Furosine Values Research Articles

Assessment of Nutritional Value and Maillard Reaction in Different Gluten-Free Pasta

Evaluating the nutritional quality and thermal damage effects of gluten-free foods is essential to ensure that people with gluten intolerance or celiac disease can safely meet their needs. In this work, fifteen different commercial gluten-free pasta samples made from cereals, pseudocereals, and pulses, alone or in mixed combinations, were analyzed to assess their nutritional value, essential amino acids composition, and protein chemical score. The occurrence of the Maillard reaction was investigated, and the levels of heat treatment markers (furosine, maltulose, hydroxymethylfurfural, and glucosylisomaltol) were determined. Analysis of the furosine values showed that pasta made with the same raw materials can have different degrees of thermal damage. There was no evidence of the Maillard reaction progressing in the advanced phase in any of the samples tested. Finally, the correlation between maltulose and furosine levels demonstrated the usefulness of combining the two markers to assess the extent of thermal damage.

Effect of harvesting time and the number of queen cell cups on royal jelly composition

Royal Jelly (RJ) is one of the many important honey bee products that is also a functional food item in the regulation of diets and in the cosmetic industry. Many factors affect the composition of RJ. There is not enough information about the composition of early harvest (earlier than 72 h) RJ. In addition, no information has been found regarding the number of grafted larvae in reviewed studies. Thus, in this article, the effect of harvest time and the number of queen cell cups on the RJ composition such as 10-HDA, total and soluble proteins, furosine, superoxide dismutase activity (SOD), phenolic compounds have been determined. Results showed that 10-HDA values ​​decreased (3.2 ± 0.195%, 2.84 ± 0.146% and 2.16 ± 0.117%) as the numbers of larvae were increased (30, 60 and 120). Similarly, as the harvest time extended (24, 48 and 72 hours) the values ​​of 10-HDA decreased (3.25 ± 0.206%, 2.71 ± 0.137% and 2.24 ± 0.13%). Total protein ratios in RJ according to harvest times (24, 48 and 72 hours) were 19.6 ± 0.71%, 16.8 ± 0.57% and 16.8 ± 0.27%, respectively. Furosine values (ranging from 17.6-20.6 mg/100 g protein) increased as RJ harvest time increased. Superoxide dismutase activity values (ranging from 1.07 ± 0.06 to 1.47 ± 0.07 U/g) decreased as the number of grafted larvae increased and the harvest time increased. Phenolic compounds (151.7 ± 2.36 µg/g) were different from 48 (83.5 ± 3.89) and 72 hours (96.81 ± 5.97) royal jelly in the harvested RJ 24 hours after larvae grafting (P < 0.05). As a result, the RJ harvest time and the number of grafted larvae influenced the RJ composition.

Evaluation of carotenoids and furosine content in air dried carrots and parsnips pre-treated with pulsed electric field (PEF)

Carrot and parsnip slices were subjected to hot drying at 50, 60 and 70 °C with or without pulsed electric field (PEF) pre-treatment at 0.9 kV/cm and 1000 and 10,000 pulses. The effect of drying on processed samples was assessed by analysis of carotenoids, the furosine value, total phenols and the Whiteness Index (WI). PEF pre-treatment is effective in reducing drying times, but the degree of cellular breakdown makes the compounds more susceptible to chemical and enzymatic reactions. In our condition PEF pre-treatment increased the carotenoid degradation and promoted the Maillard reaction above all at the highest temperature of 70 °C. The assessment of carotenoid stability, together with the furosine value, were confirmed to be useful tools for the evaluation of effects of thermal damage and quality of dried food products, also after different drying treatments.

Combined use of HMF and furosine to assess fresh honey quality

AbstractBACKGROUND: The quality of honey can be affected by practices such as adulteration, inadequate storage or the application of severe heat treatments. Because hydroxymehylfurfural (HMF) is an indicator of honey freshness and furosine (ε‐2‐furoylmethyl lysine) has proved to be a useful chemical indicator of the progress of the Maillard reaction in foods, the aim of this work was to assess their usefulness as indicators of fresh honey quality. The effect of heat treatment, storage and adulteration with different types of syrups on HMF and furosine content has been studied.RESULTS: In fresh honey, HMF and furosine values ranged from 0.9 to 14.6 mg kg−1 of product and from 3.06 to 12.06 g kg−1 of protein, respectively. Heating of honey samples with different pH (3.76 and 5.14) produced slight increases in HMF content and negligible changes were detected in furosine values. The storage of fresh honey for 2 years caused a high increase in the HMF level, reaching values above EU limits. However, furosine showed a different behavior depending on the type of honey sample. Adulteration assays using different syrups produced an increase in HMF and a decrease of furosine values by dilution effect. HMF content of adulterated honey samples with syrup of known origin did not exceed EU limits.CONCLUSION: These results show the influence of long periods of storage or adulteration, using different percentages of corn or invert sugar syrups, on HMF and furosine content of fresh honey. This seems to indicate that the combination of HMF and furosine may be useful for evaluating the quality of fresh honey. Copyright © 2009 Society of Chemical Industry

Indicators of non-enzymatic browning in the evaluation of heat damage of ingredient proteins used in manufactured infant formulas

Twelve infant formula ingredients of animal origin (caseinates, whey proteins and hydrolysates of casein and of whey proteins) and three of vegetable origin (soybean proteins) were analyzed. Furosine, hydroxymethylfurfural (HMF) and pyrraline were studied as indicators of thermal damage and available lysine as nutritional indicator, determined by HPLC in phase reverse and UV detector. The objectives were to evaluate heat damage to ingredients used in commercial infant formulas by measuring non-enzymatic browning indicators and to determine the nutritional value of these ingredients by available lysine determination. Very high furosine values were detected in whey proteins, ranging from 354 to 1,435 mg/100 g of protein. Lower furosine values were found in the remaining ingredients, ranging from 1.36 mg/100 g in hydrolyzed casein to 60.5 mg/100 g in sodium caseinate. Available lysine content ranged from 1.85 g/100 g of protein in hydrolyzed casein to 7.91 g/100 g in calcium caseinate. HMF was detected in whey protein samples between 0.16 and 2.47 mg/100 g of protein. Pyrraline was only detected in one sample of whey proteins at 41 mg/100 g of protein. Similar ingredients from different manufacturers show varied heat damage and nutritional values

Effects of overprocessing on heat damage of UHT milk

Formation of lactulose, furosine, galactosyl-|*beta*|-pyranone and lysinoalanine was studied in UHT milk samples produced by either direct or indirect heating on industrial plants and by indirect heating on a pilot plant. In particular, the effects of severe sterilization conditions, different proportions of milk recirculation, and storage of the finished product (23 °C for up to 90 days) have been investigated on the levels of the above molecules in UHT milk. An extensive increase of the values of all the indicators occurred when severe heat process was applied, but no direct relation was found between their levels and the nominal time–temperature conditions. Lactulose and furosine levels confirmed to be strictly correlated in UHT milk. In case of overheating or high proportion (60%) of milk recirculation, galactosyl-|*beta*|-pyranone formation was strongly enhanced, proving that also the advanced Maillard reaction takes place extensively, which is not detected by furosine value. Formation of lysinoalanine in UHT drinking milk on storage was pointed out for the first time. Lysinoalanine proved to be the most sensitive index of storage conditions among the four parameters studied. Data suggest that a realistic defence of UHT milk quality can be achieved only by fixing upper limits to heat damage parameters. Besides avoiding unjustified milk overheating, this approach may allow manipulations, like reprocessing expired milk, to be pointed out.

Technological properties and non-enzymatic browning of white lupin protein enriched spaghetti

Spaghetti was prepared by replacing semolina with different amounts of lupin protein, in order to increase the protein content. A detailed investigation of the rheological properties of the dough and the cooking quality of pasta was performed in comparison to standard semolina spaghetti. Moreover, the effect of the addition of lupin protein on non-enzymatic browning was evaluated by measuring ε-furoylmethyllysine (furosine) and 5-hydroxymethyl-2-furancarboxaldehyde (HMF), which are considered useful indices of semolina quality and pasta processing conditions. Dried spaghetti fortified with 5% of lupin protein isolate has a colour and rheological features comparable with the semolina sample and also the behaviour during cooking results to be satisfactory. As far as the thermal damage is concerned, the furosine values of fortified spaghetti differ only marginally from standard pasta and the percentage lysine loss is quite small (ranging from 12.1% to 15.7%).

RAPID HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC DETECTION OF FUROSINE (ε‐N‐2‐FUROYLMETHYL‐L‐LYSINE) IN YOGURT AND CHEESE MARKETED IN TURKEY*

ABSTRACT Furosine (ε‐N‐2‐furoylmethyl‐L‐lysine) content determination in the yogurt and different cheese types (pickled white, kasar, processed, canned tulum, blue‐veined and mozzarella cheeses) marketed in Turkey was performed using ion‐pair reversed‐phase high performance liquid chromatography (RP‐HPLC). Calibration study (R2 = 0.9999), analytical method validation and recovery studies gave satisfactory results. The lowest furosine values were observed in pickled white cheeses (5.35 ± 0.01 to 7.28 ± 0.02 mg/100 g protein). All cheeses except pickled white showed furosine values between 182.16 ± 0.12 (canned tulum) and 261.32 ± 0.10 mg/100 g protein (ripened kasar). The highest content of furosine was observed in whole yogurt (316.47 ± 0.17 mg/100 g protein) which could be because of severe heat treatment and the addition of milk powder during the manufacturing process. The method provides a rapid, reproducible and accurate determination of this Amadori compound (ε‐deoxy‐fructosyl‐lysine) in yogurt and cheese samples.

Storage Stability Assessment of Freeze-Dried Royal Jelly by Furosine Determination

The effect of freeze-drying and the assessment of the storage stability of freeze-dried royal jelly (RJ) were investigated by the determination of furosine and blocked lysine. The level of furosine in the RJ samples collected from cells at different times (1, 2, and 3 days after grafting) showed that the Maillard reaction had already occurred in the hive as indicated by the increase in furosine: from 9.6 to 20.8 mg/100 g of protein. Freeze-dried RJ was more prone to the early stage of the Maillard reaction than fresh RJ, as confirmed by the significantly higher furosine values found after 12 months, both at 4 degrees C (253.4 versus 54.9 mg/100 g of protein) and at room temperature (884.3 versus 332.5 mg/100 g of protein). After 18 months at room temperature, the lyophilized samples reached a furosine level of 1440.4 mg/100 g of protein, which corresponded to the blocked lysine levels, amounting to 24% of total lysine.

Estimation of equivalent egg age through furosine analysis

The aim of this research was to study furosine as a reference index for expressing the age of commercial shell eggs in terms of equivalent egg age. Seventy five commercial samples of grade A eggs purchased on the Italian market were analysed for air cell height, Haugh Units, 3,3′,5,5′ tetramethylbenzidine test, and furosine level. The values obtained were reported as a function of egg age calculated from the minimum durability dates printed on the packages. At equal egg age, a wide data variation for all indices was observed, thus indicating the great influence of commercialization condition on the assessed indices. An average kinetics of furosine development in albumen at 20 °C was also computed from nine storage experiments of shell eggs laid by hens of different ages and breeds. The equivalent egg age of the commercial samples, expressed as days at 20 °C, was computed by substituting the furosine value of each sample in the average kinetics equation.

Generation of furosine and color in infant/enteral formula-resembling systems.

The extent of the Maillard reaction was studied by measuring furosine and color formation in infant and enteral formula-resembling model systems prepared by mixing calcium caseinate, laboratory-obtained or commercial whey protein with lactose or dextrinomaltose (ingredients similar to those used in infant and enteral formula manufacture) and heating the mixture at 100, 120, or 140 degrees C for 0-30 min. The furosine determination was performed by HPLC and the color determination by measuring colorimetric parameters L, a, and b in a reflection photometer. The first steps of the Maillard reaction could be followed by furosine determination when initial ingredients had low thermal damage. Hence, furosine may be an indicator of low thermal damage in ingredients with <100 mg/100 g of protein. At the concentrations used in these model systems, similar to those in infant and enteral formulas, furosine values (indirect measure of lysine losses) were higher in lactose than in dextrinomaltose systems, in which only glucose, maltose, maltotriose, and maltotetraose among all of the sugars present showed reactivity with casein. Finally, the advanced steps could be followed by color determination when the initial ingredients had high thermal damage or the model systems were heated at high temperature or for a long time. Among the parameters assayed, b was the most sensitive.

Furosine is a useful indicator in pre‐baked breads

AbstractThere is increasing demand for pre‐baked bread. Bakers can meet consumer requirements for breads of specific flavour and colour by pre‐baking an amount of bread in the morning and completing the baking process in the afternoon. This type of product is of special interest to sandwich bars, restaurants and large communities. In order to obtain an indicator of utility to monitor the processing of pre‐baked bread, the browning indicators furosine, hydroxymethylfurfural (HMF) and glucosylisomaltol were analysed in two independent assays of bread pre‐baked at 175 °C for between 5 and 30 min. No furosine was detected in raw or fermented dough. In the pre‐baking stage, furosine increased from 1.5‐ to 5‐fold between 5 and 30 min. The furosine values obtained in the two independent experiments were similar. HMF and glucosylisomaltol were only detected after 15 min, which is the time period commonly used for processing by the industry. Thus, among these indicators, furosine is the only one with utility for monitoring the pre‐baking process. On the other hand, a study of the baking of pre‐baked bread at 220 °C showed that HMF and glucosylisomaltol can be used to monitor the latter process. Copyright © 2004 Society of Chemical Industry

Furosine content, loss of o‐phthaldiadehyde reactivity, fluorescence and colour in stored enteral formulas

Heat effects induced during the storage of enteral formula under laboratory and industrial conditions were evaluated using the following indicators: furosine; loss of available amino groups, measured by decrease in o‐phthaldialdehyde (OPA) reactivity; fluorescence associated with the Maillard reaction (345 nm excitation, 415 nm emission); and colour (absorbance at 420 nm). The storage of formulas A and B (with different protein content) at 4, 20 and 30°C during 12, 24 and 36 weeks produced an increase in furosine values. Under industrial storage conditions at 55°C for between 1 and 12 weeks the behaviour of furosine differed between the two types of formulas. In Formula A (lesser protein content), there was a decrease in furosine level after the third week, whereas in formula B (greater protein content) a decrease was observed after the eighth week.The loss of OPA reactivity reached 18% and 22%, respectively, for formula B and formula A stored at 30°C for 36 weeks. In adverse storage conditions (55°C), the loss of OPA reactivity reached 50%.Fluorescence intensity (FI) and absorbance at 420 nm increased at all time/temperatures assayed. It reached values of 22.5 and 27.5 for FI and 0.161 and 0.173 for A420, respectively, for formula A and B, stored for 36 weeks at 30°C.Furosine, loss of OPA reactivity, fluorescence intensity and colour are useful indicators of nonenzymatic browning during storage of enteral formulas.

Maillard reaction in enteral formula processing: furosine, loss of o-phthaldialdehyde reactivity, and fluorescence

In order to evaluate heat effects induced during the manufacture of enteral formula, the following indicators were determined: furosine; loss of available amino groups, measured by decrease in o-phthaldialdehyde (loss of OPA reactivity); and fluorescence intensity (FI) associated with Maillard reaction (345 nm excitation, 415 nm emission). In addition, furosine and fluorescence were determined in model systems performed with the protein and carbohydrate ingredients of these products. The precision obtained for furosine, loss of OPA reactivity and fluorescence was 2.93, 1.89 and 1.72%, respectively. Furosine values decreased during the manufacturing process (UHT, standardization and sterilization). Heating at 120 °C produced a decrease in furosine content in model systems with whey proteins and an increase in systems with casein-carbohydrates. During the manufacturing, the loss of OPA reactivity reached 26.5 and 14% in the two types of formulas assayed. FI increased during heating in the formula processing and model systems

Presence of furosine in honeys

AbstractNineteen commercial samples (with a shelf‐life of 2 years) and two artisanal samples (freshly collected and stored for 1 year respectively) of Spanish honeys were analysed for pH, protein content and furosine content. Most of the samples had pH values and protein contents within the limits reported in the literature. The presence of furosine was confirmed by comparison of its retention time with that of a furosine standard and by HPLC–MS. The level of furosine in the samples studied ranged from 4.32 to 13.62 g kg−1 protein. The lowest furosine value was observed in the freshly collected artisanal sample. Heat treatment under severe conditions (90 °C for up to 135 min) increased the furosine content from 4.43 to 14.38 g kg−1 protein. The results show that furosine seems to be a promising indicator to detect overheating during honey manufacture.© 2001 Society of Chemical Industry

Survey of the Furosine Content in Cheeses Marketed in Spain

The furosine content in 53 samples of different cheese types (fresh, ripened with molds, artisanal hard-pressed, industrial hard-pressed, and processed) marketed in Spain was analyzed. The lowest furosine values were observed in artisanal hard-pressed cheeses (4.8 to 10.2 mg per 100 g of protein) and ripened with molds cheeses (4.2 to 12.8 mg per 100 g of protein). Industrial hard-pressed cheeses showed furosine values between 3.5 and 43.8 mg per 100 g of protein. Differences between samples may be attributed to the heat-treatment intensity given to cheese milk and to cheesemaking conditions. The highest contents of furosine were observed in processed cheeses (20 to 366.6 mg per 100 g of protein). A wide range of furosine content was found in fresh cheeses (17.9 to 73.6 mg per 100 g of protein), which could be due to the different amounts of dried milk added during the manufacture of cheeses.

Improved Method for the Determination of Furosine in Food by Capillary Electrophoresis

A previously described method for determination of furosine by capillary zone electrophoresis in food has been improved for greater accuracy and sensitivity. Acid-hydrolyzed samples are subjected to solid phase extraction; then they are dried and redissolved before injection. The electrophoresis separation is performed in a fused silica capillary tube (50μm inside diameter) with an extended-path-length detection cell using a 3-(N-morpholino)-2-hydroxypropanesulfonic acid solution at pH 7.0 as run buffer. The in-laboratory repeatability was within ±7.1% at the 95% confidence level when the amount of furosine ranged between 8 and 250 mg per 100 g protein. The values of both repeatability and sensitivity fulfill the requirements stated in the EU and Italian regulations for furosine determination in pasteurized milk and Mozzarella cheese. The data obtained on 48 different food samples including heat-treated milk, cheeses, and durum wheat products were comparable with those obtained by an HPLC method and proved to be accurate for furosine values up to at least 400 mg per 100 g protein. The furosine values found in cultured fresh cheese samples suggest that the use of this furosine index holds promise for the characterization of this type of cheese.

Heat Damage Evaluation during Tomato Products Processing

To evaluate the efficiency of furosine as a heat damage index in tomato products, its content was determined in each step of tomato pulp (9% dry matter) and tomato paste (31% dry matter) processing. Furosine levels (mg/100 g protein) increased linearly as a function of heat treatment severity, although the slopes of the two products differed because of the different dry matter contents. The standardization of furosine values on the basis of dry matter content [mg furosine/(g protein·g dry matter)] highlighted an identical linear increase of furosine for both products. Hence, furosine appears to be a good heat damage index of tomato products, allowing the evaluation of both product quality and processing technology. Furosine was also determined on several tomato products collected from the Italian market, detecting values from 43 to 140 for tomato pulp, from 93 to 132 for tomato sauce, and from 220 to 468 mg/100 g protein for tomato paste. Keywords: Furosine; heat damage; tomato products

Effects of heat load gradient occurring in moulding on characterization and ripening of Grana Padano

Summary - A centripetal temperature gradient takes place in Grana Padano (GP) during moulding because of the slow heat transfer within the cheese and the fast cooling of the outer part. This gradient, in combination with the low pH value, induces a centripetal inactivation of alkaline phosphatase (ALP). Throughout the ripening process, the activity of the enzyme keeps > 3 105 mU/kg cheese in the peripheral zones and < 300 mU in the core. The objective of the present study was to determine whether the presence of heat load gradients and ALP inactivation improves the analytical distinction between GP and imitation hard cheeses and affects the ripening behaviour. DifferentIy ripened sampies of traditional GP, grana cheese of reduced size, or made from pasteurized milk following GP technology, or collected at the market were submitted to a stratigraphie study. For each cheese sample, subsequent portions collected from the rind to the core were analyzed for moi sture and water activity, aw' ALP activity, furosine, free ami no acids (FAA), casein phosphopeptides (CPPs) and free fatty acids (FFA). Regarding cheese characterization, thermal treatments of cheese milk can be recognized in GP only by determining the enzyme activity in the most peripheral portions. When the size of the cheese is reduced, cooling in moulding is faster and ALP inactivation in the core is lower. When the moulded cheese is heated, inactivation of the enzyme also takes place in the outer parts. The furosine values, which describe the extent of heat load in dairy systems, increase from the outer part to the GP core (from 10 mg to 60 mg/lOO g protein). This gradient is unaffected by prolonged ripening, but changes when modifications in technoIogical parameters such as pasteurization of milk, forced heating in moulding and reduction of cheese size are introduced. The distribution of ALP and furosine values within the cheese constitutes a distinctive parameter between GP and its imitation products. Regarding chee se ripening, ail the values of chemical indices adopted for describing the ripening of GP show a progressive increase from the inner to the outer portions of nine- or 15month-old chee se samples. These patterns are more pronounced for most of the FAA, and are marked for free serine which increases in the outer zones up to 50% more than in the core. The amount of 'enzyme resistant' CPP ~-CN(f16-22)3P, the accumulation of whieh requires the presence of active phosphatases and aminopeptidases, has the same stratigraphie behaviour as that of FAA. The close

Influence of protein standardization and UHT heating on the furosine value and freezing point of milk

Des echantillons de lait contenant environ 1,7 % de matiere grasse et de teneur en proteine entre 2,6 et 3,4 % ont ete prepares par melange de quantites predeterminees de lait entier, lait ecreme et de permeat provenant du traitement par ultrafiltration (UF) de lait ecreme ou de lactoserum acide obtenu lors de la production de quarg. Le point de congelation pour chaque echantillon de lait a ete mesure avant et apres traitement UHT. La quantite de lactuloselysine determinee par methode indirecte et representee par la teneur en furosine a ete mesuree apres des durees de stockage de 1, 4 et 12 semaines du lait UHT a des temperatures de 4 et 25 °C. La teneur en furosine s'est montree 2 a 4 fois plus elevee pour le lait traite en UHT methode directe (18-47 mg/L) compare au lait traite en UHT methode indirecte (5-12 mg/L). La valeur en furosine n'a pas change significativement lors du stockage a 4 °C, alors que pour un stockage a 25 °C durant 12 semaines une augmentation de 1,5 a 4 fois est apparue; certains echantillons de lait traites par la methode UHT directe et stockes a 25 °C avaient une valeur en furosine plus grande que celle des echantillons traites par la methode UHT indirecte et stockes a 4 °C. La standardisation avec permeat de lait ecreme et permeat de lactoserurm acide a produit une legere baisse de furosine pour le lait traite en UHT, mais les conditions de stockage on montre un effet superieur sur la teneur en furosine. L'utilisation de quantites croissantes de permeat de lait ecreme pour la standardisation en proteine a produit une croissance progressive du point de congelation, alors que la standardisation avec permeat de lactoserum acide a produit un effet inverse. Le traitement UHT par methode directe ou indirecte n'a eu aucun effet sur le point de congelation des echantillons de lait, montrant qu'aucun changement irreversible dans l'equilibre salin du lait n'est apparu et que les reactions dues au traitement thermique du lactose, reaction de Maillard incluse, n'ont pas affecte le point de congelation.