| 1. |
- Ahmadi Afzadi, Masoud, et al.
(författare)
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Biochemical contents of apple peel and flesh affect level of partial resistance to blue mold
- 2015
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Ingår i: Postharvest Biology and Technology. - : Elsevier BV. - 0925-5214. ; 110, s. 173-182
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Tidskriftsartikel (refereegranskat)abstract
- Apple fruit contains a wide range of chemical compounds that may contribute to resistance against blue mold caused by Penicillium expansum. In the present study, contents of total titratable acidity, malic acid, total phenols and 10 individual phenolic compounds were quantified in peel and flesh fractions of both control and blue mold-inoculated fruits of 24 apple cultivars. In addition to the significant variation among cultivars in terms of all quantified compounds, correlation analysis revealed a significant impact of total phenols and individual phenols like flavonols and procyanidins B2 in the peel fraction, on blue mold resistance in the inoculated fruits. Multivariate analyses on data for chemical compounds in peel tissue of inoculated fruits, could also separate resistant and susceptible cultivars. These findings can be useful in breeding programs since higher levels of phenolic compounds may indicate better resistance in apple cultivars. (C) 2015 Elsevier B.V. All rights reserved.
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| 2. |
- Ahmadi Afzadi, Masoud, et al.
(författare)
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Genetics of resistance to blue mould in apple: inoculation-based screening, transcriptomics and biochemistry
- 2016
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Ingår i: Acta Horticulturae. - 0567-7572 .- 2406-6168. ; 1127, s. 55-60
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Konferensbidrag (refereegranskat)abstract
- Blue mould caused by Penicillium expansum is a major contributor to loss of marketable fruit during storage. Damage is also aggravated by the prohibition of postharvest fungicides in many countries, and in organic production everywhere. Robust data on levels of resistance to this disease are crucial for further research and for breeding of improved cultivars. Inoculation of fruit with fungal spores and estimation of the diameter of resulting lesions after cold storage demonstrated significant variation among cultivars. In addition, cultivars with high firmness at harvest and little softening, i.e., loss of firmness during storage, had less susceptibility, as also did late-ripening cultivars. In another part of the study, a possible association between lesion diameter and chemical contents in fruit flesh and fruit peel of 23 cultivars was investigated. Content of different quercetins and procyanidin B2 was positively associated with the level of tolerance. Samples taken after inoculation showed stronger association with the chemical contents than did samples of control fruit, suggesting that disease development had triggered a defence reaction. In a third part of the study, gene regulation in apple fruit after inoculation was evaluated in two relatively resistant and two relatively susceptible cultivars using an AryANE chip covering 60K apple transcripts. Validation of the most highly up-and down-regulated genes was undertaken using qPCR. Some genes related to disease resistance, biosynthesis of flavonoids and to cell-wall structure were identified as most likely to be responsible for differences in susceptibility to blue mould. These results will be used to search for candidate genes that can be used in marker-assisted selection in apple breeding.
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| 3. |
- Andersson, Staffan, et al.
(författare)
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Effect of storage time and temperature on stability of bioactive compounds in aseptically packed beverages prepared from rose hips and sea buckthorn berries
- 2015
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Ingår i: Agricultural and Food Science. - 1795-1895 .- 1459-6067. ; 24:4, s. 273-288
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Tidskriftsartikel (refereegranskat)abstract
- Rose hips and sea buckthorn berries contain high amounts of beneficial bioactive compounds. In this study the content and stability of natural vitamins and antioxidants were investigated in two fruit beverages made from rose hip powder, sea buckthorn berry puree and white grape juice concentrate, and wheat germ oil in one of the beverages. Beverages were formulated, pasteurised and filled aseptically in Tetra Brik packages and stored up to 35 days at 4 degrees C or 22 degrees C. Samples were analysed for the content of ascorbic acid, carotenoids, major phenolics, tocochromanols, total phenols and total antioxidant capacity as ferric reducing ability. The largest changes occurred during the first 5 days of storage, thereafter mainly ascorbic acid decreased. In the wheat germ oil supplemented beverage, alpha-tocopherol was more rapidly degraded. Negative correlations between the decrease of some carotenoids and tocochromanols, and the increase of some phenolics, suggest relationships of redox reactions specific to the amount of oil supplemented. From the present study we can conclude that additions of oil to beverages should be carefully selected to avoid oxidations of bioactive compounds. Furthermore, packaging of the beverages should be carried out at higher temperatures and thereafter it should be stored at low temperatures (4 degrees C), which decreased oxidation of all bioactive compounds except ascorbic acid.
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| 4. |
- Burri, Stina C.M., et al.
(författare)
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Antioxidant capacity and major phenol compounds of horticultural plant materials not usually used
- 2017
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Ingår i: Journal of Functional Foods. - : Elsevier BV. - 1756-4646. ; 38, s. 119-127
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Tidskriftsartikel (refereegranskat)abstract
- Horticultural plant materials not usually used from onion, carrot, beetroot, sea buckthorn, black and red currants as well as a wastewater powder from olive oil production were analyzed for total phenols content (FC), ferric reducing ability of plasma (FRAP), radical scavenging capacity (ABTS), and for major phenolic compounds by HPLC-MS. Antioxidant capacity and phenol content varied significantly between species and cultivars, with extracts of sea buckthorn leaves being superior. In different species, different phenolic compounds were closely associated with FRAP, ABTS and FC. For instance, hydrolysable tannins were major antioxidants in sea buckthorn whereas quercetin was the major antioxidant in onion peel and skin. This study shows that horticultural plant materials usually left in the field or waste materials from processing may have high antioxidant properties, and that extracts of these materials therefore could be of potential interest for development of antioxidant food additives.
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| 5. |
- Burri, Stina C.M., et al.
(författare)
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Lipid oxidation inhibition capacity of 11 plant materials and extracts evaluated in highly oxidised cooked meatballs
- 2019
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Ingår i: Foods. - : MDPI AG. - 2304-8158. ; 8:9
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Tidskriftsartikel (refereegranskat)abstract
- The underlying mechanism(s) behind the potential carcinogenicity of processed meat is a popular research subject of which the lipid oxidation is a common suspect. Different formulations and cooking parameters of a processed meat product were evaluated for their capacity to induce lipid oxidation. Meatballs made of beef or pork, containing different concentrations of fat (10 or 20 g 100 g−1), salt (2 or 4 g 100 g−1), subjected to differing cooking types (pan or deep frying), and storage times (1, 7, and 14 days), were evaluated using thiobarbituric reactive substances (TBARS). The deep-fried meatball type most susceptible to oxidation was used as the model meat product for testing the lipid oxidation inhibiting capacity of 11 plant materials and extracts, in two concentrations (100 and 200 mg kg−1 gallic acid equivalent (GAE)), measured after 14 days of storage using TBARS. Summer savory lyophilized powder was the most efficient plant material, lowering lipid oxidation to 13.8% and 21.8% at the 200 and 100 mg kg−1 concentration, respectively, followed by a sea buckthorn leaf extract, lowering lipid oxidation to 22.9% at 100 mg kg−1, compared to the meatball without added antioxidants. The lipid oxidation was thus successfully reduced using these natural antioxidants.
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| 6. |
- Muzila, Mbaki, et al.
(författare)
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Alteration of neutrophil reactive oxygen species production by extracts of Devil's Claw (Harpagophytum)
- 2016
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Ingår i: Oxidative Medicine and Cellular Longevity. - 1942-0900 .- 1942-0994.
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Tidskriftsartikel (refereegranskat)abstract
- Harpagophytum, Devil's Claw, is a genus of tuberiferous xerophytic plants native to southern Africa. Some of the taxa are appreciated for their medicinal effects and have been traditionally used to relieve symptoms of inflammation. The objectives of this pilot study were to investigate the antioxidant capacity and the content of total phenols, verbascoside, isoverbascoside, and selected iridoids, as well as to investigate the capacity of various Harpagophytum taxa in suppressing respiratory burst in terms of reactive oxygen species produced by human neutrophils challenged with phorbol myristate acetate (PMA), opsonised Staphylococcus aureus, and Fusobacterium nucleatum. Harpagophytum plants were classified into different taxa according to morphology, and DNA analysis was used to confirm the classification. A putative new variety of H. procumbens showed the highest degree of antioxidative capacity. Using PMA, three Harpagophytum taxa showed anti-inflammatory effects with regard to the PBS control. A putative hybrid between H. procumbens and H. zeyheri in contrast showed proinflammatory effect on the response of neutrophils to F. nucleatum in comparison with treatment with vehicle control. Harpagophytum taxa were biochemically very variable and the response in suppressing respiratory burst differed. Further studies with larger number of subjects are needed to corroborate anti-inflammatory effects of different taxa of Harpagophytum.
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| 7. |
- Muzila, Mbaki, et al.
(författare)
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Alteration of Neutrophil Reactive Oxygen Species Production by Extracts of Devil’s Claw (Harpagophytum)
- 2016
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Ingår i: Oxidative Medicine and Cellular Longevity. - : Hindawi Limited. - 1942-0900 .- 1942-0994.
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Tidskriftsartikel (refereegranskat)abstract
- Harpagophytum,Devil’sClaw, is a genus of tuberiferous xerophytic plants native to southernAfrica. Some of the taxa are appreciated for their medicinal effects and have been traditionally used to relieve symptoms of inflammation.The objectives of this pilot study were to investigate the antioxidant capacity and the content of total phenols, verbascoside, isoverbascoside, and selected iridoids, as well as to investigate the capacity of various Harpagophytum taxa in suppressing respiratory burst in terms of reactive oxygen species produced by human neutrophils challenged with phorbol myristate acetate (PMA), opsonised Staphylococcus aureus, and Fusobacterium nucleatum. Harpagophytum plants were classified into different taxa according to morphology, and DNA analysis was used to confirmthe classification. A putative new variety of H. procumbens showed the highest degree of antioxidative capacity. Using PMA, three Harpagophytum taxa showed anti-inflammatory effects with regard to the PBS control. A putative hybrid between H. procumbens and H. zeyheri in contrast showed proinflammatory effect on the response of neutrophils to F. nucleatum in comparison with treatment with vehicle control. Harpagophytum taxa were biochemically very variable and the response in suppressing respiratory burst differed. Further studies with larger number of subjects are needed to corroborate anti-inflammatory effects of different taxa of Harpagophytum.
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| 8. |
- Muzila, Mbaki, et al.
(författare)
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Djävulsklon från Afrika
- 2016
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Ingår i: LTV-fakultetens faktablad.
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Annan publikation (populärvet., debatt m.m.)abstract
- Nyttjar man naturmedicinska preparat, har man troligen hört talas om djävulsklo från Afrika. I övrigt får denna torrmarksväxt anses tämligen okänd i Sverige. För stora delar av den fattiga befolkningen på landsbygden i Botswana, Namibia och Sydafrika utgör djävulsklo däremot en välkänd och viktig inkomstkälla.
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| 9. |
- Muzila, Mbaki, et al.
(författare)
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Harpagophytum germplasm varies in tuber peel and pulp content of important phenylpropanoids and iridoids
- 2018
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Ingår i: South African Journal of Botany. - : Elsevier BV. - 0254-6299 .- 1727-9321. ; 115, s. 153-160
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Tidskriftsartikel (refereegranskat)abstract
- Tubers of the xerophytic African plant Harpagophytum procumbens are used as an appreciated medicinal drug whereas the value of H. zeyheri remains uncertain. Due to large and sometimes continuous morphological variation, discrimination between these two species can be difficult. In addition, interspecific hybridization may occur and could further complicate the collection of proper plant material for medicinal purposes. Hence the objectives of this study were to 1) study the content of selected secondary metabolites in peel and pulp of Harpagophytum tubers of different taxa, 2) identify possible species-specific differences in content (profile and amount) of selected secondary metabolites, and 3) investigate associations between content of selected secondary metabolites and sample origin. Although composition and content of the studied compounds varied among populations within species, H. procumbens and H. zeyheri had significantly different phytochemical profiles, with putative hybrids sometimes being intermediate and sometimes transgressive. In both peel and pulp the content of isoverbascoside, verbascoside, acetylacteoside and pagoside were higher in putative hybrids and H. procumbens compared with H. zeyheri. The content of the main bioactive compound harpagoside was significantly higher in H. procumbens compared with putative hybrids and H. zeyheri, with both pulp and peel content of H. procumbens being approximately twice as high as the pulp and peel content of putative hybrids. Accurate identification, selection andmultiplication of germplasm with superior qualities should therefore be performed to provide plant material with a high content of bioactive compounds. (c) 2018 SAAB. Published by Elsevier B.V. All rights reserved.
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| 10. |
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