Orientador: Magali Leonel / Banca: Glauber José de Castro Gava / Banca: Regina Marta Evangelista / Resumo: O mercado de amido vem crescendo e se aperfeiçoando nos últimos anos, levando à busca de produtos com características específicas que atendam as exigências industriais. No presente trabalho objetivou-se avaliar a composição físico-química de tubérculos de batata e suas potencialidades industriais. Foram avaliadas oito cultivares: Beacon Chipper, BRS Ana, Colorado, Harley Beckhell, Marcy, Marlen, Pirassu e Snowden, cultivadas no município de Pouso Alegre/MG safra 2011. Os tubérculos foram caracterizados segundo os valores encontrados para teor de umidade, cinzas, proteína, fibra, matéria graxa, açúcares, amido, pH, acidez titulável e cor da casca e da polpa. Após a caracterização dos tubérculos, realizou-se a extração do amido e este foi avaliado quanto a composição centesimal, propriedades de pasta, propriedades térmicas, teor de minerais (P, K, Ca e Mg), teor de amilose aparente, pH e acidez titulável. Na caracterização da coloração dos tubérculos a cultivar Beacon Chipper apresentou maior brilho e maior intensidade do componente de cor amarela (b* positivo), as cultivares BRS Ana e Pirassu apresentaram os maiores valores para o componente de cor vermelha (a* positivo). As cultivares BRS Ana e Harley Beckhell apresentaram o maior teor de matéria seca. O maior e menor rendimento de extração de amido foi obtido com a cultivar Harley Beckhell e Colorado, respectivamente. O amido extraído dos tubérculos apresentou alto grau de pureza e a cultivar Beacon Chipper apresentou o menor teor de amilose aparente. O teor de fósforo foi elevado para as cultivares Marcy e Harley Beckhell, já para as cultivares BRS Ana e Pirassu o teor desse mineral foi menor. Nas propriedades de pasta a cultivar Marcy apresentou valores elevados para viscosidade máxima, quebra de viscosidade e tendência a retrogradação, que são... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The starch market has been growing and improving in recent years, leading to a search for products with specific characteristics that meet the industrial requirements. This work aimed to evaluate the physical and chemical composition of potato tubers (Solanum tuberosum L.) and its industrial potential. Eight cultivars were evaluated: Snowden, Harley Beckhell, Marlen, Colorado, BRS Ana, Pirassu, Beacon Chipper and Marcy grown in Pouso Alegre, Minas Gerais state, in 2011. Tubers were characterized to the moisture, ash, protein, fiber, lipids, sugars, starch, pH, titratable acidity and color of the peel and pulp. After characterization of the tubers, held the extraction of starch and this was evaluated for proximate composition, pasting properties, thermal properties, mineral content (P, K, Ca and Mg), content of apparent amylose, pH and titratable acidity . In characterizing the color of the tubers to cultivar Beacon Chipper showed higher brightness and greater intensity of the yellow color component (b* positive), the cultivars BRS Ana and Pirassu showed the highest values for the red color component (a* positive). The cultivars BRS Ana and Harley Beckhell showed the highest dry matter content. The highest and lowest... (Complete abstract click electronic access below) / Mestre

Soil Water Balance (SWB), is a generic and mechanistic crop growth model that has been successfully used to model the water balance of several crops. Its ability to combine crop water modelling and irrigation scheduling approaches allows it to be used as a research tool and an irrigation management tool. Since SWB is a tool that could be used as decision making tool for farmers, its accuracy in simulating crop growth, development and soil water balance should be high. To highlight the importance of improved irrigation management for potato crop by the means of a mechanistic soil water balance model and the importance of the photoperiod factor in potato modelling in sub-tropical region, two potato experiments were carried out in two contrasting seasons, namely, spring and autumn. Growth and development responses of potato under both well irrigated and water stressed conditions for spring and autumn plantings were examined. This study successfully quantified the water use and potato growth responses to water stress. The water use efficiency varied with irrigation treatments and planting time, and autumn experiment had generally higher values than spring. Unstressed treatment gave the highest tuber yields irrespective of planting season and marketable tuber yield was higher in autumn than spring. Water stress imposed at tuber initiation until end of tuber bulking was revealed to be the most detrimental to biomass and tuber production. This suggests that water stress at tuber initiation and bulking stage should be avoided if high tuber yield is the target. Growth analysis data were used to determine crop parameters for SWB calibration and validation. The model simulated reasonably well growth, development and soil water balance in both unstressed and stressed conditions. However, simulations results of total and harvestable dry matter towards the end of the exponential tuber bulking stage (50 - 65 DAP) were deteriorated. As a result, the model did not simulate accurately the final yield. This is an indication that the model fails to simulate the size of the canopy and its duration. The time at which tuber initiation commences appeared not be affected by the planting seasons since variation of the duration between emergence and tuber initiation in different seasons was small. This small variation could be attributed to the fact that the potato growing season in South Africa (Pretoria) in spring 2004 and autumn 2005 experiences minimum and maximum temperatures which are acceptable for the growth of potato. In Pretoria, emergence and tuberisation take place under relatively cool temperatures late in September and also early in April when temperatures are relatively cool. Consequently, potato grown in this period may escape the early autumn and late spring high temperatures. However, autumn planting experiences an abrupt change of day lengths from long days to short days towards tuber initiation. This brusque change of day length may change the crop physiology and affect the subsequent normal course of plant growth. If the day length factor could be integrated into SWB, it appears that the model will better simulate potato growth and development. The poor simulation results of total dry matter and harvestable dry matter early in the growing season suggest that the model should be improved by allowing it to simulate the start of tuber initiation. A linear function of average temperature between a base and an optimal temperature corrected with photoperiod factor was found to be the most appropriate method to estimate thermal time required for tuber initiation. This method suggests that the time of tuber initiation can be estimated from its thermal time within two days. / Dissertation (MSc (Soil Science))--University of Pretoria, 2007. / Plant Production and Soil Science / MSc / unrestricted

Thesis (M. A. Agricultural Management (Plant Production)) -- University of Limpopo, 2020 / Although potato seed priming in water is not allowed for quality-related reasons in tubers of the produced crop, it was viewed as necessary to use the technique as a carrier of active ingredients of phytonematicides, with the hope that should the technique work, then other solutions could be used for priming of potato tuber seeds. The objectives of this study were to investigate the feasibility of using potato seed tubers as carriers of cucurbitacin A, cucurbitacin B and momordin from triterpenoid- containing phytonematicides to improve management of nematode population densities in potato plants under greenhouse, microplot and field conditions, respectively. In single treatments (A1B0M0, A0B1M0 and A0M0B1), potato seed tubers were without any phytotoxicity in 3% solutions, in any two permutations (A1B1M0, A1B0M1 and A0M1B1) at 1.5% each and at three permutations (A1B1M1) at 1% each, for 7 h and then dried under shade for 2 h prior to planting. Twenty-cm-diameter plastic pots were filled with 2 700 ml growing medium under greenhouse conditions and placed on benches at 0.3 m × 0.2 m spacing. Under microplot 30-cm-diameter plastic pots were used and pots were then inserted into 20-cm-deep holes at 0. 5 m × 0.5 m spacing and under field conditions potato seed tubers were set at 30-cm-depth with a 0.6 m × 0.6 m spacing. A 2 × 2 × 2 factorial experiment was laid out in a randomised complete block design, with the eight treatments replicated 7 times. Nemarioc-AL (A), Nemafric-BL (B) and Mormodica (M) phytonematicides served as first, second and third factors, respectively. At 56 days after applying treatments, the A1B1M1 interactions were not significant on all plant variables under greenhouse and field conditions however under microplot the interaction was significant (P ≤ 0.05) on fresh tuber mass, fresh root mass and dry root mass, contributing 28, 26 and 26% in Total treatment variation (TTV) of the respective variables. In contrast, the A1B1M1 xxviii interactions were highly significant (P ≤ 0.01) on chlorophyll content, contributing 43 and 40% in TTV. Generally, relative to untreated control, the second and first order interactions, along with individual treatments, significantly increased fresh tuber mass by 31% relative to the untreated control, except for Nemarioc-AL × Mormodica and Nemafric-BL × Mormodica interactions which were not different to the untreated. The A0B1M1 interaction was highly significant on plant height, stem diameter, chlorophyll content, dry shoot mass, dry root mass and fresh tuber mass, contributing 45, 36, 37, 35, 60 and 35% in TTV of the respective variables under greenhouse conditions similar to the microplot experiment, the interaction relative to the untreated control, also did not have any effect on plant variables. However, under field conditions the first order interaction, A0B1M1, was highly significant on dry root mass, contributing 60% in TTV on the variable. Relative to untreated control, the interaction reduced dry root mass by 14%, which was not different to the effect of Mormodica phytonematicide at 13%, but was significantly different to that of Nemafric-BL phytonematicide. A1B0M1 interaction had significant effects on fresh tuber mass, contributing 33% in TTV on the variable. Relative to the untreated control, the interaction increased fresh tuber mass (yield) by 32%, which was not different to that of Nemarioc-AL phytonematicide at 40%, but significantly different to that of Mormodica phytonematicide at 16%. Nemafric-BL and Mormodica phytonematicides under greenhouse conditions, each reduced dry shoot mass by 18 and 22%, respectively, whereas their interaction effects on the variable did not differ significantly from the untreated control. Similarly, under microplot conditions Mormodica phytonematicide alone significantly reduced plant height by 12%, although this was not different from the effects of Nemafric-BL phytonematicide. Also, the effects of Nemafric-BL phytonematicide on plant height was not different to that of the untreated control. However, Mormodica phytonematicide increased FSM, xxix DSM and FTM by 31, 33 and 19%, respectively. Mormodica phytonematicide effect on the variables was significantly different to the untreated control. The phytonematicide also reduced FRM and DRM by 17% and the effect on the two variable which significantly differed from the untreated control. The second order interaction were not significant on nematode variable under greenhouse and field conditions, but the interaction was significant only on total nematodes in roots, reproductive potential (RP) and final population (Pf) of Meloidogyne species on roots of potato plants and in the soil under microplot conditions, contributing 11, 13 and 10% in TTV on the variables, respectively. Relative to untreated control Nemarioc-AL × Nemafric-BL × Mormodica phytonematicide interaction reduced total nematode, RP and PF by 18, 64 and 18%, respectively, whereas their effects on the variables differed significantly from untreated control. Generally, Nemafric-BL × Mormodica interaction consistently in all three experiment reduced all nematodes variables. Nemarioc-AL × Nemafric-BL × Mormodica interactions were only significant on Na, contributing 7% in TTV o the variable. Relative to untreated control the interaction reduced Na by 33% and effects on the variable was significantly different to those of untreated control also Nemarioc-AL, Nemafric-BL and Mormodica alone. However, the second order interactions were not significant in greenhouse and field conditions. The A0B1M1 first order interaction although the interactive effects, contributed highly in TTV on Na and Zn in potato tuber tissues, relative to untreated control, the effects were rather negligent at 2 and 4%, respectively. In all different conditions of the study validating that potato seed tubers could be used as carriers of active ingredients of phytonematicides when used through the priming technology. The Nemafric-BL and Mormodica phytonematicide interactions consistently reduced population densities of the Meloidogyne species and increased yield under microplot and field experiments.

No description available.

This study seeks to determine the value of sulfur dioxide as a method for the dehydration of sweet potatoes for use in cow feed.

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No description available.

The Virginian variety and four selections of the Porto Rico variety were planted on two soil types at Toano, and Walkerton, Virginia, and on one soil at Warsaw, Virginia. At Williamsburg, Virginia, the Virginian, Nancy Hall, and a selection of the Porto Rico were planted under aluminum foil mulch, black paper mulch, and on cultivated plots. From these plantings an attempt was made to determine the influence of aluminum foil mulch, black paper mulch, selection or variety, and soil type, on the factors studied. The following summary is given of the results obtained from the “Mulched Treatments” phases of the experiment: 1. Aluminum foil mulch tended to increase the soil moisture and lower the soil temperature as compared to black paper mulch end cultivation. 2. Where the entire plot was covered by unperforated black paper, without some provision for water to reach the soil, the soil moisture is lowered. 3. The carotene content of the Virginian was 3 to 4 times as high as the Porto Rico variety. 4. Neither the yield nor the carotene content of the Porto Rico variety was affected by the aluminum foil, or black paper mulches. 5. The carotene content and yield of the Virginian, and the total yield of the Nancy Hall was higher under aluminum foil mulch than on the cultivated plots. 6. There was no difference between the aluminum foil, black paper, and cultivated treatments in the smoothness and uniformity of shape of the three varieties considered. 7. The Virginian was smoother and more uniform in shape than the Porto Rico or Nancy Hall varieties. The Virginian was also more uniform in skin and flesh color than the Porto Rico variety. The following summary is given of the results obtained from the “Affect of Variety and Selections” and “Affect of Soil Type” phases of the experiment: 1. No variety or selection was consistently higher in yield than all the others. 2. Selection #2 of the Porto Rico variety was the only selection which was consistently among the highest in yield at all locations. 3. The Virginian sweet potato variety was smoother and more uniform in shape than any of the selections of the Porto Rico. 4. No selection of the Porto Rico variety was consistently smoother than the others. Selection #1 was the most consistent selection of the Porto Rico variety to grade high in uniformity of shape. 5. There was no appreciable difference between varieties and selections in their disease susceptibility. 6. No selection or variety was significantly better, in respect to cracking, than the others. 7. The Virginian variety was 3 to 4 times as high in carotene content than any of the selections of the Porto Rico, regardless of location or soil. It was also more uniform in skin and flesh color. 8. None of the selections of Porto Rico was consistently higher in carotene content. Selection #4 varied more than the other selections in the uniformity of skin color. 9. Variety or selection was a more important factor than soil type in determining the yield, carotene content, and uniformity of flesh, and skin color of the sweet potatoes. 10. Soil type did not affect the yield of the Virginian, or selections of Porto Rico at either of the locations. 11. Soil type had only a slight and inconsistent affect on the smoothness, and uniformity of shape of the sweet potatoes. 12. Under the conditions of this experiment there was no consistent difference in soil type in the amount and kind of disease present. / Master of Science

Controlled atmosphere (CA) storage of horticulture crops involves the holding of such produce in refrigerated storage with a reduction of oxygen and an increase in carbon dioxide. The effect of controlled atmospheres on the keeping quality of Centennial, Jersey, Goldrush, Nemagold, Oklamar, and Porto Rico sweetpotato varieties was studied in the 1963-65 period. Evaluations were made of decay loss, weight and dry matter loss, soluble solids percent, carotene content, taste of raw and baked roots, keeping after storage, and the ability of roots to sprout. In 1963-64, ranges of carbon dioxide from 0 to 15 percent were used in combination with 2 to 16 percent oxygen. Sweetpotato roots stored under atmospheres having an oxygen level below 7 percent or a carbon dioxide level above 10 percent developed a high percent of roots with either an alcoholic flavor or an off-flavor. Sweetpotatoes under an atmosphere of 3 percent carbon dioxide and 7 percent oxygen (3-7) had better quality than check lots as evaluated by low total losses due to decay and weight loss, higher dry matter content and a low dry matter loss, high total soluble solids and a high percent of acceptable tasting roots. The only disadvantage of this CA treatment was a higher loss due to decay upon holding at room temperature for one month after storage. However, this high loss was not significantly different from the open air check. In 1964-65 controlled atmosphere levels of 2 to 7 percent carbon dioxide in combination with 7 to 11 percent oxygen were used. Results similar to those of 1963-64 were obtained in 1964-65. Sweetpotatoes under an atmosphere of 2-7 in a gas generated CA room, had better storage quality as measured by low total losses, low dry matter disappearance, higher total soluble solids and a high percent of acceptable tasting roots compared to the checks. Roots removed from CA in 1964-65 and held at room temperature for one month did not exhibit the high decay found in the 1963-64 season. Decay was slightly higher than the check but not significantly different. The 2-7 atmosphere did not impair sprouting when roots were held at a warm temperature after storage. Sweetpotato roots under a 3-8 atmosphere in a sealed 55 gallon drum were relatively similar to roots held in the 2-7 room atmosphere, but were generally poorer in keeping quality. Sweetpotatoes under atmospheres 7-8 and 3-11 had lower total losses compared to the room air or open check, but not the covered drum check. Roots under these controlled atmospheres were not different from the covered check in dry matter loss and were higher in soluble solids, carotene content and percent acceptable tasting roots than the open check. Roots removed from the 7-8 and 3-11 atmospheres had higher decay losses than the checks after holding at room temperature for one month. The 7-8 and 3-11 atmospheres significantly decreased the ability of roots to sprout at room temperature. There were pronounced varietal responses to controlled atmosphere storage. CA holding had a beneficial effect on the Centennial and Jersey varieties and to a lesser degree on the Porto Rico and Goldrush varieties as evaluated by reduction of total losses, dry matter loss, higher soluble solids levels and a higher percent of acceptable tasting roots. More off-flavor developed in roots of the Nemagold and Oklamar varieties. The Nemagold and to a lesser degree the Oklawar had a higher total loss, dry matter loss, and lower soluble solids than the other varieties and after removal from CA and holding at room temperature the Nemagold variety developed more decay. / Ph. D.

The purpose of the present study is to determine the effect of cooking on the vitamin A value of "Vita-Yam" candy and cookies.