• Preventive Nutrition and Food Science
• /
• v.22 no.1
• /
• pp.37-44
• /
• 2017

Sulfur-containing amino acids play important roles in good flavor generation in Maillard reaction of non-enzymatic browning, so aqueous model systems of glucosamine and cysteine were studied to investigate the effects of reaction temperature, initial pH, reaction time, and concentration ratio of glucosamine and cysteine. Response surface methodology was applied to optimize the independent reaction parameters of cysteine and glucosamine in Maillard reaction. Box-Behnken factorial design was used with 30 runs of 16 factorial levels, 8 axial levels and 6 central levels. The degree of Maillard reaction was determined by reading absorption at 425 nm in a spectrophotometer and Hunter's L, a, and b values. ${\Delta}E$ was consequently set as the fifth response factor. In the statistical analyses, determination coefficients ($R^2$) for their absorbance, Hunter's L, a, b values, and ${\Delta}E$ were 0.94, 0.79, 0.73, 0.96, and 0.79, respectively, showing that the absorbance and Hunter's b value were good dependent variables for this model system. The optimum processing parameters were determined to yield glucosamine-cysteine Maillard reaction product with higher absorbance and higher colour change. The optimum estimated absorbance was achieved at the condition of initial pH 8.0, $111^{\circ}C$ reaction temperature, 2.47 h reaction time, and 1.30 concentration ratio. The optimum condition for colour change measured by Hunter's b value was 2.41 h reaction time, $114^{\circ}C$ reaction temperature, initial pH 8.3, and 1.26 concentration ratio. These results can provide the basic information for Maillard reaction of aqueous model system between glucosamine and cysteine.

• Korean Journal of Agricultural Science
• /
• v.15 no.1
• /
• pp.95-113
• /
• 1988

In order to find out changes of chemical components related to browning of dried jujube, four varieties were subjected to the proximate analysis. Boeun, one of the major varieties in Korea, was sun-dried and stored for 12 months and analyzed periodically for one year. Browning, titrable acidity, pH, contents of ascorbic acid, organic acid, total amino acid, free amino acid, free sugar, hydroxymethylfurfural (HMF) and phenolic compounds were determined and compared with those of fresh jujube. The results obtained are summarized as follows; 1. In comparison with other similar fruits, jujube was high contents of ascorbic acid (62-79mg%) and carbohydrate (22-28%) excluding fiber. 2. Browning was increased in both steam-treated and nontreated plot together as storage period was prolonged. 3. Ascorbic acid content of fresh jujube was as high as 297.4mg% DB, but it was decreased to 20.2mg% DB, after 12 months storage. Therefore, loss of ascorbic acid was very great up to 93% of its original content. 4. Five kinds of organic acid, oxalic, succinic, fumaric, malic and citric acid were identified as major organic acids. It was interesting that only fumaric acid content was increased while others decreased during storage. 5. Seventeen kinds of amino acid were identified in the analysis of total amino acid content. Major amino acids were found to be proline, threonine, glutamic acid and lysine. During 12 months storage, 30% of original total amino acid was decreased and this was mostly accounted for free amino acids. 6. Threonine, proline, alanine and valine were identified as free amino acids which showed 85% decrease after 12 months storage. 7. Free sugars of jujube were composed of fructose, glucose and sucrose. They showed 24% decrease after 12 months storage, Especially sucrose was not detected after 4 months storage. 8. HMF of dried jujube was isolated and identified. Its content was increased up to great extent as storage period prolonged. 9. Caffeic, ferulic and P-coumaric acid were identified as jujube phenolic compounds which were significantly decreased during storage. In conclusion, non-enzymatic browning was thought to be more important than enzymatic reaction in the dried jujube. Amino-carbonyl reaction, ascorbic acid oxidation and reaction between phenolic compounds and sugar or nitrogen compounds were observed to be related to this browning.

• Preventive Nutrition and Food Science
• /
• v.13 no.4
• /
• pp.306-312
• /
• 2008

This study investigated the influence of pH on the color development of melanoidins formed from amino acid enantiomer model systems. For this, the color development was evaluated by measuring browning at 420 nm and color measurements by spectrophotometry and colorimetry. The browning and browning index showed no difference according to the type of amino acid enantiomers, while that formed from the D-Asn system was the only difference according to pH level. The tristimulus value of melanoidins formed from all model systems was located on a dominant wavelength of 475 nm, the blue zone of the diagram. In addition, the $L^*$, $a^*$, $b^*$, $C^*_{ab}$ values, and ${\Delta}E^*$ index on the basis of the type of amino acid enantiomers, the differences were markedly found at pH 4.0. At pH 7.0, significantly differences were found in the $L^*$, $a^*$, $b^*$ values, and ${\Delta}E^*$ index and not in the case of the lysine enantiomers. In addition, at pH 10.0, the differences were found in the $a^*$ and $b^*$ values from the lysine enantiomers and $C^*_{ab}$ value from the asparagine enantiomers. Therefore, the color development of melanoidins was influenced by the type of amino acid enantiomers and pH levels. Especially, it is thought that the $a^*$ and $b^*$ values can be used to explain the differences among the amino acid enantiomers in the color development of melanoidins.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.22 no.5
• /
• pp.565-569
• /
• 1993

Antioxidative activity of browning product(BP) fractionated from fermented soybean sauce(SS) was studied during the oxidation process of linoleic acid mixture system. SSBP was a powder type product prepared from fermented soybean sauce by the fractionation through the Sephadex G-10 column and freeze drying of collected fraction. The aqueous model systems were used for the evaluation of antioxidative activity of SSBP during the oxidative reaction at $50^{\circ}C$ by the determination of peroxider and conjugated dienoic acid compounds. The linoleic acid mixture for the aqueous model systems was consisted of linoleic acid(64.6%), oleic acid(27.4%), and other acids in ethanolic phosphate buffer solution(pH 7.0). SSBP had a considerable antioxidative activity with the inhibition of formation of peroxides and conjugated dienoic acids during the autoxidation of linoleic acid mixtures in aqueous model systems. Antioxidative activity of SSBP was relatively higher than SS, however, lower than ${\alpha}-tocopherol$ and butylated hydroxyanisol. The antioxidative effect of SSBP was increased by the its concentrations from 0.05% to 0.5% in the oxidation reactions of aqueous model systems. Therefore, SSBP was considered as one of the potential natural antioxidants for the use of food products.

• Food Science and Preservation
• /
• v.13 no.6
• /
• pp.803-807
• /
• 2006

Browning of commercial Doenjang product during storage and marketing is a main concern in the industry. There have been many studies on the improvement on the quality of Doenjang during storage. In this study, phosphate and gas absorber treatment was introduced in manufacturing of Doenjang to improve the color of commercial Doenjang during storage. Doenjang treated with Phosphate and 9as absorber (sample C). Doenjang teated with Phosphate only (sample B), and the control (sample A) were prepared and their physicochemical and sensory properties were determined during storage at $30^{\circ}C$ for 28 days. Sample C was the best in terms of color as well as sensory evaluation resulting in preventing browning of Doenjang during storage. These result suggest that commercial production of Doenjang should introduce phosphate and gas absorber treatment to improve the quality of Doenjang, and to prevent undesirable browning reaction during storage and marketing.

• Korean Journal of Food Science and Technology
• /
• v.25 no.3
• /
• pp.220-224
• /
• 1993

Antioxidative activities of brown materials extracted from the three kinds of roasted coffee beans by water were examined. Antioxidative activity was assessed by the AOM at $120^{\circ}C$ and the oven test at $60^{\circ}C$ on lard. The brown materials of them showed the considerable antioxiant activity. The brown materials of Colombian coffee beans were more effective than those of Robusta or Brazil beans. The antioxidative activities of brown materials from Colombian coffee beans roasted at $210^{\circ}C$ increased in proportion to the browning intensity up to 16 minutes of roasting time, but the antioxidant activities of the brown materials upon further roasting time decreased gradually. In changes of extraction temperature from $30^{\circ}C\;to\;180^{\circ}C$ on the coffee beans roasted at $210^{\circ}C$ for 16 minutes, the antioxidative activities of brown materials did not change as the extraction temperature increased to $180^{\circ}C$. The antioxidative activities of the coffee extracts were thought to be caused by browning reaction materials produced during the roasting process only.

• Applied Biological Chemistry
• /
• v.35 no.2
• /
• pp.82-86
• /
• 1992

This research was carried out to investigate antimutagent effect of peach enzymatic browning reaction products(PEBRP) obtained by reacting each of polyphenol compounds with oxidase extracted from Korea-cultivated peach. In methods, rec-assay with B. subtilis strains $H17(rec^+)\;and\;M45(rec^-)$, and Ames test with S. typhimurium TA98 and TA100 were used. The spore rec-assay of PEBRP, pyrogallol, hydroxyhydroquinone, homocatechol and caffeic acid were not showed mutagenicity. In the effects of various metal ions$(Al^{3+},\;Cu^{2+},\;Fe^{2+},\;Mn^{2+},\;Ni^{2+},\;Pb^{2+},\;Zn^{2+})$ on the rec-assay, all PEBRP except caffeic acid was increased inhibition zone(5 mm) only with $Zn^{2+}$. In paticular, the Py-PEBRP was decreased the difference of inhibition zone of growth on MMC(mitomycin C). In results of Ames test, all PEBRP were not showed mutagenicity on S. typhimurium TA98 and TA100; however, Ca-PEBRP and Hca-PEBRP were suppressed mutagenic effects on Trp-P-1 and B(a)P in the presence of S-9Mix.

• Journal of Food Hygiene and Safety
• /
• v.27 no.4
• /
• pp.401-405
• /
• 2012

The dual effectiveness of Opuntia ficus indica extracts for browning inhibition and microbial inactivation on fresh-cut apples was investigated. Prepared apple slices were treated with 25, 50, 100, 200 mg/mL Opuntia ficus indica extracts, packaged in polyethylene bags, and stored for 10 days at 4, $21^{\circ}C$. Results indicate that Opuntia ficus indica extracts significantly (P < 0.05) inhibited the browning reaction of fresh-cut apples. This treatment also reduced peroxidase activities. The populations of Staphylococcus aureus significantly decreased with increasing extract concentration (p < 0.05). In particular, S. aureus was reduced to non-detectable levels after 2 days in 100 mg/mL treatment at $4^{\circ}C$ and $21^{\circ}C$. Opuntia ficus indica extracts therefore have antibacterial and antibrowning effects. The results suggest that Opuntia ficus indica extracts could be useful as a natural food preservative.

• Journal of the Korean Society of Industry Convergence
• /
• v.25 no.1
• /
• pp.21-26
• /
• 2022

When garlic is aged for a certain period of time while maintaining proper humidity, it causes a browning reaction by its own ingredients and enzymes. In this study, the physicochemical properties were analyzed by varying the temperature conditions for aging garlic. It was found that about 20% of the weight of garlic was reduced through the aging process. During the aging process, both samples showed the highest water content on the 10th day of aging, and the water content of the two samples was similar after the aging was completed. In the analysis of total sugar content change, AG1 (22.0±0.7 vs 21.4±0.6) showed a significantly higher sugar content on the 10th day of aging, but showed a tendency to gradually decrease thereafter, whereas AG2 showed a steady increase in sugar content during the aging process (18.7 < 21.4 < 21.7 < 22.3 < 23.7). The pH change that occurred during the aging process showed the most pH change on the 10th day. In AG1, the pH gradually decreased as the aging period increased, whereas in AG2, the pH increased significantly after the 10th day. In the analysis of browning, AG1 increased sharply on the 10th day and maintained the state, and AG2 showed a significant increase in browning according to the aging process. In conclusion, based on the results of this study, if various ripening temperature conditions are set, it is judged that it will play a positive role in improving the productivity of black garlic.

• Korean journal of food and cookery science
• /
• v.7 no.4
• /
• pp.51-61
• /
• 1991

Physical and chemical properties of glycosylsucrose were characterized as follows: 1. The moisture content of glycosylsucrose syrup (35% , w/w) was 63.6% and total sugar in solid was 35.9%. 2. Main sugar compositions of glycosylsucrose syrup were maltotetraose 54.5%, sucrose 18.0%, glycosylsucrose 15.3%, maltosylsucrose 11.3% and the content of glucose, maltose, maltotriose and fructose were very little. 3. Perceived sweetness threshold of glycosylsucrose was 0.71%, relative sweetness was 0.53, and sweetness intensity expressed as power function was S=$0.78^{\circ}$C^{1.5}$$. 4. Viscosity of glycosylsucrose was higher than that of sucrose and Japanese product at 10, 25, 35 and $65^{\circ}C$. 5. The content of water absorption of gylcosylsucrose at Aw 0.80 was 0.48 g $H_2$O/g dry weight while that of sucrose was 0.17g $H_2$O/g dryweight at Aw 0.86. 6. The stability of glycosylsucrose was decreased by acidic pH, high temperature and long heating time. 7. The glycosylsucrose showed very little browning when heated with pepton, but alkaline pH (pH8), high temperature and long heating time increased browning reaction.