• Journal of Life Science
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• v.7 no.3
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• pp.192-197
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• 1997

Italian ryegrass, red clover, sorghum, and alfalfa were used for leaf protein preparation. Fresh leaves were pulped in the presence or absence of a reducing agent(sodium ascorbate or NaHSO$_{4}$) and green juice was heated and washed with acetone. The biological evaluation of leaf proteins was carried out by the growth method with male rats weighing about 45g. Italian ryegrass, red clover, and sorghum were brown when leaves were pulped in the absence of a reducing agent. On the other hand, alfalfa had neither o-diphenolics nor polyphenolase, and hence the alfalfa leaf protein did not brown during pulping ever in the absence of a reducing agent. The brown leaf protein from Italian ryegrass hd lower digestibility than the leaf protein protected from browning, although there were no difference in growth-promoting effect and protein efficiency ratio(PER)between the two leaf protein. The feeding of brown leaf protein from red clover resulted in the lowering of weight gain, digestibility, and PER, and all the measurement including diet intake were lowered by feeding the brown leaf protein from sorghum. In the case of alfalfa leaf protein, there were no difference in nutritional quality between the two leaf protein made with and without an attempt to prevent browning. The results mentioned above indicate that the occurrence of phenolics and polyphemolase in a crop in responsible for the browning of leaf protein and that the browning of leaf protein caused its nutritional impairment.

• Korean Journal of Organic Agriculture
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• v.19 no.1
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• pp.109-120
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• 2011

Calyx-end browning in sweet persimmon (Diospyros kaki) fruits is the postharvest disorder during the storage and shows different proportions by the cultivars. This study was to evaluate fruit texture characteristics at harvest and to learn how browning in fruits affects the cell structures in different cultivars. Persimmon cultivars included 'Fuyu', 'Jiro', 'Uenishiwase', 'Daiandangam', and 'Ro-19', which were harvested at the end of October in 2003 and investigated after 100 days storage. Fruit texture varied with different cultivars. 'Jiro' and 'Ro-19' fruits did not have browning symptoms while 'Daiandangam' fruits had approximately 80% browning of them. There were no visual differences for the cell structure in fruit peels between fruits without browning, such as 'Jiro' and 'Ro-19', and fruits with browning, such as 'Fuyu', 'Uenishiwase', and 'Daiandangam'. The most outer layers in a 'Jiro' fruit peel arranged one to two epidermis which could not induce browning in the tissues, while 'Fuyu' had two to three layers, inducing a browning symptom. Although there were no differences for the tissue structure between browning and normal fruits, browning fruits did not have apparent cell organelle and proceeded degradation of cell walls in the flesh.

• Food Science and Preservation
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• v.16 no.4
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• pp.499-505
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• 2009

Quality changes in fresh-cut potatoes during storage at $4^{\circ}C$ after treatment with low-temperature blanching and antibrowning agents were studied. Fresh-cut potatoes were treated by dipping for 1.5 min in a browning inhibitor solution containing 0.5% (w/v) ascorbic acid, 0.5% (w/v) citric acid, 0.5% (w/v) sodium chloride, 0.1% (w/v) trehalose, and 0.005% (w/v) biotin, at $60^{\circ}C$, with subsequent cooling for 1.5 min and storage at $4^{\circ}C$. The browning properties of fresh-cut potatoes were examined by measurement of polyphenol oxidase (PPO) activity and total phenolic content. Changes in quality attributes over a 14-day period were assessed in terms of titratable acidity, pH, water-soluble solid level, and gas analysis at $4^{\circ}C$. During storage, PPO activity increased, with the lowest activity seen after about 7 days of storage. Treatment with antibrowning solution at $4^{\circ}C$ increased visual sensory attributes during storage. Low-temperature blanching in distilled water more effectively inhibited browning compared with exposure to browning inhibitor solution, as assessed after 7 days of storage. Fresh-cut potatoes respired aerobically after different treatments during storage at $4^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.30 no.2
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• pp.278-282
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• 1998

Peeled garlic, soybean sprouts, cut onion and cut green pepper were treated by dipping in solutions of different antibrowning agents, and then stored at $10^{\circ}C$. Surface color and polyphenol oxidase activity of produce were measured through the storage. Tested antibrowning agents include ascorbic acid, citric acid and allyl isothiocyanate. The commodities showed different responses to the antibrowning agent solutions; 1% citric acid for peeled garlic, 1% ascorbic acid for soybean sprouts, 2% citric acid for cut onion, and 1% ascorbic acid for cut green pepper showed better retardation in browning than the other treatments for respective product. For peeled garlic, surface browning was concomitant with increase in polyphenol oxidase activity during storage. On the other hand, there was no positive correlation between surface browning and polyphenol oxidase activity for the other stored products.

• Korean Journal of Medicinal Crop Science
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• v.6 no.1
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• pp.33-37
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• 1998

Browning index rised rapidly within 15 hrs to 83% of total browning in Jang - ma (Dioscorea batatas Decne) tissues at $40^{\circ}C$ while 37% in Dan - ma. Therefore, the degree of browning process of Jang - ma was faster than that of Dan - ma. Browning in Jang - ma was inhibited by treatments of NaCl which showed 48 and 39% inhibition, respectively, after 48 hrs of incubation. Also the treatment of $80^{\circ}C$ heating showed excellent inhibition within 24 hrs. In the case of Dan - ma, browning process was inhibited by treatments of 1 and 0.5M NaCl and $70^{\circ}C$ heating, which showed 43, 26 and 23% inhibition, respectively, after 48 hrs of incubation.

• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.214-219
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• 1993

Properties of the antioxidative fraction isolated from browning reaction product (BRP) that were obtained from 2 M L-ascorbic acid (AsA) solution (adjusted to pH 7.0) by heating for 25 hrs at $85^{\circ}C$ were investigated. Both of dialyzable and nondialyzable fraction isolated from BRP showed antioxidative effect. Dialyzable fraction has stronger antioxidative activity than nondialyzable. Dialyzable fraction was divided into the three fractions (A, B, C) by gel filtration. Among these fractions, the fraction (A) that had the highest reducing power and lowest browning drgree had lowest antioxidative activity. The fraction (C) that had lowest reducing power and highest browning degree showed strongest antioxidative effect. In the UV-visible spectrum of these fractions, the maximum absorption wavelengths of fraction A and B were 266.1 and 257.4nm, respectively, and fraction C showed a weaker absorption peak at 274.8nm. Infrared (IR) spectrum results showed that all fractions (A, B, C) had both hydroxy and carboxylic groups, and fraction B and C had carboxylic ester group.

• Applied Biological Chemistry
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• v.37 no.5
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• pp.379-384
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• 1994

Casein or soybean protein was subjected to the reaction with caffeic acid-tyrosinase system at $30{\sim}35^{\circ}C$ pH 6.8 with aeration for 5 hr. The effects of the modified proteins on male Wistar rats were studied by pair-feeding of a cholesterol-free diet for 2 weeks. Significant decrease in protein digestibility for the rats fed with the modified proteins was observed. The feeding of modified protein from casein caused an enlargement of caecum. The concentration of serum cholesterol and triglyceride in the rats fed with modified proteins were mostly unchanged against the rats fed with untreated proteins. These results suggest that the decrease in protein digestibility induced by enzymic browning-reaction did not cause the decrease in concentration of serum cholesterol.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.454-458
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• 2002

The effect of antibrowning agents such as PVPP (polyvinylpolypyrrolidone), bentonite, gelatin, celite 545, tannic acid and sodium sulfite in apple concentrate was investigated for the control of enzymatic browning by comparing physicochemical properties (pH, color, turbidity), polyphenoloxidase activity and contents of polyphenol compounds. In color value, apple concentrate containing PVPP showed higher L value (lightness) than control and other antibrowning agents. The turbidity (absorbance at 660 nm) of apple concentrate added PVPP, gelatin celite 545, tannic acid and sodim sulfite were 0.003, 0.038, 0.018 and 0.022, respectively. PVPP was regarded to remove suspended solids effectively. Polyphenoloxidase activity and polyphenolics(catechol, catechin, chlorogenic acid, epicatechin) content of apple concentrate used PVPP significantly reduced. Therefore PVPP was proved to be effective for enzymatic antibrowning agent considering to color, turbidity, polyphenoloxidase activity and polyphenol compounds in apple concentrate.

• Korean Journal of Food Science and Technology
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• v.23 no.4
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• pp.523-525
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• 1991

The stimulatory effect of oxygen on the browning of a soy sauce model system (glucose-glycine in 18% NaCl solution) with or without added organic acids were investigated. The group incubated aerobically browned at a significantly higher degree than the group incubated anaerobically. Organic acids also positively affected the browning of the soy sauce model system.

• Korean journal of applied entomology
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• v.14 no.1 s.22
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• pp.35-36
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• 1975

An experiment was carried out to know bow the rice root nematode, Hirschmanniella cryzae affects the root browning of rice pant growing in various combinations of media. In sterilized conditions of growing media, the root browning of rice plant was slightly promoted by the presence of the rice root nematode, while the entire roots were stained to brown in nonsterilized conditions of growing media. It seems that the root browning is due mainly to soil micro-organisms other than nematode which promotes it slightly under sterilized conditions.