Effect of different thawing methods on quality properties of stuffed pasta (manti)

Stuffed pasta or ‘manti’ is a traditional food consumed fondly in Turkey. For consumption, it is produced as fresh, frozen or dried manti. Frozen manti is cooked directly without thawing. The present study investigated the effects of different thawing processes on physicochemical properties and sensory qualities of frozen stuffed pasta (manti). The following five thawing processes were used individually: (1) infrared, (2) microwave (3) infrared-assisted microwave, (4) dry hot air and (5) running water thawing. The storing temperatures of manti found in the market were 10°C and 24.5°C. Consequently, manti samples were thawed up to these temperatures. It was determined that the shortest thawing period (20 sec) was that of infrared-assisted microwave process. The longest process was dry hot-air thawing (420 sec) in manti samples that were thawed until refrigerator (+4°C) and room temperatures (24.5°C). Thawing methods did not change pH, moisture values and weight gain (p > 0.05). It was found that sensory qualities and amount of dry matter passing into the water of samples were different (p < 0.05). It was concluded that thawing was necessary for frozen manti, and the best method was microwave thawing.

Metabolic activity in cryopreserved and grafted ovarian tissue using high-resolution respirometry

Cryopreservation of ovarian tissue followed by transplantation represents a strategy to restore ovarian function and fertility. Stress from cryopreservation-thawing processes can lead to alterations and/or damage to mitochondrial structure and functionality. High resolution respirometry and histological analysis were used to evaluate the effect of cryopreservation and transplantation on ovarian tissue. Four different conditions were performed: Fresh non-transplanted tissue, Fresh transplanted tissue, Cryopreserved non-transplanted tissue and Cryopreserved transplanted tissue. All groups were able to respond to the substrates-uncoupler-inhibitor protocol. We found a dramatic decrease in general oxygen consumption in hemi-ovaries submitted to cryopreservation and/or transplantation. The effect of cryopreservation on mitochondrial metabolism was less intense than effect of transplantation, since the transplantation affected all of the mitochondrial states. A total of 2644 follicles were analyzed. Of these, 2198 were classified as morphologically normal. The percentage of morphologically normal follicles was significantly lower in the Cryopreserved transplanted group when compared to the Cryopreserved non-transplanted group and the Fresh transplanted group (p-value < 0.05). Despite decreased follicular viability and mitochondrial activity, the cryopreservation followed by transplantation of ovarian tissue proved feasible for attempts to restore ovarian function.

Implementation of innovative technologies for the improvement of concrete properties for freezing and thawing processes

For over a hundred years, concrete has been a well-known building material and is widely used in construction. Its properties have convinced construction engineers, architects, contractors and investors, which is why it is currently difficult to find a building completed without the use of this material. However, the influence of atmospheric conditions and other environmental influences means that over time they leave more and more visible signs of progressive destruction even on the best building material of the century. Taking into account the problems related to aeration and surface hydrophobization, the aim of the work was to demonstrate that by using an admixture in the form of an anionic bitumen emulsion and a superplasticizer based on polycarboxylate ethers, it is possible to obtain hard-to-wet concretes with a favorable porosity structure and increased resistance to environmental influences. For static calculations and dimensioning, an original calculation model of the pavement made of concrete with dispersed reinforcement in the form of fibers was used, which made it possible to eliminate the reinforcement in the form of bars. Laboratory tests with the use of concrete samples taken during concreting carried out after 28 days of maturation confirmed the high compressive strength.

Soil Freeze-Thaw and Water Transport Characteristics Under Different Vegetation Types in Seasonal Freeze-Thaw Areas of the Loess Plateau

In the arid and semi-arid regions of the Loess Plateau, seasonal freezing and thawing influence soil water movement, and water movement directly influences vegetation growth. However, currently, research with regard to freezing and thawing processes under various vegetation types and the mechanism of soil water movement is lacking. Therefore, the present study explored soil water migration characteristics of two typical vegetation types [arbor land (AL) and shrub land (SL)] on the Loess Plateau during seasonal freezing and thawing processes using bare land (BL) as a control. We used field measured data for hourly soil temperature (ST) and soil water content (SWC) at a depth of 100 cm below the soil surface from November 2017 to March 2018. Freezing and thawing process was divided into three stages based on ST change (initial freezing period, stable freezing period, and thawing period). Compared with previous studies in this area, ST is lower than expected, and SWC migration characteristics are also different. The results revealed that: 1) the maximum freezing depth of AL and SL was 60 cm, which was 30 cm less than that of BL. The freezing date of each soil layer in BL was the earliest and average ST value was the lowest. BL had the highest degree of freezing. The freezing of all soil layers in AL occurred at a later date than that of SL. ST and the minimum soil freezing temperatures were higher than those of SL, and the capacity of AL to resist freezing was higher; 2) the SWCs in AL and BL at depths of 0–10 cm and 10–30 cm decreased, whereas SWCs of AL and BL at a depth of 60 cm increased by 152 and 146%, respectively. The SWCs of SL at soil depths of 0–10 cm, 10–30 cm, and 30–60 cm increased by 46.3, 78.4 and 205%, respectively. The amount and distribution of soil moisture in SL were optimum when compared to those of AL and BL. The results of the present study could provide a scientific basis for vegetation restoration in arid and semi-arid areas of the Loess Plateau.

Collection, freezing of Ban epididymal sperm and evaluation of in vitro fertility after thawing

Many researches on characteristics of porcine ejaculated semen on popular commercialized breeds collecting at breeding centers or households with pig breeding services have been carried out in Vietnam. However, very few investigation had been dealt with epididymal sperms, especially the ones from boar of Ban, a popular Vietnam native mini-pig breed which is usually freely raised in far rural and mountainous regions in some provinces of Northern Vietnam. In the present study, we surveyed on criteria of epididymal sperms from 4 Ban boars at collection, after freezing and thawing processes, and tested their fertility by an in vitro fertilization and embryo culture experiment. Approximate volume of sperm collected from a Ban boar did not differ (3-4 mL), with sperm concentration from 6.4 x 109 to 11.3 x 109 sperm/mL. Motility varied from 8.7 to 27.0%, whereas vitality was from 58.0 to 85.6%. After freezing and thawing, the motility of sperm slightly decreased to values of 6.3 to 25.7%, and viability significantly decreased to values of 41.3 to 79.6%. No difference was found between rates of abnormal morphology before and after freezing and thawing (10.6 to 31.0% and 12.0 to 32.0%, respectively). A test by in vitro fertilization with Landrace oocytes revealed that two sperm lots had acceptable in vitro fertility with rates of blastocyst formation from 14.4 to 18.8%. In conclusion, a study on collection, freezing and fertility testing of epididymal sperm collected from Ban boars has been carried out. The results of the present study could contribute necessary information as well as standardized sperm lots as important materials to further research on in vitro fertilization of Ban in Vietnam.

Finite Element Method for Freezing and Thawing Industrial Food Processes

Freezing is a well-established preservation method used to maintain the freshness of perishable food products during storage, transportation and retail distribution; however, food freezing is a complex process involving simultaneous heat and mass transfer and a progression of physical and chemical changes. This could affect the quality of the frozen product and increase the percentage of drip loss (loss in flavor and sensory properties) during thawing. Numerical modeling can be used to monitor and control quality changes during the freezing and thawing processes. This technique provides accurate predictions and visual information that could greatly improve quality control and be used to develop advanced cold storage and transport technologies. Finite element modeling (FEM) has become a widely applied numerical tool in industrial food applications, particularly in freezing and thawing processes. We review the recent studies on applying FEM in the food industry, emphasizing the freezing and thawing processes. Challenges and problems in these two main parts of the food industry are also discussed. To control ice crystallization and avoid cellular structure damage during freezing, including physicochemical and microbiological changes occurring during thawing, both traditional and novel technologies applied to freezing and thawing need to be optimized. Mere experimental designs cannot elucidate the optimum freezing, frozen storage, and thawing conditions. Moreover, these experimental procedures can be expensive and time-consuming. This review demonstrates that the FEM technique helps solve mass and heat transfer equations for any geometry and boundary conditions. This study offers promising insight into the use of FEM for the accurate prediction of key information pertaining to food processes.