| 1. |
- Aalaei, Kataneh, et al.
(författare)
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Chemical methods and techniques to monitor early Maillard reaction in milk products; A review
- 2019
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Ingår i: Critical Reviews in Food Science and Nutrition. - : Informa UK Limited. - 1040-8398 .- 1549-7852. ; 59:12, s. 1829-1839
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Forskningsöversikt (refereegranskat)abstract
- Maillard reaction is an extensively studied, yet unresolved chemical reaction that occurs as a result of application of the heat and during the storage of foods. The formation of advanced glycation end products (AGEs) has been the focus of several investigations recently. These molecules which are formed at the advanced stage of the Maillard reaction, are suspected to be involved in autoimmune diseases in humans. Therefore, understanding to which extent this reaction occurs in foods, is of vital significance. Because of their composition, milk products are ideal media for this reaction, especially when application of heat and prolonged storage are considered. Thus, in this work several chemical approaches to monitor this reaction in an early stage are reviewed. This is mostly done regarding available lysine blockage which takes place in the very beginning of the reaction. The most popular methods and their applications to various products are reviewed. The methods including their modifications are described in detail and their findings are discussed. The present paper provides an insight into the history of the most frequently-used methods and provides an overview on the indicators of the Maillard reaction in the early stage with its focus on milk products and especially milk powders.
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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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Kinetics of available lysine in stored commercial skim milk powder at moderate temperatures
- 2018
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Ingår i: International Journal of Food Science and Technology. - : Wiley. - 0950-5423. ; 53:9, s. 2159-2165
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Tidskriftsartikel (refereegranskat)abstract
- Kinetics of lysine blockage, as an early step of the Maillard reaction, was investigated in commercial skim milk powder to understand the extent of the reaction, specifically after packages are opened and during the subsequent storage. Samples were stored at six conditions including three temperatures (30, 32.5 and 35 °C) and two relative humidities (43% and 52%) for 30 days, the period in which the product is recommended to be consumed after opening. The reaction rate was determined using a dye-binding method. Based on our findings, decrease in available lysine follows first-order reaction kinetics model. Small changes in temperature (2.5 °C) caused significant increase in the reaction rate constants. Relative humidity affected temperature dependency of the reaction, and activation energies were estimated to be 142.5-170.8 kJ mol-1. This study aims to increase the awareness of the significance of storage quality in relation to the nutritional status of the products.
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| 4. |
- Ahrné, Lilia, et al.
(författare)
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Improvement of texture by modifying processing conditions
- 2003
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Ingår i: Acta Hortic.. - : International Society for Horticultural Science. - 9789066059764 ; 604, s. 277-277
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Konferensbidrag (refereegranskat)abstract
- Fruit and vegetable processors, faced with the challenge of gaining and maintaining a healthy position in the competitive fruit and vegetable sector, are optimising traditional processes towards product quality. Using frozen potatoes as a case study, the aim of this study was to evaluate the potential of improving the texture of potatoes by modifying the processing conditions. The texture of processed frozen potatoes is the result of the integral effect of the unit operations applied through the production chain. Production of frozen potatoes includes a blanching, a freezing, thawing/cooking step before being served. In this study, blanching temperatures from 70 to 97 °C up to 10 minutes were tested and combined with freezing by two freezing methods, impingement and air-blast freezing. The texture was measured after cooking of frozen potatoes in boiling water. Besides texture, water holding capacity, microstructural evaluation and pectinmethylesterase (PME) activity were determined. Blanching of potatoes prior to freezing can both improve water holding capacity and texture of potatoes, but this effect depends on the freezing rate and blanching temperature. Potatoes frozen with fastest freezing method are firmer and hold more water than the ones frozen by air-blast freezing. Blanching at 70 °C can lead to potatoes that after cooking retain a firmer texture, compared with blanching at 90 °C. The duration of the blanching treatment has also an important effect on texture changes. The studies of PME activity showed a good correlation between texture and PME for blanching at 90 °C, but for blanching at 70°C and longer times, the development of texture does not seem to be solely related to PME activity. Microstructural studies showed that the differences in texture are due to differences in the degree of starch gelatinisation and integrity of the cellular structure.
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| 5. |
- Alklint, Charlotte, et al.
(författare)
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Effects of modified atmosphere on shelf-life of carrot juice
- 2004
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Ingår i: Food Control. - 0956-7135. ; 15:2, s. 131-137
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Tidskriftsartikel (refereegranskat)abstract
- The effects of de-aeration and modification of the headspace atmosphere on carrot juice shelf-life were investigated. The shelf-life was defined by microbial growth, determined by isothermal calorimetry and plate counts. Compared with storage under air, de-aeration of carrot juice by helium or nitrogen bubbling, followed by flush packaging had no effects on shelf-life. Similar treatment with carbon dioxide, giving a carbonated drink, prolonged the shelf-life by up to 250%. This effect could not be explained by the change in pH to 5.6, since the shelf-life was not prolonged by the addition of hydrochloric acid until pH <4.5. Both the concentrations of H+ and of dissolved CO2 were correlated to the shelf-life of fresh carrot juice; higher concentrations giving shorter shelf-lives. The concentration of dissolved CO2 was also linearly correlated to the peak thermal power. (C) 2003 Elsevier Ltd. All rights reserved.
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| 6. |
- Chiau, Eulália, et al.
(författare)
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Softening of dried Vangueria infausta (African medlar) using maltodextrin and sucrose
- 2013
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Ingår i: African Journal of Food Science. - 1996-0794. ; 7:10, s. 382-391
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Tidskriftsartikel (refereegranskat)abstract
- Softening of dried Vangueria infausta using maltodextrin and sucrose was investigated experimentally. The pulp of V. infausta was dried in a convective dryer, the influence of drying temperature as well as relationship between water content and water activity were examined. In this study, 48 samples of V. infausta pulp, with and without maltodextrin or sucrose, were dried at air temperatures of 60 and 80°C, at a constant air velocity of 3 m/s, for 0-240 min, and until constant weight. The water content, water activity, hardness and toughness were evaluated throughout the drying process. Samples dried at 80°C exhibited shorter drying times than samples dried at 60°C. The water activity of fruit dried for 240 min at 80°C varied from 0.633 to 0.759, and the fruit was thus safe regarding microbiological spoilage. The hardness and toughness of the dried fruit pulp increased with the reduction in water content, and it was observed that samples of pure pulp became unacceptably hard and tough, when dried to the level needed to obtain microbiological stability. The addition of sucrose as well as maltodextrin has shown to be able to reduce the hardness as well as the toughness of the dried fruit pulp; which can be considered as a strategy to obtain dried fruit pulp with suitable consistency.
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| 7. |
- Clausén, Maria, et al.
(författare)
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Post harvest improvement of zeaxanthin content of vegetables
- 2010
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Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774. ; 98:2, s. 192-197
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Tidskriftsartikel (refereegranskat)abstract
- Zeaxanthin is a carotenoid produced by plants and has been associated with protection of the photosynthetic machinery under light stress and, together with lutein, in protection of the central retina of the eye. Zeaxanthin levels in blood plasma have been negatively correlated to the development of AMD (age-related macular degeneration) (Gale et al, 2003). Under normal conditions, plants have a low content of zeaxanthin. The aim of this study was to increase the zeaxanthin content in green vegetables by post harvest treatments. Efficient conditions for activation of the endogenous enzyme system generating zeaxanthin was established and included incubation at low pH (2.5-5.5), with the membrane permeable acetic acid/acetate buffer at room temperature or above for 30 min or more. Typically more than 20-fold increase in zeaxanthin content was obtained for spinach, corn salad, parsley, basil, lemon balm and peas. For spinach up to 4 mg/100 g fresh weight of leaves were obtained. In consequence less amount of vegetables would be needed in the diet to provide the same amount of zeaxanthin for the eye. (C) 2010 Elsevier Ltd. All rights reserved.
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| 8. |
- Escobar, Mayra Paredes, et al.
(författare)
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Effect of long-term storage and blanching pre-treatments on the osmotic dehydration kinetics of carrots (Daucus carota L. cv. Nerac)
- 2007
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Ingår i: Journal of Food Engineering. - : Elsevier BV. - 0260-8774. ; 81:2, s. 313-317
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Tidskriftsartikel (refereegranskat)abstract
- The effect of postharvest long-term storage and pre-treatments on the mass transfer rates during osmotic dehydration of carrots was investigated. Four blanching times were used and the carrots were sampled during 12 weeks of storage. Cell vitality was measured by isothermal calorimetry on cores taken from blanched slices. During the storage period, effective diffusion coefficients for water and sucrose transport were determined in the non-blanched and blanched carrot parenchyma. For every time point during long-term storage, the effective diffusion coefficients increased with an increase in blanching time which caused the death of cells in the tissue. This increase showed to be dependent on the storage time of the carrots. It was inferred that structural changes in the cell wall of the carrot parenchyma during storage substantially decreases the effect of blanching on the effective diffusion coefficients. (c) 2006 Elsevier Ltd. All rights reserved.
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| 9. |
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| 10. |
- Gomez, Federico, et al.
(författare)
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Biochemical aspects of carrot processing
- 2003
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Ingår i: International Symposium on Future Technologies for Food Production and Future Food Scientists, Proceedings. - 0280-9737. ; :162, s. 87-87
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Konferensbidrag (refereegranskat)
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