| 1. |
- Aalaei, Kataneh, et al.
(författare)
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Application of a dye-binding method for the determination of available lysine in skim milk powders.
- 2016
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Ingår i: Food Chemistry. - : Elsevier BV. - 1873-7072 .- 0308-8146. ; 196, s. 815-820
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Tidskriftsartikel (refereegranskat)abstract
- A dye-binding method using Acid Orange 12 was investigated regarding its suitability for the quantification of available lysine, as a means of monitoring the Maillard reaction in skim milk powders. The method was evaluated by analyzing a wide range of milk powders produced by three different drying methods and stored under various conditions. A pilot-scale freeze-dryer, spray-dryer and drum-dryer were used to produce skim milk powders and the samples were stored at two temperatures (20°C and 30°C) and two relative humidities (33% and 52%) under strictly controlled conditions. Moreover to validate the method, two protein isolates; bovine serum albumin and casein were investigated for their available lysine content. The results demonstrate the suitability of this method for measuring the available lysine in skim milk powders with good precision and high reproducibility. The relative standard deviations obtained from the 125 freeze-dried powders were 1.8%, and those from the 100 drum-dried samples were all 1.9%. The highest variation was found for the spray-dried powders, which showed relative standard deviations between 0.9% and 6.7%.
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| 2. |
- Aalaei, Kataneh, et al.
(författare)
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Early and advanced stages of Maillard reaction in infant formulas : Analysis of available lysine and carboxymethyl-lysine
- 2019
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 14:7
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Tidskriftsartikel (refereegranskat)abstract
- Although the literature on the Maillard reaction in infant formulas is extensive, most studies have focused on model systems, and in only a few cases on real food systems. Therefore, the objective of the present study was to determine the status of the Maillard reaction, both the early and advanced phases, in a variety of commercial infant formulas available on the Swedish market. Ten powder and liquid milk-based infant formulas from three manufacturers were selected to determine available lysine and CML contents, the two established indicators of the reaction. The products were also characterized with respect to protein content, carbohydrates composition, water content and water activity. In order to be able to compare the impact of different processing steps applied on powder and liquid formulas, the solid formulas contained similar ingredients as their corresponding liquid ones. Our findings showed that powder and liquid formulas contained similar available lysine concentrations regardless of the manufacturer, showing 27.14–36.57% decrease in the available lysine, compared to the reference skim milk powder in this study. The CML concentrations were in a broad range of 68.77–507.99 mg/kg protein. In the case of one manufacturer, liquid infant formulas had significantly higher CML content, compared to the powder products (p < 0.05). The results from this study are a step taken towards better understanding of the extent of the Maillard reaction in real complex systems of infant formulas.
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| 3. |
- Aalaei, Kataneh, et al.
(författare)
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The Impact of Different Drying Techniques and Controlled Storage on the Development of Advanced Glycation End Products in Skim Milk Powders Using Isotope Dilution ESI-LC-MS/MS
- 2017
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Ingår i: Food and Bioprocess Technology. - : Springer Science and Business Media LLC. - 1935-5130 .- 1935-5149. ; 10:9, s. 1704-1714
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Tidskriftsartikel (refereegranskat)abstract
- The impact of different drying techniques and storage conditions on the formation of carboxymethyl lysine (CML) as an advanced glycation end product (AGE) was investigated in various pilot-scale produced skim milk powders (SMP). CML, an indicator of advanced stages of the Maillard reaction, was analyzed by isotope dilution ESI-LC-MS/MS after drying and at intervals during storage for 200 days. The aim of this study is to increase the awareness that the development of AGEs can be hindered by controlled storage, which is mostly neglected at the domestic level by the consumers. Pilot-scale freeze-dryer, spray-dryer, and drum-dryer were utilized for manufacturing SMPs. The storage was designed in such a way that it simulated how an average consumer keeps the dried products at home, specifically after opening the packages and how the products may be exposed to unfavorable conditions. To do so, four storage conditions including two temperatures (20 °C, 30 °C) and two relative humidities RH (33%, 52%) were studied and CML formation was monitored using LC-MS/MS. Our results show that the spray-dried samples developed two times higher CML after 200 days, compared to the freeze-dried samples, and this value was 1.6 times for the drum-dried samples. Storage at 52% RH developed 9.8–10 times more CML in the samples, in comparison with 33% RH, at the same storage temperature (P < 0.05). Our findings demonstrate that AGEs, molecules suspected to be involved in risks factors for auto-immune diseases, may be formed during storage of SMPs after opening the packages by the consumers.
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| 4. |
- Kotova, Natalia, et al.
(författare)
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Differences in micronucleus frequency and acrylamide adduct levels with hemoglobin between vegetarians and non-vegetarians
- 2015
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Ingår i: European Journal of Nutrition. - : Springer Science and Business Media LLC. - 1436-6207 .- 1436-6215. ; 54:7, s. 1181-1190
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Tidskriftsartikel (refereegranskat)abstract
- Nutrients and food constituents can prevent or contribute to genotoxicity. In this study, the possible influence of a vegetarian/non-vegetarian diet on genotoxic effects was investigated in 58 non-smoking healthy vegetarians (V) and non-vegetarians (NV), age 21-37 years from the Stockholm area in Sweden. Physical activity and dietary habits were similar in both groups, with the exception of the intake of meat and fish. Using flow cytometry, we determined the formation of micronuclei (MN) in transferrin-positive immature peripheral blood reticulocytes (Trf-Ret) (Total: n = 53; V: n = 27; NV: n = 26). Dietary exposure to acrylamide was measured through hemoglobin (Hb) adducts in peripheral erythrocytes (Total: n = 53; V: n = 29; NV: n = 24). Hb adducts of both acrylamide and its genotoxic metabolite glycidamide were monitored as a measure of the corresponding in vivo doses. Our data demonstrated that compared with the non-vegetarians, the vegetarians exhibited lower frequencies of MN (fMN) in the Trf-Ret (p < 0.01, Student's t test). A multivariate analysis demonstrated that there was no association between the fMN and factors such as age, sex, intake of vitamins/minerals, serum folic acid and vitamin B12 levels, physical activity, and body mass index. The mean Hb adduct levels of acrylamide and glycidamide showed no significant differences between vegetarians and non-vegetarians. Furthermore, there were no significant relationships between the adduct levels and fMN in the individuals. The ratio of the Hb adduct levels from glycidamide and acrylamide, however, showed a significant difference (p < 0.04) between the two groups. These data suggest that the vegetarian diet might be beneficial in lowering genomic instability in healthy individuals. The measured Hb adduct levels indicate that the total intake of acrylamide does not differ between the two studied groups and does not contribute to the observed difference in fMN, although an influence of the diet on the metabolic rates of acrylamide was indicated. In addition, the observed significant difference in the background fMN in the two groups demonstrated that the MN analysis method has a sensitivity applicable to the biomonitoring of human lifestyle factors.
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| 5. |
- Marungruang, Nittaya, et al.
(författare)
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Heat-treated high-fat diet modifies gut microbiota and metabolic markers in apoe-/- mice
- 2016
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Ingår i: Nutrition & Metabolism. - : Springer Science and Business Media LLC. - 1743-7075. ; 13, s. 22-22
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: High-fat diet has been known to have adverse effects on metabolic markers, as well as the gut microbiota. However, the effect of heat processing of high-fat diet, which leads to formations of advanced glycation end products (AGEs) has not been clearly distinguished from the effect of unheated fat. This study compared the effect of high-fat diet with heat-treated high-fat diet on adiposity, atherosclerosis and gut microbiota composition in the caecum of apoe (-/-) mice.METHOD: Male apoe (-/-) mice were fed either low-fat (LF) control diet, high-fat (40 E% saturated fat, HF) control diet, or heat-treated high-fat (200 °C for 10 min, HT) diet, for 8 weeks. The plasma samples were used in the analysis of Nε-carboxy-methyl-lysine (CML) and Nε-carboxy-ethyl-lysine (CEL). The heart samples were analysed for atherosclerotic plaques, and the DNA from caecum was extracted and analysed for microbiota composition using 16S rRNA gene sequencing on a Miseq instrument. Additionally, the functions of microbial communities were also predicted based on the bacterial 16S rRNA gene sequence using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt).RESULTS: Here we found that HT modifies gut microbiota composition and host adiposity. Prediction of bacterial gene functions based on 16S rRNA gene sequence revealed that HF increased bacterial genera enriched in lipid metabolism genes, while HT did not. Plasma CML and CEL increased 1.7 and 2.5 times, respectively, in mice fed HT as compared to mice fed HF. Despite lower adiposity, mice fed HT maintained atherosclerosis and displayed enlarged spleens.CONCLUSIONS: The results suggested that heat processing of high-fat diet modifies the substrates reaching the lower gut of apoe (-/-) mice, resulting in different effects on gut microbiota composition. AGEs seem to maintain the effect on atherosclerosis, despite lower adiposity, and causing enlarged spleens, which possibly reflect elevated levels of inflammation in the body.
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| 6. |
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| 7. |
- Sunilkumar, Bindu A., et al.
(författare)
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Review of analytical methods for measurement of oat proteins : The need for standardized methods
- 2019
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Ingår i: Critical Reviews in Food Science and Nutrition. - : Informa UK Limited. - 1040-8398 .- 1549-7852. ; 59:9, s. 1467-1485
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Forskningsöversikt (refereegranskat)abstract
- This review summarizes the analytical methods that have been developed for quantification and characterization of oat proteins. These include sampling, sample preparation, extraction, quantification, separation, detection, and characterization of oat proteins. The review also provides a comparison of different methods for the determination of protein fraction of oat and the efficiency thereof. We conclude that there is a need for further validation of existing data or methods and for a standard methodology to quantify oat proteins.
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| 8. |
- SUNILKUMAR, BINDU, et al.
(författare)
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Identification of discrepancies in grain quality and grain protein composition through avenin proteins of oat after an effort to increase protein content
- 2016
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Ingår i: Agriculture & Food Security. - : Springer Science and Business Media LLC. - 2048-7010. ; 5:7
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Tidskriftsartikel (refereegranskat)abstract
- Background: Oat prolamin (avenin) is a family of proteins that contain several polymorphic components. The highinterspecific variability of avenin among cultivars, electrophoretic patterns have been used for grain protein comparisonand species relationships. Therefore, the present study was carried out to evaluate the effect of environment onavenin constitution following an effort to increase protein content of oat using different approaches.Results: The avenin electrophoretic patterns of 25 samples resulting from 20 oat cultivars and 5 mutated oat linesgrown or developed in different fields and greenhouses were compared. Quantification of total proteins and SDSPAGEanalysis of avenin protein extracts were carried out. Different pattern of avenin allele in electrophoretic gelallowed the comparison within and between groups. This analysis shows that the cultivars obtained from Swedishfields had differences in the number of alleles compared with the parental cultivar, so were not stable across sites. Thestudy revealed that oats treated with nitrogen and the selected mutated lines showed increase in protein concentration,with consistent avenin loci to the parental line, so these lines are now being used as potential candidates fordeveloping high-protein oat lines in the future.Conclusions: Our results provide useful information, on the stability of modifications, for breeders aiming to increasingthe content and nutritional value of oat protein. The study will increase our knowledge in the stability of differentmodifications and thus to accordingly select oat lines with stable and improved nutritional values.Keywords: Avenin, Mutation, Nitrogen, Geographical location, Electrophoresis
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| 9. |
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| 10. |
- Tareke, Eden, 1963-
(författare)
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Identification and origin of potential background carcinogens : endogenous isoprene and oxiranes, dietary acrylamide
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The primary aims of this thesis are to discover carcinogens in the general population by identification of products of reaction with hemoglobin (Hb adducts) in blood from humans without known exposure, and tracing the origin of the adducts. Chemicals and/or their metabolites forming Hb adducts mostly also react with DNA and may thus cause mutations, a key event in carcinogenesis. Factors, that may affect in vivo doses, that is cooking of food, degree of unsaturation of dietary fatty acids, and intestinal micro-flora, were investigated. Analysis of adducts to N-termini in Hb, by gas chromatography-tandem mass spectrometry (GC/MS-MS), was applied as a tool.Due to large endogenous production of isoprene the in vivo formation of reactive monoepoxides was studied. Two adducts originating from the monoepoxides were identified in rodents exposed to isoprene or isoprene monoepoxides. Relatively high in vivo doses of monoepoxides were found in mice compared to rats after treatment with isoprene, although the detoxification rates were about equal in both species. Despite an effective metabolism to monoepoxides as shown in the mouse, corresponding background adduct levels were very low in both rodents and humans, probably showing a very low cancer risk increment from endogenous isoprene.Hb adduct levels signify ubiquitous background doses of the mutagens/carcinogens ethylene oxide (EO) and propylene oxide (PO) in humans. Levels of these adducts were earlier shown to be lower in germ-free (GF) than in conventional (CV) mice. Detoxification was shown to be faster in CV mice, but, evidently due to still faster production the in vivo doses of EO and PO were higher in CV than in GF mice. The influence of unsaturated fatty acids was small. Formation of EO and PO and also of a peroxidation indicator in GF mice, that is in the absence of micro-flora, points towards ethene and propene, peroxidatively formed in tissues, being the precursors of the oxiranes. The same mechanism, amplified by changes of the host metabolism caused by the microflora, occurs also in CV animals.Background Hb adducts from acrylamide show a general occurrence, in humans at levels possibly associated with a relatively high cancer risk. Acrylamide is present in tobacco smoke. In wild animals lower adduct levels than in humans are observed. These facts indicate a role of cooking in acrylamide exposure, a hypothesis tested in animal feeding experiments. Rats fed heated feed showed increase of several adducts including un about 10 times increase of the adduct levels from acrylamide, identified by MS-MS in comparison with authentic standards, with confirmation by analysis of acrylamide in heated feed. In follow-up studies with heated foods, high acrylamide formation was found in carbohydrate-rich foodstuffs as compared to low levels in protein foods. Acrylamide was formed above 120°C in a temperature-dependent manner.These studies give support to the use of Hb adducts for the detection and identification of endogenous and exogenous genotoxic factors which are potential contributors to background cancer incidence, and for identification of determinants of their in vivo doses.
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| 11. |
- Tareke, Eden, et al.
(författare)
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Isotope dilution ESI-LC-MS/MS for quantification of free and total Nε-(1-Carboxymethyl)-l-Lysine and free Nε-(1-Carboxyethyl)-l-Lysine: Comparison of total Nε-(1-Carboxymethyl)-l-Lysine levels measured with new method to ELISA assay in gruel samples.
- 2013
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Ingår i: Food Chemistry. - : Elsevier BV. - 1873-7072 .- 0308-8146. ; 141:4, s. 4253-4259
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Tidskriftsartikel (refereegranskat)abstract
- ESI-LC-MS/MS method with isotope dilution and SPE based on cation-exchange was developed for determination of free and total Nε-(1-Carboxymethyl)-l-Lysine (CML) and free Nε-(1-Carboxyethyl)-l-Lysine (CEL). The use of nonafluoropentanoic acid in mobile phase was omitted, SPE recoveries of 82±3% and 91±10% (n=6) for CML and CEL respectively and, calibration curves (R(2)>0.9985) were attained. The method was applied to gruel samples and LoQ for the method was 5ng/ml, RSD <10% and accuracy was 115%. Total CML levels in the gruel samples varied from 103-408mg/kg protein. Free CML levels which were 1000 times lower than total CML were three times higher than free CEL levels. CML in a gruel sample was 127±7, 84±9 and 253±28mg/kg using the current ESI-LC-MS/MS, ELISA and GC-MS respectively. The described method has advantages over ELISA with respect to reproducibility and specificity and over GC-MS with respect to reproducibility.
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| 12. |
- Zhong, Yadong, et al.
(författare)
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Barley malt increases hindgut and portal butyric acid, modulates gene expression of gut tight junction proteins and Toll-like receptors in rats fed high-fat diets, but high advanced glycation end-products partially attenuate the effects.
- 2015
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Ingår i: Food & Function. - : Royal Society of Chemistry (RSC). - 2042-6496 .- 2042-650X. ; 6:9, s. 3165-3176
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Tidskriftsartikel (refereegranskat)abstract
- Barley malt, a product of controlled germination, has been shown to produce high levels of butyric acid in the cecum and portal serum of rats and may therefore have anti-inflammatory effects. The aim of the study was to investigate how four barley malts, caramelized and colored malts, 50-malt and 350-malt, differing in functional characteristics concerning beta-glucan content and color, affect short-chain fatty acids (SCFA), barrier function and inflammation in the hindgut of rats fed high-fat diets. Male Wistar rats were given malt-supplemented high-fat diets for four weeks. Low and high-fat diets containing microcrystalline cellulose were incorporated as controls. All diets contained 70 g kg(-1) dietary fiber. The malt-fed groups were found to have had induced higher amounts of butyric and propionic acids in the hindgut and portal serum compared with controls, while cecal succinic acid only increased to a small extent. Fat increased the mRNA expression of tight junction proteins and Toll-like receptors (TLR) in the small intestine and distal colon of the rats, as well as the concentration of some amino acids in the portal plasma, but malt seemed to counteract these adverse effects to some extent. However, the high content of advanced glycation end-products (AGE) in caramelized malt tended to prohibit the positive effects on occludin in the small intestine and plasma amino acids seen with the other malt products. In conclusion, malting seems to be an interesting process for producing foods with positive health effects, but part of these effects may be destroyed if the malt contains a high content of AGE.
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| 13. |
- Östman, Elin, et al.
(författare)
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On the importance of processing conditions for the nutritional characteristics of homogenized composite meals intended for infants
- 2016
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Ingår i: Nutrients. - : MDPI AG. - 2072-6643. ; 8:6
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Tidskriftsartikel (refereegranskat)abstract
- The nutritional quality of infant food is an important consideration in the effort to prevent a further increase in the rate of childhood obesity. We hypothesized that the canning of composite infant meals would lead to elevated contents of carboxymethyl-lysine (CML) and favor high glycemic and insulinemic responses compared with milder heat treatment conditions. We have compared composite infant pasta Bolognese meals that were either conventionally canned (CANPBol), or prepared by microwave cooking (MWPBol). A meal where the pasta and Bolognese sauce were separate during microwave cooking (MWP_CANBol) was also included. The infant meals were tested at breakfast in healthy adults using white wheat bread (WWB) as reference. A standardized lunch meal was served at 240 min and blood was collected from fasting to 360 min after breakfast. The 2-h glucose response (iAUC) was lower following the test meals than with WWB. The insulin response was lower after the MWP_CANBol (-47%, p = 0.0000) but markedly higher after CANPBol (+40%, p = 0.0019), compared with WWB. A combined measure of the glucose and insulin responses (ISIcomposite) revealed that MWP_CANBol resulted in 94% better insulin sensitivity than CANPBol. Additionally, the separate processing of the meal components in MWP_CANBol resulted in 39% lower CML levels than the CANPBol. It was therefore concluded that intake of commercially canned composite infant meals leads to reduced postprandial insulin sensitivity and increased exposure to oxidative stress promoting agents.
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