• Journal of Applied Tourism Food and Beverage Management and Research
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• v.15 no.1
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• pp.113-125
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• 2004

Effect of microwave radiation on physico-chemical properties of cor'n starches was studied. Waxy com, com and high amylose com starches of varying moisture content(20～35%) were subjected to microwave processing(2450MHz) at $120^{\circ}$ and the experimental starch samples were examined by a X-ray diffractometry, rapid viscosity analyzer(RVA) and. with the samples in temperature was observed and the peaks of high amylose com starches at $2^{\circ}$=5.0, 15.0 and $23.0^{\circ}$, were disappeared indicating the melting of crystallines while those of com and waxy com had not changed. A change in gelatinization pattern was observed in the case of corn starches from type A with nearly no peak-viscosity and breakdown to type C. Except a decreased viscosity, no change was observed in those of waxy com starches.

• Korean Journal of Food Science and Technology
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• v.10 no.2
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• pp.237-244
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• 1978

Among the strains isolated form the various sources, the strain AC-12 producing a powerful pectinase was selected by the extensive screening test. The selected strain was indentified and its toxicity investigated. The conditions of the pectinase production, the characteristics of the purified enzyme and the clarification effect on the apple juice were studied. 1. The selected strain AC-12 was identified by the classification method of paper and fennel and named as Aspergillus sp. AC-12. 2. As a result of the breeding test of the white mouse, no toxicity was found from this enzyme. 3. The yield of pectinase in the medium of defatted rice bran was much better than that in the medium of wheat bran. 4. The optimum conditions for the culture of the strain in the medium of defatted rice bran were that the cultural time was 72hrs, the amount of water to be added about 80%, temperature $30{\sim}35^{\circ}C$ and pH $3.0{\sim}5.0$. 5. The yield of pectinase was slightly increased by the addition of pectin to the medium of defatted rice bran and by the addition of pectin, $NaNO_3$ and $K_2HPO_4$ to the medium of wheat bran, respectively. 6. The optimum conditions for the enzyme activity were pH $3.0{\sim}4.0$ and temperature $40{\sim}50^{\circ}C$. The enzyme was stable below $40^{\circ}C$ and pH $2.0{\sim}8.0$, respectively. But above $50^{\circ}C,$ this enzyme was abruptly inactivated. The activity was slightly increased by the addition of $MnSO_4\;and\;CuSO_4.$ 7. It was regarded that the opimum temperature for the clarification of the apple juice was $40{\sim}50^{\circ}C$, the optimum pH 3.0 and the optimun concentration of the enzyme 0.1%, and the apple juice was almost clarified by the reaction at $45^{\circ}C$ for 60 minutes.

• Journal of the Korean Applied Science and Technology
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• v.37 no.2
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• pp.183-191
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• 2020

This study monitored the rheological properties of jams manufactured using the black ginseng and black garlic. The conditions for mixing black jam were black ginseng (X₁, 30-54 g), black garlic (X₂, 75-135 g), pectin 4.5 g, apple paste 270 g, and fructo-oligosaccharide 360 g. The response surface analysis was performed with springiness, cohesiveness, chewiness, brittleness and gumminess. The R²s of the regression equation for springiness, cohesiveness, chewiness, brittleness and gumminess were recognized at a significant level of 5 to 10 %, with 0.8948, 0.9103, 0.9032, 0.9097, and 0.8561, respectively. The combination conditions of black ginseng and black garlic with the highest springiness of black jam were found to be 194.39% (springiness) with black ginseng 54.00 g and black garlic 105.83 g, while the conditions of black ginseng and black garlic mixing with the lowest springiness were found to be 164.11% with black ginseng 31.48 g and black garlic 119.43 g. The mixing conditions of black ginseng and black garlic with the highest cohesiveness of black jam and its consistency were 40.96% (cohesiveness) with black ginseng 48.85 g and black garlic 129.62 g, while black ginseng and black garlic combination conditions with the lowest cohesiveness were found to be 32.96% with black ginseng 50.06 g and black garlic 82.77 g. Black ginseng and black garlic mixing conditions, which have the highest chewiness of black jam, was 43.19 g (chewiness) from black ginseng 42.95 g and black garlic 106.83 g. Black ginseng and black garlic mixing conditions and their brittleness were found to be the highest in black ginseng 32.10 g and black garlic 88.04 g to 16,874 g. Black ginseng and black garlic mixing conditions and their brittleness were found to be 678 g from black ginseng 50.53 g and black garlic 83.91 g. Black ginseng and black garlic mixing conditions and their gumminess were 14.06 g with black ginseng content of 32.91 g and black garlic content of 124.60 g. By examining the relationship between black ginseng/black garlic ratio and the rheological property of black jam from above results, it is believed that black jam can be produced for anyone to enjoy using health function material.

• Korean Journal of Food Science and Technology
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• v.34 no.1
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• pp.43-50
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• 2002

To develop commercial semi-solid apple baby food, the physicochemical characteristics of apple puree in relation to different preparing methods and the effect of the addition methods of ascorbic acid on browning reaction were investigated. The preparing methods were classified into 3 groups by initial heating treatment: no heating (A), steaming at $120^{\circ}C$ (B), and blancing at $100^{\circ}C$ (C). The viscosity of tested apple puree was $2,600{\sim}5,856\;cp$, and contents of anhydrogalaturonic acid (AGA) and neutral sugar ranged $4.15{\sim}11.92\;mg%$ and $6.18{\sim}10.65\;mg%$, respectively. Among free sugars tested, level of fructose was the highest $(5.43{\sim}8.87%)$, followed by glucose $(2.11{\sim}4.23%)$, sucrose $(1.64{\sim}2.94%)$, in that order. Since small amounts of ascorbic acid were detected $(1.54{\sim}1.83\;mg%)$, it seemed to be lost by heating process in preparing of apple puree. For apple puree A, its lightness was lower and redness was higher than those of apple puree B and C. Its degree of browning of apple puree was so high that sodium ascorbic acid was added as a antibrowning agent. Puree had low sensory score and nutrient quality. The adding methods of ascorbic acid were classified into 4 groups by adding time: dipping, blending (2), heating (3), and blending + heating (4). Considering color and preference evaluation, preparing method B and adding method 2 showed the highest inhibitory activity on apple puree browning and desirable color for retort baby food. After retort sterilization, the viscosity of apple baby food was decreased from 3,477 cp to 2,294 cp, thiamin was destroyed completely, and the contents of riboflavin and ascorbic acid were decreased 41% and 21%, respectively. However, contents of free sugar and free amino acid and sensory parameter were not influenced by retort sterilization. In overall, the preparing method B-adding method 2 was a good processing condition for the retort apple baby food.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.3
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• pp.153-162
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• 2016

We investigated the physicochemical properties and starch structure of various rice varieties including 15 colored cultivars. NKHC showed the highest level of protein, lipid, and total dietary fiber levels. Reddish brown rice showed higher lipid content than that in black rice cultivars. Apparent amylose content of waxy and non-waxy colored rice varieties was within the range of 3~5% and 15~18%, respectively. IP exhibited the highest total starch (TS) content, whereas, NKHC and HJJ showed lower TS content than that in other cultivars. Pasting temperature of all colored rice cultivars, except IP, was about $68^{\circ}C$. Peak viscosity of IP, JJJ, Hong, and GGHM showed high values of 138, 130, 128, and 124, respectively. All the colored rice cultivars presented A-type X-ray diffraction pattern and polygonal shapes of starch granules were observed using scanning electron micrographs (SEM). Major groups of amylopectin chain lengths were B (12 < DP ${\leq}$ 24) and A (DP ${\leq}$ 12). SMHC showed the highest B chain content and the lowest A chain content (P < 0.05). These experimental results provided useful information for scientists and the food industry regarding colored rice starches.

• The Korean Journal of Food And Nutrition
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• v.15 no.2
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• pp.137-143
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• 2002

Lyophilizate of immatured wax gourd extract was 3.1 %, matured wax gourd extract was 1.0%, and its main ingredient was sugar, which accounts for 89.7% in total residue. In matured wax gourd, pectin contents was 4.11 mg/ml, and in immatured wax gourd 4.43 mg/m1. In matured wax gourd sarcocarp, sugar contents was 0.1% of sucrose, 0.32% of glucose, 0.35% of fructose, the first unidentified sugar was 0.06% and the second was 0.04%, and all total 0.87%. In sarcocarp of immatured wax gourd, sucrose was 0.33%, glucose was 1.04%, frutcose was 1.12%, and the first unidentified sugar 0.18%, and the second was 0.l2, which total 2.79%. In matured wax gourd core, pH was 4.64, sarcocarp 4.94, immatured wax gourd core 4,96, sarcocarp 5.40. According to the organic acid analysis, in sarcocarp of matured wax gourd, citric acid of 0.409 was contained, magic acid 0.084, succnic acid 0.048%, in matured wax gourd core, citric acid was 0.648, magic acid 0.127, succinc acid 0.058%, in immatured wax gourd, citric acid 0.023, magic acid 0.219, succinic acid 0.298%, in immutured wax gourd, citric acid was 0.039, malic acid 0.350, succinic 0.224%. Fumaric acid was trace in all cases. Total organic acid in matured wax gourd core was 0.833, immatured wax gourd core was 0.624 and immatured wax gourd sarcocarp was 0.546, matured wax gourd sarcocarp was 0,541%. In inhibition rate to propionibacterium acnes, control was 0(ø, cm), wax gourd that was not heated was 2.6, and wax gourd which was heated was 2.5, concentrated by 1/5 was 1.9, wax gourd by 1/10 was 2.5, freezing dry was 2.3. Wax gourd which not heated on producing melanin in B-16 melanoma cell, the melanins forming unit was 15$\mu$1/m1 in addition of 0.01%, while that as a control was 29$\mu$1/m1.

• Journal of the Korean Society of Food Culture
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• v.9 no.1
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• pp.53-59
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• 1994

This study was attempted to investigate the effects of preheating treatment and chitosan addition on the textural properties of Korean radish during salting. For this study, we determined the changes in textural properties by compression, puncture, cutting tests respectively and the changes in pectin fractions were also determined. Sensory parameters such as hardness, crispness and toughness were evaluated by sensory analysis and their results were correlated with those by Instron. The results were as follows. The compression force of nonpreheated Korean radish was increased by chitosan addition, whereas that of preheated one was decreased during salting. The puncture force from all the samples of Korean radish decreased, however, chitosan addition showed higher puncture force. The cutting force of nonpreheated Korean radish increased during salting and those from nonpreheated and preheated ones were increased by chitosan addition. During salting hot water soluble pectin(HWSP) of nonpreheated Korean radish increased and 0.4% Na-hexametaphosphate soluble pectin(HXSP) and 0.05 N-HCl soluble pectin(HCISP) decreased respectively. However, HXSP was decreased by preheating treatment. On the contrary, the results were reversed by chitosan addition. Hardness and crispness of nonpreheated Korean radish decreased and toughness increased respectively during salting. However, toughness was decreased by preheating treatment and hardness was increased by chitosan addition. Compression and puncture forces were highly correlated with sensory parameters such as hardness and crispness, whereas cutting force was more correlated with toughness. From these results, it seems that the textural properties were improved by chitosan addition in both nonpreheated and preheated Korean radish. The preheating treatment was effective in the early stage of salting. However, combination of both treatments showed little effect during salting.

• Korean journal of food and cookery science
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• v.26 no.4
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• pp.367-380
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• 2010

Various contents of Rosa rugosa Thunb. fruit(0, 10, 20%), which is grown along the seashore of Gangwon province, were applied to apple jams having different sugar concentrations(20, 40, 60%). The resulting jams were analyzed using a sensory scoring test as well as a response surface methodology to identify the optimum conditions for the preparation of high-preference apple jams. The sensory properties based on sense of sight, smell and taste appeared to be linked to the sugar contents. It could be attributed to the presence of flavor compounds and pigments generated from the caramelization of sugar molecules during heat processing. On the other hand, rheological properties such as viscosity and spreadability were associated with Rosa rugosa fruit content, which was also verified by textural analysis of the jams. As the contents of Rosa rugosa increased, the hardness, gumminess, and chewiness of the jams decreased, which eventually might have contributed to the less thick and thus more spreadable sensory characteristics. Sensory evaluation revealed that apple jams were preferred when prepared with $\leq$10% of Rosa rugosa fruit and $\geq$55% of sugar contents. In particular, apple jams containing 10% Rosa rugosa and 60% sugar showed better mechanical qualities as well as higher sensory preference among 10 jams formulated using central composite design.

• Korean Journal of Food Science and Technology
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• v.36 no.5
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• pp.765-772
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• 2004

Cooking condition of Tarakjuk (milk-rice porridge) was established based on gelatinization temperature using differential scanning calorimetry (DSC) of roasted Ilpum rice flour, which has highest enzyme-resistant starch (RS) content. Effect of cooking temperature and time on DSC characteristics, crystallity with X ray diffractogram, RS content, in vitro starch digestibility (IVSD), amino acid composition, and in vitro protein digestibility (IVPD) of Tarakjuk were determined. Tarakjuk was cooked at 50, 56.5, 64, and $69^{\circ}C$ for various durations. Rice flour ingredient used was Ilpum, previously roasted at $185^{\circ}C$ for 25 min. Tarakjuk cooked at 50 and $56.5^{\circ}C$ showed two thermal transitions between $63.7-125.2^{\circ}C$ as determined by DSC, corresponding to endotherms of starch gelatinization $(63.7-73.8^{\circ}C)$ and melting of amylose-lipid complex (AM-lipid complex, $97.7-125.2^{\circ}C$), whereas that cooked at 64 and $69^{\circ}C$ showed only AM-lipid complex melting transition between $96.9-127.6^{\circ}C$. As cooking temperature increased, RS content of Tarakjuk decreased, whereas IVSD increased. Total amino acid content was between 11,558-15,601mg/100g, depending on cooking condition used. Compared with conventionally made control, contents of essential amino acids, such as lysine and tryptophane, were higher at 50 and $56.5^{\circ}C$, and IVPD showed higher increase. Results reveal degree of gelatinization in Tarakjuk with high RS content as well as low IVSD and high IVPD, which are important from physiological and nutritional point of view, can be produced by controlling cooking condition.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.9
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• pp.1412-1418
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• 2013

The nutritional components of 14 new cultivars of pak choi (Brassica rapa L. ssp. chinensis) from China were analyzed and compared with 4 cultivars of Chinese cabbage (Brassica rapa L. ssp. pekinensis) popular in Korea. Leaves were separated into green parts (GP) and white parts (WP) for the analyses. The moisture and ash content in the 14 new cultivars of pak choi were not significantly different from the currently popular cultivars of Chinese cabbage. In addition, the levels of vitamin C and E were very similar between the two kinds of Brassica rapa. In contrast, the overall mineral content was higher in the new pak choi cultivars. Specifically, minerals important for human health, calcium and magnesium, were significantly greater in pak choi cultivars (calcium GP 2.57, WP 2.04; magnesium GP 0.422, WP 0.301 mg/g fresh weight) compared to currently popular cultivars (calcium GP 0.805, WP 0.477; magnesium GP 0.244, WP 0.101 mg/g fresh weight). Although the content of reducing sugars was similar, cellulose content (which correlates with the hardness of plant tissue) was four times higher in the new pak choi cultivars compared to currently popular cultivars. These results demonstrate that the new pak choi cultivars have superb nutritional benefits for human health and could be a good food source as a daily staple vegetable.