• Title/Summary/Keyword: hot air drying

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Physicochemical Properties of Dried Anchovy (Engraulis Japonica) Subjected to Microwave Drying (마이크로파 건조 방법에 따른 멸치의 건조 특성)

  • Kum, Jun-Seok;Park, Kwang-Jang;Lee, Chang-Ho;Im, Ji-Soon
    • Korean Journal of Food Science and Technology
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    • v.30 no.1
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    • pp.103-109
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    • 1998
  • For the purpose of improving quality of dried anchovy, raw anchovies after hot air drying were subjected to six different processes: 5 min microwave and 1 min holding-12 times (MW5), 10 min microwave and 1 min holding-6 times (MW10), 5 min microwave with hot air and 1 min holding-12 times (MWH5), 10 min microwave with hot air and 1 min holding-6 times (MWH10), 5 min microwave vacuum and 1 min holding-12 times (MWV5), 10 min microwave vacuum and 1 min holding-6 times (MWV10) at 100 Watt and 2450MHz. There were no significant effects of different processes on water content, pH, color, acid value and volatile basic nitrogen. The sum of fatty acids on commercial anchovy occupied 38.34% of saturates 22.91% of monoenes and 22.91% of polyenes and dried anchovies subjected to microwave processes had similar compositions. Dominant fatty acids were palmitic acid and docosahexaenoic acid in each process. Among the free amino acids, alanine, arginine, lysine and leucine were dominant in all processes. Dried anchovies showed little significant differences in texture in all processes. Sensory evaluation data showed that the quality of dried anchovy subjected to microwave process was acceptable and microwave vacuum process was the most desirable one.

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Non-thermal treatment of Prunus mume fruit and quality characteristics of the dehydrated product (청매실의 비가열 전처리 및 건조매실의 특성)

  • Kang, Ji-Hoon;Kim, Nam-Ho;Song, Kyung Bin
    • Food Science and Preservation
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    • v.21 no.5
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    • pp.652-660
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    • 2014
  • To maintain the microbiological safety of Prunus mume fruit before it is processed, it was treated with a combination of 0.5% citric acid and 0.1% Tween 20, and stored at $4{\pm}1^{\circ}C$ for seven days. The combined treatment reduced total aerobic bacteria, yeast, and mold populations in the fruit by 2.20 and 1.70 log CFU/g, respectively, compared to those in the control. Organic acid contents and the Hunter $L^*$, $a^*$, and $b^*$ values were not affected by the treatment during the storage. In addition, the dried Prunus mume fruit prepared with 40% red algae extract (RAE) or maltodextrin (MD) treatment and hot-air drying were compared with respect to the fruit's physicochemical properties such as color, total phenolic and flavonoid content, and microstructure. The hot-air dried samples had undesirable color changes and inferior textures. The RAE-treated samples had a higher total phenolic content (225.15 mg gallic acid equivalent (GAE)/100 g) and total flavonoid content (49.25 mg quercetin equivalent (QE)/100 g) than the other treatments. The treatment of Prunus mume fruit with RAE can provide better-dried products than can MD treatment or hot-air drying. These results suggest that the combined treatment with citric acid and Tween 20 can be effective in preserving the microbiological safety of Prunus mume fruit, and its dehydration using RAE is an efficient drying method.

CHANGES IN CONTENTS OF FORMALDEHYDE AND AMINES IN ALASKA POLLACK MUSCLE DURING DRYING (명태육 건조중의 formaldehyde 및 amine 류의 변화)

  • AHN Cheol-woo;PARK Yeung-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.11 no.1
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    • pp.13-18
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    • 1978
  • The present study was conducted to elucidate the pattern in changes of trimethylamine oxide and related compounds in the muscle of Alaska pollack during drying, especially referred to formaladehyde and dimethylamine. Three kinds of dried samples of Alaska pollack, sun dried, hot-air dried, and salted-sun dried, were prepared and analyzed for their contents of trimethylamine oxide, trimethylamine, dimethylamine, and formaldehyde. The amount of trimethylamine oxide remained in the salted-sun dried sample was relatively higher than those in the other two samples. In the content of trimethylamine, the hot-air dried sample showed an exceedingly high value shelving forty-two times higher than the raw sample while the other two samples showed barely three to four times content based on the raw sample. The dimethylamine content in the hot-air fried sample was comparatively lower than those in the other two samples, the former marked about ten folds of the raw sample's and tile latter showed about fifteen folds, respectively. Refering to the content of formaldehyde, it decreased to eighty-three percent of initial content in the hot-air dried sample. On the contrary, it increased about two times initial content in the other two samples, respectively. As a tendency, the formaldehyde content appeared increased or decreased correlatively with the dimethylamine content, whereas the case was reverse for the trimethylamine content.

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Heat Processing of Edible Plants Grown in Korea Has Differential Effects on Their Antioxidant Capacity in Bovine Brain Homogenate

  • Oh, Sang-Hee;Sok, Dai-Eun;Lee, Kun-Jong;Kim, Mee-Ree
    • Preventive Nutrition and Food Science
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    • v.7 no.4
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    • pp.378-385
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    • 2002
  • Oxidant radicals are implicated as a causal factor in the pathogenesis of neurobiological disorders and neuro-degenerative diseases. The objective of this study was to investigate the antioxidant activity of edible plants against oxidative stress in bovine brain tissue. Fifty five kinds of edible plants grown in Korea were dried either by freeze-drying or hot-air drying (7$0^{\circ}C$), and evaluated for their antioxidant activity by measuring TBARS (thiobarbituric acid-reactive substances) in brain homogenates subjected to Fe$^{+2}$_mediated lipid peroxidation with or without the addition of botanical extracts. Heat-drying decreased the antioxidant activity of most plant extracts by 10~81%, compared with freeze-drying. However, Aruncus americanus, Ligularia stenocephala, Artemisia princceps var. orientalis, Petasites japonicus and Aster scaber showed very strong antioxidant activities regardless of processing, with or without heat treatment. The $IC_{50}$/ values of the methanol extracts from these edible plants were in the range of 0.093~0.379 mg/$m\ell$, which was lower than that of ascorbic acid (0.79 mg/$m\ell$). Thermal processing of some edible plants enhanced their antioxidant activity.

Physicochemical Properties of Black Rice Flours (BRFs) Affected by Milling Conditions (제분조건에 따른 흑미쌀가루 품질특성)

  • Choi, Bong-Kyu;Kum, Jun-Seok;Lee, Hyun-Yu;Park, Jong-Dae
    • Korean Journal of Food Science and Technology
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    • v.38 no.6
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    • pp.751-755
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    • 2006
  • Physicochemical properties of black rice flours (BRFs) produced under different milling conditions were investigated to explore their applications for various processed rice products. Moisture contents of BRFs after roll milling and subsequent hot-air drying or microwave drying were 10.3% and 14.4%, respectively. The BRFs with jet milling and subsequent hot-air drying or microwave drying showed moisture contents of 7.9% and 7.5%. Mean particle sizes of the BRFs obtained from roll milling, jet milling, and following air-classification were 150, 41.5, and 9.4 ${\mu}m$, respectively. Hunter L value and water soluble index (WSI) of BRFs increased with decreasing particle size, while Hunter a value decreased. Total polyphenol contents of 91.4-115.8 mg/100 g and total amino acids of 75.0-96.4 mg/100 g in three types of BRFs were higher as compared to those (6.3 mg/100 g and 30.5 mg/100 g) of polished rice flour (PRF). Physicochemical properties such as moisture content, color parameter, and WSI have close relationship with the particle size of BRFs prepared under different milling conditions.

Change of Inorganic Component, Reducing Sugar, Catalpol and Benzo[α]pyrene Contents of Rehmannia glutinosa Libosch. var. purpurea Makino by Drying Methods (지황의 건조 방법에 따른 무기성분, 환원당, Catalpol 및 Benzo[α]pyrene의 함량 변화)

  • Chang, Jun-Pok;Kil, Gi-Jung;Lee, Gun-Hee;Ji, Yoon-Sun;Kim, Bo-Ram;Kang, Ki-Hyun;Kim, Mee-Ree;Song, Mi-Ran;Park, Jong-Yoon;Doh, Eun-Soo
    • Korean Journal of Medicinal Crop Science
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    • v.19 no.6
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    • pp.501-507
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    • 2011
  • This experiment was carried out in order to collect the basic data on the standardization of the manufacturing process of Rehmannia glutinosa Libosch. var. purpurea Makino drying. By the drying methods of R. glutinosa, the content of water, inorganic components, reducing sugar, catalpol and benzo[${\alpha}$]pyrene were investigated. The water content was 15.6~17.2% when R. glutinosa was dried by cold-warm air moisture absorption drying method (CAMAD) at $60^{\circ}C$ during 6 days. Among of the inorganic components of R. glutinosa the K content was the most followed by P, Na, Ca and Mg. The reducing sugar content of R. glutinosa by the hot air drying method (HAD) was much more than that by the CAMAD. The catalpol content of R. glutinosa was not different by the drying temperature when it was dried by the CAMAD. The catalpol content of the large size tuber (about 50.0 g/unit) showed a tendency to increase from $60^{\circ}C$ until $70^{\circ}C$ drying temperature, but that of the small size tuber(about 4.0 g/unit) was decreased as being a trend as the drying temperature high when R. glutinosa was dried by the HAD, But the catalpol content R. glutinosa had a tendency to drop significantly at drying temperature above $80^{\circ}C$. The benzo[${\alpha}$]pyrene content was little detected when R. glutinosa was dried by both the SLD and the CAMAD, and the sampling by the HAD indicated within the scope of 5 ${\mu}g/kg$ which was the scope to regulate by Korean food and drug administration. In conclusion, it seemed that an appropriate drying temperature of R. glutinosa by the CAMAD and the HAD was about $60^{\circ}C$ and about $70^{\circ}C$, respectively, when we consider the catalpol content and benzo[${\alpha}$]pyrene detection in the manufacturing process of drying R. glutinosa.

Comparative Antioxidant Enzyme Activity of Diploid and Tetraploid Platycodon grandiflorum by Different Drying Methods

  • Boo, Hee-Ock;Shin, Jeoung-Hwa;Kim, Young-Seon;Park, Hee-Jeong;Kim, Hag-Hyun;Kwon, Soo-Jeong;Woo, Sun-Hee
    • Korean Journal of Plant Resources
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    • v.26 no.3
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    • pp.389-396
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    • 2013
  • The antioxidant enzyme and DPPH radical scavenging activity with variations in drying methods of diploid and tetraploid in Platycodon grandiflorum were determined. Antioxidant enzyme activities were measured as superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), and ascorbate peroxidase (APX). The roots of Platycodon grandiflorum were freeze-dried, indoor-dried, hot-air dried, and microwave dried. The root extract of P. grandiflorum have shown the highest SOD enzyme activity of 92% in tetraploid of freeze-dried and indoor-dried while diploid of microwave dried showed the lowest SOD enzyme activity of 47.5%. The activity of CAT showed higher values in the root of tetraploid than in the diploid of P. grandiflorum in all drying methods. The APX activity showed relatively higher values in the root extract of freeze-dried both the diploid and tetraploid, but the difference in comparison with other extracts was not significant. The POX activities according to drying methods of diploid and tetraploid in P. grandiflorum showed relatively high values in freeze-dried and indoor-dried compared with other drying methods, and the POX activity between the diploid and tetraploid was not significant difference in each drying method. The DPPH radical scavenging activity with variation in drying methods of diploid and tetraploid in P. grandiflorum was the highest in the freeze-dried, and was higher in tetraploid than diploid in all the concentrations. In conclusion, the root of P. grandiflorum had the potent biological activities in both diploid and tetraploid. In particular, the tetraploid root of P. grandiflorum showing high antioxidant enzyme activity could be good materials for development of source of functional healthy food.

Microwave & Hot Air Drying Characteristic of Radish (마이크로파 혼합건조 방식에 의한 무의 건조특성)

  • 김종훈;정진웅;권기현;김진주
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2003.07a
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    • pp.287-294
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    • 2003
  • UR 농산물 협상 이후 국내 농림수산물 및 가공식품 시장의 수입개방이 확대되어 생산 농어민이 직접적으로 큰 피해를 보고 있을 뿐만 아니라 국내 농산물을 원료로 사용하는 산지 가공업체도 경쟁력 학보에 어려움을 겪고 있다. 수입식품 중에서는 국내생산이 이루어지지 않아 수입이 불가피한 품목도 있고, 또한 국내의 기술수준이 뒤떨어지기 때문에 품질경쟁력에서 열위인 품목도 있지만 대다수 품목은 중국을 위시한 후발 개도국에서 낮은 기술과 저임 노동력을 이용하여 생산된 단순가공품으로서 이들 품목은 국내산에 비하여 가격은 낮지만 품질이 조악하고 안전성이 낮은 것으로 알려져 있다. (중략)

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Isolation of an Unusual Aloenin-acetal from Aloe

  • Woo, Won-Sick;Shin, Kuk-Hyun;Chung, Ha-Sook;Lee, Jung-Mi;Shim, Chang-Sub
    • Korean Journal of Pharmacognosy
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    • v.25 no.4 s.99
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    • pp.307-310
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    • 1994
  • A hitherto unknown substance was isolated from the commercial sample of Aloe arborescens, which was shown to be the 4',6'-O-ethylidene-aloenin, most likely an artifact caused by hot-air drying procedure for the product preparation.

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