Content Of Sweet Potato Research Articles

Development of NIRS models for rapid quantification of protein content in sweetpotato [Ipomoea batatas (L.) LAM.

Near-infrared spectroscopy (NIRS) is an alternative analytical method that can be used to quantify protein content in sweetpotato. It is relatively cheaper and efficient than other methods. This study was conducted to develop NIRS-based models for quantifying protein content of sweetpotato for selection or wide-area production of recommended varieties. A pool of 104 sweetpotato varieties were sampled and roots scanned using NIR spectrometer. Calibration models were developed by subjecting spectral and reference datasets to partial least squares regression. Several pre-processing methods were investigated. Models that yielded the highest coefficient of determination (R2), residual predictive deviation (RPD) and lowest root mean square error of calibration (RMSEC) and prediction (RMSEP) were selected. Optimal model performances were obtained using second derivative pre-processing, showing the highest values of R2v, RMSEP and RPDv of 0.98, 0.29, and 4.0, respectively. The regression analysis indicated that informative NIR bands for quantifying protein content of sweetpotatoes ranged between 1600 and 2200 nm. The results demonstrated that NIRS is capable of predicting protein content on sweetpotatoes, rapidly and accurately. Therefore, the NIRS model developed in this study may help to quantify protein composition of sweetpotato for rapid screening of germplasm in breeding programs with high throughput and accuracy.

Effect of different levels of sweet potato paste on physico-chemical properties of <italic>kheer</italic>

<italic>Kheer</italic> is sweetened dish of rice cooked in milk first finds mention as ‘<italic>Payas</italic>’. Sweet potato <italic>kheer</italic> was prepared from different levels of sweet potato paste <italic>viz</italic>. 2.5, 5.0 and 7.5 per cent on the basis of buffalo milk. Control <italic>kheer</italic> was prepared using 2.5 per cent rice in buffalo milk. The parameters considered for the present study were pH, viscosity, moisture, fat, protein, total solids and ash. The result showed that control <italic>kheer</italic> was significantly superior over <italic>kheer</italic> prepared from 2.5% sweet potato. PH was decreasing as the level of sweet potato paste increases. On the contrary as the level of sweet potato increased the viscosity also increased significantly. The moisture content of sweet potato <italic>kheer</italic> decreased as the level of sweet potato increased. As fat was concerned as the level of sweet potato increaseed the fat decreased with non significant effect. Similarly slight protein was also increased. However carbohydrate, total solids and ash content of <italic>kheer</italic> increased as the level of sweet potato increased with non-significant effect. The total solid, carbohydrate and ash content of sweet potato <italic>kheer</italic> increases whereas moisture and fat decreased as the level sweet potato increased. This might be due to higher carbohydrate and lower moisture content in sweet potato as compared to milk.

Sucrose, Reducing Sugars,and Carotenoid Content of Aceh Besar Sweet Potato Cultivars (Ipomoea batatas L)

Sweet potato is considered as an important food crop and it is known as one of the most productive carbohydrate-producing crop. This crop requires less inputs and water in comparison to rice, corn, or potato. Its wide adaptation to various agro ecological conditions has made sweet potato as a promising crop for saving life particularly during food (rice) shortage. The crop contained higher vitamin (A) and minerals that could help women and children aged below five preventing certain diseases. However, the nutritional value of sweet potato is various from one cultivar to another. It was assumed that geographical and environmental factors would influence the nutritional value of the tubers. Therefore, the following study was investigating the nutritional value of local cultivars in Aceh Besar District. Total carotenoid content of sweet potato varied from 1.86to 3.06 mg 100g-1 DM. The highest carotenoid was recorded by cv. Keupila from Saree Sub-district.

Identification of QTLs for Starch Content in Sweetpotato (Ipomoea batatas (L.) Lam.)

Sweetpotato (Ipomoea batatas (L.) Lam.) breeding is challenging due to its genetic complexity. In the present study, interval mapping (IM) and multiple quantitative trait locus (QTL) model (MQM) analysis were used to identify QTLs for starch content with a mapping population consisting of 202 F1 individuals of a cross between Xushu 18, a cultivar susceptible to stem nematodes, with high yield and moderate starch, and Xu 781, which is resistant to stem nematodes, has low yield and high starch content. Six QTLs for starch content were mapped on six linkage groups of the Xu 781 map, explaining 9.1–38.8% of the variation. Especially, one of them, DMFN_4, accounted for 38.8% of starch content variation, which is the QTL that explains the highest phenotypic variation detected to date in sweetpotato. All of the six QTLs had a positive effect on the variation of the starch content, which indicated the inheritance derived from the parent Xu 781. Two QTLs for starch content were detected on two linkage groups of the Xushu 18 map, explaining 14.3 and 16.1% of the variation, respectively. They had a negative effect on the variation, indicating the inheritance derived from Xu 781. Seven of eight QTLs were co-localized with a single marker. This is the first report on the development of QTLs co-localized with a single marker in sweetpotato. These QTLs and their co-localized markers may be used in marker-assisted breeding for the starch content of sweetpotato.

The influential research of processing method and extraction factors on the soluble sugar content of sweet potato

The effect of steaming, baking and frying on the soluble sugar content and moisture of sweet potato was investigated.In baking and cooking processing, the soluble sugar content of sweet potato first increased, then decreased, and rose again in processing end-stage.Being steamed, the content of soluble sugar in sweet potato increased first and then reduced. While the content of soluble sugar declined in fried process. Steaming, boiling, and roast didn't make great impact on the moisture content in sweet potato.But in fried process, moisture content of sweet potato continued to decrease as the heating time increased. The influence of extraction about temperature, time, and Liquid ratio on the extraction amount of soluble sugar was discussed by single factor and orthogonal test method.The results showed that under the condition of the steamed for 24min, liquid ratio made the greatest impact on the extraction of soluble sugar, followed by the temperature, and time was the last.The optimum technological conditions in which water soluble sugar extracted were liquid ratio 1g∶200mL, extraction time of 20min and the extraction temperature of 40℃, and the extraction rate is 41.03%.When being baked for 40min, liquid ratio also made the greatest impact on the extraction of soluble sugar, then the temperature, and last was the time.The optimum technological conditions were liquid ratio 1g ∶ 250mL, extraction time of 30min and the extraction temperature of 50℃, and the extraction rate is 51.31%.

쌀가루 첨가량에 따른 자색고구마 머핀의 품질특성

In this study, purple sweet potato muffins were made with the addition of 0, 25, 50, 75, and 100% rice flour, and their quality characteristics were determined. The weight and height increased with the increase in the amount of rice flour added. The moisture contents decreased significantly. As the amount of rice flour added increased, the pH and acidity decreased. The lightness and yellowness of the rice flour decreased significantly, but the redness increased with increasing purple sweet potato content. The textural properties, such as the cohesiveness, chewiness, and brittleness, were significantly lower in the groups with added rice flour. The DPPH radical scavenging activity was significantly higher in the purple sweet potato muffins to which 50 and 75% rice flour were added compared to those in the control. The results of the sensory evaluation showed that there was no significant difference in flavor among the samples. The chewiness was higher with 50, 75, and 100% rice flour than with 0 and 25% rice flour. The groups with 50 and 75% rice flour had significantly higher scores for overall acceptability compared to the control group.

Down-regulation of β-carotene hydroxylase increases β-carotene and total carotenoids enhancing salt stress tolerance in transgenic cultured cells of sweetpotato

Sweetpotato (Ipomoea batatas Lam.) is an important industrial crop and source of food that contains useful components, including antioxidants such as carotenoids. β-Carotene hydroxylase (CHY-β) is a key regulatory enzyme in the beta–beta-branch of carotenoid biosynthesis and it catalyzes hydroxylation into both β-carotene to β-cryptoxanthin and β-cryptoxanthin to zeaxanthin. To increase the β-carotene content of sweetpotato through the inhibition of further hydroxylation of β-carotene, the effects of silencing CHY-β in the carotenoid biosynthetic pathway were evaluated. A partial cDNA encoding CHY-β was cloned from the storage roots of orange-fleshed sweetpotato (cv. Shinhwangmi) to generate an RNA interference-IbCHY-β construct. This construct was introduced into cultured cells of white-fleshed sweetpotato (cv. Yulmi). Reverse transcription-polymerase chain reaction analysis confirmed the successful suppression of IbCHY-β gene expression in transgenic cultured cells. The expression level of phytoene synthase and lycopene β-cyclase increased, whereas the expression of other genes showed no detectable change. Down-regulation of IbCHY-β gene expression changed the composition and levels of carotenoids between non-transgenic (NT) and transgenic cells. In transgenic line #7, the total carotenoid content reached a maximum of 117μg/g dry weight, of which β-carotene measured 34.43μg/g dry weight. In addition, IbCHY-β-silenced calli showed elevated β-cryptoxanthin and zeaxanthin contents as well as high transcript level P450 gene. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH) in transgenic cells was more than twice that in NT cells. RNA-IbCHY-β calli increased abscisic acid (ABA) content, which was accompanied by enhanced tolerance to salt stress. In addition, the production of reactive oxygen species measured by 3,3′-diaminobenzidine (DAB) staining was significantly decreased in transgenic cultured cells under salt stress. Taken together, the present results indicate that down-regulation of IbCHY-β increased β-carotene contents and total carotenoids in transgenic plant cells and enhanced their antioxidant capacity.

Effect of heat treatment on quality, thermal and pasting properties of sweet potato starch during yearlong storage

Proper postharvest handling and storage of sweet potato is an important link in the chain from producer to consumer or manufacturing industry. Heat treatments have been used as a non-chemical means to modify the postharvest quality and reduce pathogen levels and disease development of a wide variety of horticultural products. The objective of this study was to investigate the effects of hot water treatment (HWT) on the quality, gelatinisation enthalpy and pasting properties of sweet potato starch during long-term storage. The weight loss, sprouting, spoilage and sugar content of sweet potato were also determined. HWT significantly inhibited the sprouting and decay of sweet potato during the storage period. There were no significant differences (P < 0.05) in the pasting properties and onset (T(O)), peak (T(P)) and endset (T(E)) temperatures of gelatinisation of sweet potato starch among all treatments, especially between heat-treated and non-heat-treated samples. HWT also had no significant impact on the quality of the internal components of the roots. Less than 4% of the yearlong-stored roots were discarded owing to spoilage. HWT supplied a lethal dose of heat to surface pathogens and black spot without damaging the nutritional and processing qualities of sweet potato. HWT was an effective method to reduce root sprouting and deterioration without significant impact on the quality of the internal components of sweet potato. This novel technique will open a new avenue to extend the storage life of sweet potato with good quality and minimal waste.

한국산 고구마의 품종별 항돌연변이 효과

22종의 고구마에 대한 총 페놀함량 및 항돌연변이원성을 평가하였다. 17종의 비자색고구마 중 수, 하얀미, 신황미 품종의 총 페놀함량이 21.4, 21.5, 20.3 ㎍(GEA/g dried sweet potato)으로 가장 높았으며, 맛나미와 연황미 품종에서 4.6과 4.8 ㎍으로 가장 낮았다. 5종의 자색고구마에서 총 페놀함량은 자미 품종이 128.3 ㎍으로 가장 높았으나, 신자미 품종에서 44.9 ㎍으로 가장 낮았다. 1-NP, daunomycin, Trp-P-1, Trp-P-2, 2-AA에 의해 돌연변이가 유도된 S.Typhimurium TA 98과 1-NP에 의해 돌연변이가 유도된 S.Typhimurium TA 100에 있어서 돌연변이 억제효과는 고구마 메탄올 추출물은 대체적으로 효과적이었으며, 자색고구마에 있어서는 자미와 아야무라사키 품종에서 높았다. 총 페놀함량이 많은 자색고구마는 2-AA에 대해서만 높은 돌연변이 억제효과를 나타내었을 뿐 1-NP, daunomycin, Trp-P-1, Trp-P-2에 대해서는 비자색고구마와 뚜렷한 차이를 보이지 않았다. 자색고구마 품종 간에 있어서는 총 페놀함량이 많을수록 돌연변이 억제효과가 높았다. 고구마의 품종별 항돌연변이 효과는 총 페놀 함량보다는 사용된 돌연변이원 및 균주에 따라 좌우되는 경향이었다.

Hot Air Drying Characteristics of Sweet Potato Using Moisture Sorption Isotherm Analysis and Its Quality Changes During Drying

Changes in the quality of sweet potato during hot air drying, such as L-ascorbic acid, sugar content, surface color and hardness, and drying characteristics, were investigated at temperatures of 30, 40, 50, and 60°C. Equilibrium moisture contents (EMC) of sweet potato samples in the desorption process were measured by a static method at the four aforementioned temperatures and six selected relative humidity levels. Using both the measured moisture content data in the drying test and the EMC values, hot air drying characteristics of sweet potato was estimated. Changes in L-ascorbic acid content of sweet potato during hot air drying was measured, wherein a first-order reaction rate equation was applied to model the change in decomposition of L-ascorbic acid content. In addition, surface color, sugar content, and surface hardness were also measured. The total color change (?E) of the samples was observed to decrease as drying temperature was increased. The effects of sample sugar concentration on surface hardening during hot air drying of sweet potato are discussed.

The Potential Contribution of Bread Buns Fortified with β-Carotene–Rich Sweet Potato in Central Mozambique

Orange-fleshed sweet potato is an efficacious source of vitamin A. Substituting wheat flour with orange-fleshed sweet potato in processed products could reduce foreign exchange outlays, create new markets for producers, and result in increased vitamin A consumption among consumers provided there is adequate retention of beta-carotene during processing. To explore whether substituting 38% of wheat flour (by weight) in bread buns ("golden bread") with boiled and mashed orange-fleshed sweet potato from fresh roots or rehydrated chips would produce economically viable beta-carotene-rich products acceptable to Mozambican rural consumers. Modified local recipes maximized sweet potato content within the limits of consumer acceptability. Sensitivity analysis determined parameters underlying economic viability. Two samples each of buns from five varieties of orange-fleshed sweet potato were analyzed for beta-carotene content. Processed products with at least 15 microg/g product of trans-beta-carotene were considered good sources of vitamin A. Golden bread made from fresh roots of medium-intensity orange-fleshed sweet potato varieties met the good source criterion, but bread from lighter-intensity sweet potato varieties did not. Bread from rehydrated dried chips was not economically viable. Consumers strongly preferred golden bread over pure wheat flour bread because of its heavier texture and attractive appearance. The ratio of the price of wheat flour to that of raw sweet potato root varied from 3.1 to 3.5 among the bakers, whose increase in profit margins ranged from 54% to 92%. Golden bread is a good source of beta-carotene and is economically viable when the price ratio of wheat flour to raw orange-fleshed sweet potato root is at least 1.5. Widespread adoption during sweet potato harvesting periods is feasible; year-round availability requires storage.

Studies on the Breeding for Improving Starch Properties in Sweet Potato

To develop new uses for sweet potato starch, we studied about breeding for improving starch properties in sweet potato. The amylose content of the germplasm collections of sweet potato ranged from 11.2 to 15.3%. There were varietal and geographical differences in the amylose content of sweet potato. Analysis of the varietal and annual variations in starch properties suggested that selection for pasting temperature, setback and amylose content can be effective. The variations of amylose content in sweet potato and its related diploid wild species could be increased by crossing and mutagenesis, and variants with a low/high amylose content could be selected. Furthermore, a new sweet potato cultivar was developed, featuring low gelatinization temperatures and altered starch fine structure. Gelatinization temperatures and pasting temperatures of Quick Sweet starch were approximately 20°C lower than those of ordinary sweet potato cultivars. The chain-length distribution of amylopectin showed that Quick Sweet starch had a higher proportion of short chains (DP6-11) than the ordinary cultivars. Starch retrogradation, evaluated by leaked water percentage and hardness of starch gels after cold storage, indicated that Quick Sweet starch had excellent cold storage stability.

Antioxidant Activity and Optimal Manufacturing Conditions of Purple Sweet Potato Lactic Acid Bacteria Drink

In the current studies, we produced a purple sweet potato lactic acid bacteria drink (PSPLABD) using a variety of lactic acid bacterial strains. The various PSPLABD were analyzed for color, pH, and flavor. We found that Lactobacillus helveticus B-1 was the most efficient strain for fermentation. In addition, optimal conditions included a purple sweet potato content of 10%, a skim milk content of 7%, a white sugar content of 7.5%, fermentation at 35°C, and a pH adjusted to 3.5 (fermentation time ∼24 h). PSPLABD had 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity (IC50 = 130 μl) and inhibited lipid peroxidation (equivalent to 103 μM butylated hydroxytoluene). Fermentation had no effect on the antioxidant activity of PSPLABD, but the purple sweet potato and the lactic acid bacteria drink components had a synergistic effect on the inhibition of lipid peroxidation. Thus, the PSPLABD could be used as a health food which has antioxidant activity and an appealing flavor and color.

Proximate composition and some functional properties of extrusion cooked soybean and sweet potato blends.

Mixtures of sweet potato flour and soy flour were made in a pilot mixer. They were moisturized with 18, 25, and 30% water and extruded in a single screw extruder at 80 rpm, using a die of 6mm. Extrusion temperature was maintained at 100 +/- 3 degrees C. Effects of adding soy flour into sweet potato flour, as well as variation in feed moisture on the composition and some functional properties of the extrudates were investigated. Increase in sweet potato content increased carbohydrate values. Protein increased with increase in soy flour. Feed moisture did not significantly (p < or = 0.05) affect extrudate composition. Increase in sweet potato content and feed moisture increased expansion ratio. Bulk density decreased with decrease in feed moisture, but increased with increase in soy flour. Starch content increased as sweet potato content increased. Degree of gelatinization increased with sweet potato content. Lower feed moisture enhanced gelatinization. Water absorption index (WAI) increased as sweet potato content increased. Feed moisture had a slight effect on WAI and water solubility index (WSI). Amylose increased with increase in sweet potato content. Increase in soy flour led to an increase in yellowness (b*) of extrudates.

NUTRIENT UPTAKE OF SWEETPOTATO CULTIVARS

The uptake of nutrients by sweetpotato (Ipomoea batatas) is critical in determining crop yield. Research was conducted to assess the effects of gypsum application on the nutrient uptake in three sweetpotato cultivars; `Carver II', `Georgia Jet' and `Jewel'. Gypsum application did not influence leaf P content of sweetpotato. However application of 3 tons per acre of gypsum increased leaf N and K content in `Carver II' and `Jewel' at 60 and 90 days after planting. There was a similar increase observed in Ca and Mg content of the leaf. While rate of gypsum did not influence nutrient uptake, date of sampling significantly influenced leaf nutrient concentration. It was noted that leaf K for `Jewel' and Ca for `Carver II' were greatest at 60 days after planting. Overall, Mg content was decreased following the application of gypsum in both `Carver II' and `Georgia Jet' cultivars.

Effect of cooking on nutrient content of tropical root crops from the south pacific

AbstractThe changes in nutrient content of sweet potato (Ipomoea batatas), taro (Colocasia esculenta), yam (Dioscorea alata) and cassava (Manihot esculenta) as a result of boiling, steaming and baking were determined. These changes were similar for all root crops (except in the case of sweet potato) and may be explained largely in terms of breakdown of nutrients with heat and in solubilisation of water‐soluble constituents. Major changes observed were (1) an approximate doubling of the apparent dietary fibre content due to formation on cooking of starch which was resistant to degradation by the enzymes used in the starch assay procedure; (2) a decrease in the content of potassium by up to one‐fifth and smaller decreases of other water‐soluble salts; (3) a very large increase in the maltose content of sweet potato on cooking, which did not occur with the other root crops.In terms of human nutrition dry baking, generally speaking, appears to be the best method of cooking, followed by steaming, then boiling with retention of water and, finally, boiling with discarding of the water. However, in the particular cases of cassava and the edible aroids, which include taro, antinutritional factors may need to be removed by special cooking methods.

Carotene Content of Sweet Potato (Ipomoea batatas Lam.) Roots as Affected by Various Nematicide Treatments1

Abstract It has been reported (2, 3, 4) that the nematicides Nemagon and Telone C increased carotene content in carrots and sweet com. Since the carotene content of sweet potatoes is important nutritionally, an attempt was made to extend the observations to this crop and to various nematicides.

Changes in carbohydrate content of sweet potato in response to cutting and infection by black rot fungus.

Changes in carbohydrate content of sweet potato in response to cutting and infection by black rot fungus.

Studies on the Effects of Soil Physical Conditions on the Growth and Yield of Crop Plants : IV. Effects of the different soil Structures on a few plysiological characters of sweet potato plants.

These experiments were made on the relationship between the effects of soil structure on the growth and yield of sweet potato Plant, and a few physiological characteristics. The results obtained may be sammarized as follows. (1) By aggregating the soil, the growth of sweet potato plant was promoted and its total dry weight increased. As for the relationship between soil treatment and growth of different stage, it was found that the aggregate formation of the soil affected its growth in its late growth stage to a large extent and promoted especially the thickening of tuberous root. When the soil was made compact, the growth of the top parts of the plant became flourishing, but the thickening of its tuberous root was hampered considerably. (2) The authors examined the internal tissure of sweet potato's root in the aggregated soil treatment. As a result, it was found that the activity of cambium was vigorous and that the number of primary xylem was few. It was also observed that its root presented the condition liable to become tuberous root, and that the differentiation of root had advanced. (3) The nitrogen content of sweet potato was larger in the aggregated soil treatment than in the standard soil treatment, and the rate of soluble nitrogen content against total nitrogen content was liable to be higher in the standard soil treatment. (4) The phosphorylase and amylase activity in tuberous root of sweet potato was lower in its early growth stage, highest in its middle growth stage, and decreased slightly in its late growth stage. The value of isoelectric point of cell protoplasm of parenchyma in tuberous root was low in its early growth stage and became higher as its growth advanced. (5) With regard to the relationship between the soil managing methods and a few emyzme activities, phosphorylase activity was higher in the standard soil treatment in its early growth stage, but decreased in and after its middle growth stage, whereas amylase activity was higher in the aggregated soil treatment in its early growth stage but decreased in and after its middle growth stage. All this goes to show that the aggregated soil treatment offered more favourable internal conditions for the accumulation of starch in tuberous root than the standard soil treatment.