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1.
Summary Tubers of the potato cultivars Record, Wilja, Pentland Dell and Brodick (formerly clone 137371) were sampled before and after
storage at either 4°C or 10°C. Reducing sugar content stayed constant during storage at 10°C in all four cultivars but rose
greatly during the first 6–12 weeks of storage at 4°C in Record, Wilja and Pentland Dell but not in Brodick. Amylolytic activity
was determined after 5 weeks storage using blockedp-nitrophenyl maltoheptaoside as substrate for α-amylase,p-nitrophenyl maltopentaoside as substrate for β-amylase, andp-nitrophenylglucopyranoside as substrate for α-glucosidase. The values obtained from tubers stored at 4°C were higher than
those from tubers stored at 10°C, the differences being much less in Brodick than in the other three cultivars. 相似文献
2.
Summary 23 potato cultivars were grown in fields infested with potato mop-top virus and spraing was assessed on tubers at harvest
and after storage. Large differences in spraing susceptibility were found between cultivars. Compared with other countries,
spraing in Denmark is characterised by a high incidence at harvest, a low increase during storage and a very low proportion
of superficial spraing. Decrease in spraing during storage was recorded in two cultivars. DASELISA tests for PMTV in tubers
revealted a high reliability. Mapping of PMTV in important Danish potato growing areas showed that the virus is widespread.
Occurrence of spraing did not influence total yield or dry matter content. Soil acidity did not influence incidence of spraing
but it was more common on coarse-grained soil than on finer sandy soils. PMTV in viruliferous resting spores ofSpongospora subterranea was inactivated by heating to 90°C for 15 minutes. 相似文献
3.
Summary Empirical mathematical models are described for calculating the effects of varying supplies of nitrogen, phosphorus and potassium
on pot and field grown tubers. Through optimization and simulation, potato tuber fresh and dry weight losses and chemical
composition changes (ascorbic acid, citric acid, glucose, fructose, sucrose, nitrate) are calculated over a 6-month period
of storage at 4°C. The effects of variation in single nutrients as well as of increasing N fertilization on storage are calculated.
Calculations giving the maximum vitamin C content at harvest and after storage indicate the nutrient supply required. 相似文献
4.
Increase in phosphorylase activity during cold-induced sugar accumulation in potato tubers 总被引：2，自引：1，他引：2
Pieternel A. M. Claassen Miriam A. W. Budde Martha H. Van Calker 《Potato Research》1993,36(3):205-217
Summary The accumulation of reducing sugars, sucrose and hexose phosphates in cv. Bintje and genotype KW77-2916 during storage at
2, 4, or 8°C was studied in relation to several catalytic activities. Bintje tubers accumulated sugars during storage at 2
or 4°C, whereas KW77-2916 showed reduced cold-sweetening at 2°C. The increase in glucose 6-phosphate and sucrose occurred
concurrently and preceded the increase in reducing sugar concentration. Phosphorylase activity showed a strong interaction
with temperature, storage duration and sugar accumulation in both genotypes. Invertase activity increased in Bintje concomitantly
with the increase in reducing sugars, but this effect was less obvious in KW77-2916. The activities of other glycolytic and
Krebs cycle enzymes showed no obvious correlation with sugar accumulation. It is suggested that the increase in phosphorylase
activity acts as a triggering event in the sweetening of potato tubers during cold storage. 相似文献
5.
Summary A comparative study of nine Indian potato varieties showed a good correlation between their total carotenoid content and the
tuber flesh colour. Regardless of varietal differences, carotenoid level showed an increase during storage at ambient temperature
(25–30°C) and to a lesser extent at 2–4°C and 15°C. Tubers exposed to an irradiation dose of 10 krad for sprout inhibition
showed decreased levels of carotenoids during storage, particularly at 15°C where 50% loss was observed after 6 months of
storage. Irradiated tubers stored for seven months at 15°C, on reconditioning at 34–35°C for 6 to 12 days showed a 2- to 6-fold
increase in their carotenoid content. 相似文献
6.
Summary Reducing sugar and sucrose content of potato tubers (cv. Record) grown in Tayside (northern United Kingdom (UK)) and Lincolnshire
(southern UK) were monitored during the 1984 growing season and after two months storage at 10°C. Neither latitude nor agronomic
factors were shown to affect sugar content. Significant correlations were found between the post storage reducing sugar content
and the sugar contents measured at harvest. Regression analyses indicated that in immature tubers sucrose breakdown was responsible
for reducing sugar accumulation during storage. 相似文献
7.
Tubers of three potato cultivars were stored at room temperature (20–39°C, 30–75% RH), under an insulated storage run on passive evaporative cooling (16–30°C, 70–90% RH) and a refrigerated storage (2–4°C, 90–95% RH) for 14 weeks and studied periodically for storage losses, reducing sugar content and dry matter percent of tubers, in order to explore the possibility of storing potatoes for processing at higher temperatures. Physiological losses in tubers remained less than 10% until 12 weeks of storage under evaporatively cooled storage. Reducing sugar contents increased by only 52.4–242.1% in tubers stored in evaporatively cooled storage as compared to 90.5–484.2% increase in tubers stored in refrigerated storage until 14 weeks. Potatoes stored in evaporatively cooled store were more suitable for processing into chips and french fries due to lower physiological losses and lower reducing sugar content of tubers. 相似文献
8.
The internal quality of the potato going into storage is an important parameter for proper storage management. Unfortunately, a rapid and accurate estimate of this parameter is not available. Respiration analysis has potential to be such a guide. This paper reports work completed during the 1978–79 storage season comparing respiration analysis with the important storage indicators of maturity, dry matter, invert sugars, harvest injury, bruise susceptibility and weight loss. Harvests were made at biweekly intervals over a ten-week period. Samples were evaluated in the respirometer for ten days, then placed in storage at 6°C for six months. Following storage, respiration and invert sugar analyses were reported. Evaluations of bruise susceptibility were made on each harvest date and bruise evaluation of several different harvesters made on the last date. The treatments with the highest invert sugar content and greatest weight loss also had the highest respiration rates. 相似文献
9.
Summary We investigated the changes in the content of L-ascorbic acid (L-AA), glucose, fructose, surose and total glycoalkaloids (TGA)
during storage of potatoes, cv. Bintje, for 12 weeks at 7,16 and 28°C. The initial amount of L-AA was 8.2 mg/100g fresh weight;
after 12 weeks' storage at 7°C it had decreased, while at 16 and 28°C it had increased. The sugar content went up most in
potatoes stored at 28°C, but remained below the level at which potatoes taste sweet. The sugar content rose slightly at 16°C,
while it decreased in tubers stored at 7°C. The initial TGA content, in equivalent amounts of α-solanine, was 3.6 mg/100 g
fresh weight; after 12 weeks' storage it had decreased slightly at all three storage temperatures. 相似文献
10.
Summary Pot and field experiments were carried out to test fertilizer treatments on the behaviour of potato tubers stores at 4°C and
≥90% relative humidity for 6 months. Weight losses (separated into water and dry matter) were enhanced after N and K fertilization
and decreased by increasing P supply. Glucose and fructose contents were reduced at harvest by high N-fertilizer rates compared
to no or low fertilization, but throughout storage reducing sugar accumulation was increased, sucrose reduction was decreased
and ascorbic acid was increased. K fertilization affected the chemical composition of the tubers somewhat similar to that
of nitrogen fertilization. High initial nitrate content of the tubers seemed to be increased and low nitrate values were decreased
during storage. The tubers from pot experiments showed similar changes but of greater magnitude. 相似文献
11.
Summary Several clones from a potato breeding programme at the Scottish Crop Research Institute (SCRI) produced acceptable (pale)
coloured fry products after five months' storage at 4°C. Chemical analysis of tuber samples taken at five-week intervals during
storage at 4°C and 10°C gave a substantial variation in glucose, fructose and sucrose concentrations among the 22 clones examined.
Several unnamed SCRI clones showed little accumulation of reducing sugars when stored at 4°C. In marked contrast, the cultivars
Record and Pentland Dell, currently the most widely used cultivars for fry processing in the UK, accumulated far greater levels
of sugar during low temperature storage. Glucose concentration proved more important than fructose concentration in determining
fry colour. Clones with the lowest concentrations of glucose after storage at 4°C also showed lowest concentrations when stored
at 10°C. These results are in agreement with previous reports on the predictive value of glucose levels at harvest, but this
is the first identification of such low temperature, low sweetening variants in agronomically adapted clones of the cultivated
tetraploid potato. 相似文献
12.
Summary Four experiments (three with four cultivars, one with twenty cultivars) investigated the effect of different storage temperature
regimes on the duration of dormancy of seed potatoes harvested immature. Regimes included constant temperatures (18 and 28°C),
hot pre-treatments (20 days at 28°C and subsequently 18°C) and cold pre-treatments (20 days at 2°C and subsequently 18°C).
Compared with 18°C, storage at 28°C slightly prolonged dormancy of some cultivars with a genetically short dormancy and shortened
dormancy by up to 45 days in cultivars with a long dormancy. Some tubers of one cultivar lost their ability to sprout after
storage at 28°C for 90 days.
A hot pre-treatment shortened dormancy by 2–3 weeks on average, for all cultivars examined. A cold pre-treatment shortened
dormancy by 2 weeks on average in some cultivars with a short dormancy and in all cultivars with a long dormancy. 相似文献
13.
Summary In trials with potato tubers infected with tobacco rattle virus (TRV), symptoms of spraing in cvs Bellona, King Edward, Maris
Bard, Matilda, Sv 82146 and Sv 82149 increased during storage when the tubers were cut. Storage of intact tubers at a constant
temperature of 9°C or at fluctuating temperatures (2 weeks at 18°C, 2 weeks at 9°C and 2 weeks at 18°C) did not increase the
frequency of symptoms. 相似文献
14.
Summary Infection and lesion expansion studies were carrried out on potato tubers. In the infection study, the tubers were inoculated
withErwinia carotovora ssp.carotovora (Ecc) and exposed to incubation temperatures of 10–25 °C for 3–48 h of wetness. In the lesion expansion study, the tubers were
exposed to 12 h of wetness at 20 °C to establish infection, and then·stored at temperatures of 4–16 °C for 15–90 d, at 95%
RH. The volume of diseased tissue was determined and the data were transformed to proportion of maximum volume diseased (PVD).
Infection was close to zero for 3 and 6 h wet incubation time, regardless of incubation temperature, and reached the maximum
in 12 h of wetness at 20 °C. Significant lesion expansion occurred at a storage temperature of 16 °C after about 60 d of storage
time. Cubic models of infection and lesion expansion potentials explained 95 and 96% of the variations in infection and lesion
expansion, respectively. 相似文献
15.
N. Poulsen A. S. Johansen J. N. Sørensen 《Plant foods for human nutrition (Dordrecht, Netherlands)》1995,47(2):157-162
Crisphead lettuce (Lactuca sativa L. varcapitata cvs.Marius andSaladin) were grown with a nitrogen supply from 50 to 200 kg N/hectare. Heads were stored for one or two weeks at 1 °C in cold storage or ice bank cooling. Samples were taken for measurement of dry matter, sugars, vitamin C and nitrate. The content of dry matter, sugars (glucose, fructose) and vitamin C decreased with increasing level of nitrogen, and the content of nitrate increased. Except for nitrate the contents of the other quality attributes decreased at all nitrogen supply levels during storage. No differences were found between the storage systems, and beside fructose no significant differences were found between the two cultivars. The content of dry matter, vitamin C, and nitrate decreased from the outer to the inner head fraction, while the content of sugars increased. Trimming decreased the content of dry matter, vitamin C and nitrate and increased the content of sugars. To obtain heads from storage with a relatively high content of dry matter, sugars and vitamin C, and a relatively low content of nitrate the nitrogen supply must be as low as possible. Except for nitrate where no distinct results were found in this experiment it must also be recommended to store the heads as short time as possible. Possibly the cv.Saladin has some advantage quality attributes after storage compared with the cv.Marius. 相似文献
16.
Summary Microtubers of potato cultivar Kennebec were stored for two months at 2 or 8°C and sampled at selected intervals for the determination
of glucose, fructose, sucrose and sprout weight. The aim of this experiment was to determine whether these microtubers show
the same response to storage temperature with respect to sweetening as field grown tubers. During storage at 2 °C, reducing
sugars and sucrose increased rapidly to a concentration of over 1.0 and 0.7 g/100 g fresh weight, respectively. In contrast,
in tubers kept at 8°C, only a relatively slight increase in reducing sugar concentration to 0.3 g/100 g fresh weight was observed
and sucrose concentration remained virtually the same. 相似文献
17.
Summary In pot culture experiments over 2 consecutive years, 20 potato genotypes of varying heat tolerance were grown under long day
conditions and heat stressed by being exposed to high (38 °C/21 °C mean day/night) temperature. The percent increase in mean
internode length of heat stressed plants over those grown at normal temperatue (25°C/16°C day/night) was correlated with the
percent tuber dry matter yield of the heat stressed plants (r=0.618, P=0.01). In the same 20 genotypes, grown under short
day conditions at normal temperature, the fraction of leaf bud cuttings exposed to high night temperature (23°C) that produced
tuber initials correlated with the percentage increase in internode elongation in stem cuttings exposed to 25°C compared with
those exposed to 15°C (r=0.680. P=0.01). Thus the relative changes in internode elongation are related to thermal tolerance,
and it is suggested that this can be used as a selection criterion for heat tolerance. 相似文献
18.
Loss of vitamin C (L-ascorbic acid) during long-term cold storage of Dutch table potatoes 总被引：1，自引：0，他引：1
Summary Loss of vitamin C (L-ascorbic acid) from Dutch table potatoes during storage at 5–6°C over 8 months from November to July,
was studied in two seasons. L-Ascorbic and dehydroascorbic acid were analysed by HPLC. The amount of dehydroascorbic acid
was negligible. Total loss of L-ascorbic acid varied between 21 and 60%.
Some potato lots lost L-ascorbic acid rapidly in the first four months, others more gradually over the whole storage period.
The L-ascorbic acid levels detected were 75–150% higher in the period March–June, but 35% lower in the period December–February
than those indicated by the step-wise decreases in the Dutch Food Composition Table. 相似文献
19.
Summary The content of reducing sugars decreases rapidly in the last part of the growing season. It is shown that one week's storage
(7 C) at this stage of the tubers' development induces a remarkable increase in the reducing sugar content.
Storage experiments during the period December–March show first-order interactions, viz. variety storage temperature, and
time of sampling during the storage period, storage temperature. Six weeks' conditioning of the above mentioned potato material
eliminated the earlier differences in the content of reducing sugars. After only 4 weeks conditioning, however, highly significant
differences between potatoes from previously differing storage temperatures were obtained. The treatment comprising previous
storage at 7.3 C dusted with sprout inhibitor, gave about the same amount of reducing sugars after 4 weeks as the other treatments
after 6 weeks conditioning. 相似文献
20.
Summary In measuring fructose 1,6-bisphosphatase (EC 3.1.3.11; FBPase) in potato tubers, we used anti PFP antibodies to ensure that
the assay was specific for FBPase and that PPi:fructose 6-phosphate 1-phosphotransferase (EC 2.7.1.90: PFP) did not contribute
to the production of fructose 6-phosphate (Fru-6-P). The involvement of cytosolic FBPase in cold sweetening was determined
by monitoring enzyme activity during storage ofSolanum tuberosum cv. Erntestolz tubers at 2 or 8°C. In contrast to the rapid increase in sucrose and reducing sugars, the specific activity
of FBPase showed no change and PFP rose slightly during storage at 2°C. Sugar concentrations and enzyme activities remained
virtually unchanged during storage at 8°C. These data allow the interconversion of fructose 1.6-bisphosphate (Fru-1,6-P2) to Fru-6-P and vice versa by FBPase and PFP, respectively, in potato tubers, but do not support a causal relationship between
coarse metabolic control of FBPase and cold-induced sweetening. 相似文献