Showing papers on "Browning published in 1983"
81 citations
TL;DR: The results suggest that dehydration and rearrangement of the Amadori product, epsilon-fructosyllysine, has occurred in vivo, thus leading to the formation of at least two nonenzymatic browning products.
64 citations
01 Jan 1983
52 citations
TL;DR: In this article, the relationship between enzymatic browning of foods and the responsible food constituents (e.g. phenol oxidase, phenolic substrates, inhibitors) is discussed.
Abstract: Quantitative relationships between enzymatic browning of foods and the responsible food constituents (e.g. phenol oxidase, phenolic substrates, inhibitors) are discussed. Attention is also given to the effects of extrinsic factors (e.g., climatic factors, fertilizers, phytohormones, pesticides,γ-irradiation, storage time and temperature) on the rates of browning.
46 citations
TL;DR: In this article, the appearance of nonenzymatic browning products in sucrose-based systems (5-20%; pH 1-5) during freeze drying and during subsequent room temperature storage in the dry state was investigated.
Abstract: The appearance of nonenzymatic browning products in sucrosebased systems (5-20%; pH 1-5) during freeze drying and during subsequent room temperature storage in the dry state was investigated. Results showed that following the completion of the primary sublimation stage of drying, sucrose hydrolysis to glucose and fructose was initiated. Glucose and fructose undergo further breakdown, and at the same time products which absorb in the UV (280 nm) were formed. A short time later observable brown colors are noted (absorbance at 400 nm). The extent of UV absorbance and brown color formation increased with decreasing sucrose concentration and decreasing pH in the initial solution.
45 citations
TL;DR: In this article, a 6-month storage of pear juice concentrates with 0.2 mM cysteine was reported to reduce the Maillard reaction in the concentrates, and the rate of decrease was a function of storage temperature.
Abstract: Pear juice concentrates were prepared from juices treated with 0–2 mM cysteine and color changes of the concentrates were observed during storage at 1°, 21°, and 38°C for 6 months. Initial browning of the concentrates were eliminated by the cysteine treatment of the pear juice. Rate of browning of the concnetrates increased with increasing storage temperature and decreasing cysteine concentration. Cysteine concentration of the concentrates decreased during storage and the rate of decrease was a function of storage temperature. Cysteine appeared to retard the Maillard reaction in the concentrates. No deleterious changes in flavor intensity were noted in the stored cysteine-treated concentrates.
45 citations
TL;DR: In this paper, storage stability of intermediate moisture apples was studied as a function of storage temperature and water activity, and the criteria for storage stability were based on three quality factors, namely, nonenzymatic browning reactions, vitamin C degradation and microbial growth.
Abstract: Storage stability of intermediate moisture apples was studied as a function of storage temperature and water activity. The criteria for storage stability was based on three quality factors, namely, nonenzymatic browning reactions, vitamin C degradation and microbial growth. Analysis of kinetic data suggested a zero order reaction for nonenzymatic browning, and a first order reaction for vitamin C degradation. The effect of temperature on the rate constant followed the Arrhenius relationship. Based on this study, it was not possible to generate a kinetic model for microbial growth. However, growth/no growth regions based on temperature and water activity were identified.
43 citations
TL;DR: In this paper, a simulation-optimization procedure based on the complex method was used to determine optimal drying schemes for minimizing browning during dehydration of white potatoes, and the optimal dryer temperature control path reduced the temperature while the sample disk moisture content was in the range 0.1 − 0.2 g/g-solids, where the browning rate is maximal.
Abstract: A simulation-optimization procedure based on the complex method was used to determine optimal drying schemes for minimizing browning during dehydration of white potatoes. Browning kinetics were obtained from the literature, and the heat and mass transfer characteristics of the potatoes were based on experimental data obtained previously. The optimal dryer temperature control path reduced the temperature while the sample disk moisture content was in the range 0.1–0.2 g/g-solids, where the browning rate is maximal. Excellent agreement was obtained between optimal dryer temperatures based on local moisture and those based on average moisture contents.
42 citations
37 citations
TL;DR: In the absence of an exogenous hydrogen donor (AH2), H2O2 at different concentrations (3.6-364 mM) shortens the lag period of tyrosine hydroxylation and this effect was abolished when catalase was included in the reaction mixture as discussed by the authors.
30 citations
Journal Article•
TL;DR: For a large number of grape varieties, browning potential and polyphenol oxidase activities were measured at maturity as discussed by the authors, and classification in accordance with these criteria was made, and it was confirmed that polyphenolic oxidase of the grape is a strongly bound enzyme and browning is concentrated for a large part in the non-soluble fractions of the juice.
Abstract: For a large number of grape varieties, browning potential and polyphenol oxidase activities were measured at maturity. Classification in accordance to these criteria was made. It was confirmed that polyphenol oxidase of the grape is a strongly bound enzyme and that browning is concentrated for a large part in the non-soluble fractions of the juice. Phenolic substrate appears to be the limiting factor in browning.
TL;DR: In this paper, an experiment was designed to determine the influence of chemical additives, ascorbic acid and storage time on grape juice color, and the results showed that adding low concentrations of CaSO4 and SnCl2 increased retention of color as measured by Color Difference Meter (CDM) L, a and b values and by color expression a/L, aL and ab/L.
Abstract: The experiment was designed to determine the influence of chemical additives, ascorbic acid and storage time on‘Concord’grape juice color. Adding low concentrations of CaSO4 and SnCl2 increased retention of color as measured by Color Difference Meter (CDM) L, a and b values and by color expression a/L, aL and ab/L. Rapid color changes occurred during storage after 3 months except in juice with added CaSO4 and SnCl2. Ascorbic acid fortification accelerated color loss in some of the treatments. The highest correlations between sensory quality and instrumental color were those between sensory ratings for browning, flavor and hue and CDM L values, anthocyanins and absorbancies at 535/430 nm.
TL;DR: In this paper, enzymatic activites and carotenoid content were estimated in the yellow portion of the mesocarp of six avocado cultivars differing in their browning potential.
Abstract: Enzymatic activites (polyphenoloxidase, catalase and peroxidase) and carotenoid content were estimated in the yellow portion of the mesocarp of six avocado cultivars differing in their browning potential. The results do not support our assumption of the existence of an inverse relationship between browning potential and carotenoid content in the tissue.
Patent•
13 Apr 1983
TL;DR: A crisp apple wafer-shaped snack is made from apples which are thinly sliced, exposing the seeds as discussed by the authors, and the slices are treated to prevent browning and are steeped in a sugar solution.
Abstract: A crisp apple wafer-shaped snack is made from apples which are thinly sliced, exposing the seeds. The seeds are removed by washing, the slices are treated to prevent browning and are steeped in a sugar solution. Then the slices are rapidly dried, in thirty minutes or less, to form a crisp delicious snack which may include the apple peel as well as the carpels in which the seeds were contained.
TL;DR: The relationship between the color and fluorescence of a Maillard browning mixture and the antioxidant activity of ethnol extracts of the mixture was investigated by comparing the peroxide value development of soybean oil substrates containing the extracts with that of a control as discussed by the authors.
Abstract: The relationship between the color and fluorescence of a Maillard browning mixture (0.1M glucose+0.1M glycine, heated at 100 C) and the antioxidant activity of ethnol extracts of the mixture was investigated. The activity was estimated by comparing the peroxide value development of soybean oil substrates containing the extracts with that of a control. The excitation and emission maxima of the mixture were 365 and 440 nm, and those of the extract 367 and 430 nm. The relative fluorescence (that of 1 µg quinine sulfate/mL 0.01N H2SO4=100) of the mixture after 16 hr browning was 450, whereas that of the corresponding extract was 175.8. The fluorescence of the mixture increased in parallel to the color (absorbance at 490 nm), which, in turn, was almost proportional to reaction time, except at the earlier stages of browning. The change of the fluorescence with the reaction time at the earlier stages was far greater than that of the absorbance at the same stages. Determination of fluorescence seems to provide a more sensitive method for tracing early browning than that of absorbance. The ethanol extracts from very early stages of the browning exhibited considerable antioxidant activity, and, unlike the absorbance of the mixture or the fluorescence of the extract, the activity of the extract changed very little with the reaction time. It appears that effective antioxidants with almost no color but with considerable fluorescence were already formed at the earlier stages of browning.
TL;DR: Alkaline pH of the medium was found to promote the formation of the compounds yielding a caramel odour and the most desirable organoleptic characteristics were obtained at pH 4.0-5.5 and temperature 140 degrees C.
Abstract: The effect of temperature and pH on the formation and changes of volatile flavour compounds in thermally treated malt extracts was studied. The dependence of thermal treatment parameters on organoleptic properties of the extracts was stated. Alkaline pH of the medium was found to promote the formation of the compounds yielding a caramel odour. The most desirable organoleptic characteristics were obtained at pH 4.0-5.5 and temperature 140 degrees C. Thirty compounds typical for nonenzymatic browning were identified.
TL;DR: In this paper, the influence of various factors on the stability of free tryptophan was evaluated in several reaction systems, such as heating, protein, and glucose, in a system undergoing Maillard browning.
Abstract: The influence of various factors on the stability of free tryptophan was evaluated in several reaction systems. After treatment, tryptophan was measured by high performance liquid chromatography. Factors such as heating, protein, and glucose were responsible for tryptophan losses in a system undergoing Maillard browning. Hydrogen peroxide caused extensive losses while pH and light had minimal effect on tryptophan stability in solution. When the stability of tryptophan was compared to lysine and threonine during browning, threonine had the highest retention. At low water activity (0.22), tryptophan had the lowest retention (42%) while at a high water activity (0.75) lysine had the lowest retention (5%). When fortified corn tortillas were made using the typical heat treatment involved in preparation, retention of added lysine and tryptophan was 85–90%.
TL;DR: In this paper, fresh 4-day-old etiolated mung bean seedlings were analysed for proteins, carbohydrates and lipids, and vitamins A and C. Exposure of the sprouts to artificial light for 24 hours increased the content of most constituents, especially provitamin A.
Abstract: Fresh 4-day-old etiolated mung bean seedlings were analysed for proteins, carbohydrates and lipids, and vitamins A and C. Exposure of the sprouts to artificial light for 24 h increased the content of most constituents, especially provitamin A. Changes in the composition of the seedlings after preservation and storage for 6 months were followed. The sprouts were either canned or bottled, and then kept at various storage temperatures, regardless of storage conditions, hydrolysis of complex carbohydrates took place. There is some evidence that the reducing sugars released during storage underwent a Maillard reaction, leading to browning of the sprouts.
Journal Article•
01 Jan 1983
TL;DR: To inhibit the production of dopachrome in sliced disks of raw potatoes, a much-higher concentration of sodium sulfite (Na2SO3) was required than that bleaching dopachchrome which had been already formed.
Abstract: Dopachrome, the initial pigment leading to enzymatic browning, was produced in the presence of crude enzyme preparation from homogenized tissues or sliced disks of raw potatoes.
Patent•
13 May 1983
TL;DR: In this article, powdery glycine is coated with a coating composition consisting of citric acid, L-ascrobic acid and starch hydrolyzate or cyclodextrin in a specific proportion to inhibit glycine used as a food additive from browning.
Abstract: PURPOSE:Powdery glycine is coated with a coating composition consisting of citric acid, L-ascrobic acid and starch hydrolyzate or cyclodextrin in a specific proportion to inhibit glycine used as a food additive from browning. CONSTITUTION:Powdery glycine, preferably 32-200 mesh particle sizes, is coated with a coating composition consisting of 0.1-1wt% of citric acid, 0.1-1wt% of L-ascorbic acid, 1-3wt% of propylene glycol, 1-5wt% of glucosylurea and 5-20wt% of starch hydrolyzate or cyclodextrin to inhibit the glycine from browning. The resultant glycine contains glucose as a preparation with other chemicals in the field of breed additives. The coating is carried out by the fluid spraying method.
Journal Article•
TL;DR: In this article, change of color, browning index, soluble protein, reducing sugar content, and available lysine were monitored for raw and extruded barely powders during four months of ambient and accelerated storage temperatures with of 0.31 and 0.71, respectively.
Abstract: Change of color, browning index, soluble protein, reducing sugar content, and available lysine were monitored for raw and extruded barely powders during four months of ambient and accelerated storage temperatures with of 0.31 and 0.71, respectively. Loss of whiteness and soluble browning pigments increased with increased and temperature. The raw sample had an increased rate of browning intensity than the extruded samples. Among the extruded samples, the added sucrose sample had the lowest rate of browning during storage. Loss of reducing sugar content in all samples increased with increased and temperature. The loss of soluble protein and of the available lysine also increased with increased and temperature. The loss of reducing sugar and of the available lysine was at least partly due to the Maillard browning reaction. These results have important implications in teh processing and storage of raw and extruded burleys.
Patent•
06 Jan 1983
TL;DR: In this paper, onion is treated with aqueous alum to keep in shape and from browning, when boiled, and sliced onions are dipped in 1wt% alum solution at 90 deg.C for 5-30minutes under heating.
Abstract: PURPOSE:Onions are treated with aqueous alum to keep in shape and from browning, when boiled. CONSTITUTION:Onions are dipped in an aqueous alum of 0.1-2, preferably 0.6- 1wt% concentration, for example, sliced onions are dipped in 1wt% alum solution at 90 deg.C for 5-30minutes under heating.
01 Jan 1983
TL;DR: The relationship between the color and fluorescence of a MaiUard browning mixture and the antioxidant activity of ethnol extracts of the mixture was investigated by comparing the peroxide value development of soybean oil substrates containing the extracts with that of a control.
Abstract: The relationship between the color and fluorescence of a MaiUard browning mixture (0.1M glucose + O.1M glycine, heated at 100 C) and the antioxidant activity of ethnol extracts of the mixture was investigated. The activity was estimated by comparing the peroxide value development of soybean oil substrates containing the extracts with that of a control. The excitation and emission maxima of the m/xmre were 365 and 440 rim, and those of the extract 367 and 430 nm. The relative fluorescence (that of 1 vg quinine sulfate/mL 0.01N H 2 SO 4 = 100) of the mixture after 16 hr browning was 450, whereas that of the corresponding extract was 175.8. The fluorescence of the mixture increased in parallel to the color (absorbance at 490 nm), which, in turn, was almost proportional to reaction time, except at the earlier stages of browning. The change of the fluorescence with the reaction time at the earlier stages was far greater than that of the absorbance at the same stages. Determination of fluorescence seems to provide a more sensitive method for tracing early browning than that of absorbance. The ethanol extracts from very early stages of the browning exhibited considerable antioxidant activity, and, unlike the absorbance of the mixture or the fluorescence of the extract, the activity of the extract changed very little with the reaction time. It appears that effective antioxidants with almost no color but with considerable fluorescence were already formed at the earlier stages of browning.