• 한국식품영양학회지
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• 제31권5호
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• pp.689-695
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• 2018

This study was carried out to select apple cultivars suited for the fresh cutting or minimal processing as investigating correlation between total phenol and ascorbic acid as browning factors and the enzymatic browning degree. In soluble solid-acid ratio, 'Gamhong' and 'Arisoo' were highest value of 71.69 and 71.52 compared with other cultivars. And the change of lightness (${\Delta}L$) and color (${\Delta}E$) in 'Gamhong' and 'Arisoo' showed lower than other cultivars while 'Arkansas black' was highest change of lightness and color as ${\Delta}L$ 8.27, ${\Delta}E$ 13.86 respectively. Total phenol and ascorbic acid contents in 'Arkansas black' were highest such as 334.3 mg GAE/100 g and 9.22 mg/100 g, respectively. And polyphenol oxidase (PPO) activity also was the highest such as 14.43unit in 'Arkansas black'. The correlation test showed browning of apple was significantly dependent on ${\Delta}L$, ${\Delta}E$, total phenol, ascorbic acid contents and PPO activity (p<0.01). On the contrary, no significant correlation had been determined between the browning and ascorbic acid oxidase (AAO) activity. Thus, it seemed that the browning of apple was not only due to oxidation of ascorbic acid but also total phenol. It was suggested that 'Gamhong' and 'Arisoo' were suitable for fresh cutting or minimal processing.

• 한국버섯학회지
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• 제16권4호
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• pp.331-333
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• 2018

The incorporation of Shiitake culture into sawdust is a widely utilized technique that can assist in reducing the cost and time consumption associated with oak cultivation. In sawdust cultivation, browning of the surface mycelia is an important stage with respect to the utility and longevity of the sawdust media. Surface browning forms a protective coating on the substrate, which can inhibit the invasion of pathogens and suppress water evaporation. Several different light sources (red LED, white LED, blue LED, and fluorescent light) were used and the intensity of illumination was carefully controlled (1.5, 10.5, $20.5{\mu}mol/m^2s$ for LEDs and 10, 100, 300 lux for the fluorescent light) to induce browning. The light sources were regulated via a 1 h on/off cycle in a controlled room environment at a temperature of $20^{\circ}C$, 60% humidity, and 1200 ppm $CO_2$ concentration for 60days. The browning effect varied depending on the source and the intensity of illumination. This effect was most effectively induced at $1.5{\mu}mol/m^2s$ for the red and blue LEDs. All light sources induced less browning at the highest intensity of illumination. This indicates that intensity values higher than $20.5{\mu}mol/m^2s$ in the case of the LEDs and 300 lux for the fluorescent light are not effective. After harvesting of the fruit bodies, we measured the weight, length, and width of the pileus and stipe in addition to their chromaticity and hardness. Treatment with $1.5{\mu}mol/m^2s$ blue LED produced the best harvest with the highest average chromaticity, weight (21.2 g), stipe length (30.8 mm), and hardness (377.9 g), with a fine length and width of the pileus.

• 한국식품영양학회지
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• 제9권4호
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• pp.504-508
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• 1996

들깨를 15$0^{\circ}C$에서부터 21$0^{\circ}C$까지 10~30분간 볶아서 착유한 들기름에 존재하는 갈색물질의 갈색도와 전자제공력과, 또한 기호성 및 산화 안정성을 검토하였다. 들기름으로 추출한 갈색물질은 들깨의 볶는 온도와 시간이 증가에 따라 증가하였다. 들깨를 210~에서 30분간 볶아 착유한 들기름으로부터 추출한 갈색물질은 15$0^{\circ}C$에서 10분간 볶은 것에 비해 13배 정도 증가하였다. 한편 볶음조건에 따라 착유한 들기름 중의 갈색물질 추출물의 DPPH에 대한 전자제공력은 볶음온도와 시간 증가에 따라 향상되었다. 21$0^{\circ}C$에서 30분 볶아 착유한 들기름중의 갈색물질은 15$0^{\circ}C$에서 10분 볶은 것에 비해 전자제공력이 약 3배 증가하였다. 기호성이 가장 우수한 들기름에 산화 안정성이 가장 좋은 들기름을 5~20% 혼합한 15% 혼합량 것 중 기호도와 산화 안정성이 가장 우수하였다. 21$0^{\circ}C$에서 30분 볶아 착유한 들기름 중의 갈색물질은 19$0^{\circ}C$에서 20분 볶아 착유한 들기름의 산화 안정성을 증가시켰다.

• 한국수산과학회지
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• 제6권1_2호
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• pp.37-43
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• 1973

In this paper, non-enzymatic browning reactions as a factor of self stability of boiled and dried anchovy were studied to discuss the effect of water activity to the discoloring reaction and the preservative moisture content. The development of rancidity of the fish meat was also mentioned since the fish is fatty and the lipid oxidation is a functional deteriorative reaction. Fresh anchovies were boiled in $10\%$ salt solution immediately after the catch, sun dried, and stored at room temperature ($20^{\circ}C$) for two months in humidistat chambers maintaining different levels of water activity as described in Table 1. The pigments formed by non-enzymatic browning reations were extracted in two fractions, those were chloroform-methanol soluble and water dialyzed fraction, and analyzed spectrophotometrically at the wavelength of 460 nm. These two fractions were considered, respectively to be the brown pigments formed by lipid oxidation reactions for the formler and for the latter, to be the pigments developed by sugar-amino or Maillard reaction. The oxidation of lipid in anchovy meat during the storage was measured as the changes in Peroxide value and the color development of thiobarbituric acid reaction. It is summarized from the results that the rate of both reactions, lipid oxidation and browning, was affected by water activity levels. In regard to the changes in peroxide and TBA value during the storage, the propagation of lipid oxidation was obviously accelerated at lower humidities whereas the development of browning progressed at the higher. These two reactions occurring simultaneously and contrary in activity resulted in that the rate of deterioration occurring oxidatively or by browning, was the minimum at the water activity of 0.32-0.45 which were $7-9\%$ as moisture content and slightly higher value than that of monolayer (Aw=0.21, $5.11\%$ as moisture content). It is also noted that the lipid oxidative browning was presumed to dominate sugar-amino reactions so that the rate of browning of the meat was ultimately depended on the development of rancidity although sugar-amino reactions initiated earlier than the other at the first ten days of storage, particulary at higher humidity. At the lower humidity sugar-amino reactions were occurred gradually but lower levels in color development in contrast to the consistent increase in lipid oxidative browning.

• Food Science and Biotechnology
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• 제17권5호
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• pp.931-939
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• 2008

The objective of this study was to investigate the enolization reaction and the antioxidant activity of caramelization products (CPs) obtained by caramelization browning of glucose and fructose solutions prepared at a pH ranging from 7.0 to 12.0 at varying temperatures ($80-180^{\circ}C$). The degradation of sugars rapidly increased at a high alkaline pH (10.0-12.0), and fructose degraded more rapidly than glucose (p<0.05). As the pH increased, the degree of sugar enolization was higher in fructose than in glucose. Browning and the formation of intermediate degradation products increased with the increase in heating temperatures. The browning development was dependent upon the type of sugar, and it was generally higher at alkaline pH than at neutral pH. The reducing power and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the CPs increased with the increase in browning and formation of large amounts of intermediates. Therefore, the CPs with pronounced antioxidant activity can be prepared by heating fructose or glucose solutions that have a very alkaline pH to high temperatures.

• Food Science and Biotechnology
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• 제16권3호
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• pp.421-425
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• 2007

The inhibitory effect of onion extract on polyphenol oxidase (PPO) and browning of peach juice was investigated. Various reducing agents such as L-ascorbic acid, L-cysteine, dithiothreitol, glutathione, and sodium pyrosulfite strongly inhibited polyphenol oxidase extracted from peach. The enzyme was also inhibited by addition of water extract of onion. Regardless of substrates used, the addition of heated onion extract exhibited stronger inhibitory effect on peach polyphenol oxidase activity than that of the fresh one. The inhibitory effect of onion extract was dependent on heating temperature and time. The onion extract inhibited the peach polyphenol oxidase non-competitively. The heating of onion extract in the presence of glucose, glycine stimulated the inhibitory effect of the onion extract, which suggests non-enzymatic browning products produced during heating might be responsible for the stronger inhibitory action of the heated onion extract. The retardation of peach juice browning by onion extract seems to be caused by inhibition of peach PPO.

• Food Science and Biotechnology
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• 제18권4호
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• pp.932-938
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• 2009

Browning of tea infusion is an obstructive factor influencing shelf life of ready-to-drink green tea. Effects of temperature and illumination on the browning of green tea infusion were investigated. It was shown that both elevated temperature and illumination led to the browning of green tea infusion, but temperature had greater effect on infusion color and level of catechins than illumination. The levels of unoxidized catechins such as (-)-epigallocatechin gallate (EGCg), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg), (-)-epicatechin (EC), and total catechins remaining in the tea infusion were significantly correlated to color parameters of the tea infusion. Sodium ascorbate inhibited the infusion browning by suppressing the oxidation of tea catechins and it is considered to be a more suitable preservative for prolonging shelf life of ready-to-drink green tea than ascorbic acid because it has less effect on tea taste. The effects of temperature and illumination on the epimerization of catechins were also discussed.

• Preventive Nutrition and Food Science
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• 제17권3호
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• pp.210-216
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• 2012

The use of suitable sanitizers can increase the quality of fresh-cut produce and reduce the risk of foodborne illnesses. The objective of this study was to compare the washing effects of 100 mg/L sodium hypochlorite (SH) and 500 mg/L acidified sodium chlorite (ASC) on the prevention of enzymatic browning and the growth of microbial populations, including aerobic plate counts, E. coli, and coliforms, throughout storage at $4^{\circ}C$ and $10^{\circ}C$. Fresh-cut zucchini, cucumbers, green bell peppers, and root vegetables such as potatoes, sweet potatoes, carrots, and radishes were used. Compared to SH washing, ASC washing significantly (p<0.05) reduced microbial contamination on the fresh-cut produce and prevented browning of fresh-cut potatoes and sweet potatoes during storage. More effective inhibition of aerobic plate counts and coliforms growth was observed on fresh-cut produce treated with ASC during storage at $10^{\circ}C$. Polyphenol oxidase (PPO) activity of fresh-cut potatoes and sweet potatoes was more effectively inhibited after washing with ASC. The use of 500 mg/L ASC can provide effective antimicrobial and anti-browning treatments of fresh-cut produce, including processed root vegetables.

• 한국수산과학회지
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• 제21권3호
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• pp.169-176
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• 1988

In order to obtain the objective indices which can assess the quality and the shelf-life of dried squid, nonenzymatic browning, carbonyl value, trimethyl amine (TMA) and trimethyl amine oxide (TMAO) decrease and panel test were determined in dried squid at various water activity levels. When the data of nonenzymatic browning fit a zero order equation, $r^2$ value were more than 0.92 except aw 0.52 for 0.8241. Through variance analysis for the data of browning extent and TMAO decrease, the confidence limits of regression equation were $99\%$ and their limit values of shelf-life were shown 0.45390 O. D./g. solid and 190.322 g/g respectively. In case of TMAO, $r^2$ value was calculated more than 0.95. Linear regression equation for the correlation between browning data and average panel score was Y=0.6138-0.053X and its $r^2$ value was 0.9285. Also in TMAO decrease, the equation was InY=2.0314+0.08269x and $r^2$ value was 0.7854. The shelf-life, evaluated by nonenzymatic browning, TMAO decrease and panel test, was 110-170 days at aw 0.45-0.76 except aw 0.15.

• Journal of Applied Biological Chemistry
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• 제54권3호
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• pp.190-196
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• 2011

Effectiveness of edible coatings containing soy protein isolate (SPI), in reducing oxidative browning and moisture loss during storage ($4^{\circ}C$) of cut apples, potatoes, carrots, and onions was investigated. The SPI coatings were shown to have antioxidative activity. Furthermore, addition of carboxymethyl cellulose (CMC) to the formulations significantly improved its antioxidative activity. Oxidative discoloration, as determined by Commission Internationale De I'Eclairage (CIE) lightness ($L^*$), redness ($a^*$), and yellowness ($b^*$) color scale, was significantly reduced (p <0.05) by SPI coating treatments over a storage time of 120 min. Loss of lightness was reduced by SPI coatings with and without CMC. These respectively showed 4.03 and 3.71% change of $L^*$ value compared to 8.56% for control. Browning of the control in cut potatoes was significantly increased by 106.6% in contrast to 34.3 and 35.2% for SPI coatings with and without CMC, respectively. The $b^*$ values also reflected effectiveness of SPI. Moisture barrier effect was significantly better for the treatments, compared to the control. SPI coatings reduced moisture loss in apples and potatoes, respectively, by 21.3 and 29.6% over the control. Cut onions did not show any treatment effect both in terms of browning and moisture loss. SPI coatings prove to be good moisture barrier and antioxidative property.