• Food Science and Preservation
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• v.17 no.2
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• pp.202-207
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• 2010

The effects of ultrasound treatment, in combination with ascorbic acid, on the quality of fresh-cut 'Jonathan' apples was investigated. Prepared apple slices were ultrasonicated in distilled water (US) or in 1%(w/v) ascorbic acid solution (UA) and the other samples were just dipped in 1%(w/v) ascorbic acid solution (AA). All samples were stored at$10^{\circ}C$ for 12 days. UA-treated samples showed high $L^{*}$ and hue values and low $a^{*}$, $b^{*}$, chroma, and ${\Delta}E$ value. Both control and US-treated samples showed considerable browning. A significant inhibition of polyphenol oxidase activity was observed after UA treatment. The level of total phenolics in UA-treated samples was higher on the day of treatment compared with other samples. Total soluble solids, pH, titratable acidity, and gas concentrations were similar in all samples. This study demonstrated that the simultaneous treatment of ultrasound and ascorbic acid was effective in preventing enzymatic browning of fresh-cut 'Jonathan' apples and maintaining total phenolics contents.

• Food Science and Preservation
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• v.19 no.3
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• pp.323-327
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• 2012

The effects of ultrasound and ascorbic acid cotreatment on the browning inhibition and microbial growth of fresh-cut Tsugaru apples were investigated. The prepared samples were dipped in distilled water (Cont) or 1% (w/v) ascorbic acid solution (AA) and were then ultrasonicated in distilled water (US) or 1% (w/v) ascorbic acid solution (AA+US). The samples were then packed in a 0.04mm polypropylene bag ($20{\times}15$ cm) and were stored at $10^{\circ}C$ for eight days. The AA+US treated samples showed high $L^*$ and low $a^*$, $b^*$ values as well as inactivated PPO activity. The growth of the total aerobic bacteria also inhibited the AA+US treated samples more. The physicochemical properties were not different among all the samples. It was demonstrated in this paper that the ultrasonication treatment with ascorbic acid prevented the enzymatic browning of and microbial growth in fresh-cut Tsugaru apples.

• Food Science and Preservation
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• v.18 no.4
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• pp.475-480
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• 2011

This papers were studies the effects of high $CO_2$ concentration pretreatment and ascorbic acid on the browning of fresh-cut apples. The prepared samples were dipped in 1% (w/v) ascorbic acid solution (AA). Fresh-cut apples (3 pieces) were packed in polypropylene bags (0.03 mm, $20{\times}15$ cm), and stored at $10^{\circ}C$ for 16 days. AA-treated samples showed higher L value than those of non-treated and control (dipped in water without $CO_2$ pretreatment), while non-treated samples showed higher hardness than AA-treated sample. Total soluble solids, pH, titratable acidity were not affected by high $CO_2$ pretreatment and AA treatment. These result shows high $CO_2$ concentration pretreatment with dipping in 1% ascorbic acid solution (AA) has an effects on controlling enzymatic browning during the storage of fresh-cut 'Fuji' apples.

• Food Science and Biotechnology
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• v.15 no.4
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• pp.529-533
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• 2006

To produce fresh-cut fruit products of high quality, the combined effects of postharvest calcium and heat treatment on Tsugaru apple were examined. Whole fruits were treated for 20 min at three different conditions: dipping in 3% $CaCl_2$ solution at $45^{\circ}C$ or ambient temperature, or in heated water at $45^{\circ}C$. The calcium content of the apples dipped in $CaCl_2$ solution at $45^{\circ}C$ was higher than that of the control and the non-heated calcium dipping. The fruits with calcium and heat treatment showed the same pattern of respiration rates as the control did during storage. The browning degree of the apple slices increased to approximately 3% after one-day storage, but no significant difference was observed between the treated and untreated apples. The fruits with $CaCl_2$ solution dipping at $45^{\circ}C$ had higher firmness than those with calcium dipping or heat treatment alone.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.7
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• pp.1009-1013
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• 2012

We investigated the antibacterial effects of Opuntia ficus indica extracts on foodborne pathogens, Escherichia coli O157:H7 and Listeria monocytogenes, on the medium of sliced apples. Pathogens were inoculated on sliced apples and immersed for 10 min in Opuntia ficus indica extracts. Each sample was packaged and stored at $4^{\circ}C$ and $21^{\circ}C$ for 8 days. The populations of E. coli O157:H7 and L. monocytogenes significantly decreased with increasing extract concentration (p<0.05). In particular, L. monocytogenes was reduced to non-detectable levels after 2 days in 50 mg/mL treatment at $4^{\circ}C$ and $21^{\circ}C$ Opuntia ficus indica extracts therefore have antibacterial effects on the two foodborne pathogens. Sensory evaluation results indicated that treated apples had better sensory characteristics than did the control. Therefore, the results suggest that Opuntia ficus indica extracts could be useful as a natural food preservative to improve microbial safety.

• Korean Journal of Food Science and Technology
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• v.33 no.4
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• pp.469-473
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• 2001

Fuji apples were sliced and dipped in distilled water, 1% (w/v) ascorbic acid and 1% (w/v) oxalic acid. After minimal processing, the slices were packaged with three films which have different gas transmission rate and stored in cold room$(0-2^{\circ}C)$. The visual quality, gas composition, pH, texture, soluble solids content and titratable acidity were determined. The most deteriorative effects on quality were produced by browning of flesh. Ascorbic acid inhibited the development of browning and extended storage life from 7 days of control to 14 days at $0-2^{\circ}C$. Minimally processed Fuji apple treated with ascorbic acid and P640 film showed exhausting of oxygen in the packaging after 14 days. It showed only a slight reduction of pH from 3.73 to 3.72. The visual quality, gas composition, pH, texture, soluble solids content, titratable acidity were slightly changed, indicating that higher quality was maintained during storage. Ascorbic acid inhibited the development of browning and extended storage life of fresh-cut Fuji apple.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.167.1-167
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• 2003

To maintain high quality and to extend the shelf life of intact and minimally processed apple cubes, the effect of heat shock on the texture and color of apple cubes (Fuji) was evaluated in this study. After peeled and cored, the apples were cut into cubes of 1.5 cm. The heat shock was immersion in heated water from 25$^{\circ}C$ to 95$^{\circ}C$ in 10$^{\circ}C$ increments for 2 min and cooling to storage temperature as soon as possible after heat treatment. The effect of heat treatment in terms of color and texture measurements with respect to time was investigated, respectively during 7 days storage at in LDPE film bags without sealing at 4$^{\circ}C$, and 95% relative humidity air. Results suggest that heat shock (55$^{\circ}C$, 2 min) may have effectively delayed browning, and there were significant changes in color of apple cube when the temperature of heat shock is above 75$^{\circ}C$. And hardness, stiffness and firmness, which were used to describe texture, behaved similarly in the textural qualities. It was shown that the texture of the apple cubes was decreased with temperature increase. The value of them were most decreased to 70% of the initial ones after treated with 85$^{\circ}C$ and 95$^{\circ}C$ on the lust day.

• Korean Journal of Food Science and Technology
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• v.45 no.5
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• pp.598-604
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• 2013

This study was designed to evaluate the usability of the following citrus peel extracts (CPEs): Citrus sinensis (orange), C. unshiu (mandarin orange), C. limon (lemon), and C. paradise (grapefruit) as natural antibrowning agents. Overall, 0.1% of the CPEs were effective in reducing the browning of apple slices. The appearance of apple slices dipped in C. limon peel extracts (LPE) were found to be excellent and their Hunter L and ${\Delta}E$ values were similar to the values obtained when apple slices were dipped in ascorbic acid. The pH values of the different CPEs were not significantly different from each other, but were higher than that of ascorbic acid. LPE was found to possess the highest total phenolic content, flavonoid content, DPPH radical scavenging activity, and copper ($Cu^{2+}$) chelating activity. All these results suggest that citrus peel extracts, especially lemon peel extract, can be used as natural antibrowning agents.