• Food Science and Preservation
• /
• 제24권1호
• /
• pp.84-92
• /
• 2017

Chicken breast jerky (CJ) was prepared by drying chicken breast at $50^{\circ}C$ for 9 hrs after marinating it in a various sweetening sauce including white sugar (WS), brown sugar (BS), rice syrup (RS), fructooligosaccharide (FO), pineapple concentrate (PC), Rubus coreanus extract (RCE), or honey (H), and its physicochemical and sensory properties were investigated. The CJ was found to contain 22.5-25.0% moisture, 41.0-46.6% protein, and 0.4-1.0% fat, which indicates that it could serve as a high-protein and low-fat snack. The type of sweeteners significantly affected the yield, pH, total viable cell count, and water activity of the CJ, showing ranges of 40.9-50.1%, 5.2-5.9, $2.5-6.2{\times}10^4CFU/g$, and 0.74-0.81, respectively. Both the water activity and pH were the lowest in CJ-RCE where of the highest in CJ-WS. The cohesiveness, springiness, and chewiness of the CJ significantly differed depending on the type of sweeteners (p<0.05). CJ-RCE showed the best taste and overall acceptability in a sensory test. After storage at $50^{\circ}C$ for 2 weeks, thiobarbituric acid reactive substance (TBARS) content (58.3 malondialdehyde (MDA) mg/kg) of CJ-RCE was much lower than those of control beef (75.6 MDA mg/kg) and pork jerky (98.0 MDA mg/kg), showing the good oxidative stability of CJ-RCE. Overall, marination in RCE sauce was suitable for the preparation of CJ with good quality in terms of its water activity, fat and protein contents, sensory property and oxidative stability.

• Food Science and Preservation
• /
• 제24권1호
• /
• pp.68-73
• /
• 2017

The main objective of this study was to investigate the effects of various commercial pectin enzyme treatments on juice yield from Aronia fruits (Aronia melanocarpa) as well as changes in physicochemical properties such as pH, total acid, reducing sugar, soluble solid, total anthocyanin, total phenolic compounds, and DPPH radical scavenging activity. Different types and reaction conditions of pectinase were also investigated in order to improve extraction yield of Aronia juice. The optimal conditions of enzyme treatment were 0.1% of concentration (w/w) at $50^{\circ}C$ for 120 min. Among enzymes used in this study, extraction yield with Rapidase Press L treatment from Aronia juice was the highest and resulted in a significant increase in juice from 51.0 to 69.1%. Rapidase C80 MAX showed 68.83% extraction yield while Plantase TCL showed 66.70% extraction yield. Reducing sugar and soluble solid contents increased after enzyme treatment. Total acids also slightly increased after enzyme reaction. No significant difference was observed in pH regardless of pectin enzyme treatment. However, enzyme treatment resulted in an increase in total phenolic compounds, total anthocyanin, and DPPH radical scavenging in Aronia juice compared to the juice prepared juice.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 한국자원식물학회 2003년도 춘계 학술발표대회
• /
• pp.61-62
• /
• 2003

Clonal propagation of high-value forest trees through somatic embryogenesis (SE) has the potential to rapidly capture the benefits of breeding or genetic engineering programs and to improve raw material uniformity and quality. A major barrier to the commercialization of this technology is the low quality of the resulting embryos. Several factors limit commercialization of SE for Corsican pine, including low initiation rates, low culture survival, culture decline causing low or no embryo production, and inability of somatic embryos to fully mature, resulting in low germination and reduced vigour of somatic seedlings. The objective was to develop a Corsican pine maturation medium that would produce cotyledonary embryos capable of germination. Treatments were arranged in a completely randomized design. Data were analyzed by analysis of variance, and significant differences between treatments determined by multiple range test at P=0.05. Corsican pine (Pinus nigra var. maritima) cultures were initiated on modified !P6 medium. Modifications of the same media were used for culture multiplication and maintenance. Embryogenic cultures were maintained on the same medium semi solidified with 2.5 g/l Gelrite. A maturation medium, capable of promoting the development of Corsican pine somatic embryos that can germinate, is a combination of iP6 modified salts, 2% maltose, 13% polyethylene glycol (PEG), 5 mg!l abscisic acid (ABA), and 2.5 g/l Gelrite. After initiation and once enough tissue developed they were grown in liquid medium. Embryogenic cell suspensions were established by adding 0.951.05 g of 10- to 14-day-old semisolid-grown embryogenic tissue to 9 ml of liquid maintenance media in a 250ml Erlenmeyer flask. Cultures were then incubated in the dark at 2022$^{\circ}$C and rotated at 120 rpm. After 2.53 months on maturation medium, somatic embryos were selected that exhibited normal embryo shape. Ten embryos were placed horizontally on 20 ml of either germination medium ($\frac{2}{1}$strength Murashige and Skoog (1962) salts with 2.5 g/l activated charcoal) or same medium with copper sulphate adjusted to 0.25 mg/1 to compensate for copper adsorption by activated carbon. 2% and 4% maltose was substituted by 7.5% and 13% PEG respectively to improve the yield of the embryos. Substitution of' maltose with PEG was clearly beneficial to embryo development. When 2% of the maltose was replaced with 7.5% PEG, many embryos developed to large bullet-shaped embryos. At latter stages of development most embryos callused and stopped development. A few short, barrel-shaped cotyledonary embryos formed that were covered by callus on the sides and base. When 4% of the maltose was removed and substituted with 13% PEG, the embryos developed further, emerging from the callus and increasing yield slightly. Microscopic examination of the cultures showed differing morphologies, varying from mostly single cells or clumps to well-formed somatic embryos that resembled early zygotic embryos only liquid cultures with organized early-stag. A procedure for converting and acclimating germinants to growth in soil and greenhouse conditions is also tested. Seedling conversion and growth were highly related to the quality of the germinant at the time of planting. Germinants with larger shoots, longer, straighter hypocotyls and longer roots performed best. When mature zygotic embryos germinate the root emerges, before or coincident with the shoot. In contrast, somatic embryos germinate in reverse sequence, with the cotyledons greening first, then shoot emergence and then, much later, if at all, the appearance of the root. Somatic seedlings, produced from the maturation medium, showed 100% survival when planted in a field setting. Somatic seedlings showed normal yearly growth relative to standard seedlings from natural seed.

• Archives of Pharmacal Research
• /
• 제21권4호
• /
• pp.458-464
• /
• 1998

Search for a new $\alpha$-methylene-$\gamma$-butyrolactone-bearing 6-substituted purine as a potental antitumor agent has led to synthesize seven, hitherto unreported, $5^1$-Methyl-$5^1$-[(6-substituted-9H-purin-9-yl)methyl]-$2^1$-oxo-$3^1$- methylenetetrahydrofurans (H, Cl, l, $CH_3$, $NH_2$, SH, >C=O) (6a-g). These include $5^1$-Methyl-$5^1$-[(9H-purin-9-yl)methyll-$2^1$-oxo-$3^1$ -methylenetetrahydrofurans (6a), $5^1$-Methyl-$5^1$-[(6-chloro-9H-purin-9-yl)methyl]-$2^1$-oxo-$3^1$-methylenetetrahydr ofurans (6b), $5^1$-Methyl-$5^1$-[(6-chloro-9H-purin-9-yl) methyl]-$2^1$-oxo-$3^1$-methylenetetrahydrofurans (6c), $5^1$-Methyl-$5^1$-[(6-methyl-9H-purin-9-yl) methyl]-$2^1$-oxo-$3^1$-methylenetetrahydrofurans (6d), $5^1$-Methyl-$5^1$-[(9H-adenin-9-yl)methyll-$2^1$-oxo-$3^1$-methylenetetrahydrofurans (6e), $5^1$-Methyl-$5^1$-[(6-mercapto-9H-purin-9-yl) methyl]-$2^1$-oxo-$3^1$-methylenetetrahydrofurans (6f) and $5^1$-Methyl-$5^1$-[(9H-hypoxanthin-9-yl)methyll-$2^1$-oxo-$3^1$-methylenetetrahydrof urans (6g) which were made by the Reformatsky-type reaction of ethyl $\alpha$-(bromomethyl) acrylate with the corresponding (6-substituted-9H-purin-9-yl)-2-propanone intermediates (5a-g). These ketone intermediates 5a-g, 1-(9H-purin-9-yl)-2-propanone (5a), 1-(6-chloro-9H-purin-9-yl)-2-propanone (5b), 1-(6-iodo-9H-purin-9-yi)-2-propanone (5c), 1-(6-methyl-9H-purin-9-yl)-2-propanone (5d), 1-(9H-adenin-9-yl)-2-propanone (Se), 1-(6-mercapto-9H-purin-9-yl)-2-propanone (5f), and 1-(9H-hypoxanthin-9-yl)-2-propanone (5g) were directly obtained by the alkylation of the 6-substituted purine bases with the chloroacetone in the presence of $K_2$$CO_3$ (or NaH) under DMF (or DMSO). The preliminary in vitro cytotoxcity assay for the synthetic .alpha.-methylene-y-butyro-lactone compounds (6a-g) were determined against three cell lines (PM-3A, P-388, and K-562) and showed the moderate antitumor activity ($IC_50$ ranged from 1.4 to 4.3 $\mu\textrm{g}$/ml) with the compound $5^1$-methyl-$5^1$ -[(9H-hypoxanthin-9-yl)methyl]-$2^1$-oxo-$3^1$-methylenetetrahydrofuran (6g) showing the least antitumor activity.

• Korean Journal of Food Science and Technology
• /
• 제37권4호
• /
• pp.636-641
• /
• 2005

Mulberry leaves, high in dietary fiber and some nutritional materials, are thought to have hypocholesterolemic effect. Therefore, effect of mulberry leaf powder on serum lipid profiles were studied using rats with diet-induced hypercholesterolemia. Male Sprague-Dawley rats were fed AIN-93 diet (control group), and diets containing high-cholesterol and 0% mulberry leaves powder, high-cholesterol and 5% mulberry leaves powder, and high-cholesterol and 10% mulberry leaves powder for 4 weeks. Hypercholesterolemia was induced by adding 1% cholesterol and 0.5% cholic acid to all diets except in control group. Although no differences were observed in food intake and initial body weight among groups, mulberry leaf treatment resulted in significant decreases in food efficiency ratio and body weight gain. Mulberry leaf treatment decreased serum lipid profiles, atherogenic index, cardiac risk factor, low density lipoprotein cholesterol ratio, serum aspartate transaminase, and liver lipid levels. High density lipoprotein cholesterol, total cholesterol, serum HDL-cholesterol, and fecal lipid levels increased, suggesting mulberry leaves could improve hyperlipidemia and liver action, thereby proventing cardiovascular disease.

• Korean Journal of Food Science and Technology
• /
• 제31권6호
• /
• pp.1523-1528
• /
• 1999

The consumer's demands for minimally processed fruits and vegetables have been increased rapidly because of its convenient handling, fresh-like quality as well as producing less wastes from the environmental point of view. Asian pears which are one of the main fruits widely produced and consumed in Korea easily lost their characteristics due to browning and softening after cutting. The objective of this study is to investigate the effects of various treatments on delaying deterioration of sliced Asian pears. 'Shingo' pear slices were treated with various solutions $(1%\;NaCl,\;0.2%\;L-cysteine,\;1%\;CaCl_2\;or\;1%\;calcium\;lactate)$ and were packaged with low density polyethylene $(LDPE,\;60\;{\mu}m)$, ceramic $(CE,\;60\;{\mu}m)$ or vacuum $(Ny/PE,\;80\;{\mu}m)$ film at $20^{\circ}C\;and\;0^{\circ}C$. In order to evaluate the quality of packaged sliced pears, quality index was determined in terms of color, firmness, soluble solids, titratable acidity. ascorbic acid, changes of gas composition, microbial test, and sensory quality. The results showed that sliced 'Shingo' pears packaged with CE and vacuum film maintained better quality than with LDPE at $0^{\circ}C\;and\;20^{\circ}C$. To retard browning and softening. 0.2% L-cysteine and 1% NaCl solutions applied for 1 minute were effective to reduce surface browning of sliced pears, and 1% $CaCl_2$ was the most effective to prevent softening.

• Korean Journal of Food Science and Technology
• /
• 제36권2호
• /
• pp.233-238
• /
• 2004

Foxtail Millet Takju was treated with heat ($65^{\circ}C/30\;min$) (HT) or high hydrostatic pressure ($27^{\circ}C/400\;MPa/10\;min$) (PT), and changes in microbial count, enzyme activity, and quality were determined during 30-day storage at 10 and $25^{\circ}C$. Total viable cellcount remained constant, while lactic acid bacteria and yeast were not detected in HT and PT Takjus. Relative activities of ${\alpha}-amylase$ in PT Takju significantly increased by 169.7% at 3 days storage, then decreased to 137.7 and 68.7% at 10 and $25^{\circ}C$, respectively, at 30 days. Relative activities of glucoamylase in HT Takju showed reversible change, and were 36.5 and 54.3% at $10\;and\;25^{\circ}C$, respectively, at 30 days storage. Activities in PT Takju increased with storage period, 158.2% at 30 days storage at $10^{\circ}C$. Titratable acidity in untreated Takju increased, while those in HT and PT Takjus remained almost constant during 30 days storage. Reducing sugar content in untreated Takju showed no change, while that in HT Takju increased gradually, reaching 2.9% at 30 days, whereas that in PT increased sharply after 3 days, reaching 4.8% at 30 days. Sensory evaluation showed sourness and bitterness were low, and sweetness and overall acceptance were high in PT Takju after 30 days storage at $10^{\circ}C$.

• Korean Journal of Food Science and Technology
• /
• 제11권4호
• /
• pp.217-223
• /
• 1979

The present study was to investigate the effect of sugars on the psychrophillic spoilage in ground meat. The obtained results were summarized as follows: 1. The minimum pH values for the ground beef containing 2, 5 and 10 % glucose were 5.25, 5.15 and 4.5, respectively. For the ground pork, the respective values were 5.1, 4.45 and 4.1. 2. Total aerobes, coliform, lactic acid bacteria and lactobacillus counts per gram for the control and 2% glucose-contained ground beef after 9 days for storage at $5^{\circ}C$ were $8.3{\times}10^9vs\;6.0{\times}10^7,\;3.5{\times}10^5vs\;2.4{\times}10^3,\;5.8{\times}10^7vs\;4.7{\times}10^6$ and $3.6{\times}10^5vs\;4.2{\times}10^6$ respectively. For the ground pork, the respective values were $1.2{\times}10^{10}vs\;7.8{\times}10^8,\;3.4{\times}10^5vs\;3.1{\times}10^4,\;5.5{\times}10^7vs\;4.5{\times}10^6$ and $3.3{\times}10^5vs\;3.7{\times}10^5$. The glucose-added ground meat showed higher counts than those of the controls only in the case of lactobacillus without any apparent adverse effects. 3. The length of storage time until the depletion of added glucose was 12, 16 and 28 days for the 2, 5 and 10 % glucose contained ground beef and 9, 16 and 30 days for the ground pork, respectively. pH did not start to increase until the added glucose was depleted completely. 4. The addition of glucose extended significantly the average shelf-life of ground beef at refrigeration condition $(5^{\circ}C)$. The extended shelf-life over the control was 7, 9 and 12days for the 2, 5 and 10 % glucose contained ground beef and 8, 10 and 12 days for the respective ground porks. 5. Although the addition of disaccharides (maltose, lactose, saccharose) lowered the pH of ground meat, the extension of shelf-life as seen in glucose treatment was not affected. In fact, the higher the concentration of added disaccharides was, the greater the degree of putrefaction occurred.

• Korean Journal of Food Science and Technology
• /
• 제7권4호
• /
• pp.229-237
• /
• 1975

An attempt was made to utilize the enzyme produced by Asp. oryzae as meat tenderizer. The production, purification, and various properties of proteinase produced by Asp. oryzae were investigated. Results obtained are as follow; 1. A strain which had the highest proteolytic activity was selected among 9 Aspergillus species. 2. Culture medium consisted of wheat bran 10g, 2% glucose, 0.03% urea and 0.1% $MgSO_4$ (pH 6.5). Mold was incubated at $30^{\circ}C$ for 3 days. 3. Enzyme extract from culture medium were fractionated with ammonium sulfate and purified by Sephadex G-75 column chromatography. 4. When pH of reaction mixture was controlled, maximal activity of proteinase by Asp. oryzae was obtained at pH 3, pH 6.6, $8.4{\sim}8.5$ and pH 10.0 to 10.5. Those results were interpreted to show that enzyme consists of acid proteinase, neutral proteinase and alkaline proteinase. Enzyme was stable at pH 6 to 10. 5. Opt. temperature for proteinase activity was $50^{\circ}C$, but enzyme was stable up to $40^{\circ}C$. 6. The proteinase was inhibited by $Ag^+$. It was also inhibited by EDTA. 7. When myofibrillar proteins were treated by proteinase from Asp. oryzae, ATPase activities of myofibrillar proteins changed remarkably. Accordingly, it was concluded that proteinase produced by Asp. oryzae were able to be used as meat tenderizer.

• Korean Journal of Food Science and Technology
• /
• 제31권6호
• /
• pp.1471-1476
• /
• 1999

A simple and practical method for determination of caffeine in foods was developed. The analysis of caffeine was performed by reverse phase high performance liquid chromatography using a ${\mu}-Bondapak\;C_{18}$ column at isocratic condition with methanol-acetic acid-water(20 : 1 : 79) on UV detector at 280 nm. The clean-up and extraction of caffeine in samples were based on a simple pretreatment using a Sep-Pak $C_{18}$ cartridge. Recovery rates obtained with this method for cider, candy, cookie, milk, ice cream and persimmon leaf tea were 99.23%, 99.50%, 99.17%, 99.37%, 98.93% and 99.10% respectively. And the detection limit of caffeine was $0.1\;{\mu}g/mL$. With this method, the range of caffeine contents extracted from coffee, green tea, black tea, Oolong tea(tea bag), soft drinks, ice cream, milk and commercial confectionery were $3.38{\sim}37.50\;mg/g,\;16.30{\sim}26.10\;mg/g,\;10.80{\sim}16.65\;mg/g,\;11.25\;mg/g,\;0.06{\sim}0.11\;mg/g,\;0.04{\sim}0.44\;mg/g,\;0.04{\sim}0.39\;mg/g\;and\;0.10{\sim}1.80\;mg/g$, respectively. But caffeine was not detected in the other tea such as Acanthopanax sessiliflorum tea, Angelica gigas tea, Angelica tea, Arrow root tea, Duchu'ng tea, Dunggulle tea, Ganoerma lucidum tea, Ginger tea powder, Persimmon leaf tea, Ssanghwa tea and Cocoa mix powder.