진공 해동과 침수 해동에 의한 냉동 가다랑어K(atsuwonus pelamis)의 품질 차이에 관한 연구

구재근 ( Jae Geun Koo ),이태헌 ( Tae Hun Lee ) 한국수산과학회 2012 한국수산과학회지 Vol.45 No.6

Thawing is very important in tuna canning because it affects the yield and quality of the canned tuna, and productivity. The effects of vacuum thawing on the quality, yield, and thawing times of frozen skipjack were compared with conventional water immersion thawing. The time required to thaw frozen skipjack tuna (weight 2.5-3.0 kg) from -10℃ to -2℃ was 75, 60, and 37 min at a pressure of 17, 23, and 31 mmHg, respectively, corresponding to temperatures of 20, 25, and 30℃. The thawing time decreased with increasing pressure. Vacuum thawing shorten the thawing time by 58-80% compared with water immersion thawing at 20℃, and there was less difference between the core and skin temperatures than with water immersion thawing. No significant change in pH or histamine was observed according to thawing method, while the volatile basic nitrogen (VBN), trimethylamine (TMA), and K value were lower with vacuum thawing than water immersion thawing. Based on these results, we believe that vacuum thawing minimizes the biochemical and microbial changes that occur while thawing frozen skipjack tuna.

주파수에 따른 초음파 해동처리가 냉동 돈육의 이화학적 특성에 미치는 효과

김진세,박석호,최동수,김용훈,이수장,박천완,한귀정,조병관,박종우 한국식품저장유통학회 2017 한국식품저장유통학회지 Vol.24 No.2

This study was carried out to investigate the effects of ultrasonic thawing on physicochemical characteristics of frozen pork sirloin. To determine the velocity of an ultrasonic thawing machine, -80℃ frozen pork sirloins were thawed using 132, 580, and 1,000 kHz ultrasonic thawing machines, and the physicochemical properties of pork sirloin thawed with 15℃ tap water and those using the ultrasonic thawing machines were compared. As a result, thawing speed by ultrasonic thawing was three times faster than that of tap water, but drip weight loss rate is increased by about 5% during ultrasonic thawing compared to that during thawing in tap water. However, biochemical properties, such as pH, volatile basic nitrogen, thiobarbituric acid, and total aerobic bacteria, were not improved by ultrasonic thawing. Hunter values, such as total color change and redness, improved slightly after 580 kHz ultrasonic thawing. The hardness and chewiness of the pork sirloin decreased significantly after 580 kHz ultrasonic thawing; however, springiness was not changed. These results indicate that ultrasonic thawing is faster than thawing in tap water, but the physicochemical characteristics of frozen pork sirloin was not significantly improve by ultrasonic sound.

Effect of different thawing methods on the quality of mackerel (Pneumatophorus japonicus)

Peng-cheng Zhou,Jing Xie 한국식품과학회 2021 Food Science and Biotechnology Vol.30 No.9

Five thawing methods such as flow waterthawing, ultrasonic flowing water thawing, air thawing,microwave thawing and low temperature thawing wereused, and the physical, chemical properties and structure ofmackerels after thawing were assessed. The results showedthat the low temperature thawing had the best waterretention, lower protein and fat oxidation. The microwavethawing had the shortest thawing time, but uneven heatingleads to partial maturation. Air thawing prolonged exposureto air leads to high levels of protein and fat oxidation. The flow water thawing had better water retention than thatof the ultrasonic flowing water thawing, only the thawingtime was slightly longer than that of the ultrasonic flowingwater thawing. In general, the low temperature thawingperformed well after thawing. The flow water thawing usedonly 1/43 of the low temperature thawing’s elapsed timeafter sacrificing some acceptable qualities. Thus, flowwater thawing is more suitable for thawing frozenmackerel.

냉동과 해동방법에 따른 백향과의 품질 특성

황영,박지현,조용식,김경미,장현욱 한국식품조리과학회 2023 한국식품조리과학회지 Vol.39 No.1

Purpose: As tropical and subtropical fruit cultivation areas are increasing due to climate warming, this study evaluated the quality characteristics of each freezing and thawing method for passion fruit storage to find out how to minimize quality changes. Methods: As the freezing method, air cooled freezing, immersion freezing, and quick freezing were applied, and as the thawing method, room temperature thawing, running water thawing, and high pressure thawing method were applied. Drip loss, color, soluble solids, pH, acidity, hardness, and microbial properties after storage were evaluated. Results: The freezing speed was 0.05°C/min for air freezing, 0.47°C/min for immersion freezing, and 7.83°C/min for quick freezing and thawing in running water was faster than air cooled freezing after immersion or quick freezing. The drip loss was small in all thawing treatments of immersion freezing, and in quick freezing, except for high pressure thawing. Soluble solid content was highest in immersion freezing in room temperature thawing and air cooled freezing in running water thawing, and the lowest in quick freezing in case of high pressure thawing. Overall, the hardness decreased compared to the fresh fruit through freezing and thawing. When penetrating the peel, there was no significant difference between immersion freezing and quick freezing, and it was further decreased in air freezing. Conclusion: In conclusion, running water thawing after immersion freezing had the lowest drip loss and high soluble solids content, so it was advantageous for quality maintenance. And high pressure thawing after quick freezing, which is excellent for freezing speed and color maintenance, significantly affected the increase of drip loss due to outflow of nectar and the reduction of soluble solids, suggesting that it is not a suitable method for passion fruit storage.

해조류의종보존에서의 생존율향상을위한해동공정의 열역학적특성

김민용,신영우,이영복,신종암,김종덕 한국생물공학회 2023 KSBB Journal Vol.38 No.4

To achieve a high viability by minimizing thawing damage, ice crystallization must be reduced in the process of thawing. Thermophysical properties of suspensions of Porphyra seriata, Undaria pinnatifida, and Sargassum fulvellum were measured to determine the optimal thawing conditions in the thawing process for species conservation of sea algae. The range of final thawing temperature was –2.49 ~ –0.50°C at thawing speed 1.25°C/min and 2~3°C at 1.5~2.0°C/min, and thawing was completed at temperatures above 3.0°C, enabling the removal process of cryoprotectant. The optimum thawing speed with the minimum thawing time was 0.75~1.0°C/min, and the latent heat of thawing was Undaria pinnatifida 128.37 J/g, Porphyra seriata 118.53 J/g, and Sargassum fulvellum 94.42 J/g, which can be useful for the design and manufacture of algae cryopreservation system. From the change of enthalpy, entropy and free energy according to each thawing rate, the optimum thawing rate for recrystallization temperature pan and viability improvement is suitable over Porphyra seriata, Sargassum fulvellum, Undaria pinnatifida 0.75°C/min, 1.0°C/min, 1.5°C/min respectively. From the results of the thawing process, the optimal method of freezing-thawing process of seedlings for aquaculture will be set up to increase the viability and contribute to the aquaculture industry by being used for growth in the farm. In addition, the results of this study will contribute to the establishment of gene bank, seed bank, and seed vault for various kinds of sea algae

다양한 냉·해동 방법을 사용한 냉동 밀키트 무채 제조 및 품질특성 관찰

김두리(Duri Kim),남정현(Jung-Hyun Nam),현지용(Ji-Yong Hyun),김창숙(Chang-Sook Kim),천지연(Ji-Yeon Chun) 한국식품영양과학회 2022 한국식품영양과학회지 Vol.51 No.5

본 연구는 밀키트 무채 제조를 위한 무의 최적 냉동 및 해동 분석 조건을 확립하기 위해 다양한 냉동 및 해동 방법에 따른 무의 이화학적 및 영양학적 특성을 비교하였다. 일반냉동(CF-20°C), -25°C 강제송풍냉동, -35°C 강제송풍냉동으로 중심부가 -20°C가 될 때까지 냉동한 후 냉장 해동, 상온 해동, 유수 해동을 이용하여 중심부의 온도가 4°C가 될 때까지 해동하였다. 강제송풍냉동을 사용할 경우 일반냉동에 비해 냉동 소요시간이 약 10배 감소했으며 해동은 유수 해동, 상온 해동, 냉장 해동 순으로 빠르게 일어났다. 냉·해동 후 L<SUP>*</SUP>값과 a<SUP>*</SUP>값은 전체적으로 낮아졌으며 ΔE의 최솟값이 12 이상으로 냉해동 후 색 변화가 일어난 것을 알 수 있다. pH는 일반냉동(-20°C)이 6.43~6.65로 가장 큰 변화를 보였다. 가용성 고형분(°Brix)은 수분함량이 감소하면서 전체적으로 증가했고 수분함량은 냉·해동 후 감소했지만, 그 차이는 미미한 수준이라고 판단된다. 해동 감량은 냉동 방법에 의한 변화가 더 두드러지게 나타났으며 냉동속도가 빠를수록 낮아지는 경향을 보였다. 이에 따라 -35°C 강제송풍냉동이 높은 경도를 나타냈고 냉장 해동이 다른 해동에 비해 경도가 낮아지는 경향을 보였다. 영양성분 분석 결과 비타민 C, 총페놀 함량, DPPH 라디칼 소거능 모두 냉・해동 전 무보다 전체적으로 감소했으며 냉장 해동이 다른 해동 방법에 비해 변화폭이 가장 큰 것으로 나타났다. 냉·해동 후 무의 미생물수는 냉·해동 전과 유의적 차이가 없었으며 모든 처리구가 식중독으로부터 안전한 범위인 것으로 확인되었다. 또한, 전자주사현미경 측정 결과 냉・해동 속도가 빠를수록 기공이 작고 세포벽을 유지하는 것으로 나타났다. -35°C 강제송풍 냉동한 후 해동 방법을 달리한 무를 이용해 무채를 제조한 후 관능검사를 실행한 결과, 원물을 사용했을 때 조직감(아삭아삭한 정도, 질긴 정도, 씹힘성), 유수 해동했을 때 시각적 특성(외관, 색), 냉장 해동했을 때 맛(단맛, 짠맛, 쓴맛, 매운맛)에서 높은 기호도를 나타내었다. 전체적으로 냉동온도가 낮고 냉동속도가 빠를수록 품질이 우수했으며 해동 방법도 마찬가지로 속도가 빠를수록 냉동 전 무와 품질 차이가 적은 것으로 나타났다. 따라서 본 연구 결과 -35°C 강제송풍냉동과 유수 해동을 적용하는 것이 냉동 무채 제품 제조에 효과적일 것으로 판단되며, 식품 종류에 따라 중요시되는 품질특성을 고려하여 적절한 냉동 및 해동 조건을 설정하여 식품 가공공정에 이용할 수 있다고 생각된다. This study was conducted to find the optimal freezing and thawing conditions for shredded radish (0.5×0.5×5 cm), which was frozen by conventional slow freezing (−25°C), or individual quick freezing (air blast freezing, −25°C, and −35°C). The frozen shredded radish was thawed using natural air convection thawing (25°C), running water thawing (18°C), and refrigeration thawing (4°C). The freezing and thawing were stopped when the core temperature reached −20°C and 4°C, respectively. The freezing time for air-blast freezing (7 min) was faster than conventional slow freezing, and the thawing time was faster in the order of running water thawing, natural air convection thawing, and refrigeration thawing. The pH of the radish increased after freezing and thawing. But no consistent trend of pH or °Brix as per the variance in thawing conditions was observed. Moreover, there was no significant difference seen in the moisture content. The thawing loss was affected by thawing rather than freezing. The hardness of the radish decreased after being subjected to all the freezing and thawing conditions. However, air blast freezing (−35°C) was most similar to the raw radish. The nutritional aspects of the air blast freezing (−35°C) and running water thawing samples were most similar to that of the raw radish (vitamin C contents, antioxidant activity, and total phenol contents). The sensory attributes of texture, visual form, and taste showed high scores in the raw material, running water thawing, and refrigeration thawing samples, respectively. It was observed from these results that the thawing conditions had a greater effect on radish qualities than the freezing conditions. Also, based on these results, we recommend that a combination of air blast freezing (−35°C) and running water thawing (18°C) could maintain the quality of shredded radish.

염수 침지식 및 전극 접촉식 저전압 Ohmic 해동 처리가 돈육의 이화학적 특성에 미치는 효과

홍근표,민상기,고세희,심국보,서은주,최미정,Hong, Geun-Pyo,Min, Sang-Gi,Ko, Se-Hee,Shim, Kook-Bo,Seo, Eun-Ju,Choi, Mi-Jung 한국축산식품학회 2007 한국축산식품학회지 Vol.27 No.4

This study investigated the effect of ohmic thawing on the physicochemical properties of pork meat. The physicochemical properties of pork meat thawed by brine immersion and electrode contact ohmic systems were compared. A more rapid thawing rate was seen with the electrode contact thawing system than with brine immersion. No significant differences in pH were found with increasing voltage for both thawing methods (p>0.05). Increasing the voltage level tended to decrease drip loss, resulting in increased water holding capacity. The shear forces of pork thawed at 50 V did not differ from the control (p>0.05) for both thawing methods. Although significantly high TBARS (p<0.05) values were found at 20 and 40 V for immersion, and 0 V for contact thawing, increasing the voltage level tended to decrease the TBARS values. Regarding TVBN, no significant effect was observed with increasing voltage levels (p>0.05). The total color difference of pork was significantly higher (p<0.05) with immersion thawing than with electrode contact thawing. These results indicate that brine immersion thawing is favorable at high voltage levels, while lower voltage levels are applicable for electrode contact thawing. 본 실험은 전압의 증가에 따른 염수 침지식 및 전극 접촉식 ohmic 해동 처리가 돈육의 이화학적 특성에 미치는 효과를 규명하고자 실시되었다. 염수 침지식 ohmic 해동방법은 전압에 의한 염수의 온도 상승에 의하여 시료가 해동 됨으로써 시료 표면의 과열 현상이 효과적으로 억제되었고, 해동 후 높은 보수력 및 전단력의 저하가 관찰되었지만, 육색이 다소 저하되는 단점을 나타내었다. 반면 전극 접촉식 ohmic 해동 방법은 해동 과정 중 얼음의 상전이 구간을 빠르게 통과함으로써 빠른 해동이 가능하였고, 해동 후 식육의 품질 저하가 최소화되었지만, 시료의 크기 및 전압의 증가에 따른 심한 표면 과열 현상이 발생할 수 있는 단점을 보였다. 따라서 염수 침지식 해동은 보다 높은 전압을 이용하여 식육을 빠르게 해동하고, 전극 접촉식 해동은 낮은 전압을 이용하여 표면 과열을 억제하면 보다 효과적인 해동이 가능할 것으로 사료되었다.

Effects of aging and freezing/thawing sequence on quality attributes of bovine Mm. gluteus medius and biceps femoris

Kim, Hyun-Wook,Kim, Yuan H. Brad Asian Australasian Association of Animal Productio 2017 Animal Bioscience Vol.30 No.2

Objective: The effects of aging and freezing/thawing sequence on color, physicochemical, and enzymatic characteristics of two beef muscles (Mm. gluteus medius, GM and biceps femoris, BF) were evaluated. Methods: Beef muscles at 3 d postmortem were assigned to four different combinations of aging and freezing/thawing sequence as follows; aging at $2^{\circ}C$ for 3 wk (A3, never-frozen control), freezing at $-28^{\circ}C$ for 2 wk then thawing (F2, frozen/thawed-only), aging at $2^{\circ}C$ for 3 wk, freezing at $-28^{\circ}C$ for 2 wk then thawing (A3F2), and freezing at $-28^{\circ}C$ for 2 wk, thawing then further aging at $2^{\circ}C$ for 3 wk (F2A3). Results: No significant interactions between different aging/freezing/thawing treatments and muscle type on all measurements were found. Postmortem aging, regardless of aging/freezing/thawing sequence, had no impact on color stability of frozen/thawed beef muscles (p<0.05). F2A3 resulted in higher purge loss than F2 and A3F2 treatments (p<0.05). A3F2 and F2A3 treatments resulted in lower shear force of beef muscles compared to F2 (p<0.05). Although there was no significant difference in glutathione peroxidase (GSH-Px) activity, F2A3 had the highest ${\beta}-N-acetyl$ glucominidase (BNAG) activity in purge, but the lowest BNAG activity in muscle (p<0.05). GM muscle exhibited higher total color changes and purge loss, and lower GSH-Px activity than BF muscle. Conclusion: The results from this present study indicate that different combinations of aging/freezing/thawing sequence would result in considerable impacts on meat quality attributes, particularly thaw/purge loss and tenderness. Developing a novel freezing strategy combined with postmortem aging will be beneficial for the food/meat industry to maximize its positive impacts on tenderness, while minimizing thaw/purge loss of frozen/thawed meat.

다양한 냉동 및 해동공정 조합이 표고버섯의 품질에 미치는 영향

심준보 ( Jun Bo Shim ),조연지 ( Yeon Ji Jo ),최미정 ( Mi Jung Choi ),민상기 ( Sang Gi Min ),유선미 ( Seon Mi Yoo ),천지연 ( Ji Yeon Chun ) 한국산업식품공학회 2015 산업 식품공학 Vol.19 No.3

본 연구는 다양한 냉동방법(강제송풍식냉동, 극저온냉동, 일반냉동)과 해동방법(자연해동, 유수해동, 초음파해동, 전자레인지해동)을 조합하여 처리했을 때 표고버섯의 물리적 품질에 미치는 영향을 관찰하고, 표고버섯의 품질을 유지하는 가장 효과적인 냉·해동 공정을 탐색하는 것이 목적이었다. 급속냉동법(강제송풍식냉동, 극저온냉동)으로 처리한 경우 표고버섯의 해동감량, 보수력, 수분함량은 큰 변화 없이 품질을 유지 하는데 효과적인 것으로 관찰되었다. 특히 보수력은 저속냉동(일반냉동) 및 저속해동(자연해동) 처리의 유무가 영향을 미치는 것으로 나타났다. 전단력의 경우 냉동방법에 의한 영향보다, 전처리 및 해동방법에 더 영향을 받는 것을 판단된다. pH 및 색도는 냉동방법 및 해동방법에 따라 거의 차이가 없는 것으로 관찰되었다. 표고버섯의 물리적 특성을 효과적으로 유지 할 수 있는 처리 조합은 급속냉동(극저온냉동) 및 급속해동(유수해동, 초음파해동, 전자레인지해동)을 한 경우이며, 또한 유지하고 하는 물리적 특성에 따라 냉동 및 해동방법을 다양하게 조합하여 처리한다면, 식품의 품질을 보존하는데 더욱 효과적일 것으로 사료된다. In this study, the potential of various freezing and thawing combinations was investigated for frozen storage of mushroom (Lentinula edodes). Lentinula edodes were sliced (5×5×50 mm) and then blanched in boiling water for 1 min. Samples were frozen by either natural air convection freezing (NCF, -24℃), air-blast freezing (ABF, -45℃), or liquid nitrogen freezing (LNF, -100℃). Frozen Lentinula edodes were thawed to a central temperature of 4℃ using either flowing water thawing (FT, 10℃), microwave thawing (MT, 400 W), sonication thawing (ST, 40 kHz, 10℃), or natural air convection thawing (NT, 20±5℃). In LNF Lentinula edodes, MT showed the most rapid thawing within 2.5 min followed by ST (30 min), FT (37 min), and NT (75 min). Quality attributes were evaluated by thawing loss, texture (hardness), water content, water holding capacity, pH, and color. A combination of LNF and MT induced the lowest thawing loss among tested combinations of each freezing and thawing. Thawing loss of frozen Lentinula edodes by LNF method was the lowest by MT. pH values NT of ABF method were significantly higher than blanched Lentinula edodes. In our study, MT minimized the quality changes of frozen Lentinula edodes when it was combined with ABF or LNF.

Study of Radio Frequency Thawing for Cylindrical Pork Sirloin

Kim, Jinse,Park, Jong Woo,Park, Seokho,Choi, Dong Soo,Choi, Seung Ryul,Kim, Yong Hoon,Lee, Soo Jang,Park, Chun Wan,Han, Gui Jeung,Cho, Byoung-Kwan Korean Society for Agricultural Machinery 2016 바이오시스템공학 Vol.41 No.2

Purpose: Radio frequency (RF) heating is a promising thawing method, but it frequently causes undesirable problems such as non-uniform heating. This can occur because of the food shape, component distribution, and initial temperature differences between food parts. In this study, RF heating was applied to the thawing of cylindrically shaped pork sirloin by changing the shape of electrodes and the surrounding temperature. Methods: Curved electrodes were utilized to increase the thawing uniformity of cylindrically shaped frozen meat. Pork sirloin in the shape of a half-circle column was frozen in a deep freezer at $-70^{\circ}C$ and then thawed by RF heating with flat and curved electrodes. In order to prevent fast defrosting of the food surface by heat transfer from air to the food, the temperature of the thawing chamber was varied by -5, -10, and $-20^{\circ}C$. The temperature values of the frozen pork sirloin during RF thawing were measured using fiber-optic thermo sensors. Results: After multiple applications of curved electrodes resembling the food shape, and a cooled chamber at $-20^{\circ}C$ the half-cylindrically shaped meat was thawed without surface burning, and the temperature values of each point were similarly increased. However, with the parallel electrode, the frozen meat was partially burned by RF heating and the temperature values of center were overheated. The uniform heating rate and heat transfer prevention from air to the food were crucial factors for RF thawing. In this study, these crucial factors were accomplished by using a curved electrode and lowering the chamber temperature. Conclusions: The curved shape of the electrode and the equipotential surface calculated from the modeling of the parallel capacitor showed the effect of uniform heating of cylindrically shaped frozen food. Moreover, the low chamber temperature was effective on the prevention of the surface burning during RF thawing.