Potential application of infrared assisted freeze drying (IRAFD) for banana snacks: Drying kinetics, energy consumption, and texture

Khampakool, Apinya,Soisungwan, Salinee,Park, Sung Hee Elsevier 2019 FOOD SCIENCE AND TECHNOLOGY -ZURICH- Vol.99 No.-

<P><B>Abstract</B></P> <P>Efficacy of infrared assisted freeze drying (IRAFD) was investigated to produce banana snacks. Infrared (IR) lamp was installed into freeze dryer. Various IRAFD trials including the continuous IRAFD-2.7 kW/m<SUP>2</SUP>, IRAFD-2.7 kW/m<SUP>2</SUP> at 20% weight reduction (WR), and IRAFD-2.7 kW/m<SUP>2</SUP> at 20% WR to 4.0 kW/m<SUP>2</SUP> at 0 °C were performed. Continuous IRAFD could significantly reduce the drying time up to 213 min compared to freeze drying (FD) (696 min), resulting in more than 70% time saving. Drying kinetics of IRAFD trials were estimated using exponential, Page, and diffusion models. Page model best explained the drying kinetics of IRAFD banana. FD consumed the highest total electrical energy (27.0 × 10<SUP>3</SUP> kJ), whereas, continuous IRAFD-2.7 kW/m<SUP>2</SUP> saved the electrical energy consumption up to 8.4 × 10<SUP>3</SUP> kJ with rapid drying. IRAFD improved the crispness of banana snacks. This study demonstrated the potential of IRAFD to produce the high-quality banana snack and to save significant time and energy during drying.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Infrared assisted freeze drying showed the potential for rapid freeze drying. </LI> <LI> Infrared assisted freeze drying could produce crispy banana snacks. </LI> <LI> Infrared radiation could save electric energy during freeze drying. </LI> </UL> </P>

The effect of temperature and storage time on DNA integrity after freeze-drying sperm from individuals with normozoospermia

Farzaneh Mohammadzadeh Kazorgah,Azam Govahi,Ali Dadseresht,Fatemeh Nejat Pish Kenari,Marziyeh Ajdary,Rana Mehdizadeh,Roya Derakhshan,Mehdi Mehdizadeh The Korean Society for Reproductive Medicine 2024 Clinical and Experimental Reproductive Medicine Vol.51 No.1

Objective: This study evaluated the effects of temperature and storage time on the quality and DNA integrity of freeze-dried sperm from individuals with normozoospermia. Methods: Normal sperm samples from 15 men aged 24 to 40 years were studied. Each sample was divided into six groups: fresh, freezing (frozen in liquid nitrogen), freeze-dried then preserved at room temperature for 1 month (FD-1m-RT), freeze-dried then preserved at room temperature for 2 months (FD-2m-RT), freeze-dried then preserved at 4 ℃ for 1 month (FD-1m-4 ℃), and freeze-dried then preserved at 4 ℃ for 2 months (FD-2m-4 ℃). The morphology, progressive motility, vitality, and DNA integrity of the sperm were evaluated in all groups. Results: In all freeze-dried groups, sperm cells were immotile after rehydration. The freeze-dried groups also showed significantly less sperm vitality than the fresh and frozen groups. Significantly more morphological sperm abnormalities were found in the freeze-dried groups, but freeze-drying did not lead to a significantly higher DNA fragmentation index (DFI). The DFI was significantly higher in the FD-2m-RT group than in the other freeze-dried groups. Conclusion: The freeze-drying method preserved the integrity of sperm DNA. The temperature and duration of storage were also identified as factors that influenced the DFI. Accordingly, more research is needed on ways to improve sperm quality in the freeze-drying process.

Effect of Cryoprotectant and Freeze-Drying Process on the Stability of W/O/W Emulsions

Choi, M. J.,Brianç,on, S.,Bazile, D.,Royere, A.,Min, S. G.,Fessi, H. Taylor Francis 2007 Drying Technology Vol.25 No.5

<P> In order to protect a hydrophilic drug and to prolong its further delivery, the formulation of multiple emulsions could be worthy. However, the double emulsions are not stable, their structure can change, leading to the formation of a single emulsion as the destruction of the system, and the drug can release easily from the globules in liquid state. The freeze-drying technology could be used to produce dry emulsion, the powder form being much more stable. The aim of this work was to study the influence of a cryoprotectant and a freeze-drying process on the stability of W/O/W emulsions. Samples were frozen at two different freezing rate (νf = 0.55°C/min and 1.25°C/min) and successively dried at two different sublimation temperature (Ts = - 10°C and - 20°C). The particle size distributions were measured by granulometer and UV spectrophotometer was performed to investigate the leakage of internal constituent. The glass transition temperature (Tg) of the double emulsions was analyzed by DSC. The particle sizes became even smaller after freeze drying, except when &kgr;-carrageenan is used as a cryoprotectant. In that case, the particles became aggregated after freeze drying, whatever the process conditions. The mean size is considerably reduced when the globules are diluted at low concentration in glucose and trehalose solution. When the concentration is increased, the size distribution is not significantly affected. The leakage of the internal aqueous phase to the external one during freeze drying was measured as an indicator of the structure stability. It is affected by the nature of the cryoprotectant and the conditions of the freeze-drying process. The leakage of the internal phase was smaller when cycle III (νf = 1.25°C/min, Ts = - 10°C) was processed. From our experiments, we suppose that the water transfer from the inner phase to the outer aqueous phase results in the diminution of the globules size in double emulsion. The Tg of the double emulsions diluted with trehalose and glucose were determined at - 33.8°C and - 47.1°C. In contrast, the Tg of double emulsion with &kgr;-carrageenan and HES did not appear.</P>

저장기간에 따른 동결건조 농후 발효유 내 유산균 생균수 변화

임예서 ( Ye Seo Lim ),홍식 ( Shik Hong ),신용국 ( Yong Kook Shin ),강신호 ( Shin Ho Kang ) 한국유가공기술과학회 2015 Journal of Dairy Science and Biotechnology (JMSB) Vol.33 No.3

본 연구에서는 동결건조 공정에 의한 유산균의 생균수 감소를 최소화 할 수 있는 농후 발효유를 개발하고자 하였다. 이를 위해 농후 발효유 제조에 첨가되는 당의 종류 및 구성을 달리하여 동결 건조 전후의 유산균 생존율을 비교 분석하였다. 그 결과, 포도당의 일부를 이소말토올리고당으로 대체하였을 때, 발효유 내 초기 유산균 생균수 및 동결건조 공정이후의 유산균 생존율 또한 높아졌다. 또한 동결 건조 시 열판 온도가 낮을 경우, 건조 효율은 떨어지지만, 동결건조 이후의 동결건조 농후 발효유 내 초기 유산균 생존율이 높았다. 16주간의 저장기간에 따른 유산균 생균수 변화를 살펴본 결과, 상온보관 조건에서 유산균은 지수적으로 감소하였다. 하지만 16주가 경과한 후에도 1.63×108 CFU/g의 생균수를 유지하여 약 0.6 g 이상의 동결건조 농후 발효유만 섭취하여도 체내에서 유산균 증식 및 유해균 억제·배변활동 원활 등의 건강기능성을 가질 수 있는 수준이었다. 하지만 본 연구에서는 식품 매트릭스에 따른 동결방지 효과를 파악할 때, 유산균 생균수를 유일한 지표로 삼았다는데 한계가 있다. 유산균 생균수뿐만 아니라, 유산균의 활성을 살펴보기 위해 동결건조 이후의 젖산 생성능력이나 실질적으로 체내에 들어갔을 때 위액이나 담즙액에 대한 저항성 측면에서의 추가 연구가 필요할 것으로 사료된다. The majority of food drying processes are based on the use of thermal energy. However, such methods may deteriorate the quality of the final product. Freeze-drying is one of the most useful processes for drying thermosensitive substances. Food that contains beneficial bacteria, for example, is susceptible to heat treatment, but during freeze-drying beneficial bacteria are preserved in these food items. The primary goals of this study were to develop yogurt snacks and to compare the viability of lactic acid bacteria (LAB) in yogurt snacks under different freeze-drying temperatures. In addition, the survival of LAB during storage was investigated. Survival of LAB in freeze-dried yogurt snacks gradually decreased over 16 weeks of storage. LAB had a residual viability of 25.5% after 16 weeks of storage at room temperature. LAB survived better in freeze-dried plain yogurt snacks than in freeze-dried strawberry yogurt snacks during storage. Freeze-dried yogurt snacks contained 11.9% fat, 57.1% carbohydrate, and 18.7% protein. In conclusion, the viability of LAB in freeze-dried yogurt snacks depends on the temperature during freeze-drying: the higher the freeze-drying temperature, the lower the viability of LAB in yogurt snacks. The viability of LAB in yogurt snacks was also dependent on the moisture content and nutritional value.

동결건조 시스템에서 동결속도가 향미물질 보존에 미치는 영향

변명희,최미정,이성,민상기,Byun, Myung-Hee,Choi, Mi-Jung,Lee, Sung,Min, Sang-Gi 한국축산식품학회 1998 한국축산식품학회지 Vol.18 No.2

The objective of this study was to investigate the effects of freezing rate on aroma retention and to examine the mechanism of aroma retention during freeze drying process. Our experiments were carried out with self-manufactured freeze-dryer. Gelatin gels (2% w / w, 80${\times}$20mm) containing diacetyl(2mg/ml) were frozen unidirectionally (Neumann's model) from the bottom at -45, -30, -20, and -15$^{\circ}C$ and followed with freeze-drying. Under the upper conditions we measured freezing rate and the change of temperature and pressure during freeze drying. Freeze-dried gelatins were cut horizontally into 5 mm thickness from the bottom measured and diacetly contents. Besides, we observed the effect of the relative humidity of the diacetyl contents freeze-dried gelatin during storage. The retained diacetyl content was increased at high freezing temperature and in order of 0∼5, 5∼10, 10∼15, 15∼20 mm section from the bottom of the sample. It was observed that the retained diacetyl content was high in 15∼20 mm section. The retained diacetyl content and freeze-dried gelatin stored in the condition of high relative humidity was decreased significantly but in the low relative humidity case, was it decreased in small amount. The results of our experiment resents that the low temperature freezing and low humidity storing condition is effective for preserving aroma compound in food.

화학적 박리법으로 제조된 산화그래핀 분말의 건조방법에 따른 물성 비교

노상균,노경훈,엄성훈,허승현,임형미,Rho, Sangkyun,Noh, Kyung-Hun,Eom, Sung-Hun,Hur, Seung Hyun,Lim, Hyung Mi 한국재료학회 2013 한국재료학회지 Vol.23 No.10

Graphene oxide powders prepared by two different drying processes, freeze drying and spray drying, were studied to compare the effect of the drying method on the physical properties of graphene oxide powder. The graphene oxide dispersion was prepared from graphite by chemical delamination with the aid of sulfuric acid and permanganic acid, and the dispersion was further washed and re-dispersed in a mixed solvent of water and isopropyl alcohol. A freeze drying method can feasibly minimize damage to the sample, but it requires a long process time. In contrast, spray drying is able to remove a solvent in a relatively short time, though this process requires exposure to a high temperature for a rapid evaporation of the solvent. The powders prepared by freeze drying and spray drying were characterized and compared by Raman spectroscopy, X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, and by an elemental analysis. The graphene oxide powders showed similar chemical compositions; however, the morphologies of the powders differed in that the graphene oxide prepared by spray drying had a winkled morphology and a higher apparent density compared to the powder prepared by freeze drying. The graphene oxide powders were reduced at $900^{\circ}C$ in an atmosphere of $N_2$. The effect of the drying process on the properties of the reduced graphene oxide was examined by SEM, TEM and Raman spectroscopy.

열풍, 진공 및 동결건조가 눈개승마의 항산화 및 품질특성에 미치는 영향

김아나,이교연,하명화,허호진,최성길 한국식품저장유통학회 2018 한국식품저장유통학회지 Vol.25 No.7

The purpose of this study was to evaluate the effect of drying methods including freeze, hot-air, and vacuum drying on the nutritional properties, antioxidant activities, and drying properties of Aruncus dioicus var. kamtschaticus. The optimum temperature of hot-air drying was 100℃ based on the total phenolic and flavonoid content and antioxidant activities, which were altered as a function of drying temperatures of 60, 80, 100, and 120℃. In addition, based on the drying curve, the optimum condition of hot-air and vacuum drying was 100℃ for 10 min, whereas that of freeze drying was 210 min. Vacuum drying was most effective for removal of moisture compared with the other drying methods. The water activity and water solubility index of dried samples obtained by the different drying methods were not significantly different. The water absorption index and rehydration ratio increased in the order of freeze, vacuum, and hot-air drying because of differences in porous structure of A. dioicus. Thus, vacuum drying of A. dioicus leads to the highest total phenolic and flavonoid content and antioxidant activities, followed by hot-air, and freeze drying.

The biomechanical properties of deep freezing and freeze drying bones and their biomechanical changes after in-vivo allograft

Kagn, Joon Soon,Kim, Nam Hyun Yonsei University, College of Medicine 1995 Yonsei medical journal Vol.36 No.4

마늘의 건조과정 중 Alliinase 활성 변화에 관한 연구

채수규,Chae, Soo-Kyu 대한환경위생공학회 2007 대한환경위생공학회지 Vol.22 No.1

Changes in the alliinase activity during the hot air drying and vacuum freeze drying of garlic samples treated as the whole, sliced and crushed state were investigated. The specific activity of alliinase in raw garlic was 8.52 units/mg protein. The activity in the whole garlic prepared by the hot air drying for 8 hrs was reduced remarkably to 5.22 units/mg protein with 61% remaining and to 4.25 units/mg protein with 50% remaining for 36 hrs. The activity in the sliced garlic prepared by the hot air drying for 36 hrs was reduced to 3.55 units/mg protein with 42% remaining and the activity in the crushed garlic prepared by the hot air drying for 36 hrs was reduced to 3.12 units/mg protein with 37% remaining. The garlic sample sliced or crushed was higher than the whole state in the efficiency of drying but was lower in the remaining activity of alliinase. The activity in the whole garlic prepared by the vacuum freeze drying for 8 hrs was reduced to 7.21 units/mg protein with 85% remaining and to 5.53 units/mg protein with 65% remaining for 36 hrs. The activity in the sliced garlic prepared by the vacuum freeze drying for 36 hrs was reduced to 4.55 units/mg protein with 53% remaining and the activity in the crushed garlic prepared by the vacuum freeze drying for 36 hrs was reduced to 4.16 units/mg protein with 49% remaining. The remaining activity of alliinase in the garlic samples prepared by the vacuum freeze drying was higher than the remaining activity in the garlic samples prepared by the hot air drying.

Preservation of allograft bone using a glycerol solution: a compilation of original preclinical research

Brian Samsell,Davorka Softic,Xiaofei Qin,Julie McLean,Payal Sohoni,Katrina Gonzales,Mark A. Moore 한국생체재료학회 2019 생체재료학회지 Vol.23 No.1

Background: Bone allografts are used in many orthopedic procedures to provide structural stability as well as an osteoconductive matrix for bone ingrowth and fusion. Traditionally, bone allografts have been preserved by either freezing or freeze-drying. Each of these preservation methods has some disadvantages: Frozen grafts require special shipping and storage conditions, and freeze-drying requires special lyophilization equipment and procedures that may impact biomechanical integrity. This report describes an alternate type of preservation using glycerol, which allows storage of fully-hydrated tissues at ambient temperature avoiding the potential complications from freeze-drying. Methods: In the in vitro three-point bend test, cortical bone was processed and frozen, freeze-dried, or treated with glycerol-based preservation (GBP). Load was applied to each graft at a rate of 2.71mm/min. The flexural strain, flexural strength, and flexural modulus were then calculated. In the in vitro axial compression test, iliac crest wedges, fibular segments, and Cloward dowels were processed and either freeze-dried or GBP treated. The compressive strength of the grafts were tested at time zero and after real time aging of 1, 4, and 5 years. In the in vivo rat calvarial defect assessment, freeze-dried, frozen, and GBP bone implants were compared after being implanted into a critical sized defect. Samples underwent histological and biomechanical evaluation. Results: Bone grafts subjected to GBP were found to be at least biomechanically equivalent to frozen bone while also being significantly less brittle than freeze-dried bone. GBP-preserved bone demonstrated significantly greater compressive strength than freeze-dried at multiple time points. Preclinical research performed in calvaric defect models found that GBP-preserved bone had similar osteoconductivity and biocompatibility to frozen and freeze-dried samples. Conclusion: Preclinical research demonstrated that glycerol–preservation of bone yields a material that maintains biomechanical strength while eliminating the need for extensive rehydration or thaw periods if used clinically. Additionally, in vivo evidence suggests no negative impact of glycerol-preservation on the ability of bone grafts to successfully participate in new bone formation and fusion.