scholarly journals The most important quality criteria of some homegrown black-currant varieties I. Ascorbic acid

1965 ◽  
Vol 37 (4) ◽  
pp. 264-281
Author(s):  
Taina Kuusi

A comparative study has been made with a view to clarification of the quality properties of some home-grown black-currant varieties. Twelve varieties were examined; samples were obtained from 6 different localities, of which the southernmost was Piikkiö, and the northernmost Rovaniemi, over a period of three years. The analytical results were compared with the totals of heat, the totals of hours of sunshine, and the precipitaition during the years concerned. Ascorbic acid, one of the most important criteria of quality, was assayed by application of the method of Robinson & Stotz, slightly modified. On the basis of the results obtained, mutual comparison of the varieties studied is possible along with consideration of the possible effects of weather conditions and the degree of north latitude of the place of growth. It is well known that the ascorbic acid content is dependent upon the variety. Accordingly, the following diminishing sequence was found in the ascorbic acid content of the varieties studied: Boskoop, Roodknop, Westwick Choice, Wellington XXX, Gerby, Wellington X, Åström, Brödtorp, Goliath, Silvergieter, Janslunda and Black of Lepaa. In this series, the amount of ascorbic acid fell from 250 to 127 mg/100g; considerable variations occurred in each variety. As for weather conditions, the summer temperature showed the greatest effect; in general, low temperature increased the amount of ascorbic acid. However, Brödtorp and Black of Lepaa often formed an exception. The number of hours of sunshine produced a similar effect, but to a lesser degree; by contrast, precipitation evinced no clear-cut effect. The degree of north latitude of the locality also seems to exert some effect, probably mainly because a latitude further north means a lowering of the temperature, and consequent retardation of the ripening, which again causes higher ascorbic acid values. Comparison with published reports shows that in principle the present results are in line with those presented earlier. The differences might be attributable to different methods of assay, or variability in the varieties concerned. The northern latitude of the place of growth and the degree of maturity may be of importance.

1966 ◽  
Vol 38 (3) ◽  
pp. 162-179
Author(s):  
Taina Kuusi ◽  
Alpo Siiriä ◽  
Terttu Kuusi

A gas chromatographic study has been made of the volatile aroma components of black-currant. The material consisted of 12 home-grown varieties from 6 localities taken over a period of 2 years, although the series are not complete. Separate investigation was made of the low-boiling and high-boiling parts of the aroma; in the former case, material of two years was studied, and in the latter case, that of one year only. The lower-boiling components were isolated in chilled adsorption tubes from a nitrogen stream led through a berry homogenate at room temperature. Analysis was effected at 80°C with a polyetylene glycol/teflon column (the same mass served as filling for the adsorption tubes). In all, 13 components were registered, although their occurrence, and the amounts in the different samples, were somewhat variable. As regards the different factors, the variety exercised no more than a slight effect on the aroma picture, whereas weather conditions were important, influencing the frequency of the peaks and the general aroma level; a cool summer increased the level. The northernness of the growing locality had a similar effect, although this result its of preliminary nature. The degree of ripeness and the condition had a considerable effect; the level of aromagrams was higher with more ripe samples, and in particular the ethanol content, which forms the bulk of the low-boiling aroma, was increased. A positive correlation was detected between the height of the ethanol peak and the total aroma or aroma number. By contrast, the height of the methanol peak exhibited a slight negative correlation with the degree of esterification of the pectin. The higher-boiling compounds were isolated by vacuum distillation and subsequent extraction with ether. In the gas chromatography, use was made of a butandiol succinate polyester/celite column, and the temperatures were 120 and 150°C. In all, 25 components were observed. Of the various factors, the variety showed a clear-cut influence on the aroma picture, as differences in the occurrence of the peaks and the relative heights were noted between the varieties; in this series, quantitative comparisons between the samples were impossible. The effect of locality and degree of ripeness is less well defined. Organoleptic checking showed that the changes were small in isolation of the lower-boiling components. In contrast, isolation of the higher-boiling compounds induced more changes, so that an aroma fraction obtained in the organic solvent was more terpene-like than the original aroma.


Author(s):  
N. Osokina ◽  
◽  
K. Kostetska ◽  
H. Gerasymchuk

The ascorbic acid content of five varieties of black currants during 15 years of research is given. During the growing season of black currant it was counted: the sum of effective temperatures above 5 °C; the sum of effective temperatures above 10 °С; amounts of active temperatures; amount of rainfall; hydrothermal coefficient (HTC). The research objective was to analyze ascorbic acid content in black currant fruit during many years of research. Research tasks were meant to establish black currant growth duration and agroclimatic indicators during this period; ascorbic acid content in black currant fruits depending on the variety and the year of the harvest. It is established that the duration of the black currant growing season in the conditions of the Right-Bank Forest-Steppe of Ukraine is 96±3–4 days for thermal resources: the sum of effective temperatures is above 5 °С – 750–950°, the sum of effective temperatures is above 10 °С – 300–600°, the sum of active temperatures is 1050–1300° and the rainfall is 120–300 mm, for the HTC it is 0,7–3,0. The regularities of ascorbic acid synthesis are shown depending on the features of the variety and agroclimatic indices during vegetation of plants. The analysis of the received data shows the ambiguous influence of the HTC indicator on the accumulation of ascorbic acid in black currant fruits. A comprehensive and comprehensive study of the most complex details of the metabolism of substances showed that ascorbic acid plays one of the crucial roles in the entire cycle of intrauterine development of plants from emergence to disappearance - the role of a direct participant in the process of respiration, photosynthesis, regulation of the activity of enzymes and coenzymes, general metabolism and transport of substances, protecting cells from oxidative stress caused by abiotic factors. Thus, the high C-vitality of black currant fruit depends to a large extent on the variety, and only then on weather conditions during the formation of the harvest.


Planta Medica ◽  
2011 ◽  
Vol 77 (12) ◽  
Author(s):  
A Haskovic ◽  
A Copra Janicijevic ◽  
A Topcagic ◽  
L Klepo ◽  
A Kapur ◽  
...  

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.


1987 ◽  
Vol 67 (1) ◽  
pp. 331-335
Author(s):  
HAK-YOON JU ◽  
W. JOHN MULLIN

The ascorbic acid (vitamin C) content of fresh imported field tomatoes and Nova Scotia greenhouse and field tomatoes was determined on a bi-weekly basis during the period of availability of each type of tomato to the Nova Scotia consumer in 1984. The average ascorbic acid contents of imported and Nova Scotia field and greenhouse tomatoes were 13.3, 16.7 and 17.7 mg 100 g−1 fresh weight, respectively. A study of nine recommended or promising field tomatoes for the Atlantic region showed significant differences in ascorbic acid content among the cultivars. The cultivar Quick Pick had the highest ascorbic acid content of 22.5 ± 1.5 mg 100 g−1, the cultivar Campbell 18 had the lowest content, 12.0 ± 2.9 mg 100 g−1. In Dombito greenhouse tomatoes the stage of maturity and the effect of cluster location were tested against ascorbic acid content. The lowest ascorbic acid content of 9.1 ± 1.0 mg 100 g−1 was found with the small green tomatoes while others from mature green to overripe contained 14.0–16.7 mg 100 g−1. Tomatoes from different cluster locations showed no significant difference in ascorbic acid content.Key words: Vitamin C, L-ascorbic acid, tomatoes


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Vijendren Krishnan ◽  
Syahida Ahmad ◽  
Maziah Mahmood

Plants from Gynura family was used in this study, namely,Gynura procumbensandGynura bicolor.Gynura procumbensis well known for its various medicinal properties such as antihyperglycaemic, antihyperlipidaemic, and antiulcerogenic; meanwhile,G. bicolorremains unexploited. Several nonenzymatic antioxidants methods were utilized to study the antioxidant capacity, which include ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, total flavonoid content, total phenolic content, and ascorbic acid content determination. DPPH assay revealsG. procumbensshoot as the lowest (66.885%) andG. procumbensroot as the highest (93.499%) DPPH radical inhibitor. In FRAP assay, reducing power was not detected inG. procumbensleaf callus (0.000 TEAC mg/g FW) wherebyG. procumbensroot exhibits the highest (1.103 TEAC mg/g FW) ferric reducing power. Total phenolic content and total flavonoid content exhibited similar trend for both the intact plants analysed. In all antioxidant assays,G. procumbenscallus culture exhibits very low antioxidant activity. However,G. procumbensroot exhibited highest phenolic content, flavonoid content, and ascorbic acid content with 4.957 TEAC mg/g FW, 543.529 QEµg/g FW, and 54.723 µg/g FW, respectively. This study reveals thatG. procumbensroot extract is a good source of natural antioxidant.


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