerides, globulin and blood urea nitrogen with significant decrease in the triglycerides (mg/dl) and globulin (g/dl) content of T2(24.80 and 0.37), T3(47.01 and 1.07) and T4(48.50 and 1.41) respectively as compared with the control group (61.54 and 1.95 respectively). Therefore, inclusion of OFSP root meal up to 18% did not negatively affect the haematological parameters of the birds and also reduced the risk of metabolic diseases in the birds while improving the cardiovascular health of the birds.

Convolutional neural networks in the qualitative improvement of sweet potato roots

The objective was to verify whether convolutional neural networks can help sweet potato phenotyping for qualitative traits. We evaluated 16 families of sweet potato half-sibs in a randomized block design with four replications. We obtained the images at the plant level and used the ExpImage package of the R software to reduce the resolution and individualize one root per image. We grouped them according to their classifications regarding shape, peel color, and damage caused by insects. 600 roots of each class were destined for training the networks, while the rest was used to verify the quality of the fit. We used the python language on the Google Colab platform and the Keras library, considering the VGG-16, Inception-v3, ResNet-50, InceptionResNetV2, and EfficientNetB3 architectures. The InceptionResNetV2 architecture stood out with high accuracy in classifying individuals according to shape, insect damage, and peel color. Image analysis associated with deep learning may help develop applications used by rural producers and improve sweet potatoes, reducing subjectivity, labor, time, and financial resources in phenotyping.

Survey and Cost–Benefit Analysis of Sorting Technology for the Sweetpotato Packing Lines

Supplying high-quality fresh sweetpotato roots to the consumer requires sorting the roots by quality and removing culls deemed unsuitable for fresh markets at packing facilities. The sorting operation is traditionally performed by manual labor. This study surveyed the sorting lines of seven commercial sweetpotato packinghouses in Mississippi during the packing season of 2021. Sorting for defects entirely relied on labor, which accounted for up to 50% of the total labor in packinghouses. A cost–benefit analysis was conducted to determine the cost-effectiveness of implementing automated sorting technology as an alternative to manual sorting. The net benefits of automated sorting depended on labor savings and equipment costs. Machines at or less than USD 100,000 were economically beneficial with payback periods of less than three years when four or more workers could be replaced, while machines of USD 350,000 and higher would be not justifiable when quick economical returns were sought. Automated sorting promises to increase the profitability and competitiveness of fresh market sweetpotato packing industries.

Effect of Growth Stages on Anthocyanins and Polyphenols in the Root System of Sweet Potato.

The storage roots of purple-fleshed sweet potato contain a variety of anthocyanins and polyphenols. Little is known about changes in the total content and composition of anthocyanins and polyphenols in the early growth stages of the root system. In this study, we investigated the changes in anthocyanins and polyphenols in the root system of purple-fleshed sweet potato cultivars at 15, 30, 45, and 60 days after transplant (DAT). Unexpectedly, the highest percentage of acylated anthocyanins in three purple-fleshed cultivars among all growth stages was at 15 DAT. On the other hand, the total polyphenol content in the early growth stages of the root system increased rapidly toward 45 DAT, just before the beginning of storage root enlargement, and then decreased rapidly as the storage roots began to enlarge. These data indicate that the early growth stage of the root system is a critical time. This timing may present a strategy to maximize the accumulation of polyphenols with high antioxidant activity, as well as acylated anthocyanins, to protect against abiotic and biotic stresses.

Photosynthesis Product Allocation and Yield in Sweet Potato in Response to Different Late-Season Irrigation Levels.

Soil water deficit is an important factor affecting the source-sink balance of sweet potato during its late-season growth, but water regulation during this period has not been well studied. Therefore, the aim of this study was to determine the appropriate irrigation level in late-season sweet potato, and the effect of irrigation level on accumulation and allocation of photosynthetic products. In this study, two yield-based field trials (2021-2022) were conducted in which five late-season irrigation levels set according to the crop evapotranspiration rate were tested (T0: non-irrigation, T1: 33% ETc, T2: 75% ETc, T3: 100% ETc, T4: 125% ETc). The effects of the different irrigation levels on photosynthetic physiological indexes, 13C transfer allocation, water use efficiency (WUE), water productivity (WP), and the yield and economic benefit of sweet potato were studied. The results showed that late-season irrigation significantly increased the total chlorophyll content and net photosynthetic rate of functional leaves, in addition to promoting the accumulation of above-ground-source organic biomass (p < 0.05). The rate of 13C allocation, maximum accumulation rate (Vmax), and average accumulation rate (Vmean) of dry matter in storage root were significantly higher under T2 irrigation than under the other treatments (p < 0.05). This suggests that both non-irrigation (T0) and over-irrigation (T4) were not conducive to the transfer and allocation of photosynthetic products to storage roots in late-season sweet potato. However, moderate irrigation (T2) effectively promoted the source-sink balance, enhanced the source photosynthetic rate and stimulated the sink activity, such that more photosynthate was allocated to the storage sink. The results also showed that T2 irrigation treatments significantly increased yield, WUE and WP compared to T0 and T4 (p < 0.05), suggesting that moderate irrigation (T2) can significantly promote the potential of storage root production and field productivity. There was a close relationship between economic benefit and marketable sweet potato yield, and both were highest under T2 (p < 0.05), increasing by 36.1% and 59.9% compared with T0 over the two-year study period. In conclusion, irrigation of late-season sweet potato with 75% evapotranspiration (T2) can improve both the yield and production potential. Together, these results support the use of late-season water management in the production of sweet potato.

The Role of IAA in Regulating Root Architecture of Sweetpotato (Ipomoea batatas [L.] Lam) in Response to Potassium Deficiency Stress.

Plants can adapt to the spatial heterogeneity of soil nutrients by changing the morphology and architecture of the root system. Here, we explored the role of auxin in the response of sweetpotato roots to potassium (K+) deficiency stress. Two sweetpotato cultivars, Xushu 32 (low-K-tolerant) and Ningzishu 1 (low-K-sensitive), were cultured in low K+ (0.1 mmol L-1, LK) and normal K+ (10 mmol L-1, CK) nutrient solutions. Compared with CK, LK reduced the dry mass, K+ content, and K+ accumulation in the two cultivars, but the losses of Xushu 32 were smaller than those of Ningzishu 1. LK also affected root growth, mainly impairing the length, surface area, forks number, and crossings number. However, Xushu 32 had significantly higher lateral root length, density, and surface area than Ningzishu 1, closely related to the roots' higher indole-3-acetic acid (IAA) content. According to the qPCR results, Xushu 32 synthesized more IAA (via IbYUC8 and IbTAR2) in leaves but transported and accumulated in roots through polar transport (via IbPIN1, IbPIN3, and IbAUX1). It was also associated with the upregulation of auxin signaling pathway genes (IbIAA4 and IbIAA8) in roots. These results imply that IAA participates in the formation of lateral roots and the change in root architecture during the tolerance to low K+ stress of sweetpotato, thus improving the absorption of K+ and the formation of biomass.

Transcriptome Characterization and Gene Changes Induced by Fusarium solani in Sweetpotato Roots.

Sweetpotato (Ipomoea batatas) is an important root crop that is infected by Fusarium solani in both seedling and root stages, causing irregular black or brown disease spots and root rot and canker. This study aims to use RNA sequencing technology to investigate the dynamic changes in root transcriptome profiles between control check and roots at 6 h, 24 h, 3 days, and 5 days post-inoculation (hpi/dpi) with F. solani. The results showed that the defense reaction of sweetpotato could be divided into an early step (6 and 24 hpi) without symptoms and a late step to respond to F. solani infection (3 and 5 dpi). The differentially expressed genes (DEGs) in response to F. solani infection were enriched in the cellular component, biological process, and molecular function, with more DEGs in the biological process and molecular function than in the cellular component. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the main pathways were metabolic pathways, the biosynthesis of secondary metabolites, and carbon metabolism. More downregulated genes were identified than upregulated genes in the plant-pathogen interaction and transcription factors, which might be related to the degree of host resistance to F. solani. The findings of this study provide an important basis to further characterize the complex mechanisms of sweetpotato resistance against biotic stress and identify new candidate genes for increasing the resistance of sweetpotato.

EFFECT OF TILLAGE PRACTICES AND FERTILIZER RATES ON GROWTH, AND YIELD OF SWEET POTATO (IPOMEA BATATA)

A field experiment was conducted at the Research Farm of National Root Crops Research Institute Sub-Station, Igbariam to study the effect of tillage practices and fertilizer application rates on the growth and productivity of sweet potato (var. Umuspo1) during the 2021 and 2022 cropping seasons. The experiment was set up as a 4 × 3 factorial fitted in a randomized complete block design (RCBD) with three replications. The main factor comprised four levels of fertilizer rates (0, 200, 400, and 600 NPK 20:10:10/ha) while the sub-factor consisted of three tillage methods (flats, mounds, and ridges). Data collected on the growth and yield of the crop were subjected to analysis of variance (ANOVA) using Genstat 4TH Edition statistical software. The significant means were separated using the least significant difference (LSD) at a 5% probability level. The result indicated that tillage practice had a significant effect on vine length in the 2021 and 2022 cropping seasons whereas the number of leaves showed no significant difference. On the other hand, tillage practice had significant effect on number of roots in the 2022 cropping season. The result obtained on the length of root indicated that both tillage practices and fertilizer application rates had no significant effect on sweet potato root length in the 2021 and 2022 cropping seasons. However, the results on the yield showed that ridges had the best performance in almost all the yield parameters while the application of fertilizer at the rate of 200 kg/ha gave the highest yield.

Biochemical responses to chilling injury in sweet potato after cold storage

This study examined biochemical changes associated with chilling injury (CI) in sweet potato roots stored at low temperatures and reconditioned at ambient temperature. Sweet potato cultivars BRS Amélia and BRS Rubissol were stored at 6 or 13°C for 4 days at ambient temperature (“ambient reconditioning”: 21 ± 2°C). CI on the outer surface of the roots occurred earlier in BRS Amélia than in BRS Rubissol. The CI index on the inner surface of the BRS Amélia was higher when it was stored at 6°C for 40 + 4 days. BRS Amélia showed higher proline content and electrolyte leakage when stored at 6°C. Ascorbate peroxidase was induced by storage at 6°C for 30 + 4 days in BRS Amélia and from 40 + 4 days in BRS Rubissol. The malondialdehyde and phenolic compounds of BRS Rubissol increased during storage at 6°C. CI in both cultivars was associated with increased peroxidase and polyphenol oxidase activities. Storage of sweet potato cultivars at 6°C for 50 + 4 days caused severe damage to the roots. Cultivars BRS Amélia and BRS Rubissol showed similar symptoms of CI and can be characterized as being sensitive to low temperatures.

Comparative proteome profiling in the storage root of sweet potato during curing-mediated wound healing

Comparative proteome profiling in the storage root of sweet potato during curing-mediated wound healing

Integrated metabolic and transcriptional analysis reveals the role of carotenoid cleavage dioxygenase 4 (IbCCD4) in carotenoid accumulation in sweetpotato tuberous roots

BackgroundPlant carotenoids are essential for human health, having wide uses in dietary supplements, food colorants, animal feed additives, and cosmetics. With the increasing demand for natural carotenoids, plant carotenoids have gained great interest in both academic and industry research worldwide. Orange-fleshed sweetpotato (Ipomoea batatas) enriched with carotenoids is an ideal feedstock for producing natural carotenoids. However, limited information is available regarding the molecular mechanism responsible for carotenoid metabolism in sweetpotato tuberous roots.ResultsIn this study, metabolic profiling of carotenoids and gene expression analysis were conducted at six tuberous root developmental stages of three sweetpotato varieties with different flesh colors. The correlations between the expression of carotenoid metabolic genes and carotenoid levels suggested that the carotenoid cleavage dioxygenase 4 (IbCCD4) and 9-cis-epoxycarotenoid cleavage dioxygenases 3 (IbNCED3) play important roles in the regulation of carotenoid contents in sweetpotato. Transgenic experiments confirmed that the total carotenoid content decreased in the tuberous roots of IbCCD4-overexpressing sweetpotato. In addition, IbCCD4 may be regulated by two stress-related transcription factors, IbWRKY20 and IbCBF2, implying that the carotenoid accumulation in sweeetpotato is possibly fine-tuned in responses to stress signals.ConclusionsA set of key genes were revealed to be responsible for carotenoid accumulation in sweetpotato, with IbCCD4 acts as a crucial player. Our findings provided new insights into carotenoid metabolism in sweetpotato tuberous roots and insinuated IbCCD4 to be a target gene in the development of new sweetpotato varieties with high carotenoid production.

Modulation of anthocyanin accumulation in storage roots of sweetpotato by transcription factor IbMYB1-2 through direct binding to anthocyanin biosynthetic gene promoters

The storage roots of purple-fleshed sweetpotato rich in anthocyanins are considered nutrient-rich foods with health effects. However, the molecular mechanism underlying anthocyanin biosynthesis and regulation remains to be revealed. In this study, IbMYB1-2 was isolated from purple-fleshed sweetpotato “Xuzishu8”. The phylogenetic and sequence analysis indicated that IbMYB1-2 belongs to the SG6 subfamily with a conserved bHLH motif. Subcellular localization analysis and transcriptional activity assay revealed that IbMYB1-2 is a key transcriptional activator and is specific to the nucleus. Agrobacterium rhizogenes-mediated overexpression of IbMYB1-2 in sweetpotato through in vivo root transgenic system led to an increase in anthocyanins in the root of sweetpotato. qRT-PCR and transcriptome analysis depicted that the transcript levels of IbMYB1-2, IbbHLH42, and eight structural genes that are associated with the synthesis of anthocyanin were upregulated in overexpressed IbMYB1-2 transgenic roots. Dual-luciferase reporter (DLR) assay and yeast one-hybrid (Y1H) assay demonstrated IbMYB1-2 binding to the promoter regions of IbbHLH42 and other anthocyanin biosynthetic genes, including IbCHS, IbCHI, IbF3H, IbDFR, IbANS, IbGSTF12, IbUGT78D2, and IbUF3GT. Moreover, IbbHLH42 was shown to be an active enhancer for the formation of MYB-bHLH-WD40 (MBW) complex, which strongly supports the promoter activities of the IbCHS, IbANS, IbUGT78D2, and IbGSTF12 genes to induce anthocyanin accumulation. Taken together, our findings not only revealed the underlying regulatory molecular mechanism of IbMYB1-2 for anthocyanin accumulation in the storage roots of sweetpotato but also uncovered a potential mechanism by which IbbHLH42 modulated anthocyanin biosynthesis through a positive feedback regulatory loop.

Cooking sweetpotato roots increases the in vitro bioaccessibility of phytochemicals and antioxidant activities, but not vitamin C

The percent bioaccessibility of phytochemicals and antioxidant activities (ABTS and FRAP) of cooked sweetpotato storage roots (peeled and unpeeled) of varying flesh colours was assessed in vitro. Generally, the phytochemicals’ bioaccessibility increased with cooking compared to the raw roots, except in vitamin C. The raw roots had vitamin C bioaccessibility of 92 %, while for cooked, it ranged between 61 % (baking) and 73 % (frying). For phenolics and flavonoids, peeling the roots significantly (P < 0.001) increased bioaccessibility by 11 % and 4 %, respectively. For the other phytochemicals, the bioaccessibility of peeled roots did not differ significantly (P > 0.05) from unpeeled ones. Cooked roots had higher antioxidant activities than in raw. Vitamin C may have acted as a pro-oxidant as it was the only phytochemical with inverse relation with antioxidant activities. Boiling, steaming, baking, frying, or microwaving sweetpotato roots increases the in vitro bioaccessibility of phytochemicals and antioxidant activities, but not vitamin C.

Isolation, characterization, and functional verification of salt stress response genes of NAC transcription factors in Ipomoea pes-caprae.

Adverse environmental stress is a major environmental factor threatening food security, which is why improving plant stress resistance is essential for agricultural productivity and environmental sustainability. The NAC (NAM, ATAF, and CUC) transcription factors (TFs) play a dominant role in plant responses to abiotic and biotic stresses, but they have been poorly studied in Ipomoea pes-caprae. In this research, 12 NAC TFs, named IpNAC1-IpNAC12, were selected from transcriptome data. The homologous evolution tree divided IpNACs into four major categories, and six IpNACs were linearly associated with Arabidopsis ANAC genes. From the gene structures, protein domains, and promoter upstream regulatory elements, IpNACs were shown to contain complete NAC-specific subdomains (A-E) and cis-acting elements corresponding to different stress stimuli. We measured the expression levels of the 12 IpNACs under abiotic stress (salt, heat, and drought) and hormone treatment (abscisic acid, methyl jasmonate, and salicylic acid), and their transcription levels differed. IpNAC5/8/10/12 were located in the nucleus through subcellular localization, and the overexpressing transgenic Arabidopsis plants showed high tolerance to salt stress. The cellular Na+ homeostasis content in the mature and elongation zones of the four IpNAC transgenic sweetpotato roots showed an obvious efflux phenomenon. These conclusions demonstrate that IpNAC5/8/10/12 actively respond to abiotic stress, have significant roles in improving plant salt tolerance, and are important salt tolerance candidate genes in I. pes-caprae and sweetpotato. This study laid the foundation for further studies on the function of IpNACs in response to abiotic stress. It provides options for improving the stress resistance of sweetpotato using gene introgression from I. pes-caprae.

Comprehensive Evaluation of Raw Eating Quality in 81 Sweet Potato (Ipomoea batatas (L.) Lam) Varieties.

The raw eating quality of sweet potato is complex. As consumers start paying more attention to the raw eating quality of tuberous roots in sweet potato, the evaluation of the raw eating quality of sweet potato is becoming an important issue. Therefore, we measured 16 quality indicators in 81 varieties of sweet potato. It was found that these 16 quality traits had different coefficients of variation (C.V.). Among them, the C.V. of fructose, glucose, and adhesiveness were the largest: 87.95%, 87.43% and 55.09%, respectively. The cluster analysis method was used to define six categories of the different tuberous roots of sweet potato. Group I, III, and IV had a stronger hardness and higher starch and cellulose content. Groups II, V, and VI were softer, with a high moisture and soluble sugar content. The principal component analysis method was used to comprehensively evaluate 16 quality indicators of 81 sweet potato varieties. It was found that Futian1, Taishu14, and Nanshu022 are good varieties in terms of raw eating quality. These varieties have low hardness, high adhesiveness in texture, high soluble sugar content, and low starch and cellulose. Future research should focus on improving the raw eating quality of sweet potato by reducing hardness, starch, and cellulose, while increasing adhesiveness, soluble sugar, and moisture content.

Effect of potassium intake on cadmium transporters and root cell wall biosynthesis in sweet potato

Large areas of farmland soil in southern China are deficient in potassium (K) and are contaminated with cadmium (Cd). Previously, we suggested that the K supplementation could reduce Cd accumulation in sweet potatoes (Ipomoea batatas (L.) Lam). In the present study, we investigated the underlying physiological and molecular mechanisms. A hydroponic experiment with different K and Cd treatments was performed to compare the transcriptome profile and the cell wall structure in the roots of sweet potato using RNA sequencing, Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The results showed that K supply inhibits the expressions of IRT1 and YSL3, which are responsible for root Cd uptake under Cd exposure. Furthermore, the expressions of COPT5 and Nramp3 were downregulated by K, which increased Cd retention in the root vacuoles. The upregulation of POD, CAD, INT1 and SUS by K contributed to lignin and cellulose biosynthesis and thickening of root xylem cell wall, which further reduced Cd translocation to the shoot. In addition, K affected the expressions of LHT, ACS, TPS and TPP associated with the production of ethylene and trehalose, which involved in plant resistance to Cd toxicity. In general, K application could decrease the uptake and translocation of Cd in sweet potatoes by regulating the expression of genes associated with Cd transporters and root cell wall components.

Reducing Pb accumulation in roots of sweet potato under low lead-contaminated soil by Azotobacter inoculation

Agricultural soil is possibly threatened by lead (Pb) contamination due to the intensive use of fertilizers. The rhizobacteria were recommended for the bioremediation of soils contaminated by low concentrations of Pb. The experiment was conducted to observe the Azotobacter's ability to proliferate in Pb-contaminated broth and to decrease the Pb availability in soil, Pb uptake by sweet potato roots, and sweet potato growth. The resistance test was performed by growing five Azotobacter isolates in N-free broth with various Pb levels. A pot experiment was conducted in a factorial randomized block design to test three levels of Pb in soil and two Azotobacter isolates. The results showed that Azotobacter Azv4 and &lt;em&gt;A. choroococcum&lt;/em&gt; were resistant to 100 mg L&lt;sup&gt;-1&lt;/sup&gt; Pb in N-free broth. In the pot experiment, Azotobacter Azv4 Inoculation caused less Pb in soil and roots of sweet potatoes grown in Pb-contaminated soil than &lt;em&gt;A. choroococcum&lt;/em&gt;. Either Azotobacter or Pb soil did not influence vine length. However, Azv4 was more prominent in increasing branch number, root volume and length; higher Pb in soil reduced branch number but did not affect root parameters. Azotobacter Azv4 increased more shoot and root dry weight compared to &lt;em&gt;A. choroococcum,&lt;/em&gt; but both isolates did not change the shoot-to-root ratio (S/R). The Pb contamination only reduced root dry weight and reduced the S/R. This research considered utilizing rhizobacteria Azotobacter for reducing Pb levels in soil and roots; and increasing sweet potato biomass.

ASSESSMENT OF CAUSES AND EXTENT OF POST-HARVEST LOSSES OF WHITE SWEET POTATO ROOTS DURING STORAGE IN MOROGORO REGION, TANZANIA

Many studies have revealed that losses of sweet potatoes occur due to mechanical injury, high moisture content of the roots, attack by rodents, physiological spoilage and weevil. This study was conducted to assess the causes and extent of post-harvest losses of white-coloured sweet potato roots during storage in Gairo district and Morogoro municipality in Morogoro region, Tanzania. The assessment was conducted in eight (8) wards of the two areas by using a questionnaire to capture data on bio-data of farmers’ and traders’, awareness of white-coloured sweet potato root losses and storage practices. The collected data were analyzed using Statistical Package for Social Science (SPSS) version 25. According to the findings, the most major cause of post-harvest losses was rodent attack, which was reported by 26.53% and 25% of farmers and traders in Gairo and Morogoro municipalities, respectively, and the extent of white-coloured sweet potato root losses observed was 18.36% of farmers and traders in Gairo and 79% of farmers and traders in Morogoro municipality have reported to suffer from moderate post-harvest losses. The study results indicate that there is a need to improve post-harvest loss awareness among white-colored sweet potato farmers and traders in order to reduce loss and thus begin producing profitably. Controlling rodents, avoiding injury, building a proper storage facility and inspecting the stores on a regular basis are the most important aspects to consider when preventing losses

FUNCTIONAL, PASTING AND SENSORY PROPERTIES OF COMPLEMENTARY FOOD FROM ORANGE FLESHED SWEETPOTATO- ROASTED AFRICAN YAM BEAN-TIGERNUT COMPOSITE FLOUR USING RESPONSE SURFACE METHODOLOGY

This study investigated the functional, pasting and sensory properties of complementary food from blends of orange fleshed sweet potato, roasted African yam bean and tigernut composite flour using response surface methodology. Orange fleshed sweetpotato root, roasted African yam bean and tigernut seed were blended into composite flours based on D-optimal mixture design resulting into fourteen experimental runs. The Orange fleshed sweetpotato, roasted African yam bean and tigernut flour blends were analyzed for their functional and pasting properties using standard laboratory procedures. The composite flours were optimized using D-optimal of the mixture design. The optimized composite flours were used to prepare complementary food and sensory properties (taste, colour, aroma, thickness and overall acceptability) were evaluated using nine point Hedonic scale of preference. The bulk density, water absorption capacity, swelling power, dispersibility, least gelation capacity and wettability ranged from 0.82-0.85g/ml, 300.00-359.00%, 6.00-6.51%, 60.20-65.99%, 2.72-3.69% and 22.71to 40.81% respectively. Significant differences (p&lt;0.05) were observed in the pasting properties of orange fleshed sweetpotato, roasted African yam bean and tigernut flour blends. However optimized complementary prepared from the different composite flours were all accepted by the panelists except complementary food prepared from 82.95% orange fleshed sweetpotato, 10.26% roasted African yam bean and 6.78% tigernut composite flour blend.