Quality of potato tubers as affected by freezing: I. texture, ascorbic acid and enzymatic discoloration

1979 ◽  
Vol 56 (3) ◽  
pp. 119-124 ◽  
Author(s):  
N. I. Mondy ◽  
Subhash Chandra
2020 ◽  
pp. 26-28
Author(s):  
Н.Т. Чеботарев ◽  
Н.Н. Шергина

Пахотные угодья Республики Коми в основном представлены дерново-подзолистыми почвами с низким естественным плодородием, которые без применения удобрений быстро подвергаются деградационным процессам, что резко снижает их продуктивность. Цель исследований: оценка эффективности долговременного применения органических и минеральных удобрений при выращивании картофеля в кормовом севообороте в условиях Республики Коми. Методической основой выполнения работ были комплексные исследования дерново-подзолистых почв, клубней картофеля на участках многолетнего полевого эксперимента, заложенного на землях Института агробиотехнологий ФИЦ Коми НЦ УрО РАН в соответствии с «Методическими указаниями географической сети опытов с удобрениями». Длительный период исследований (более 40 лет) характеризовался различными климатическими условиями, которые отразились на количестве урожая и качестве клубней картофеля. Было проведено 7 ротаций (14 лет) с выращиванием картофеля. Вносили органические удобрения – торфонавозный компост (ТНК) в дозах 40 и 80 т/га (1 и 2 фон, соответственно) под картофель и минеральные удобрения – NPК в дозах 1/3; 1/2 и 1 для восполнения выноса растениями элементов питания. Установлено положительное влияние комплексного применения органических и минеральных удобрений на урожайность и качество картофеля, а также на плодородие дерново-подзолистой легкосуглинистой среднеокультуренной почвы в кормовом севообороте в почвенно-климатических условиях Республики Коми. В результате применения шестипольного севооборота и комплексного внесения удобрений с 1978 года к 2019 году в почвах снизилась обменная и гидролитическая кислотность; повысилось содержание гумуса на 0,5% (в контроле); на 0,2–0,5% (с тремя дозами минеральных удобрений); на 0,3–1,1% (с ТНК); на 0,2–1,6% (при совместном применении органических и минеральных удобрений). Наибольшие урожаи картофеля получены при совместном применении органических (80 т/га) и минеральных удобрений (1 NPК) и составили 37,1 т/га клубней (8,5 тыс/га кормовых единиц). При таком соотношении удобрений показано высокое качество клубней картофеля: содержание крахмала 15,5%, витамина С – 19,4 мг%, сырого протеина – 14,1%. Количество нитратного азота не превышало ПДК (ПДК 250 мг.с.м.). Экономические расчеты показали, что при внесении ТНК 40 т/га + 1 NPК в дерново-подзолистые почвы с.-х. использования в среднетаежной зоне Республики Коми при выращивании картофеля, условный чистый доход составит 68,4 тыс. р. с 1 га, себестоимость 1 т картофеля – 2,8 тыс. р., рентабельность 188,7%. The arable land of the Republic of Komi is mainly represented by dern-sub-ground soils with low natural fertility, which without the use of fertilizers are quickly subjected to degradation processes, which dramatically reduces their productivity. The aim of the research is to evaluate the efficiency of long-term use of organic and mineral fertilizers in the growing of potatoes in feed crop rotation in the conditions of the Komi Republic. The methodological basis for carrying out the works was comprehensive studies of dern-subhead soils, potato tubers on the sites of a multi-year field experiment laid on the lands of the Institute of Agrobiotechnology of the FRC Komi SC UB RAS in accordance with the «Methodological Instructions of the Geographical Network of Experiments with Fertilizers». A long period of research (more than 40 years) was characterized by different climatic conditions, which affected the number of crops and the quality of potato tubers. There were 7 rotations (14 years) with potato cultivation. Organic fertilizers – peat-avous compost (TNK) in doses of 40 and 80 t/ha (1 and 2 background, respectively) for potatoes and mineral fertilizers – NPK in doses of 1/3; 1/2 and 1 to replenish the carry-out of food elements by plants. The positive effect of the integrated use of organic and mineral fertilizers on the yield and quality of potatoes, as well as on the fertility of soddy-podzolic light loamy medium cultivated soil in fodder crop rotation in the soil and climatic conditions of the Komi Republic, has been established. As a result of the use of six-bed crop rotation and the integrated application of fertilizers, metabolic and hydrolytic acidity decreased in soils from 1978 to 2019; humus content increased by 0.5% (in control); 0.2–0.5% (with three doses of mineral fertilizers); 0.3–1.1% (with TNCs); 0.2–1.6% (with combined use of organic and mineral fertilizers). The largest potato yields were obtained from the combined use of organic (80 t/ha) and mineral fertilizers (1 NPK) and amounted to 37.1 t/ha tubers (8.5 thousand/ha feed units). The largest potato harvests were obtained with the combined use of organic (80 t/ha) and mineral fertilizers (1 NPK) and amounted to 37.1 t/ha of tubers (8.5 thousand/ha of feed units). With this ratio of fertilizers, the high quality of potato tubers was also determined: the starch content was 15.5%, vitamin C – 19.4 mg%, crude protein – 14.1%. The amount of nitrate nitrogen did not exceed the MPC (MPC 250 mg.s.m.). Economic calculations showed that if TNK is added 40 t/ha 1 NPK to the dern-sub-ground soils of agricultural use in the medium-sized zone of the Komi Republic when growing potatoes, the conditional net income will be 68.4 thousand rubles from 1 ha, the cost of 1 t of potatoes – 2.8 thousand rubles, profitability 188.7%.


Introduction of complex mineral fertilizer of an azofoska in combination with ammonium nitrate and urea to early ripe potatoes of Zhukovsky and Red Scarlett variety on the planned productivity of 40 t/hectare has allowed to achieve a goal. At the same time in control option without fertilizers the productivity was 23,2-24,8 t/hectare. Use of encapsulated urea has led to decrease in productivity and level of profitability by 26,3-30,9%. Early ripe potatoes of Zhukovsky and Red Scarlett variety on natural fertility of the chernozem leached in the northern forest-steppe of the Tyumen region have created average yield of 23,2-24,8 t/hectare for years of researches. Use of complex mineral fertilizer of an azofoska in combination with ammonium nitrate and urea on the planned productivity of 40 t/hectare has led to increase in productivity on the first variety to 39,5 on the second variety up to 41,4 t/hectare. Introduction of the encapsulated urea has led to decrease in productivity of the early ripe potato tubers studied. At the same time, the peel was gentle and when cleaning it was strongly injured. As to the content of starch (11,9-12,6%) at both varieties the big difference between ex-perience options isn't revealed. The similar picture was observed also according to tastes of tubers. It has made 3,2-3,5 points at Zhukovsky variety and 3,4-3,7 points at Red Scarlett's variety. Profitability level in con-trol option at Zhukovsky variety was 157,3%, at Red Scarlett's variety – 140,5%. In options with non-encapsulated ammonium nitrate and urea the first variety got 172,6-184,1%, second variety – 190,4-207,2%. In option with encapsulated urea at varieties under study the profitability level has decreased 26,3-30,9.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dalila Lopes da Silva ◽  
Renato de Mello Prado ◽  
Luis Felipe Lata Tenesaca ◽  
José Lucas Farias da Silva ◽  
Ben-Hur Mattiuz

AbstractCalcium (Ca) deficiency in cabbage plants induces oxidative damage, hampering growth and decreasing quality, however, it is hypothesized that silicon (Si) added to the nutrient solution may alleviate crop losses. Therefore, this study aims at evaluating whether silicon supplied in the nutrient solution reduces, in fact, the calcium deficiency effects on cabbage plants. In a greenhouse, cabbage plants were grown using nutrient solutions with Ca sufficiency and Ca deficiency (5 mM) without and with added silicon (2.5 mM), arranged as a 2 × 2 factorial in randomized blocks, with five replications. At 91 days after transplanting, the plants were harvested for biological evaluations. In the treatment without added Si, Ca deficiency promoted oxidative stress, low antioxidant content, decreased dry matter, and lower quality leaf. On the other hand, added Si attenuated Ca deficiency in cabbage by decreasing cell extravasation while increasing both ascorbic acid content and fresh and dry matter, providing firmer leaves due to diminished leaf water loss after harvesting. We highlighted the agronomic importance of Si added to the nutrient solution, especially in crops at risk of Ca deficiency.


2009 ◽  
Vol 13 (2) ◽  
pp. 74-81 ◽  
Author(s):  
Seon-Wook Hwang ◽  
Doo-Jin Oh ◽  
Deborah Lee ◽  
Jung-Wook Kim ◽  
Sung-Wook Park

Background: l-Ascorbic acid is used to treat melasma; however, it is quickly oxidized in aqueous solutions. Thus, C'ensil, a formulation containing 25% l-ascorbic acid and a chemical penetration enhancer, was created to promote the penetration of l-ascorbic acid into the skin. Objective: To evaluate the efficacy of C'ensil in patients with melasma. Methods: Forty subjects with melasma were treated with C'ensil during an open-label trial over a period of 16 weeks. Each subject's skin pigmentation was assessed every 4 weeks using the Melasma Area and Severity Index (MASI) and mexameter score. In addition, transepidermal water loss, skin dryness and irritation, and quality of life (Melasma Quality of Life Scale [MelasQoL]) were evaluated. Results: After 16 weeks, a significant decrease was noted in the degree of pigmentation based on the patients' MASI and mexameter scores. MelasQoL scores also decreased, indicating an increase in the subjects' quality of life. Conclusion: Our data indicate that C'ensil is an effective treatment modality for melasma.


2021 ◽  
Vol 0 (0) ◽  
pp. 0-0
Author(s):  
Rowaa Ghannam ◽  
Shimaa Abdelsalam ◽  
Afaf Amin ◽  
Maha Hewedy

2016 ◽  
Vol 46 (12) ◽  
pp. 2249-2256 ◽  
Author(s):  
Camila Batista da Silva ◽  
Eveline Lopes Almeida ◽  
Yoon Kil Chang

ABSTRACT: This study aimed to verify the performance of xylanase and its interaction with oxidants agents (glucose oxidase and ascorbic acid) on the quality of whole wheat bread. The experiment was based on a central composite rotational design and the Response Surface Methodology was used to analyze the results. None of the xylanase, glucose oxidase or ascorbic acid concentrations within the studied range led to a significant difference in the specific volume. The highest moisture content and the lowest firmness values were reported in the bread with lower and intermediate levels of xylanase and larger amounts of glucose oxidase and ascorbic acid. This effect was observed mainly at the end of the storage period. A minimum amount of xylanase (from 33 to 63 EDX kg-1 flour) showed to be essential for obtaining best results. Levels of ascorbic acid above 63mg kg-1 and glucose oxidase above 91 SRU kg-1 proved to be necessary to offer the beneficial effect of xylanase.


1966 ◽  
Vol 21 (9) ◽  
pp. 879-888 ◽  
Author(s):  
Volkmar Loeschcke ◽  
Hermann Stegemann

Up to 25 proteins have been found in the sap of potato tubers by polyacrylamid electrophoresis. The mode of preparation and concentration of the plant material was investigated as well as the pretreatment of the polyacrylamid gel to avoid undue retardation of the migrating bands.Sulfite was the most active inhibitor of sap-browning compared with ascorbic acid and cysteine. which did not influence the protein pattern except for one line. The juice had to be dialyzed or filtered through Sephadex G 25 to remove an unkown acidic material which interferes with the more acidic proteins and causes spreading and diffusing of bands. Proteins were concentrated by means of Carbowax MW 20000. For best results ionic contaminations inherent in the gels was removed by electrophoresis before applying the proteins or dyes. Very few proteins were affected by decreasing the pore size of the gel. Ammonium sulfate (40% saturation) precipitated mainly those proteins which are similar in electrophoretic behavior to the albumin- and transferrinregion of human plasma.


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