| 1. |
- Ekvall, Jimmy, et al.
(författare)
-
Content of low molecular weight carbohydrates in vining peas (Pisum sativum) after blanching and freezing: effect of cultivar and cultivation conditions
- 2005
-
Ingår i: Journal of the Science of Food and Agriculture. - : Wiley. - 1097-0010 .- 0022-5142. ; 85:4, s. 691-699
-
Tidskriftsartikel (refereegranskat)abstract
- The content of low molecular weight carbohydrates (LMWC, glucose, fructose, sucrose, raffinose, stachyose and verbascose) was investigated in 29 cultivars of vining peas after blanching and freezing. The peas were harvested at about the same degree of ripeness. There was a positive correlation between the amount of raffinose, stachyose and sorbitol, while a high content of verbascose only could be seen when there was a low content of these sugars. High concentrations of sucrose were generally associated with high concentrations of glucose and fructose. Samples from 1999 had a significantly (p < 0.001) higher content of raffinose, stachyose and sorbitol and lower of verbascose, probably because of the drier and warmer summer that year compared with 1998. Furthermore, medium and late maturing cultivars contained larger amounts of raffinose, stachyose and sorbitol than early cultivars, possibly due to the fact that these cultivars, to a greater extent, were exposed to a higher temperature and more intense sunlight for a longer time. Considerable differences in the content of LMWC could be seen both between the different cultivars and the various trials. Glucose and sucrose were generally similarly affected by cultivar and cultivation conditions, while cultivation conditions had a greater influence on the content of sorbitol and the raffinose family oligosaccharides (RFO; raffinose, stachyose, verbascose) in late-maturing groups. It is concluded that many factors affect the content of LMWC in peas. However, as the content of RFO is comparatively small in vining peas, any nutritional significance of these sugars in the human colon is probably rather small. (C) 2004 Society of Chemical Industry
|
|
| 2. |
- Ekvall, Jimmy, et al.
(författare)
-
Content of low molecular weight carbohydrates in vining peas (Pisum sativum) related to harvest time, size and brine grade
- 2006
-
Ingår i: Food Chemistry. - : Elsevier BV. - 1873-7072 .- 0308-8146. ; 94:4, s. 513-519
-
Tidskriftsartikel (refereegranskat)abstract
- Knowledge of how the content of low molecular weight carbohydrates (LMWC), including the raffinose family oligosaccharides (RFO; raffinose, stachyose and verbascose), changes in unripe peas (Pisum sativum) around harvest time, is today limited. An early and a late maturing cultivar of peas were harvested with 24 h of each other on seven different occasions, of which three were chosen for this study. The pea samples were divided into three groups by size and brine grading, and then analysed with regard to the content of low molecular weight carbohydrates. The content of raffinose and stachyose increased in all groups during a period of 5 days. Peas that sank (sinkers) in the brine grading test had a higher content of raffinose and stachyose and a lower content of sucrose than floating peas, indicating that sinkers have reached a greater degree of maturation. The content of verbascose remained the same or decreased during the study period. In conclusion, the date of harvesting green peas for freezing affects the contents of RFO.
|
|
| 3. |
- Ekvall, Jimmy, et al.
(författare)
-
Optimization of extraction methods for determination of the raffinose family oligosaccharides in leguminous vine peas (Pisum sativum L.) and effects of blanching
- 2007
-
Ingår i: Journal of Food Composition and Analysis. - : Elsevier BV. - 0889-1575. ; 20:1, s. 13-18
-
Tidskriftsartikel (refereegranskat)abstract
- The extraction procedure for analysis of the raffinose family oligosaccharides (RFOs) in blanched leguminous vine peas was optimized. For this purpose, 25 pea samples from different cultivars and of different maturity were chosen at random. The effect of blanching was also studied in four cultivars. The yield of oligosaccharides was almost double on average when extracted with 50% ethanol as compared with 80% ethanol. This was generally valid for all three oligosaccharides, with some exceptions for verbascose, where 80% ethanol was shown to be as effective as 50% ethanol. Extraction at room temperature and at boiling temperature gave similar yields, while 15 min of extraction gave lower yields than 30 and 60 min of extraction, which were similar. The loss of oligosaccharides following blanching was 32% on average, with verbascose showing the highest loss (56.4%), followed by raffinose (28.4%) and stachyose (16.3%). It can be concluded that the procedure used for extraction is of great importance when analysing the RFOs in immature peas, and that there is considerable loss of these sugars during blanching, which is the process commonly used to prepare the frozen commercial product. (c) 2006 Elsevier Inc. All rights reserved.
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
- Nilsson, Jessica, et al.
(författare)
-
Total antioxidant capacity in different pea (Pisum sativum) varieties after blanching and freezing
- 2004
-
Ingår i: Food Chemistry. - : Elsevier BV. - 1873-7072 .- 0308-8146. ; 86:4, s. 501-507
-
Tidskriftsartikel (refereegranskat)abstract
- Thirty-five varieties of the green pea (Pisum sativum L.) were analysed for their total antioxidant capacity (TAC. After blanching and freezing, the water-soluble fraction had, on average, a TAC of 0.61(0.22) mumol/g (mean(SD)) and the water-insoluble fraction a value of 0.23(0.08) mumol/g. There was a significant correlation between the TAC in the water-soluble and water-insoluble fractions (r = 0.41; p < 0.001). The peas had been grown during two consecutive years and were harvested at two different periods during the second year, 1999. Regarding the antioxidant capacity in both the water-soluble and the water-insoluble extract, there was a significant difference between the varieties but not between the harvest periods. A significant correlation (r = 0.72) between TAC in the water-soluble fraction and ascorbic acid content was found. Ascorbic acid accounted for a large part of the water-soluble antioxidant capacity. Further studies are necessary to reveal other compounds explaining the variation in pea antioxidant capacity and the mechanisms involved. Measurement of TAC may be a convenient route for the selection of pea varieties with optimal functional and health effects. (C) 2003 Elsevier Ltd. All rights reserved.
|
|
| 7. |
- Noren, H., et al.
(författare)
-
Expression of the early light-induced protein but not the PsbS protein is influenced by low temperature and depends on the developmental stage of the plant in field-grown pea cultivars
- 2003
-
Ingår i: Plant, Cell and Environment. - : Wiley. - 0140-7791 .- 1365-3040. ; 26:2, s. 245-253
-
Tidskriftsartikel (refereegranskat)abstract
- Plant cells exposed to photo-inhibitory conditions respond by accumulation of the early light-induced proteins (Elips) with a potential photoprotective function. Here we studied the expression of Elip in various pea cultivars grown under agricultural or climate-chamber conditions. We demonstrated that the expression of Elip in all cultivars was developmentally regulated and its level decreased during flowering and post-flowering periods. Surprisingly, significant amounts of Elip transcripts, but not proteins, accumulated in senescing leaves already under low light conditions and the exposure to light stress resulted in a 10-times higher induction of Elip transcripts. Furthermore, the expression pattern of Elip transcript and protein significantly differed under field and growth-chamber conditions. First, the expression level of Elip was much higher in field-grown than in chamber-grown cultivars. Second, substantial amounts of Elip transcripts and protein were detected during the night in field-grown plants in contrast to chamber-grown cultivars due to a synergistic effect of light stress occurring during the day and low temperature present during the following night. The expression of the PsbS protein related to Elips and involved in the photoprotection of the photosystem II was relatively constant under all conditions tested.
|
|
