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This study focused on the factors that soften the crumb texture of vacuum-cooled bread by examining the effect of residual heat applied to bread during the vacuum cooling process, focusing on how suppressing residual heat affects the starch and protein content of the bread. The results showed that in vacuum cooling breads, the removal of residual heat preserved the grain shape and crystallinity of the starch and inhibited the progress of gelatinization. In addition, residual heat also enhanced the insolubilization of proteins caused by baking, indicating that protein insolubilization was suppressed in vacuum cooled breads with less residual heat. To further elucidate the effect on protein properties, the isoforms of gliadin that were soluble in the EtOH fraction, whose hydrophobicity was reduced by residual heat, were identified. The results showed that α-/β- and γ-gliadins, which exhibit higher hydrophobicity among gliadin isoforms, demonstrated increased solubility in vacuum-cooled bread where residual heat was suppressed. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Honey has great benefits to humans, both as medicine and food. It contains glucose, fructose and water in addition to small quantities of proteins, minerals, organic acids, and vitamins. Vacuum cooling is a rapid cooling technique based on the principle of evaporation, which lowers the boiling point of water based on the vacuum pressure inside a cooler room. A prototype vacuum-cooling jet water system was used to process the honey. Raw honey obtained from the forests of Riau was used in the present study. This study aimed to determine the effect of jet water vacuum cooling with variations in volume (V/V), capacity (12.5%, 25%, and 50%) on the quality of honey (Apis dorsata Fabricus) to accelerate the cooling process and preserve product quality. The cooling mechanical analysis parameters reviewed included the processing time and the lowest maximum pressure. The parameters of the quality of honey observed included moisture content, viscosity, density and total dissolved solids. As a result, the vacuum cooling process can suppress damage to the quality of honey owing to the heating process. At the cooling time and lowest maximum pressure value, the mechanical aspects of the water jet system vacuum cooling process showed the maximum results. The water contents of 12.5% (V/V), 25% (V/V) and 50% (V/V) filling were 13.69%, 12.89%, and 14.25%, respectively. The viscosities at 12.5% (V/V), 25% (V/V) and 50% (V/V) filling were 2.604 Pa.s, 2.355 Pa.s, and 1.644 Pa.s, respectively. Density with 12.5% (V/V), 25% (V/V) and 50% (V/V) filling were 1.52 g/cm3, 1.53 g/cm3 and 1.50 g/cm3, respectively. Total dissolved solid values of honey with 12.5 % (V/V), 25 % (V/V), and 50 % (V/V) fillings were 78.16%, 78.16% and 77.66%, respectively. Water jet vacuum cooling with a 25% chamber volume capacity accelerates honey with the best total dissolved solids, density and moisture content. Vacuum cooling can be used to improve product quality, shorten handling time, extend product shelf life and improve security. [ABSTRACT FROM AUTHOR]

The cabbage cultivar 'K-Y cross' is the most important vegetable crop in Taiwan, but it is not easy to produce through the whole year because of the hot summer. For year-round supply, the different postharvest methods such as precooling and modified atmosphere packaging (MAP) were applied to extend the storage period. The respiration rate and ethylene production were measured in a wide range of temperatures from 1 to 30 °C, and the end of precooling temperature was recommended to be around 7 °C (3/4 precooling times). Vacuum precooling (VC) took cabbages only 30 min to decrease from around 27 °C to 7 °C, which was 19 times faster than room precooling (RC). After 3/4 precooling times, temperature distribution from surface to central parts of cabbages was shown to be more uniform by VC than that by RC. After VC, the MAP was applied to maintain the quality traits of cabbages. The passive MAP could decrease the weight loss, yellowing, and physiological disorders and maintain around 2% O2 and 4% CO2 in the 0.03 mm LDPE bags at 1 °C after 12-week storage. Therefore, the quality of cabbages could be maintained over 3 months by combing VC and passive MAP. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Refrigeration Technology is the property of Shanghai Society of Refrigeration and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The sCMOS imaging system with deep vacuum cooling technology has become a necessary way to improve the detection capability of space targets. In order to improve the detection capability of the photoelectric detection equipment for space targets, this paper developed the Highly Sensitive Deep Vacuum Cooling Imaging System (HSDVCIS). Firstly, we designed the imaging readout processing circuit using the GSENSE4040 sCMOS image sensor designed and manufactured by Gpixel and the deep vacuum cooling structure using thermoelectric cooling. Then, we tested the designed HSDVCIS with readout noise, dark current, and dynamic range of 3.96 e − , 0.12 e − /pixel/sec, and 84.49 dB, respectively, and tested the image sensor with a minimum cooling temperature of −40 °C. Finally, according to the results of observation experiments, we validated that the photoelectric detection equipment equipped with HSDVCIS improved the limiting detection magnitude (at SNR = 5 level) from 13.22 to 13.51 magnitudes within a 3 s exposure time by turning on the cooling function. Therefore, HSDVCIS designed in this paper can achieve highly sensitive detection of space targets. At the same time, the development of HSDVCIS also provides technical reserves and strong support for future research on the imaging systems using multiple image sensor mosaics. [ABSTRACT FROM AUTHOR]

A microscale modelling framework to compute effective properties related to flow, heat and mass transfer during vacuum cooling (VC) of porous foods was developed. A heterogeneous computational domain reconstructed from steamed bread (SB) was used for modelling, while the cellular water transport in SB investigated using nuclear magnetic resonance was applied for model validation. The computed porosity (63.47 ± 1.05%), effective permeability (1.91 ± 0.39 × 10−11 m2), effective thermal conductivity, (0.33 ± 0.08 W m−1 K−1), and effective diffusivity (5.56 × ± 0.24 10−8 m2 s−1) were in the same range as those measured from the experiment/literature. Also, the analysis revealed that microstructural variability significantly affected the estimated effective properties. The microscale model yielded results similar to the lumped formulation but provided details not visible in the latter. Therefore, the developed model provides a framework for multiscale modelling, which could lead to a better understanding of the underlying moisture loss mechanisms during VC. [ABSTRACT FROM AUTHOR]

Madu berguna untuk proses metabolisme tubuh pada manusia namun memiliki sifat higrokopis sehingga perlu penanganan pascapanen. Kualitas madu dipengaruhi oleh kadar air. Kadar air yang tinggi menyebabkan madu mudah berfermentasi dengan khamir. Proses pengolahan pascapanen madu yaitu pasteurisasi dan evaporasi. Pada proses pasteurisasi dan evaporasi suhu yang digunakan tidak boleh melebihi 70ºC karena akan merusak kualitas madu. Penggunaan ohmic heating untuk pasteurisasi dan vacuum cooling untuk proses evaporasi dan pendinginan menggunakan suhu di bawah 70ºC. Tujuan penelitian ini adalah menganalisis perubahan enzim diastase, kadar air, total padatan terlarut, dan viskositas madu karet setelah proses pasteurisasi menggunakan ohmic heating dan setelah pendinginan cepat menggunakan vacuum cooling. Hasil penelitian menunjukkan bahwa hasil pengukuran enzim diastase raw memiliki nilai DN yaitu 12,06 ± 0,146, setelah dipasteurisasi yaitu 8,79 ± 0,132 dan setelah pendinginan yaitu 7,98 ± 0,327. Hasil pengukuran kadar air raw sebesar 17,1 ± 0,153%, setelah pasteurisasi sebesar 16,4 ± 0,306% dan setelah pendinginan menjadi 14,1 ± 0,153%. Hasil pengukuran total padatan terlarut pada madu raw sebesar 62,7 ± 0,577 ºBrix, setelah dipasteurisasi sebesar 64,3 ± 0,577 ºBrix, dan setelah pendinginan menjadi 65± 0,000 ºBrix. Hasil pengukuran viskositas raw sebesar 5,681 ± 0,002 poise, kemudian setelah di pasteurisasi sebesar 5,921± 0,013 poise, dan setelah pendinginan yaitu menjadi 9,506 ± 0,000 poise. Penelitian ini menghasilkan madu dengan kadar air dan enzim diastase yang memenuhi baku mutu, viskositas mendekati baku mutu, walaupun total padatan terlarut belum memenuhi baku mutu.

Reducing energy costs in Europe is more challenging than before due to extreme price increases. The use of local renewable energy sources is one way to contribute to this effort. In the case of spa resorts, the use of heat from hot springs for therapeutic baths is an option. It is necessary to cool down this thermal mineral water to a temperature acceptable to the human body. However, due to the high mineral content of this water, heavy fouling can be a problem for conventional heat exchangers. The purpose of this study is to identify the suitable cooling technology in terms of required cooling capacity and waste heat recovery capability. The cooling technology was selected on the basis of a literature search. A pilot cooling unit consisting of vacuum cooler and plate heat exchanger was designed and tested in a real spa resort for six months. Both selected technologies have demonstrated the ability to cool thermal mineral water in long-term operation, as well as the possibility to utilize waste heat for domestic hot water heating. However, fouling problems occur in the plate heat exchanger. The vacuum cooler demonstrated greater operational robustness and resistance to encrustation. [ABSTRACT FROM AUTHOR]

In order to avoid the adverse effects of high-temperature sterilization on stewed beef and explore the feasibility of green low-temperature treatment in ensuring the safety and good quality of stewed beef, taking the total number of colonies, TVB-N, TBARS, sensory and moisture distribution as indicators, the effects of vacuum cooling combined with ultrasonic sterilization on the quality of stewed beef were studied by single factor experiment and comparative experiment. The results showed that the ultrasonic treatment power, temperature and time based on vacuum cooling had an obvious impact on the sterilization effect. The sterilization effect was the best when the ultrasonic power was 2500 W, the treatment temperature was 70 ℃ and the sterilization time was 20 min, which significantly reduced the total number of colonies, TVB-N and TBARS (P

Copyright of Tobacco Science & Technology is the property of Tobacco Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The cabbage cultivar ‘K-Y cross’ is the most important vegetable crop in Taiwan, but it is not easy to produce through the whole year because of the hot summer. For year-round supply, the different postharvest methods such as precooling and modified atmosphere packaging (MAP) were applied to extend the storage period. The respiration rate and ethylene production were measured in a wide range of temperatures from 1 to 30 °C, and the end of precooling temperature was recommended to be around 7 °C (3/4 precooling times). Vacuum precooling (VC) took cabbages only 30 min to decrease from around 27 °C to 7 °C, which was 19 times faster than room precooling (RC). After 3/4 precooling times, temperature distribution from surface to central parts of cabbages was shown to be more uniform by VC than that by RC. After VC, the MAP was applied to maintain the quality traits of cabbages. The passive MAP could decrease the weight loss, yellowing, and physiological disorders and maintain around 2% O2 and 4% CO2 in the 0.03 mm LDPE bags at 1 °C after 12-week storage. Therefore, the quality of cabbages could be maintained over 3 months by combing VC and passive MAP.

Copyright of Packaging & Food Machinery is the property of Packaging & Food Machinery Magazine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The sCMOS imaging system with deep vacuum cooling technology has become a necessary way to improve the detection capability of space targets. In order to improve the detection capability of the photoelectric detection equipment for space targets, this paper developed the Highly Sensitive Deep Vacuum Cooling Imaging System (HSDVCIS). Firstly, we designed the imaging readout processing circuit using the GSENSE4040 sCMOS image sensor designed and manufactured by Gpixel and the deep vacuum cooling structure using thermoelectric cooling. Then, we tested the designed HSDVCIS with readout noise, dark current, and dynamic range of 3.96 e−, 0.12 e−/pixel/sec, and 84.49 dB, respectively, and tested the image sensor with a minimum cooling temperature of −40 °C. Finally, according to the results of observation experiments, we validated that the photoelectric detection equipment equipped with HSDVCIS improved the limiting detection magnitude (at SNR = 5 level) from 13.22 to 13.51 magnitudes within a 3 s exposure time by turning on the cooling function. Therefore, HSDVCIS designed in this paper can achieve highly sensitive detection of space targets. At the same time, the development of HSDVCIS also provides technical reserves and strong support for future research on the imaging systems using multiple image sensor mosaics.

Aiming to clarify the influence mechanism of water molecule cooling on the machining of single-crystal Cu nanocutting, this study conducts an in-depth investigation through molecular dynamics simulations, incorporating both qualitative and quantitative analyses. The focal points of the research include the distribution of Von Mises stress, shear strain, cutting temperature, and dislocation formation. In terms of Von Mises stress, water molecule cooling significantly reduces the average stress at a cutting speed of 10 Å, and exhibits a turning point in stress reduction at a speed of 300 m/s. The average stress under water molecule cooling is consistently lower than that under vacuum cooling, and the difference diminishes at a cutting speed of 20 Å. Shear strain analysis reveals that at a cutting speed of 10 Å, the chip height under water molecule cooling is notably lower than that under vacuum cooling, while at 15 Å, it shows a trend of first decreasing and then increasing. The average chip height under vacuum cooling is 1.1 times that of water molecule cooling. At a cutting depth of 15 Å, speeds of 200 m/s and 300 m/s both demonstrate superior cooling performance, with cutting temperatures significantly lower than vacuum cooling, with temperature differences of approximately 85K and 180K, respectively. Dislocation analysis indicates that under water molecule cooling, the number of dislocations at greater cutting depths is significantly higher than under vacuum cooling, predominantly consisting of 1/6<112> (Shockley) dislocations. Overall, water molecule cooling shows significant advantages in several aspects, significantly reducing stress, chip height, and cutting temperature, while increasing the number of dislocations. These results provide quantified empirical data for ultra-precision nanocutting machining, offering important references for engineering practice and positively contributing to the optimization of nanocutting process parameters. • The cooling mechanism of water molecular cooling nanocrystals is studied. • The influence of water molecular cooling and vacuum cooling on the mechanism of nano-cutting is studied. • The influence mechanism of water molecular cooling on nano-cutting temperature was analyzed. [ABSTRACT FROM AUTHOR]

Fresh-cut leafy vegetable has an image as a healthy, nutritious, and delicious product. However, the product still faces the challenge of quality retention and short shelf life, especially in tropical climate regions. Enzymatic browning in fresh-cut leafy vegetables is considered one of the most important attributes limiting the shelf life of the product. The hurdle approach using commercial vacuum precooling in combination with modified atmosphere packaging (MAP) as an alternative to the use of chemical preservatives to prevent enzymatic browning, an undesirable attribute that is easily detected by consumers, was investigated. The hurdle technology exhibited synergistic effects on fresh-cut lettuce, namely frillice iceberg, romaine, and red oak, in slowing down cut-surface browning, maintaining quality, delaying microbial growth, and extending shelf life of salad products at the retail level. The findings of the study verified the potential of the hurdle approach in delaying the effect of cutting as well as extending shelf life of the product stored at 4 ± 1 °C with 85% RH from three days to nine days with an additional unit cost of 1.05%. Therefore, our hurdle approach is anticipated as the practice with non-chemical and economical approach in the supply chain of the fresh-cut, leafy vegetables industry. [ABSTRACT FROM AUTHOR]

A novel vacuum cooling system, which mainly consists of a 49-stage thermal transpiration based vacuum pump and a 100 L vacuum vessel, is proposed. The novel system can directly be driven by heat, while its structure and operation are similar to those of traditional mechanical vacuum systems. Then, a mathematic model is established to predict the performance of the novel system. The cooling capacity and coefficient of performance of the novel system increase with the rises of both parameters related to vacuum pump (the temperature difference between cold and hot chamber and pressure difference coefficient) and parameters related to vacuum vessel (mass transfer coefficient, chilled water temperature and supplement water temperature). It is a feasible way to raise system performance by cooling cold chambers, while heating hot chambers except for enhancement of mass transfer. The novel vacuum cooling system can produce relatively large cooling capacity exceeding 10,000 W at chilled water temperature over 289 K, the coefficient of performance (ranges from 0.71 to 1.48) of which is still comparable to that of the existing absorption refrigeration. It is clear that the novel thermal transpiration vacuum cooling is competitive among lots of emerging refrigeration technologies. [ABSTRACT FROM AUTHOR]

Vacuum cooling of baked goods can deliver many advantages in terms of product quality and productivity, such as higher volumes and shorter cooling times. However, the associated high costs and the need to adjust baking protocols are of relevance and more information is needed. This paper examines the influence of two main baking protocol parameters on the quality of toast bread, i.e. oven temperature and baking time reduction. Resulting toast bread characteristics including specific bread volume, concavity, browning index, crust and crumb hardness and aw-value were analysed as well as process-dependent core temperature and water loss. In order to compensate for water loss during vacuum cooling and still achieve optimal toast bread quality, a final bread core temperature of 98 °C at the end of baking gave best results, regardless of oven temperature. It was further shown that cooling time can be reduced by a factor of 10 if the baking protocol is optimally adjusted, hinting at a huge potential to increase productivity for industrial applications. In summary, it can be stated that vacuum cooling requires a tailored reduction in baking time in order to compensate for water loss from vacuum cooling while retaining sufficient structural cohesion to resist deformation of the bread. [ABSTRACT FROM AUTHOR]

Poor and inconsistent quality is a major barrier to increasing produce consumption, and the lack of shelf-life after purchase is the quality issue at retail displays of produce. This research aimed to investigate and identify cooling techniques, namely vacuum cooling and package icing used in supply chains, and any resulting extension of broccoli shelf-life, maintenance of physicochemical quality, and delay in microbial growth at retail stores. Broccoli (Brassica oleracea var. italica cv. Montop) sustainably grown in the highlands of northern Thailand, Chiang Mai Province, under the Royal Project Foundation was experimented on vacuum cooling and package icing were selected to precool broccoli to 4 ± 1 °C. The effects of vacuum cooling using a final pressure of 0.6 kPa for 30 min and package icing using liner Styrofoam boxes (the best ratio of broccoli to crushed ice was 1:1 w/w) on physicochemical qualities, microbial growth, and shelf-life in simulated refrigerated retail displays were examined. The results illustrated that the shelf-life and quality of broccoli could be extended using both vacuum cooling and package icing. Both precooling techniques inhibited the yellowing of florets, provided high sensory scores, delayed microbial growth, and could be able to extend the shelf-life of broccoli. However, package icing offered greater potential for maintaining quality, especially retaining bioactive compounds, and extending shelf-life, thereby increasing the produce market window from 5 to 12 days at 8 ± 1 °C with 85% RH. Therefore, package icing was recommended in the supply chain for fresh broccoli cv. Montop grown in northern Thailand. [ABSTRACT FROM AUTHOR]

This study was designed to investigate both energy and exergy analyses, exergy efficiency and coefficient of performance (COP) of the vacuum cooling system as a case study for boiled cauliflower (Brassica Oleracea Var). In literature, there is only one study investigated exergy analysis of vacuum cooling, and it is on pre cooling of the harvested mushroom. This paper is aimed to investigate the energy and exergy analyses of vacuum cooling for the cooked foods. First time in literature, the variation of the exergy product and total exergy due to pressure drop, relative humidity and average temperature in the vacuum chamber is determined and discussed in this study. In the paper, the effect of important parameters on the exergetic efficiency and COP for the vacuum cooling system is presented and discussed. An experimental study carried out in the paper to cool the boiled cauliflower in the vacuum cooling system and the center, surface, and ambient temperatures, pressure and humidity values are measured and presented. Experimental results were used energy and exergy analyses of the vacuum cooling system. In addition to energy and exergy analyses, mass conservation, first law of thermodynamics and second law of thermodynamics are also presented for vacuum cooling process. In this study, the parameters affecting energy and exergy analyses, performance coefficient (COP) and exergy efficiency for vacuum cooling systems is to determine. Results show that COP of vacuum cooling archives to 26 and exergy efficiency increases to 91% for the when pressure close to absolute zero pressure. [ABSTRACT FROM AUTHOR]

Summary: During vacuum cooling, polypropylene turnover boxes are repeatedly used for containing vegetables for cooling, while Pectobacteriumcarotovorum subsp. carotovora (Pcc) can form a biofilm on polypropylene adhesion surface. This study evaluated the effects of multiple cycles of vacuum cooling on the morphology and composition of Pcc biofilm formed on polypropylene turnover boxes. Results showed that Pcc biofilm in different growth stages including adhesion, development and mature phases displayed different responses to vacuum cooling. Pcc biofilm in adhesion stage decreased from 106 to 105 CFU cm−2, indicating the positive interference of vacuum cooling on biofilm formation in the initial developmental stage. However, with the increasing of the number of vacuum cooling cycles from 0 to 3, the biomass of Pcc biofilm in the development stage increased from 107 to 108 CFU cm−2 and the polysaccharide secretion increased from 7.96 to 16.7 mg cm−2, showing the promotion of biofilm formation and the secretion of extracellular polymeric substances. Therefore, regular cleansing and sterilisation of turnover boxes are necessary to prevent cross‐contamination during vacuum cooling. [ABSTRACT FROM AUTHOR]

Fresh-cut leafy vegetable has an image as a healthy, nutritious, and delicious product. However, the product still faces the challenge of quality retention and short shelf life, especially in tropical climate regions. Enzymatic browning in fresh-cut leafy vegetables is considered one of the most important attributes limiting the shelf life of the product. The hurdle approach using commercial vacuum precooling in combination with modified atmosphere packaging (MAP) as an alternative to the use of chemical preservatives to prevent enzymatic browning, an undesirable attribute that is easily detected by consumers, was investigated. The hurdle technology exhibited synergistic effects on fresh-cut lettuce, namely frillice iceberg, romaine, and red oak, in slowing down cut-surface browning, maintaining quality, delaying microbial growth, and extending shelf life of salad products at the retail level. The findings of the study verified the potential of the hurdle approach in delaying the effect of cutting as well as extending shelf life of the product stored at 4 ± 1 °C with 85% RH from three days to nine days with an additional unit cost of 1.05%. Therefore, our hurdle approach is anticipated as the practice with non-chemical and economical approach in the supply chain of the fresh-cut, leafy vegetables industry.

In this study, ultrasound application at two different frequencies (37 or 80 kHz) and durations (15 or 30 min) was used as a pre-treatment for raw broiler breasts, and its effect on cooling, color, textural and sensory characteristics of cooked broiler breasts during vacuum cooling process was determined. The anterior and posterior parts of broiler breast halves were carefully removed, and these parts with a 20 mm width were named as the regions A and B, respectively. Both regions were vacuum-packed and pre-treated by ultrasound, followed by oven-cooking in aluminum foils, and cooling time, weight loss and temperature distribution characteristics were determined. Besides sensory and textural properties, the effect of the ultrasound pre-treatment on the pH, dry matter and ash contents and color (CIELAB) values of cooked breasts was determined. During vacuum cooling, ultrasound pre-treatment significantly reduced cooling time required to cool cooked broiler breasts from 85 °C to 12.5 °C, and the lowest values for the regions A and B were obtained for the 30 min ultrasound pre-treatment at 37 kHz as 12.72 and 14.61 min, respectively (p 0.05). In conclusion, ultrasound pre-treatment can be successfully used for the vacuum cooling process of broiler breasts for the reduction of cooling time, and a 30 min ultrasound pre-treatment at 37 kHz can provide relatively superior cooling characteristics.

Summary: In this paper, immersion vacuum cooling with ultrasonic assistance (IVCUA) is compared with immersion vacuum cooling alone (IVC) and vacuum cooling (VC) for cooling time, mass loss, colour, texture profile and water mobility and compartmentalization for cooked meat products. The results reveal that IVCUA clearly enhances the boiling intensity of impregnation liquid compared to IVC. The total cooling time using IVC (126.56 min) for samples from 72 to 4 °C was significantly longer (P < 0.05) than that of IVCUA (96.89 min) and VC (80.48 min). The cooling time of samples from 10 to 4 °C by IVC (46.26 min) was higher (P < 0.05) than that by IVCUA (28.55 min). There were no significant differences (P > 0.05) in mass loss, colour and texture profile among all samples. However, IVCUA had a higher transverse relation time of bulk water (T24) and MRI proton densities (P < 0.05), as well as a more uniform water distribution compared to IVC. [ABSTRACT FROM AUTHOR]

In this study, two types of cooling methods (vacuum cooling and air cooling) were used to cool cooked macro‐porous sausage. Alterations in the microbiological conditions, pH, instrumental color (L*, a*, and b*), total volatile nitrogenous bases (TVB‐N), lipid oxidation (TBARS), water activity (aW), moisture content, and texture indicators were evaluated to determine sausages' quality changes during storage under refrigeration for up to 10 days. In general, the shelf life of sausages chilled by vacuum cooling (8 days) was similar to that of sausages cooled by air cooling (9 days). For pH, no significant difference (p >.05) was obtained between two cooling methods. However, vacuum‐cooled sausages have lower L* value (p <.05), lower moisture content, and water activity compared with the air‐cooled sausages. However, sausages cooled by vacuum cooling showed a sharp increase in TBARS and TVB‐N values but maintained texture characteristics for a longer time compared with air‐cooled sausages. Although the results indicated that the quality of sausages treated by those two methods remarkably decreased after 7 days, characteristics of sausages cooled by vacuum cooling are better within accepted standards compared with air‐cooled sausages. In conclusion, vacuum cooling can be a feasible cooling method with great potential to be used in cooked macro‐porous sausages to maintain the quality and may provide reference experiences for the food with similar structure. [ABSTRACT FROM AUTHOR]

Vacuum cooling is a rapid cooling method widely used in cooling some food products. Simulating the vacuum cooling process with mathematical models helps to acquire a more intuitive understanding and optimize the whole cooling process. However, there is no review summarizing the mathematical models of vacuum cooling. In this review, heat and mass transfer process during vacuum cooling, types of mathematical models for vacuum cooling, and numerical methods including finite difference method, finite element method and finite volume method used for process simulation are introduced in details. The food products used in numerical simulation study of vacuum cooling generally include liquid food, vegetables and cooked meat. The ranges of application of various numerical methods are also discussed. Moreover, heat and mass transfer coefficients have a great influence on the accuracy of the model, and are generally provided by the literature. The investigations presented in this review invariably demonstrate that mathematical modeling can provide good prediction of key information of vacuum cooling process, and has a great potential to improve vacuum cooling process in the food industry. However, more efforts are still needed to realize the industrial translation of laboratory results. [ABSTRACT FROM AUTHOR]

Abstract Background Vacuum cooling (VC) is a cooling technology for moist and porous foodstuffs with superiority in cooling rate, uniformity and hygiene, and low energy consumption. However, there are still some disadvantages that weaken the competitiveness of industrial applications such as the inevitable mass loss and uneven cooling in different parts of leafy vegetables. In order to improve the performance of VC, many efforts have been performed. Scope and approach In this review, the basic information of VC and the main applications for fruit, vegetables and meat products as well as limitations are described first. Improvements for enhancing performances of this technology in terms of operation processes including pre-treatment, technical optimization and integration, as well as equipment upgrade, and optimized operation conditions such as final pressure and pressure reduction rate are discussed. In addition, the limitation and further prospects of VC in the food industry are also mentioned. Key findings and conclusions The findings presented in this review demonstrated that optimizing operation processes and controlling operation conditions can effectively improve the performance of VC including mass loss, cooling rate and energy consumption and temperature distribution. However, many enhancing strategies still have limitation for applied in the food industry. Future trends of VC are the study of moisture migration characteristics based on food microstructure and multi-functional optimization of VC process or system. It is hoped that the current review can provide some guidance for further developments of the VC technology. Highlights • Contemporary applications of vacuum cooling to foods are presented. • Limitations in application and performance of vacuum cooling are discussed. • Innovative operation processes to improve vacuum cooling technology are assessed. • Strategies to refine operation conditions of vacuum cooling are outlined. • Key research trends comprise moisture migration and multi-functional optimization. [ABSTRACT FROM AUTHOR]

Driven by the bakery industry urge to satisfy consumer demand for fresh, diverse and high quality bakery products, we investigated the influence of barley sourdough and vacuum cooling on shelf life quality of partially baked bread stored in modified atmosphere packaging at ambient conditions. Barley sourdough was fermented with Lactobacillus reuteri (DSM 20016, F275). Partially baked bread with sourdough was microbiologically acceptable during 30 days of storage, while bread without sourdough had detectable mould on the 30th day. Stored bread samples were rebaked after 1, 8, 15, 22 and 30 days to determine moisture content, physical and sensorial properties. Moisture loss (5 %) was detected on the 15th day, after which it remained stable until the end of investigated storage period. Nevertheless, textural quality of stored bread continuously declined due to crumb firming. Bread flavour did not change during mould-free storage time. The principal component analysis identified major differences in the flavour of sour and control bread, also in crumb firmness and moisture content of samples. This study indicates the positive role of barley sourdough fermented with L. reuteri in improving crumb texture for at least 15 days, and ensuring mould- and bacteria-free partially baked bread for 30 days. Vacuum cooling combined with sourdough improved bread shape, porosity, and reduced sour taste, crust colouring and rumbliness. Hence, it can successfully extend shelf life quality of partially baked bread in modified atmosphere packaging.

Summary: In this paper, bubbling vacuum cooling (BVC) was compared with immersion vacuum cooling (IVC) in cooling time, weight loss, colour, texture profile, and uniformity of water temperature around the cooked meat. Results showed that the total cooling time of BVC (16.58 min) from 72 to 4 °C was shorter than that of IVC (19.12 min), while a significantly positive effect was observed in reducing cooling time for BVC at the lower temperature range (under 25 °C). For the cooling time from 10 to 4 °C, BVC (4.65 min) was significant (P < 0.05) less than that of IVC (6.47 min). Furthermore, water temperature of BVC can reach lower and distribute more uniformity than that of IVC. However, there was no significant difference (P > 0.05) in weight loss, colour and textural profile of cooled meat between these two cooling methods. Bubbling vacuum cooling can accelerate the cooling of cooked meats compared with immersion vacuum cooling, especially at low‐temperature average (under 25 °C), and meanwhile the efficiency of average cooling time can be improved about 10%–15%. [ABSTRACT FROM AUTHOR]

A Chinese and Patent Cooperation Treaty (PCT) invention patented process defined as “modified atmosphere vacuum cooling (MAVC)” was developed in the current study. In traditional vacuum cooling (VC), air enters the vacuum chamber during pressure recovery stage at the end of the cooling process. In this study, instead of air, a gas mixture consisting of 7% O 2 , 7% CO 2 and 86% N 2 enters the chamber to achieve modified atmosphere storage. Three types of cabbages with different morphological structure, including flowering cabbage, Chinese cabbage and green cabbage were treated by MAVC and stored for 21 d under 4 ± 0.5 °C, relative humidity was controlled in the range of 90%–95%. The changes of color, sensory score, ascorbic acid, chlorophyll, respiration rate, peroxidase (POD) and catalase (CAT) activity were measured throughout the storage period. The results showed that MAVC achieved the maximum values of color, sensory score, ascorbic acid, chlorophyll and CAT, and reduced the rate of respiration and the activity of POD during storage. A comparative analysis on the three cabbages found that different leaf morphology characteristics were not the main factor affecting gas retention during MAVC, and the intercellular spaces of leaves might have greater impact on the maintaining the quality of the cabbages. [ABSTRACT FROM AUTHOR]

Global warming has become a serious problem facing the international community. All countries strive to reduce greenhouse gas (GHG) emissions. The food system produces a large amount of GHGs, and thus study of the carbon footprint (CF) in the food industry has attracted the attention of researchers. Based on the lifecycle assessment (LCA) method, the present study calculated CFs of cooling of cooked rice, as a unit operation under different operational conditions. The results showed that the carbon footprints for cooling 200 g cooked rice were 54.36 ± 1.07 gCO 2 eq for refrigerator cooling at 0 °C, 66.05 ± 2.00 g CO 2 eq for refrigerator cooling at 8 °C, 741.55 ± 27.26 g CO 2 eq for vacuum cooling, 1914.10 ± 141.24 g CO 2 eq for air blast cooling at 0 °C, 2463.61 ± 221.21 g CO 2 eq for air blast cooling at 3 °C, and 3916.54 ± 202.28 g CO 2 eq for air blast cooling at 8 °C. In addition, the CF for the cooling process was positively correlated with the output power of equipment and the cooling time. The carbon emissions arising from electricity consumption contributed to most of the CF for the cooling process. Sensitivity analysis of the parameters for the CF for the cooling process revealed that the CF of cooling process was stable for the applied equipment emission factor, but sensitive to the efficiency of electricity use and the extent of load. Improving the efficiency of electricity use and increasing cooling load could reduce the final CF of a product. [ABSTRACT FROM AUTHOR]

Fresh fruits and vegetables are important parts of the human diet. The consumer demand for fruits and vegetables is increasing due to their rich nutritional value, appealing taste, and healthy perception. However, due to their highly perishable nature, appropriate preservation technologies must be developed to meet the consumer’s demand for healthy, additive-free, microbiologically safe, and high quality fresh fruits and vegetables. The preservation technologies based on modification or control of pressure alters the normal atmospheric pressure of the preservation environment. The materials to be preserved are subjected to either very high or low pressure to extend their shelf life. The mechanism, advantages, and limitations of pressure modification-based preservation methods such as high hydrostatic pressure, hyperbaric treatment, vacuum cooling, hypobaric storage, and vacuum packaging focusing on their applicability to fresh fruits and vegetables have been reviewed. This review suggests that these technologies have potential to extend the shelf life and achieve a better preservation of the quality of fresh fruits and vegetables. [ABSTRACT FROM AUTHOR]

Driven by the bakery industry urge to satisfy consumer demand for fresh, diverse and high quality bakery products, we investigated the influence of barley sourdough and vacuum cooling on shelf life quality of partially baked bread stored in modified atmosphere packaging at ambient conditions. Barley sourdough was fermented with Lactobacillus reuteri (DSM 20016, F275). Partially baked bread with sourdough was microbiologically acceptable during 30 days of storage, while bread without sourdough had detectable mould on the 30th day. Stored bread samples were rebaked after 1, 8, 15, 22 and 30 days to determine moisture content, physical and sensorial properties. Moisture loss (5 %) was detected on the 15th day, after which it remained stable until the end of investigated storage period. Nevertheless, textural quality of stored bread continuously declined due to crumb firming. Bread flavour did not change during mould-free storage time. The principal component analysis identified major differences in the flavour of sour and control bread, also in crumb firmness and moisture content of samples. This study indicates the positive role of barley sourdough fermented with L. reuteri in improving crumb texture for at least 15 days, and ensuring mould- and bacteria-free partially baked bread for 30 days. Vacuum cooling combined with sourdough improved bread shape, porosity, and reduced sour taste, crust colouring and crumbliness. Hence, it can successfully extend shelf life quality of partially baked bread in modified atmosphere packaging. [ABSTRACT FROM AUTHOR]

The food industry, especially the cooling of the food, is a major consumer of energy. The high energy consumption forces the food cooling industry for new refrigeration systems and cooling foods with the low energy consumption. Vacuum cooling method is fast and an evaporative process while it has many advantages such as shorter processing times, improved product shelf life, consequent energy savings, safety and quality. In the open literature, there is no study that has investigated exergy analysis, exergetic efficiency and Coefficient of Performance (COP) of vacuum cooling to the best of the authors’ knowledge. The performance of the vacuum cooling system using mushroom (Agaricus Bisporus) is determined through these metrics. The results have indicated that the COP value of the vacuum cooling reaches 12 and the exergy efficiency is maximum 80 percent for 23.9 °C. Both the exergetic efficiency and COP values for the vacuum cooling are achieved at the lowest pressure. The variations of energy and exergy of evaporation and the exergy rate of the product for the vacuum cooling are also given. [ABSTRACT FROM AUTHOR]

Vacuum cooling is a rapid evaporative cooling technique and can be used for pre-cooling of leafy vegetables, mushroom, bakery, fishery, sauces, cooked food, meat and particulate foods. The aim of this study was to apply the vacuum cooling and the conventional cooling techniques for the cooling of the meatball and to show the vacuum pressure effect on the cooling time, the temperature decrease and microbial growth rate. The results of the vacuum cooling and the conventional cooling (cooling in the refrigerator) were compared with each other for different temperatures. The study shows that the conventional cooling was much slower than the vacuum cooling. Moreover, the microbial growth rate of the vacuum cooling was extremely low compared with the conventional cooling. Thus, the lowest microbial growth occurred at 0.7 kPa and the highest microbial growth was observed at 1.5 kPa for the vacuum cooling. The mass loss ratio for the conventional cooling and vacuum cooling was about 5 and 9% respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hyperspectral imaging (HSI) was first time used to study vacuum cooling (VC) process. • Quality attributes of mushroom were dynamically evaluated during (VC) by HSI. • Partial least squares regression models realized good prediction for the attributes. • Pseudocolour maps were developed to visualize the distribution of the attributes. • The study provides a rapid and real-time nondestructive detection strategy. Visible near-infrared (400–1000 nm) hyperspectral imaging technology (HSI) was first time used to evaluate changes in various quality attributes including moisture contents (MC), lightness (L*), yellowness (b*), hardness (H) and chewiness (ch) of Agaricus bisporus as affected by vacuum cooling (VC). Partial least squares regression (PLSR) models based on Savitzky-Golay (SG) smoothing combined with the first derivative (SG-1st der) spectral preprocessing achieved good results for predicting MC with R2 P of 0.823 and RMSEP of 0.341%. Similarly, PLSR models based on full wavelengths achieved good results for predicting L*, b* and H, and ch with R2 P of 0.796, 0.848 and 0.810, and 0.903, with RMSEP of 1.253, 0.808 and 9.254, and 2.717. Finally, pseudocolour maps were developed to visualize the distribution of these attributes during VC. The current study provides a rapid, real-time and non-destructive detection strategy for evaluating the VC process. [ABSTRACT FROM AUTHOR]

A vacuum cooling system and the parameters which affect on its performance were studied experimentally and theoretically. For the experimental study the rig was built up to studying the performance of cooling system in three cases. These cases are: Cooling water by vacuum only, cooling water in conventional method, and cooling water by vacuum with condensation. The experimental results show that the addition of a condenser to the vacuum cooling system leads to sweep of largest amount of generated vapor, also the time consumed for the process was decreased. The times required for cooling 45 g from water from temperature 29oC to 10oC for the three test cases were 4375 second, 3535 second and 263 second, respectively. Vacuum cooling with condenser is a fast cooling of three systems test, which is about (13.7 times) faster than the system of natural convection cooling. To work properly, the existence of condenser is very important in vacuum cooling. It normally removes the large amount of water vapor generation (about 94%). For the theoretical study, a computer program was built up by employing the governing equation to simulate the performance of the vacuum cooling system. The theoretical results indicate an acceptable agreement with the experimental results. Also, the results show that the decreasing of condenser temperature causes decreasing of cooling time according to the equation (t = 0.2031Tcd4 - 2.8958 Tcd3 + 16.406 Tcd2 - 21.104 Tcd + 313.39), and increasing the evaporation surface area leads to decreasing of cooling time according to the equation (t=1/ (0.0006*Area+0.0005)), and the increasing of water mass causes in increasing of cooling time according to the equation (t=7.2667*mass+14).