A comprehensive review of the principles,key factors,application, and assessment of thawing technologies for muscle foods

For years, various thawing technologies based on pressure, ultrasound, electromagnetic energy, and electric field energy have been actively investigated to minimize the amount of drip and reduce the quality deterioration of muscle foods during thawing. However, existing thawing technologies have limitations in practical applications due to their high costs and technical defects. Therefore, key factors of thawing technologies must be comprehensively analyzed, and their effects must be systematically evaluated by the quality indexes of muscle foods. In this review, the principles and key factors of thawing techniques are discussed, with an emphasis on combinations of thawing technologies. Furthermore, the application effects of thawing technologies in muscle foods are systematically evaluated from the viewpoints of eating quality and microbial and chemical stability. Finally, the disadvantages of the existing thawing technologies and the development prospects of tempering technologies are highlighted. This review can be highly instrumental in achieving more ideal thawing goals.     

新型解冻技术及其对鱼肉品质影响的研究进展

冷冻是水产品保藏的常用手段,冷冻水产品在加工烹饪前首先需要进行解冻。传统解冻技术具有耗时长、能耗高、解冻损失大、品质劣化等缺陷,水产品解冻后可能出现风味变化、外观受损、蛋白质变性、脂肪氧化等问题,造成水产品品质大大下降,营养严重流失,无法满足消费者的感官需求。因而,电磁波（微波、射频、远红外等）解冻、真空解冻、欧姆解冻、高压静电场解冻以及利用超声波、磁性纳米粒子作为辅助手段的众多新型解冻技术逐渐得到应用和推广,这些新型解冻技术可有效改善传统解冻技术出现的品质不佳、感官劣变等问题。本文综述了几种新型解冻技术的技术原理、应用方法及各自的优缺点,重点阐述了不同解冻技术对鱼肉中水分分布状态和肌肉纤维组织状态的影响,主要体现为对鱼肉的保水性,新鲜度,蛋白质的氧化变性、构象变化、聚集特性等方面的影响,以期为新型低耗高效水产品解冻技术的开发及工业化应用提供理论参考与启发。     

冻结食品的解冻技术

就冻结食品的解冻技术进行了综述。对各种解冻方法的解冻原理及其在食品中的应用做了论述和分析,着重介绍了微波解冻、超声波解冻和高静水压解冻技术。     

磁性纳米粒子辅助加热技术在鱼类解冻中的应用

随着食品工业的快速发展和消费者安全意识的提高,人们越来越注重食品质量与安全。冻藏是食品长期贮藏的最常用方法,但食品品质在冷冻解冻后还存在一些劣变,如由解冻汁液流失造成的营养损失,脂质和蛋白质氧化严重,肌肉纤维组织受到破坏等,因而寻求一种安全高效的新型解冻技术尤为重要。磁性纳米粒子辅助加热是一种新型食品解冻方法,它大大改善了传统解冻和新型解冻方法出现的氧化严重、感官不佳等问题。作者综述了食品解冻中存在的品质劣变问题和磁性纳米粒子辅助加热在鱼类解冻中的应用,以期为该技术在食品解冻中的应用提供参考。     

Recent developments in novel freezing and thawing technologies applied to foods

This article reviews the recent developments in novel freezing and thawing technologies applied to foods. These novel technologies improve the quality of frozen and thawed foods and are energy efficient. The novel technologies applied to freezing include pulsed electric field pre-treatment, ultra-low temperature, ultra-rapid freezing, ultra-high pressure and ultrasound. The novel technologies applied to thawing include ultra-high pressure, ultrasound, high voltage electrostatic field (HVEF), and radio frequency. Ultra-low temperature and ultra-rapid freezing promote the formation and uniform distribution of small ice crystals throughout frozen foods. Ultra-high pressure and ultrasound assisted freezing are non-thermal methods and shorten the freezing time and improve product quality. Ultra-high pressure and HVEF thawing generate high heat transfer rates and accelerate the thawing process. Ultrasound and radio frequency thawing can facilitate thawing process by volumetrically generating heat within frozen foods. It is anticipated that these novel technologies will be increasingly used in food industries in the future.     

不同强度DENBA+电场辅助处理冻结草莓后对其解冻品质影响的比较

DENBA+技术可利用高压静电,通过共振食品细胞中的水分子使其更为活性化,达到保持营养成分完整、延迟氧化、实现食材保鲜的目的,可与食品速冻保鲜配合使用。为系统地考察外加DENBA+静电场对冻藏草莓超声解冻后品质的影响,该实验以丹东九九草莓作为研究对象,通过对比分析感官评价、色差、硬度、汁液流失率、可溶性固形物、总糖、总酚等7项指标,探究草莓在外加不同强度DENBA+静电场条件下冻结对其解冻品质的影响。实验结果表明,经外加高低电场辅助草莓冻结解冻品质均优于空白对照组,且与2 000 V高强度DENBA+电场辅助冻结相比,经外加500 V低强度DENBA+电场辅助冻结后,感官评价综合分数最高,色差下降1.70%,硬度提高22.45%,汁液流失率下降27.72%;可溶性固形物含量提高8.16%、总糖含量提高4.79%、总酚含量提高9.90%,上述各项指标低电场辅助处理较高电场辅助处理效果更优且差异显著（P<0.05）,其解冻特性呈现相对较好的状态,综合分析得出500 V的低电场辅助冻藏草莓的品质较优。     

Novel Approaches in Gluten‐Free Breadmaking: Interface between Food Science,Nutrition, and Health

The evidence that celiac disease is one of the commonest food intolerances in the world is driving an increasing demand for gluten‐free foods. However, gluten is a structure‐building protein essential for formulating leavened baked goods. Therefore, obtaining high‐quality gluten‐free bread (GFB) is a technological challenge. This review focuses on contemporary approaches in gluten‐free baking that allow improvements at the structure, texture, acceptability, nutritive value, and shelf life of GFB. Gluten‐free breadmaking is a relatively new, emerging research topic that is attracting worldwide attention in order to develop different kinds of GFB, including regional varieties. Several approaches have been used to understand and improve GFB systems by evaluating different flours and starch sources, ingredients added for nutritional purposes, additives, and technologies or a combination of these elements. Some studies aimed to assess or improve GFB's technological or nutritional properties, while others had multiple objectives. Several studies used food science tools in order to improve technological and sensory quality of GFB, together with nutritional value. Some GFBs are vehicles of nutrients and bioactive compounds. Furthermore, extensive research on interfacing food science, nutrition, and health is needed so that a GFB with both good technological and nutritional properties can be prepared and made more available to those with celiac disease, which will help them adhere to a strict gluten‐free diet, increase social inclusion, and improve their quality of life.     

物理场技术在水产品冷冻冷链中的应用

在冷链流通过程中, 对新鲜水产品进行冷冻处理能够大大提高其保质期。然而, 传统的冷冻和解冻方法有传热效率低、耗时较长的缺陷, 且难以控制冰晶对食品原料的损伤。所以冷冻水产品经常会面临一系列的质量问题, 如质构劣化、蛋白质变性、持水能力下降等。因此有必要采用高效的冷冻/解冻技术以防止品质劣变。相比于传统方法, 基于物理场(如高压、超声、电场等)的新型冷冻和解冻技术具有高冷冻/解冻速率、低能耗、对产品品质维持更好等优点。本文综述了近年来物理场技术在水产品中的应用, 分析了它们各自的原理、特点、缺陷及未来的发展趋势, 为这些新技术在水产品冷冻冷链中的应用提供相关参考。     

Texture Modification Technologies and Their Opportunities for the Production of Dysphagia Foods: A Review

Dysphagia or swallowing difficulty is a common morbidity experienced by those who have suffered a stroke or those undergone such treatments as head and neck surgeries. Dysphagic patients require special foods that are easier to swallow. Various technologies, including high‐pressure processing, high‐hydrodynamic pressure processing, pulsed electric field treatment, plasma processing, ultrasound‐assisted processing, and irradiation have been applied to modify food texture to make it more suitable for such patients. This review surveys the applications of these technologies for food texture modification of products made of meat, rice, starch, and carbohydrates, as well as fruits and vegetables. The review also attempts to categorize, via the use of such key characteristics as hardness and viscosity, texture‐modified foods into various dysphagia diet levels. Current and future trends of dysphagia food production, including the use of three‐dimensional food printing to reduce the design and fabrication time, to enhance the sensory characteristics, as well as to create visually attractive foods, are also mentioned.     

Antioxidant and Antimicrobial Activities of (‐)‐Epigallocatechin‐3‐gallate (EGCG) and its Potential to Preserve the Quality and Safety of Foods

Quality deterioration of fresh or processed foods is a major challenge for the food industry not only due to economic losses but also due to the risks associated with spoiled foods resulting, for example, from toxic compounds. On the other hand, there are increasing limitations on the application of synthetic preservatives such as antioxidants in foods because of their potential links to human health risks. With the new concept of functional ingredients and the development of the functional foods market, and the desire for a “clean” label, recent research has focused on finding safe additives with multifunctional effects to ensure food safety and quality. (‐)‐Epigallocatechin‐3‐gallate (EGCG), a biologically active compound in green tea, has received considerable attention in recent years and is considered a potential alternative to synthetic food additives. EGCG has been shown to prevent the growth of different Gram‐positive and Gram‐negative bacteria responsible for food spoilage while showing antioxidant activity in food systems. This review focuses on recent findings related to EGCG separation techniques, modification of its structure, mechanisms of antioxidant and antimicrobial activities, and applications in preserving the quality and safety of foods.     

Nonthermal Processes for Shelf‐Life Extension of Seafoods: A Revisit

For the past two decades, consumer demand for minimally processed seafoods with good sensory acceptability and nutritive properties has been increasing. Nonthermal food processing and preservation technologies have drawn the attention of food scientists and manufacturers because nutritional and sensory properties of such treated foods are minimally affected. More importantly, shelf‐life is extended as nonthermal treatments are capable of inhibiting or killing both spoilage and pathogenic organisms. They are also considered to be more energy‐efficient and to yield better quality when compared with conventional thermal processes. This review provides insight into the nonthermal processing technologies currently used for shelf‐life extension of seafoods. Both pretreatments such as acidic electrolyte water and ozonification and processing technologies, including high hydrostatic pressurization, ionizing radiation, cold plasma, ultraviolet light, and pulsed electric fields, as well as packaging technology, particularly modified atmosphere packaging, have been implemented to lower the microbial load in seafood. Thus, those technologies may be the ideal approach for the seafood industry, in which prime quality is maintained and safety is assured for consumers.     

压力辅助解冻过程相变及传热模拟

本文比较了食品中冰在常压和高压下的解冻过程.利用显热容法处理潜热释放,分析了不同因素对处理效果影响,考虑了不同样品尺寸不同压力条件下解冻时间.计算得到了不同操作条件下的解冻温度曲线,结果表明,相变温度降低是影响压力辅助解冻过程解冻时间缩短的主要因素,同一样品的解冻时间与处理压力成二次曲线关系.     

Effects of high‐pressure processing on fungi spores: Factors affecting spore germination and inactivation and impact on ultrastructure

Food contamination with heat‐resistant fungi (HRF), and their spores, is a major issue among fruit processors, being frequently found in fruit juices and concentrates, among other products, leading to considerable economic losses and food safety issues. Several strategies were developed to minimize the contamination with HRF, with improvements from harvesting to the final product, including sanitizers and new processing techniques. Considering consumers’ demands for minimally processed, fresh‐like food products, nonthermal food‐processing technologies, such as high‐pressure processing (HPP), among others, are emerging as alternatives to the conventional thermal processing techniques. As no heat is applied to foods, vitamins, proteins, aromas, and taste are better kept when compared to thermal processes. Nevertheless, HPP is only able to destroy pathogenic and spoilage vegetative microorganisms to levels of pertinence for food safety, while bacterial spores remain. Regarding HRF spores (both ascospores and conidiospores), these seem to be more pressure‐sensible than bacterial spores, despite a few cases, such as the ascospores of Byssochlamys spp., Neosartorya spp., and Talaromyces spp. that are resistant to high pressures and high temperatures, requiring the combination of both variables to be inactivated. This review aims to cover the literature available concerning the effects of HPP at room‐like temperatures, and its combination with high temperatures, and high‐pressure cycling, to inactivate fungi spores, including the main factors affecting spores’ resistance to high‐pressure, such as pH, water activity, nutritional composition of the food matrix and ascospore age, as well as the changes in the spore ultrastructure, and the parameters to consider regarding their inactivation by HPP.     

超声波解冻与传统解冻方式的比较与竞争力评估

超声波解冻通过空化效应、机械效应和热效应对冷冻食品进行解冻,解冻效率高、对冷冻食品的损伤较小。该文简要介绍了空气解冻、水解冻和电解冻的解冻机制及研究进展,详细阐述了超声波解冻的机制及研究进展。将超声波解冻与空气解冻、水解冻和电解冻进行对比,发现超声波解冻的解冻效率最优,且将超声波与这3种传统解冻方式结合可以提高解冻效率,并且获得更好的解冻效果。超声波频率和强度以及冻结食品的解冻温度是影响解冻效果的主要参数。超声波在食品中的衰减程度受到解冻温度的影响极大,因此在调节超声波频率和强度同时调控解冻温度对解冻效果至关重要。     

Physicochemical and structural changes of myofibrillar proteins in muscle foods during thawing: Occurrence,consequences, evidence,and implications

Myofibrillar protein (MP) endows muscle foods with texture and important functional properties, such as water-holding capacity (WHC) and emulsifying and gel-forming abilities. However, thawing deteriorates the physicochemical and structural properties of MPs, significantly affecting the WHC, texture, flavor, and nutritional value of muscle foods. Thawing-induced physicochemical and structural changes in MPs need further investigation and consideration in the scientific development of muscle foods. In this study, we reviewed the literature for the thawing effects on the physicochemical and structural characters of MPs to identify potential associations between MPs and the quality of muscle-based foods. Physicochemical and structural changes of MPs in muscle foods occur because of physical changes during thawing and microenvironmental changes, including heat transfer and phase transformation, moisture activation and migration, microbial activation, and alterations in pH and ionic strength. These changes are not only essential inducements for changes in spatial conformation, surface hydrophobicity, solubility, Ca²⁺-ATPase activity, intermolecular interaction, gel properties, and emulsifying properties of MPs but also factors causing MP oxidation, characterized by thiols, carbonyl compounds, free amino groups, dityrosine content, cross-linking, and MP aggregates. Additionally, the WHC, texture, flavor, and nutritional value of muscle foods are closely related to MPs. This review encourages additional work to explore the potential of tempering techniques, as well as the synergistic effects of traditional and innovative thawing technologies, in reducing the oxidation and denaturation of MPs and maintaining the quality of muscle foods.     

Non-thermal technologies and its current and future application in the food industry: a review

In recent years, consumers have been demanding convenient and healthy foods which have ‘fresh-like’ characteristics while still being safe and a long shelf-life. These requirements are hard to achieve using existing traditional thermal food processing technologies and the innovative new food process and preservation technologies based on thermal processing systems are needed. However, non-thermal technologies in food processing do not generate high temperature and use short treatment times. This means that the nutritional components of foodstuffs are better retained, and the sensory properties of foods are less changed compared with traditional thermal processing. The aim of this review was to present non-thermal technologies applications and its mechanism in food industry in recently, and to explore the potential application prospects of combining non-thermal treatments applied in food industry because it not only could overcomes the drawback of single technology, but also can enhances the processing efficiency at lower treatment intensity.     

Skim milk cryoconcentration as affected by the thawing mode: gravitational vs. microwave‐assisted

In the present study, skim milk was successfully cryoconcentrated up to 43.72 ± 0.69% (w/w) total dry matter after four cryoconcentration cycles. Total proteins were concentrated up to 22.49 ± 0.31% (w/w). It was found that the cryoconcentrated skim milk fraction was rich in potassium ions. The effect of the cryoconcentration cycle and thawing mode on process efficiency was studied. The obtained data showed that the cryoconcentration cycle effect was significant (P < 0.001). The thawing mode (gravitational and microwave assisted thawing) had no effect on process efficiency. However, the microwave assisted thawing mode was more efficient regarding to the time needed to obtain the desired thawed fraction. To achieve high process efficiency, three cryoconcentration cycles were sufficient since the process efficiency drastically decreased after this cycle. The concentration of the dry mater entrapped in the ice fraction was the highest at the fourth cryoconcentration cycle.     

食品解冻技术

食品解冻是冷冻食品加工中十分重要的操作。不同的解冻方法具有不同的特点,对于不同的物料和同一种物料解冻后的用途不同,应选择合适的解冻方法。这里对各种解冻方法及其特点进行了分析。对一些解冻新技术如过热水蒸气解冻、通电加热解冻、高频波解冻、微波加热解冻和高压静电场解冻等做了较详细的介绍。     

Recent Applications of Spectroscopic and Hyperspectral Imaging Techniques with Chemometric Analysis for Rapid Inspection of Microbial Spoilage in Muscle Foods

Muscle food is one of the most perishable food products because of its vulnerability to microbial spoilage, which can result in critical food safety problems. Traditional techniques for detection and evaluation of microbial spoilage in muscle foods are tedious, laborious, destructive, and time‐consuming. In recent years, spectroscopic and imaging technologies have shown great potentials for the assessment of food quality and safety due to their nondestructive, noninvasive, cost‐effective, and rapid responsive nature. This review focuses on the applications of several valuable spectroscopic techniques including visible and near‐infrared spectroscopy, Fourier transform infrared spectroscopy, fluorescence spectroscopy, Raman spectroscopy, and hyperspectral imaging for the rapid and nondestructive detection of microbial spoilage in common muscle foods such as meat, poultry, fish, and related products. Combined with chemometric analysis, such as spectral preprocessing and modeling methods, these potential technologies have been successfully developed for the determination of total viable count, aerobic plate count, Enterobacteriaceae, Pseudomonas, Escherichia coli, and lactic acid bacteria loads in muscle foods. Moreover, the advantages and disadvantages of these techniques are discussed and some perspectives about future trends are also presented.     

Effects of different thawing methods on the quality of chicken breast

Freezing and thawing technologies are widely used in meat industry. This study aimed to investigate the effects of freezing and different thawing methods (Control group, CG; water immersing thawing, WT; low temperature combined with high‐humidity thawing, LT; combined thawing 1 (WT 15 min, then LT), CT1; combined thawing 2 (LT 2 h, then WT), CT2) on the quality of chicken breast. The results showed that all thawing methods significantly increased shear force value, the gap between muscle fibres, the contents of malondialdehyde (MDA) and carbonyl compounds, meanwhile, decreased the pH, CIE a* value, total protein solubility and sarcoplasmic protein solubility, compared with CG (P < 0.05). Among different thawing methods, LT was most effective in decreasing thawing loss but it had the highest contents of MDA and carbonyl compounds (P < 0.05). CT1 significantly decreased shear force value and MDA content (P < 0.05). Overall, freezing and thawing process had a detrimental effect on the quality of chicken breast, and the extent was pronounced with different thawing methods. On the basis of shortening thawing time and keeping meat quality, the results of this study suggested that CT1 could be chosen as the better thawing method.