Maillard Products Research Articles

Casein–casein interactions in the presence of dairy associated carbohydrates analysed using surface plasmon resonance

Ultrahigh temperature (UHT) processed and lactose-free milk are for export to Eastern markets. Free galactose and glucose in lactose-free milk increase occurrence of Maillard products and hence lower milk quality. Notably, enzymatic conversion of galactose into galacto-oligosaccharides (GOS) mitigates such undesirable reactions. As little is known about the effect of GOS on caseins, interactions between caseins in presence or absence of GOS or lactose were assessed by surface plasmon resonance analysis. Based on steady state binding constants (KD) soluble αS-casein showed one order of magnitude lower affinity than soluble β-casein and κ-casein for chip-immobilised αS- and β-casein. By contrast, αS-casein had higher affinity for immobilised κ-casein, followed by β- and κ-casein. The interaction between the caseins did not obey a 1:1 binding model and it was not possible to calculate a precise stoichiometry. Importantly, lactose and GOS exerted very modest or no effect on the various interaction between the caseins.

Effects of microwave heating on the protein structure, digestion properties and Maillard products of gluten

As a kind of traditional food, gluten is widely studied for its physical and chemical properties after processing, while little attention is paid to the simulation cooking processing, digestion and safety. In this paper, gluten was heated with microwave to study its structural transformations, nutritional efficiency, and food safety under Chinese home cooking (CHC). After microwave treatment, intermolecular and intramolecular cross-linking of gluten were formed to result in more aggregation. The secondary structure of gluten changed significantly as well as the formation of α-helix and β-turn promoted under the high power input. Treated with 1000W for 5min, cross-linking between amino acids increased, leading the reduction of total amino acids, in vitro protein digestibility and the increase of high molecular weight peptides, while the proportion of essential amino acids kept the same. In the simulation of CHC, the highest content of 5-hydroxymethyl furfural was observed after adding all condiments under 1000W for 5min. In addition, sugar played a major role in Maillard reaction to promote the formation of melanoidin and fructosamine while salt and oil did not significantly affect these two Maillard products. Vinegar inhibited the reaction due to the acidic condition but provided some melanoidin and fructosamine itself.

Relationship among the minor constituents, antibacterial activity and geographical origin of honey: A multifactor perspective

Some minor constituents of honey samples were determined through a fluorometric-chemical characterization method and related multifactorially with their antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa and with their geographical origin. Rotated principal component analysis identified five significant components in honey: three related to antibacterial activity and linked to phenolic compounds; Maillard products; proteins; the concentration of H2O2 at 3 and 24 h of incubation; and a tyrosine-containing entity. On the other hand, five constituents (phenolic compounds were the most relevant) allowed the classification of honey samples by geographical origin with 87% certainty. The results showed that phenolic compounds and Maillard products are related to the sustained production of H2O2 over time, which in turn boosts the antibacterial activity of honey. Native flora could promote this capability. The results showed the effect of geographic origin on the content of the analyzed minor constituents of honey, particularly phenolic compounds.

Advanced Glycation End Products (AGEs) May Be a Striking Link Between Modern Diet and Health.

The Maillard reaction is a simple but ubiquitous reaction that occurs both in vivo and ex vivo during the cooking or processing of foods under high-temperature conditions, such as baking, frying, or grilling. Glycation of proteins is a post-translational modification that forms temporary adducts, which, on further crosslinking and rearrangement, form permanent residues known as advanced glycation end products (AGEs). Cooking at high temperature results in various food products having high levels of AGEs. This review underlines the basis of AGE formation and their corresponding deleterious effects on the body. Glycated Maillard products have a direct association with the pathophysiology of some metabolic diseases, such as diabetes mellitus type 2 (DM2), acute renal failure (ARF), Alzheimer’s disease, dental health, allergies, and polycystic ovary syndrome (PCOS). The most glycated and structurally abundant protein is collagen, which acts as a marker for diabetes and aging, where decreased levels indicate reduced skin elasticity. In diabetes, high levels of AGEs are associated with carotid thickening, ischemic heart disease, uremic cardiomyopathy, and kidney failure. AGEs also mimic hormones or regulate/modify their receptor mechanisms at the DNA level. In women, a high AGE diet directly correlates with high levels of androgens, anti-Müllerian hormone, insulin, and androstenedione, promoting ovarian dysfunction and/or infertility. Vitamin D3 is well-associated with the pathogenesis of PCOS and modulates steroidogenesis. It also exhibits a protective mechanism against the harmful effects of AGEs. This review elucidates and summarizes the processing of infant formula milk and the associated health hazards. Formulated according to the nutritional requirements of the newborn as a substitute for mother’s milk, formula milk is a rich source of primary adducts, such as carboxy-methyl lysine, which render an infant prone to inflammation, dementia, food allergies, and other diseases. We therefore recommend that understanding this post-translational modification is the key to unlocking the mechanisms and physiology of various metabolic syndromes.

Impact of Packaging and Muscle Type on Beef Flavor Development

ObjectivesThe objective of this study was to determine the influence of packaging type on production of beef flavor volatile compounds.Materials and MethodsBeef strip loins (IMPS #180) and top sirloin butts (IMPS #184) were selected from USDA Low Choice carcasses (n = 40, 20/subprimal). Seven d postmortem, subprimals were fabricated into 2.54 cm representative steaks of the Longissimus lumborum (LL) and Gluteus medius (GM). Steaks were then placed into one of four randomly assigned packaging treatments: carbon monoxide motherbag (0.4% CO/30% CO2/69.6% N2; CO), high oxygen modified atmosphere packaging (80% O2/20% CO2; HIOX), traditional polyvinyl chloride overwrap (OW), and rollstock (ROLL). Steaks designated for the OW treatment were placed in ROLL treatment until retail display. Steaks were aged in the absence of light for 14 d, then subjected to a 48-h retail display under fluorescent lighting in coffin cases. Following retail display, steaks were immediately vacuum packaged and frozen at –20°C until further analysis. Prior to volatile compound analysis, steaks were thawed at 2–4°C. Steaks were then cooked to 71°C using clamshell grills. Immediately after cooking, six 1.27 cm cores were removed, then minced using a coffee grinder. Five g of sample was weighed into a glass vial, sealed, then analyzed using gas chromatography-mass spectrometry. Compounds evaluated were chosen from major flavor pathways.ResultsThree compounds, carbon disulfide, 2-pentylfuran, and benzaldehyde elicited a packaging type × muscle interaction (P ≤ 0.048). Carbon disulfide was present in the highest concentration (P < 0.05) in CO GM and ROLL LL steaks, but was present in the lowest amount (P < 0.05) in OW GM and ROLL GM steaks. For benzaldehyde, HIOX GM steaks produced the greatest concentration (P < 0.05) compared to all other treatments, with the exception of ROLL LL, which was similar (P > 0.05). A similar trend existed for 2-pentylfuran, as high oxygen GM steaks produced over three times higher concentrations (P < 0.05) of 2-pentylfuran compared to all other treatments. Nine compounds, primarily lipid derived, were impacted by a packaging main effect (P < 0.043). For 2-propanone, pentane, and hexanoic acid, methyl ester, HIOX packaging produced the greatest concentration (P < 0.05) compared to all other treatments. Additionally, HIOX steaks produced a greater amount (P < 0.05) of methanethiol than OW or ROLL steaks. High oxygen steaks produced more (P < 0.05) 1-pentanol, 1-octen-3-ol, and nonanal than CO steaks, but were similar to ROLL and OW steaks. Carbon monoxide packaging produced the greatest amount (P < 0.05) of 2,3-butanediol compared to all other treatments. Five compounds were impacted by the muscle main effect (P ≤ 0.039). The GM steaks produced a greater concentration of 2,3-butanedione (P = 0.011), 3-hydroxy-2-butanone (P = 0.002), octanoic acid (P < 0.001), and dodecanal (P = 0.021) than the LL steaks. The LL produced a greater amount of decanal (P = 0.039) than the GM.ConclusionThese results indicate packaging and muscle each impact flavor, however, packaging effects are primarily lipid derived and muscle more readily impacts Maillard product production. Additionally, HIOX packaging produces a large amount of lipid derived compounds from degradation and oxidation, which may form the basis for its negative flavor profile. This indicates HIOX packaging should be avoided to produce more positive flavor notes in beef.

Cooking up low-acrylamide foods

The Maillard reaction is arguably the world’s most beloved chemical process. Cooks learned long ago that raw, unappetizing ingredients such as potatoes and grains can be turned into toasty treats with the addition of heat and a bit of time. Chemists know our enjoyment is due to the magic that happens when amino acids meet sugars to produce mouthwatering organic compounds such as pyrazines, pyrroles, and furanones. But in 2002 the food world learned that this browning reaction has a dark side. It turns out that one of those Maillard products is acrylamide, a chemical long known to cause cancer in animal studies. In humans, it is considered likely to be carcinogenic and has been identified as a cancer-causing agent in tobacco smoke. Acrylamide is used industrially to make polyacrylamides–water-soluble thickeners widely used in grouts and water treatment facilities. Because of acrylamide’s human health effects, regulators including the US Environmental

Levels of Furaneol in Msalais Wines: A Comprehensive Overview of Multiple Stages and Pathways of Its Formation during Msalais Winemaking.

4-Hydroxy-2,5-dimethyl-3(2H)-furanone (furaneol) is present in food. It has a caramel-like flavor, which affects the quality of food, and is formed via multiple pathways. Msalais is a traditional wine fermented from boiled local grape juice in Xinjiang (China). It has a strong caramel odor, which suggests high furaneol content. Furaneol formation during Msalais-making had not been investigated to date. Here, high-performance liquid chromatography and different fermentation models of Msalais-making were used to investigate the furaneol content and formation during Msalais-making. The furaneol content of Msalais is high, between 27.59 ± 0.493 mg/L and 117.6 ± 0.235 mg/L. It is formed throughout the entire Msalais-making process. The formation pathways include the Maillard reaction and chemical hydrolysis of bound furaneol during grape juice concentration; enzymatic release and/or chemical acidic hydrolysis of furaneol glucosides, and biosynthesis from Maillard products and d-fructose-1,6-diphosphate during fermentation; chemical transformation of Maillard products at room temperature (16–25 °C) and hydrolysis of furaneol glucosides during storage. Importantly, furaneol is formed by an efficient biotransformation of Maillard products. These findings suggest that furaneol content can be used as an important indicator of wine quality, and could be controlled by controlling the grape quality, grape juice concentration, fermentation, and wine storage.

Novel unfiltered beer-based marinades to improve the nutritional quality, safety, and sensory perception of grilled ruminant meats

Ruminant meat is considered an excellent source of proteins, dietary fatty acids and essential minerals. Grilling is a popular cooking method; however, the high temperatures employ could modify the grilled meat quality and safety. In this study, the effects of novel beer-based marinades infused with herbs and spices on the quality, safety, and sensory perception of grilled beef and moose meat is examined. Unmarinated meat showed high content of volatile lipid oxidation and Maillard reaction products compared to the marinated samples, which contained higher number and abundance of terpenes and sulfur based compounds. Strong relationships between Maillard products and heterocyclic amines formation, as well as between volatile terpenes and the lipophilic antioxidant activity, were observed in the grilled meats. The findings suggest the unfiltered beer-based marinades were effective in reducing lipid oxidation and Maillard reaction compounds formation, while improving the nutritional quality, safety and sensory preference of grilled ruminant meats.

Effects of ultrasonic treatment on Maillard reaction and product characteristics of enzymatic hydrolysate derived from mussel meat

AbstractMussel meat is rich in amino acids and is a good source of flavor enhancers. To find a high‐efficiency and suitable method for the Maillard reaction (MR) of enzymatic hydrolysate derived from mussel meat, we studied the changes of Maillard reaction between enzymatic hydrolysate and glucose/xylose under ultrasonic treatment (UsT), heat treatment (HT) and ultrasonic‐assisted heat treatment (Us‐HT). It was found the Us‐HT displayed the highest Maillard reaction rate and a significant increase in intermediate products and melanoidins compared to HT and UsT. The Maillard reaction products (MRPs) derived from the three treatments showed higher antioxidant activity, while the MRPs from Us‐HT had the highest antioxidant activity and ideal sensory properties. Therefore, Us‐HT is a potential method to prepare the Maillard flavor enhancer from mussel meat.Practical ApplicationsThe ultrasonic technology was applied as a novel food processing technique and can effectively promote the interaction of certain ingredients. Compared with single ultrasonic or heat treatment, ultrasonic‐assisted heat treatment can accelerate the reaction and improve sensory properties and antioxidant activities of MRPs derived from mussel meat hydrolysate. The ultrasonic‐assisted heat treatment is a potential technology for preparing the Maillard flavor enhancer. This efficient method supports the utilization of mussel meat and the development of flavoring essence and functional foods in the future.

79 Cooking method and beef flavor: a multivariate approach

Abstract The objective of this study was to determine the impact of sous vide cookery followed by finishing on four dry heat cookery methods and two quality grades on beef volatile flavor compound production in beef strip loin steaks. Beef strip loins (n = 40, 20/grade) were procured from two USDA quality grades: upper 2/3rds of Choice and Select. Strip loins were aged for 21 d at 2 to 4°C. Following aging, strip loins were sliced into 2.54 cm steaks, vacuum packaged, and frozen at -20°C. Steaks were thawed, then cooked sous vide in a circulating water bath at 63.5°C for 1.5 h. Steaks were finished to a medium degree of doneness (71°C) on one of four cooking methods: charbroiler grill (CHAR), clamshell grill (CLAM), convection oven (OVEN), and salamander broiler (SALA). Steaks were immediately submerged into ice to stop cooking, vacuum packaged and frozen at -20°C until analysis. Volatile compounds (n = 73) were identified using gas chromatography-mass spectrometry and were selected from the Maillard reaction and lipid degradation pathways. Principal component analysis (PCA) was used to observe the relationships between volatile compounds and consumer ratings of beef strip loin steaks. When PCA was conducted, principal component (PC) 1 represented 50.59% and PC 2 represented 29.76% of the variation. Salamander steaks of both quality grades were the most closely associated with flavor, tenderness, juiciness, and overall liking. Charbroiler steaks were the most closely related with Maillard products, especially pyrazines, sulfur containing compounds, and pyrroles. Oven steaks were more associated with compounds associated with lipid degradation, including hexanol, hexanal, and 2-pentylfuran. Clamshell steaks were negatively associated with consumer palatability traits, which was expected, due to the poor liking ratings from consumers. These data indicate cooking method can directly impact flavor of beef strip loin steaks, regardless of quality grade

Solutes in sap obtained from supercritical CO2 dewatering of radiata pine sapwood, and a new role of sap cyclitols in brown stain formation during kiln drying of green wood

Abstract Xylem sap obtained from radiata pine sapwood using a supercritical CO2 (scCO2) dewatering process contained a complex mixture of solutes comprising carbohydrates, amino acids, alkanoic and diterpene acids, neutral diterpenoids, β-sitosterol and cyclitols. Sap also contained free phosphoric acid which is known to catalyse the condensation reactions between glutamic and aspartic amino acids and glucose, galactose and fructose to form Maillard products. When heated these Maillard products lead to the formation of melanoidins, which are partly responsible for the formation of kiln brown stain (KBS) when green radiata pine sapwood is kiln dried. The cyclitols, which are major components in sap, have been shown to undergo phosphoric acid-catalysed dehydration reactions under kiln drying conditions to give methoxyl derivatives of hydroquinone, catechol, resorcinol and O-methylphloroglucinol. These reactive phenols are known to exothermally condense with formaldehyde and could also react with other short carbon chain aldehydes generated during kiln drying. The products of these chemical reactions are extended π-orbital aromatic polymers which are darkly-coloured and would be expected to contribute to KBS. This paper describes the chemistry of sap from radiata pine sapwood using scCO2 dewatering and proposes new theory on KBS formation invoking thermal dehydration and retro Diels-Alder chemical reactions of the sap cyclitols.

Determination of thermal transitions of gluten-free chestnut flour doughs enriched with brown seaweed powders and antioxidant properties of baked cookies

A protocol for determining the characteristic temperatures of thermomechanical transitions on gluten-free flour doughs is proposed. This protocol is based on the mathematical analysis of experimental curve of storage modulus (G′) vs temperature obtained by means of Dynamic Mechanical Thermal Analysis (DMTA) technique. Doughs at constant consistency of chestnut flour with different levels (3, 6 and 9% flour basis, f.b.) of brown seaweed (Bifurcaria bifurcata, Fucus vesiculosus and Ascophyllum nodosum) powders addition, 2% f.b. of guar gum and 1.8% f.b. of salt with different water absorption were used to test the proposed protocol. The ranges of temperatures corresponding to starch gelatinization (59–97 °C), amylopectin crystallites melting (82–101 °C), reversible dissociation of lipid-amylose complexes (107–128 °C) and amylose melting (133–171 °C) showed a strong dependence with water absorption of samples. Doughs with the same water absorption submitted to starch gelatinization during mixing were also analysed to corroborate the protocol suitability. Total polyphenols content and radical scavenging activity of extracts from chestnut flour-seaweed powder blends and seaweed-enriched chestnut cookies baked at 180 °C were determined. Extraction assisted with ultrasounds was carried out employing acetone-water (70:30 v/v) solution as solvent during 4 min with a liquid/solid ratio of 30 w/w. Seaweed powder addition had a positive effect on antioxidant properties of doughs before baking. However, the seaweed powder addition effect on baked products (cookies) is not clear due to antioxidant activity is overlapped by Maillard's products generated during baking.

Functional properties of muffin as affected by substituing wheat flour with carob powder

Carob (Cerationa soliqua L.) pod is the good source of dietary fiber, minerals and polyphenolic substances. The aim of this study was to prepare muffin where wheat flour was substituted with carob powder, and determine some physicochemical properties. Carob powder was prepared by milling dry carob pods to particles smaller than 600 μm. Then wheat flour in muffin dough was replaced by carob powder in 5, 10, 15 and 20% (w/w) and subsequently baked at 180 °C for 20 min. It was found that the height of the muffin fortified with carob powder decreased in comparison with that in control muffin sample. Although the height of muffins decreased with the increase in level of carob powder, the differences were not statistically significant. Weight loss was similar for all the muffin samples in this study. Moisture content of muffins with carob powder was significantly higher than that in control. Addition of carob powder had also effect on water activity of muffin. While 0.905 aw was observed in control sample, significantly higher aw values were determinated in fortified muffins (0.912 – 0.923 aw). The antioxidant characteristics were determinated using spectrophotometric assays for total phenolics (TPC), total flavonoids (TFC), radical scavenging activities (DPPH, ABTS) and hydrogen peroxide scavenging (HPS). TPC values gradually increased with the increase in level of carob powder from 348.1 to 829.1 μg gallic acid.g-1 dry matter but TFC values significantly increased in muffin with 15 and 20% (w/w) of carob powder. All the antioxidant assays showed strong and positive association with the increase in level of carob powder. Addition of carob powder resulted in the increase of browning index and FAST index as a metrics of the formation of Maillard products.

Carbohydrate-Based Fat Mimetics Can Affect the Levels of 3-Monochloropropane-1,2-Diol Esters and Glycidyl Esters in Shortbread Biscuits

Shortbread biscuits have become one of the most desirable snacks in all population groups but due to its high fat content it is searching for new solutions of fat reduction such as the use of carbohydrate-based fat mimetics. However, the thermal processing of food containing lipids in the presence of certain carbohydrates can contribute to the formation of toxic compounds or alter its levels. Therefore, the aim of the study was to evaluate the use of inulin and pectin gels as partial fat replacers (10–40%) in classical shortbread biscuits in a view of the changes of 3-monochloropropane-1,2-diol ester (3-MCPDE) and glycidyl ester (GE) levels after baking, and also after a two-months storage. The experiment showed that the amount of inulin gel higher than 10% promoted the endogenous formation of 3-MCPDE probably due to the higher amount of Maillard products formed in the biscuits, but after two months the levels decreased and were comparable with those transferred from shortening. Pectin did not demonstrate such phenomenon, owing to the presence of bound water in gel. Glycidyl esters were partially decomposed during baking and also during storage, particularly in the samples with the addition of pectin gel, which presumably caused by low stability of GE under acidic conditions resulting from the occurrence of galacturonic acid in pectin.

Preparation of microcapsule antioxidative wall materials of pine nut oil by the Maillard reaction.

Maillard reaction products contribute to the amelioration of the biological functions or physical properties of foods and can be used to make dependable antioxidant wall materials for microcapsules of pine nut oil. The present study aimed to analyze the effects of temperature on the Maillard reaction of dry heat processes using gelatin/gum arabic (GE/GA) or gelatin/gum arabic/maltodextrin (GE/GA/MD) models and the products of the Maillard reaction as encapsulants to protect pine nut oil, as well as to evaluate the characteristics of the microcapsules. The grafting degree of the product increased with the temperature increments during the Maillard reaction. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the polysaccharide covalently linked to the protein. The antioxidant capability of the Maillard products at 80°C was the highest. The 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity, lipid peroxidation-inhibiting activity and reducing power of the GE/GA/MD model were higher than those of the GE/GA model. With in vitro digestion of Maillard products, GE/GA/MD pine nut oil microcapsules exhibited greater oil release in artificial gastric and enteric juices. Microencapsulated pine nut oil had more stable oxygen, which protected the oil, compared to unencapsulated pine nut oil. Temperature affects the degree of the Maillard reaction on GE/GA and GE/GA/MD models. © 2018 Society of Chemical Industry.

The Impact of Enhancement, Degree of Doneness, and USDA Quality Grade on Beef Flavor Development

The objective of this study was to determine the impact of enhancement, degree of doneness (DOD), and USDA quality grade on beef volatile flavor compounds from cooked strip loin steaks. This study also aimed to evaluate relationships between volatile compounds and consumer sensory responses. Beef strip loins (n = 72; 24/grade) of 3 quality grades (USDA Prime, Low Choice, and Low Select) were enhanced (8% of green weight with brine containing 0.35% salt and 0.4% sodium phosphate) or not enhanced, and cooked to 3 DOD (Rare: 60°C; Medium: 71°C; Very Well Done: 83°C) before volatile analysis. Volatile compounds were evaluated through a split-plot design where enhancement level and quality grade were used as the whole plot factors and DOD served as the subplot factor. Principal component analysis (PCA) was utilized to explore relationships between volatile compounds, consumer response, and treatments. The majority of compounds (n = 32) were impacted (P < 0.05) by the interaction between DOD × enhancement × quality grade. Four compounds- methanethiol, dimethyl-disulfide, methyl-benzene, and acetic acid were affected (P < 0.05) by enhancement × DOD. Two compounds- dimethyl sulfone and d-limonene, were impacted (P < 0.05) by quality grade × enhancement. Phenylacetaldehyde and hexanoic acid, methyl ester was affected (P < 0.05) by the interaction of USDA quality grade × DOD. The DOD main effect was only implicated in Maillard products (P < 0.05), including 2-methylbutanal, a Strecker aldehyde, and 2 pyrazines (methyl-pyrazine and trimethylpyrazine). Nonanal was the only compound impacted (P < 0.05) by a quality grade effect. No enhancement main effects were observed for any compounds (P > 0.05). In agreement, PCA indicated volatile compound production was primarily driven by degree of doneness and quality grade. There was no strong link between enhancement and beef volatile flavor compound development, despite the dramatically improved flavor liking scores from consumers.

Impact of Packaging and Muscle Type on Beef Flavor Development

ObjectivesThe objective of this study was to determine the influence of packaging type on production of beef flavor volatile compounds.Materials and MethodsBeef strip loins (IMPS #180) and top sirloin butts (IMPS #184) were selected from USDA Low Choice carcasses (n = 40, 20/subprimal). Seven d postmortem, subprimals were fabricated into 2.54 cm representative steaks of the Longissimus lumborum (LL) and Gluteus medius (GM). Steaks were then placed into one of four randomly assigned packaging treatments: carbon monoxide motherbag (0.4% CO/30% CO2/69.6% N2; CO), high oxygen modified atmosphere packaging (80% O2/20% CO2; HIOX), traditional polyvinyl chloride overwrap (OW), and rollstock (ROLL). Steaks designated for the OW treatment were placed in ROLL treatment until retail display. Steaks were aged in the absence of light for 14 d, then subjected to a 48-h retail display under fluorescent lighting in coffin cases. Following retail display, steaks were immediately vacuum packaged and frozen at –20°C until further analysis. Prior to volatile compound analysis, steaks were thawed at 2–4°C. Steaks were then cooked to 71°C using clamshell grills. Immediately after cooking, six 1.27 cm cores were removed, then minced using a coffee grinder. Five g of sample was weighed into a glass vial, sealed, then analyzed using gas chromatography-mass spectrometry. Compounds evaluated were chosen from major flavor pathways.ResultsThree compounds, carbon disulfide, 2-pentylfuran, and benzaldehyde elicited a packaging type × muscle interaction (P ≤ 0.048). Carbon disulfide was present in the highest concentration (P 0.05). A similar trend existed for 2-pentylfuran, as high oxygen GM steaks produced over three times higher concentrations (P < 0.05) of 2-pentylfuran compared to all other treatments. Nine compounds, primarily lipid derived, were impacted by a packaging main effect (P < 0.043). For 2-propanone, pentane, and hexanoic acid, methyl ester, HIOX packaging produced the greatest concentration (P < 0.05) compared to all other treatments. Additionally, HIOX steaks produced a greater amount (P < 0.05) of methanethiol than OW or ROLL steaks. High oxygen steaks produced more (P < 0.05) 1-pentanol, 1-octen-3-ol, and nonanal than CO steaks, but were similar to ROLL and OW steaks. Carbon monoxide packaging produced the greatest amount (P < 0.05) of 2,3-butanediol compared to all other treatments. Five compounds were impacted by the muscle main effect (P ≤ 0.039). The GM steaks produced a greater concentration of 2,3-butanedione (P = 0.011), 3-hydroxy-2-butanone (P = 0.002), octanoic acid (P < 0.001), and dodecanal (P = 0.021) than the LL steaks. The LL produced a greater amount of decanal (P = 0.039) than the GM.ConclusionThese results indicate packaging and muscle each impact flavor, however, packaging effects are primarily lipid derived and muscle more readily impacts Maillard product production. Additionally, HIOX packaging produces a large amount of lipid derived compounds from degradation and oxidation, which may form the basis for its negative flavor profile. This indicates HIOX packaging should be avoided to produce more positive flavor notes in beef.

Skim milk powder with high content of Maillard reaction products affect weight gain, organ development and intestinal inflammation in early life in rats

BackgroundThe intestinal tract is important for development of immune tolerance and disturbances are suggested to trigger autoimmune disorders. The aim of this study was to explore the effect of Maillard products in skim milk powder obtained after long storage, compared to fresh skim milk powder. MethodsYoung rats were weaned onto a diet based on skim milk powder with high concentration of Maillard products (HM-SM, n = 18) or low (C-SM, n = 18) for one week or four weeks. Weekly body weight and feed consumption were noted. At the end, organ weights, intestinal histology, permeability and inflammatory cytokines were evaluated. ResultsRats fed with HM-SM had after one week, 15% less weight gain than controls, despite equal feed intake. After one week thymus and spleen were smaller, intestinal mucosa thickness was increased and acute inflammatory cytokines (IL-17, IL-1β, MCP-1) were elevated. After four weeks, cytokines associated with chronic intestinal inflammation (fractalkine, IP-10, leptin, LIX, MIP-2, RANTES and VEGF) were increased in rats fed with HM-SM compared to C-SM. ConclusionHigh content of Maillard products in stored milk powder caused an intestinal inflammation. Whether this is relevant for tolerance development and future autoimmune diseases remains to be explored.

The umami intensity enhancement of peanut protein isolate hydrolysate and its derived factions and peptides by Maillard reaction and the analysis of peptide (EP) Maillard products

This study aimed to examine the feasibility of improving umami taste of peanut protein isolate hydrolysate (PPIH) and its fractions (obtained via ethanol precipitation and gel filtration chromatography) and peptide constituents, through their reactions with glucose at 98 °C for 70 min (Maillard reaction). To get insights into the characteristics of the peptide contributors with high umami intensity and/or umami-enhancing activity, Maillard reaction-guided and sensory-guided fractionation and characterization using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) and eXpose algorithm calculation method were subsequently involved. Three umami and umami-enhancing peptides, three umami-enhancing peptides with other tastes, three bitter peptides and one astringent peptide were found. For the first time, peptide TP was reported to suppress umami intensity of monosodium glutamate (MSG) aqueous solution. Combined treatments of enzymatic hydrolysis and Maillard reaction on PPI facilitated umami enhancement. Maillard products of identified peptides had higher umami intensities and/or greater umami-enhancing abilities. Pyroglutamylproline (pyroEP) and glucosylated EP were discovered as the major compounds of EP Maillard product.

Application of front-face fluorescence spectroscopy as a tool for monitoring changes in milk protein concentrate powders during storage

This study investigated the feasibility of front-face fluorescence spectroscopy (FFFS) to predict the solubility index and relative dissolution index (RDI) of milk protein concentrate (MPC) powders during storage. Twenty MPC powders with varying protein contents from 4 different commercial manufacturers were used in this study. The MPC powders were stored at 2 temperatures (25 and 40°C) for 0, 1, 2, 4, 8, and 12 wk. The front-face fluorescence spectra of tryptophan and Maillard products were recorded and analyzed with chemometrics to predict solubility of MPC powders. The similarity maps showed clear discrimination of the MPC samples stored at 25 and 40°C. Partial least squares regression models were developed using the fluorescence spectra of tryptophan and Maillard products to predict the solubility index and RDI measurements of MPC powders, and the prediction models were validated using an independent test set. Coefficients of determination (R2) of 0.76, 0.84, and 0.68 were obtained between fluorescence spectra (tryptophan emission, Maillard emission, and Maillard excitation, respectively) and solubility index. The R2 values for the RDI predictions were 0.58 and 0.60 for the data set of tryptophan emission and Maillard emission, respectively. The ratio of prediction error to standard deviation was >2 for Maillard emission fluorescence spectra and solubility index measurements, indicating good practical utility of the partial least squares regression prediction models. The results indicated that the solubility and dissolution behavior of MPC powders were related to their protein content and storage conditions that could be measured using FFFS. Hence, FFFS can be used as a rapid nondestructive analytical technique to predict the solubility and dissolution characteristics of MPC powders.