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Theodore P Labuza - One of the best experts on this subject based on the ideXlab platform.
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storage stability of a commercial hen egg yolk powder in dry and Intermediate Moisture Food matrices
Journal of Agricultural and Food Chemistry, 2013Co-Authors: Mary Catherine Fisher, Theodore P LabuzaAbstract:Quality loss in Intermediate-Moisture Foods (IMF) such as high-protein nutrition bars (HPNB) in the form of hardening, nonenzymatic browning, and free amino group loss is a general concern for the manufacturers. To measure the extent of quality loss over time in terms of these negative attributes, through changing the ratio by weight between two commercial spray-dried hen egg powders, egg white (DEW) and egg yolk (DEY), the storage stability of 10 IMF systems (water activity (aw) ∼ 0.6) containing 5% glycerol, 10% shortening, 35% protein, and 50% sweetener (either maltitol or 50% high-fructose corn syrup/50% corn syrup (HFCS/CS)) were studied. Additionally, the storage stability of the DEY powder itself was investigated. Overall, during storage at different temperatures (23, 35, and 45 °C), the storage stability of DEY in dry and IMF matrices was mainly controlled by the coaction of three chemical reactions (disulfide bond interaction, Maillard reaction, and lipid oxidation). The results showed that by re...
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Storage stability of hen egg white powders in three protein/water dough model systems
Food Chemistry, 2013Co-Authors: Qinchun Rao, Jeancarlo R. Rocca-smith, Theodore P LabuzaAbstract:In recent years, due to the specific health benefits associated with bioactive peptides and the reduction of protein allergenicity by enzymatic hydrolysis, the utilisation of protein hydrolysates in the Intermediate-Moisture Food (IMF) market, such as high protein nutrition bars (HPNB), has significantly increased. Currently, no reported study is related to the storage stability of dried hen egg white (DEW) and its hydrolysates (HEW) in an IMF matrix. Therefore, three DEW/HEW dough model systems (100%HEW + 0%DEW, 75%HEW + 25%DEW and 50%HEW + 50%DEW) were established using two commercial spray-dried egg white powders to study the effect of temperature and fraction of HEW on these IMF models (water activity (aw): ∼0.8). During storage at three different temperatures (23, 35 and 45 °C) for 70 days, the selected physicochemical properties of the dough systems were compared. Overall, kinetic analysis showed an apparent zero-order model fit for the change in the colour (L*), fluorescence intensity (FI) and hardness, as a function of time, for different dough model systems. As expected, the L*, FI and hardness increased as a function of time mainly due to the Maillard reaction. The amount of free amino groups decreased, with an increase in rate of loss, as temperature increased in the 100%HEW + 0%DEW model. When DEW was substituted for some HEW, the regeneration of the free amino groups after loss was observed as a function of time. Furthermore, when the percentage of HEW was decreased, the incidence of mouldy samples occurred sooner, which indicates that HEW has some antimicrobial ability, especially in the 100%HEW + 0%DEW system where mould growth did not occur. © 2012 Elsevier Ltd. All rights reserved.
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Storage stability of a commercial hen egg yolk powder in dry and Intermediate-Moisture Food matrices
Journal of Agricultural and Food Chemistry, 2013Co-Authors: Qinchun Rao, Mary Catherine Fisher, Mufan Guo, Theodore P LabuzaAbstract:Quality loss in Intermediate-Moisture Foods (IMF) such as high-protein nutrition bars (HPNB) in the form of hardening, nonenzymatic browning, and free amino group loss is a general concern for the manufacturers. To measure the extent of quality loss over time in terms of these negative attributes, through changing the ratio by weight between two commercial spray-dried hen egg powders, egg white (DEW) and egg yolk (DEY), the storage stability of 10 IMF systems (water activity (aw) ∼ 0.6) containing 5% glycerol, 10% shortening, 35% protein, and 50% sweetener (either maltitol or 50% high-fructose corn syrup/50% corn syrup (HFCS/CS)) were studied. Additionally, the storage stability of the DEY powder itself was investigated. Overall, during storage at different temperatures (23, 35, and 45 °C), the storage stability of DEY in dry and IMF matrices was mainly controlled by the coaction of three chemical reactions (disulfide bond interaction, Maillard reaction, and lipid oxidation). The results showed that by replacing 25% of DEW in an IMF model system with DEY, the rate of bar hardening was significantly lower than that of the models with only DEW at all temperatures due to the softening effect of the fat in DEY. Furthermore, the use of maltitol instead of HFCS/CS in all bar systems not only resulted in decreased hardness but also drastically decreased the change in the total color difference (ΔE*). Interestingly, there was no significant loss of free amino groups in the maltitol systems at any DEW/DEY ratio.
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effect of fructose and glucose on glycation of β lactoglobulin in an Intermediate Moisture Food model system analysis by liquid chromatography mass spectrometry lc ms and data independent acquisition lc ms lc mse
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Ying Jia Chen, Theodore P Labuza, Peng Zhou, Li LiangAbstract:To evaluate the effect of glucose and fructose on the glycation of β-lactoglobulin (β-Lg) in Intermediate-Moisture Food (IMF), model systems consisting of β-Lg, glucose/fructose/sorbitol, glycerol, and water were established. All systems were stored at 25 and 35 °C for 2 months. The progress of the Maillard reaction and the mass change of β-Lg were investigated by the browning assay and gel electrophoresis, respectively. Meanwhile, liquid chromatography–mass spectrometry (LC–MS) and data-independent acquisition LC–MS (LC–MSE) were used to monitor the glycation extent and the glycated sites of β-Lg. The results indicated that glucose had a higher reaction activity of glycation than fructose, but both sugars had similar preference on the glycation site for β-Lg. The ranking order from high to low for the 9 detected glycated sites was L 1, K 91 > K 47 > K 70, K 77, K 83, K 100 > K 75 > K 135 for both sugars.
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effects of sucrose crystallization and Moisture migration on the structural changes of a coated Intermediate Moisture Food
Frontiers of Chemical Engineering in China, 2009Co-Authors: Tiancheng Li, Peng Zhou, Theodore P LabuzaAbstract:The purpose of this study was to investigate whether Moisture migration and sugar crystallization play an important role in the changes of IMF matrix structure. The migration of water was monitored with changes of water activity in different physical domains of samples during storage, while the crystallization of sucrose was determined with X-ray powder diffraction (XRD). The formation of both a hard inner-layer and agglomerated particles in the inner matrix was observed during storage. Our results suggested that both Moisture loss and sucrose crystallization were mainly responsible for the formation of the crusty Intermediate inner layer, and the agglomerated matrix particles were the result of sucrose crystallization.
Peng Zhou - One of the best experts on this subject based on the ideXlab platform.
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effects of addition of hydrocolloids on the textural and structural properties of high protein Intermediate Moisture Food model systems containing sodium caseinate
Food & Function, 2017Co-Authors: Jinwei Li, Y Wu, N Lu, Joe M Regenstein, Peng ZhouAbstract:High-protein Intermediate Moisture Food (HPIMF) containing sodium caseinate (NaCN) often gave a harder texture compared with that made from whey proteins or soy proteins, due to the aggregation of protein particles. The objectives of this study were to explore whether the addition of hydrocolloids could soften the texture and illustrate the possible mechanism. Three kinds of hydrocolloids, xanthan gum, κ-carrageenan, and gum arabic were chosen, and samples including of these three kinds of hydrocolloids were studied through texture analysis using a TPA test and microstructure observation by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The texture analysis results showed that xanthan gum was more effective at softening the HPIMF containing NaCN compared to κ-carrageenan and gum arabic. In addition, with the increase of xanthan gum concentration from 0.2 to 2%, the HPIMF matrix became softer, and fractures were observed during the compression for samples with xanthan gum added at low concentrations but not 2%. Microstructure observation suggested that the matrix originally dominated by the network formed through the aggregation of swollen protein particles was inhibited by the addition of xanthan gum, resulting in the softening of the texture and also contributing to the fracture during compression. With the increase of xanthan gum concentration up to 2%, the protein dominating network would be gradually replaced with a matrix dominated by the newly formed network of xanthan gum with protein particles as fillers. Furthermore, this formation of a xanthan gum dominating network structure also resulted in changes in small molecule distribution, as observed using low-field NMR.
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effect of fructose and glucose on glycation of β lactoglobulin in an Intermediate Moisture Food model system analysis by liquid chromatography mass spectrometry lc ms and data independent acquisition lc ms lc mse
Journal of Agricultural and Food Chemistry, 2012Co-Authors: Ying Jia Chen, Theodore P Labuza, Peng Zhou, Li LiangAbstract:To evaluate the effect of glucose and fructose on the glycation of β-lactoglobulin (β-Lg) in Intermediate-Moisture Food (IMF), model systems consisting of β-Lg, glucose/fructose/sorbitol, glycerol, and water were established. All systems were stored at 25 and 35 °C for 2 months. The progress of the Maillard reaction and the mass change of β-Lg were investigated by the browning assay and gel electrophoresis, respectively. Meanwhile, liquid chromatography–mass spectrometry (LC–MS) and data-independent acquisition LC–MS (LC–MSE) were used to monitor the glycation extent and the glycated sites of β-Lg. The results indicated that glucose had a higher reaction activity of glycation than fructose, but both sugars had similar preference on the glycation site for β-Lg. The ranking order from high to low for the 9 detected glycated sites was L 1, K 91 > K 47 > K 70, K 77, K 83, K 100 > K 75 > K 135 for both sugars.
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effects of sucrose crystallization and Moisture migration on the structural changes of a coated Intermediate Moisture Food
Frontiers of Chemical Engineering in China, 2009Co-Authors: Tiancheng Li, Peng Zhou, Theodore P LabuzaAbstract:The purpose of this study was to investigate whether Moisture migration and sugar crystallization play an important role in the changes of IMF matrix structure. The migration of water was monitored with changes of water activity in different physical domains of samples during storage, while the crystallization of sucrose was determined with X-ray powder diffraction (XRD). The formation of both a hard inner-layer and agglomerated particles in the inner matrix was observed during storage. Our results suggested that both Moisture loss and sucrose crystallization were mainly responsible for the formation of the crusty Intermediate inner layer, and the agglomerated matrix particles were the result of sucrose crystallization.
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effects of polyols on the stability of whey proteins in Intermediate Moisture Food model systems
Journal of Agricultural and Food Chemistry, 2009Co-Authors: Amy Tran, Peng Zhou, Theodore P LabuzaAbstract:The objective of this study was to investigate the influence of polyols on the stability of whey proteins in an Intermediate-Moisture Food model system and to elucidate the effect of polyols on the hardening of whey protein-based bars during storage. Four major polyols, glycerol, propylene glycol, maltitol, and sorbitol, were evaluated in model systems, which contained whey protein isolate, polyols, and water. The results showed that glycerol was the most effective polyol in lowering water activity and provided the soft texture of Intermediate-Moisture Foods, followed by sorbitol and maltitol. These three polyols stabilized the native structure of whey proteins, provided a desired texture, and slowed the hardening of the model systems. Propylene glycol should not be used in whey protein-based high-protein Intermediate-Moisture Foods because it caused changes in protein conformation and stability as observed by differential scanning calorimeter and Fourier transform infrared spectroscopy and resulted in ag...
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Effects of polyols on the stability of whey proteins in Intermediate-Moisture Food model systems
Journal of Agricultural and Food Chemistry, 2009Co-Authors: Xiao Ming Liu, Amy Tran, Peng Zhou, Theodore P LabuzaAbstract:The objective of this study was to investigate the influence of polyols on the stability of whey proteins in an Intermediate-Moisture Food model system and to elucidate the effect of polyols on the hardening of whey protein-based bars during storage. Four major polyols, glycerol, propylene glycol, maltitol, and sorbitol, were evaluated in model systems, which contained whey protein isolate, polyols, and water. The results showed that glycerol was the most effective polyol in lowering water activity and provided the soft texture of Intermediate-Moisture Foods, followed by sorbitol and maltitol. These three polyols stabilized the native structure of whey proteins, provided a desired texture, and slowed the hardening of the model systems. Propylene glycol should not be used in whey protein-based high-protein Intermediate-Moisture Foods because it caused changes in protein conformation and stability as observed by differential scanning calorimeter and Fourier transform infrared spectroscopy and resulted in aggregation of whey proteins and hardening of the bar texture during storage, causing loss in product quality.
Juan A. Ordóñez - One of the best experts on this subject based on the ideXlab platform.
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Headspace volatile compounds from salted and occasionally smoked dried meats (cecinas) as affected by animal species
Food Chemistry, 2004Co-Authors: Eva Hierro, Juan A. OrdóñezAbstract:Abstract “Cecina” is a traditional Intermediate Moisture Food prepared by salting, drying and, occasionally, smoking meat pieces. The stability and long shelf-life of these products are due to their low water activity ( a w ), ranging from 0.90 to 0.60. The headspace volatile compounds from samples of dry meats from venison, beef, horse and goat cecina were analysed by gas chromatography–mass spectrometry (GC/MS) to characterise the volatile profile of these meat products. In general, about 110 volatile compounds were identified and quantified. Typical breakdown products derived from lipid oxidation, amino acid catabolism and carbohydrate fermentation were the main volatiles detected in all cecinas, together with the volatiles generated by the smoking process. However, horse cecina also presented important concentrations of esters and showed very few volatiles coming from the smoke.
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Headspace volatile compounds from salted and occasionally smoked dried meats (cecinas) as affected by animal species
Food Chemistry, 2004Co-Authors: Eva Hierro, Lorenzo De La Hoz, Juan A. OrdóñezAbstract:"Cecina" is a traditional Intermediate Moisture Food prepared by salting, drying and, occasionally, smoking meat pieces. The stability and long shelf-life of these products are due to their low water activity (aw), ranging from 0.90 to 0.60. The headspace volatile compounds from samples of dry meats from venison, beef, horse and goat cecina were analysed by gas chromatography-mass spectrometry (GC/MS) to characterise the volatile profile of these meat products. In general, about 110 volatile compounds were identified and quantified. Typical breakdown products derived from lipid oxidation, amino acid catabolism and carbohydrate fermentation were the main volatiles detected in all cecinas, together with the volatiles generated by the smoking process. However, horse cecina also presented important concentrations of esters and showed very few volatiles coming from the smoke. © 2003 Elsevier Ltd. All rights reserved.
D. S. Nielsen - One of the best experts on this subject based on the ideXlab platform.
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growth no growth models for zygosaccharomyces rouxii associated with acidic sweet Intermediate Moisture Food products
International Journal of Food Microbiology, 2015Co-Authors: C. L. Marvig, R. M. Kristiansen, D. S. NielsenAbstract:Abstract The most notorious spoilage organism of sweet Intermediate Moisture Foods (IMFs) is Zygosaccharomyces rouxii, which can grow at low water activity, low pH and in the presence of organic acids. Together with an increased consumer demand for preservative free and healthier Food products with less sugar and fat and a traditionally long self-life of sweet IMFs, the presence of Z. rouxii in the raw materials for IMFs has made assessment of the microbiological stability a significant hurdle in product development. Therefore, knowledge on growth/no growth boundaries of Z. rouxii in sweet IMFs is important to ensure microbiological stability and aid product development. Several models have been developed for fat based, sweet IMFs. However, fruit/sugar based IMFs, such as fruit based chocolate fillings and jams, have lower pH and aw than what is accounted for in previously developed models. In the present study growth/no growth models for acidified sweet IMFs were developed with the variables aw (0.65–0.80), pH (2.5–4.0), ethanol (0–14.5% (w/w) in water phase) and time (0–90 days). Two different strains of Z. rouxii previously found to show pronounced resistance to the investigated variables were included in model development, to account for strain differences. For both strains data sets with and without the presence of sorbic acid (250 ppm on product basis) were built. Incorporation of time as an exploratory variable in the models gave the possibility to predict the growth/no growth boundaries at each time between 0 and 90 days without decreasing the predictive power of the models. The influence of ethanol and aw on the growth/no growth boundary of Z. rouxii was most pronounced in the first 30 days and 60 days of incubation, respectively. The effect of pH was almost negligible in the range of 2.5–4.0. The presence of low levels of sorbic acid (250 ppm) eliminated growth of both strains at all conditions tested. The two strains tested have previously been shown to have similar tolerance towards the single stress factors included in the study, but when the stress factors were combined the two strains showed difference in their ability to grow illustrating the importance of including more strains when developing growth/no growth models. The developed models can be useful tools for development of new acidic sweet IMFs.
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Growth/no growth models for Zygosaccharomyces rouxii associated with acidic, sweet Intermediate Moisture Food products
International Journal of Food Microbiology, 2015Co-Authors: C. L. Marvig, R. M. Kristiansen, D. S. NielsenAbstract:The most notorious spoilage organism of sweet Intermediate Moisture Foods (IMFs) is Zygosaccharomyces rouxii, which can grow at low water activity, low pH and in the presence of organic acids. Together with an increased consumer demand for preservative free and healthier Food products with less sugar and fat and a traditionally long self-life of sweet IMFs, the presence of Z. rouxii in the raw materials for IMFs has made assessment of the microbiological stability a significant hurdle in product development. Therefore, knowledge on growth/no growth boundaries of Z. rouxii in sweet IMFs is important to ensure microbiological stability and aid product development. Several models have been developed for fat based, sweet IMFs. However, fruit/sugar based IMFs, such as fruit based chocolate fillings and jams, have lower pH and awthan what is accounted for in previously developed models.In the present study growth/no growth models for acidified sweet IMFs were developed with the variables aw(0.65-0.80), pH (2.5-4.0), ethanol (0-14.5% (w/w) in water phase) and time (0-90days). Two different strains of Z. rouxii previously found to show pronounced resistance to the investigated variables were included in model development, to account for strain differences. For both strains data sets with and without the presence of sorbic acid (250ppm on product basis) were built.Incorporation of time as an exploratory variable in the models gave the possibility to predict the growth/no growth boundaries at each time between 0 and 90days without decreasing the predictive power of the models. The influence of ethanol and awon the growth/no growth boundary of Z. rouxii was most pronounced in the first 30days and 60days of incubation, respectively. The effect of pH was almost negligible in the range of 2.5-4.0. The presence of low levels of sorbic acid (250ppm) eliminated growth of both strains at all conditions tested. The two strains tested have previously been shown to have similar tolerance towards the single stress factors included in the study, but when the stress factors were combined the two strains showed difference in their ability to grow illustrating the importance of including more strains when developing growth/no growth models. The developed models can be useful tools for development of new acidic sweet IMFs.
Eva Hierro - One of the best experts on this subject based on the ideXlab platform.
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Headspace volatile compounds from salted and occasionally smoked dried meats (cecinas) as affected by animal species
Food Chemistry, 2004Co-Authors: Eva Hierro, Juan A. OrdóñezAbstract:Abstract “Cecina” is a traditional Intermediate Moisture Food prepared by salting, drying and, occasionally, smoking meat pieces. The stability and long shelf-life of these products are due to their low water activity ( a w ), ranging from 0.90 to 0.60. The headspace volatile compounds from samples of dry meats from venison, beef, horse and goat cecina were analysed by gas chromatography–mass spectrometry (GC/MS) to characterise the volatile profile of these meat products. In general, about 110 volatile compounds were identified and quantified. Typical breakdown products derived from lipid oxidation, amino acid catabolism and carbohydrate fermentation were the main volatiles detected in all cecinas, together with the volatiles generated by the smoking process. However, horse cecina also presented important concentrations of esters and showed very few volatiles coming from the smoke.
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Headspace volatile compounds from salted and occasionally smoked dried meats (cecinas) as affected by animal species
Food Chemistry, 2004Co-Authors: Eva Hierro, Lorenzo De La Hoz, Juan A. OrdóñezAbstract:"Cecina" is a traditional Intermediate Moisture Food prepared by salting, drying and, occasionally, smoking meat pieces. The stability and long shelf-life of these products are due to their low water activity (aw), ranging from 0.90 to 0.60. The headspace volatile compounds from samples of dry meats from venison, beef, horse and goat cecina were analysed by gas chromatography-mass spectrometry (GC/MS) to characterise the volatile profile of these meat products. In general, about 110 volatile compounds were identified and quantified. Typical breakdown products derived from lipid oxidation, amino acid catabolism and carbohydrate fermentation were the main volatiles detected in all cecinas, together with the volatiles generated by the smoking process. However, horse cecina also presented important concentrations of esters and showed very few volatiles coming from the smoke. © 2003 Elsevier Ltd. All rights reserved.