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

Effects of different thawing methods on physical and physicochemical properties of frozen dough and quality of corresponding steamed bread

The thawing method is critical for the final quality of products based on the frozen dough. The effects of ultrasound thawing, proofer thawing, refrigerator thawing, water bath thawing, ambient thawing, and microwave thawing on the rheology, texture, water distribution, fermentation characteristics, and microstructure of frozen dough and the properties of steamed bread were investigated. The results indicated that the ultrasound thawing dough had better physicochemical properties than other doughs. It was found that ultrasound thawing restrained the water migration of dough, improved its rheological properties and fermentation capacity. The total gas volume value of the ultrasound thawing dough was reduced by 21.35% compared with that of unfrozen dough. The ultrasound thawing dough displayed a thoroughly uniform starch-gluten network, and an enhanced the specific volume and internal structure of the steamed bread. In conclusion, ultrasound thawing effectively mitigated the degradation of the frozen dough and enhanced the quality of steamed bread.

Effect of two-stage low-temperature tempering process assisted by electrostatic field application on physicochemical and structural properties of myofibrillar protein in frozen longissimus dorsi of tan mutton

The effects of refrigerator tempering, two-stage low-temperature tempering (TLT), and a combination of TLT with electrostatic field tempering (TLT-1500/2000/2500/3000) on the physicochemical and structural properties of the myofibrillar protein (MPs) in Longissimus dorsi of Tan mutton were investigated. The results from differential scanning calorimetry and dynamic rheology indicated that TLT-2000/2500 had the least impact on the thermal stability of MPs. While the carbonyl and dityrosine contents of MPs in TLT-2000/2500 were the lowest, the total sulfhydryl content and Ca2+-ATPase activity were the highest, suggesting that TLT-2000/2500 preserved the properties of MPs more effectively. The smaller and uniformly distributed particle size, highest zeta potential, and SDS-PAGE analysis confirmed that TLT-2000/2500 had minimal impact on the aggregation and degradation of MPs. Additionally, results from surface hydrophobicity, Fourier transform infrared spectroscopy, intrinsic fluorescence, and UV second-derivative absorption spectra suggested that TLT-2000/2500 was more conducive to stabilizing the primary, secondary, and tertiary structures of MPs.

Effects of umami substances as taste enhancers on salt reduction in meat products: A review

Sodium is one of the essential additives in meat processing, but excessive sodium intake may increase risk of hypertension and cardiovascular disease. However, reducing salt content while preserving its preservative effect, organoleptic properties, and technological characteristics poses challenges. In this review, the mechanism of salt reduction of umami substances was introduced from the perspective of gustation-taste interaction, and the effects of the addition of traditional umami substances (amino acids, nucleotides, organic acids(OAs)) and natural umami ingredients (mushrooms, seaweeds, tomatoes, soybeans, tea, grains) on the sensory properties of the meat with reduced-salt contents were summarized. In addition, the impacts of taste enhancers on eating quality (color, sensory, textural characteristics, and water-holding capacity (WHC)), and processing quality (lipid oxidation, pH) of meat products (MP) and their related mechanisms were also discussed. Among them, natural umami ingredients exhibit distinct advantages over traditional umami substances in terms of enhancing quality and nutritional value. On the basis of salt reduction, natural umami ingredients improve the flavor, texture, WHC and antioxidant capacity. This comprehensive review may provide the food industry with a theoretical foundation for mitigating salt consumption through the utilization of umami substances and natural ingredients.

The Effects of Four Different Thawing Methods on Quality Indicators of Amphioctopus neglectus

Amphioctopus neglectus is a species of octopus that is favored by consumers due to its rich nutrient profile. To investigate the influence of different thawing methods on the quality of octopus meat, we employed four distinct thawing methods: air thawing (AT), hydrostatic thawing (HT), flowing water thawing (FWT), and microwave thawing (MT). We then explored the differences in texture, color, water retention, pH, total volatile basic nitrogen (TVB-N), total sulfhydryl content, Ca2+-ATPase activity, and myofibrillar protein, among other quality indicators in response to these methods, and used a low-field nuclear magnetic resonance analyzer to assess the water migration that occurred during the thawing process. The results revealed that AT had the longest thawing time, leading to oxidation-induced protein denaturation, myofibrillar protein damage, and a significant decrease in water retention. Additionally, when this method was utilized, the content of TVB-N was significantly higher than in the other three groups. HT, to a certain extent, isolated the oxygen in the meat and thus alleviated protein oxidation, allowing higher levels of Ca2+-ATPase activity, sulfhydryl content, and springiness to be maintained. However, HT had a longer duration: 2.95 times that of FWT, resulting in a 9.84% higher cooking loss and a 28.21% higher TVB-N content compared to FWT. MT had the shortest thawing time, yielding the lowest content of TVB-N. However, uneven heating and in some cases overcooking occurred, severely damaging the protein structure, with a concurrent increase in thawing loss, W value, hardness, and shear force. Meanwhile, FWT improved the L*, W* and b* values of octopus meat, enhancing its color and water retention. The myofibrillar protein (MP) concentration was also the highest after FWT, with clearer subunit bands in SDS-PAGE electrophoresis, indicating that less degradation occurred and allowing greater springiness, increased Ca2+-ATPase activity, and a higher sulfhydryl content to be maintained. This suggests that FWT has an inhibitory effect on oxidation, alleviating protein oxidation degradation and preserving the quality of the meat. In conclusion, FWT outperformed the other three thawing methods, effectively minimizing adverse changes during thawing and successfully maintaining the quality of octopus meat.

Coexisting with Ice Crystals: Cryogenic Preservation of Muscle Food─Mechanisms, Challenges, and Cutting-Edge Strategies

Cryopreservation, one of the most effective preservation methods, is essential for maintaining the safety and quality of food. However, there is no denying the fact that the quality of muscle food deteriorates as a result of the unavoidable production of ice. Advancements in cryoregulatory materials and techniques have effectively mitigated the adverse impacts of ice, thereby enhancing the standard of freezing preservation. The first part of this overview explains how ice forms, including the theoretical foundations of nucleation, growth, and recrystallization as well as the key influencing factors that affect each process. Subsequently, the impact of ice formation on the eating quality and nutritional value of muscle food is delineated. A systematic explanation of cutting-edge strategies based on nucleation intervention, growth control, and recrystallization inhibition is offered. These methods include antifreeze proteins, ice-nucleating proteins, antifreeze peptides, natural deep eutectic solvents, polysaccharides, amino acids, and their derivatives. Furthermore, advanced physical techniques such as electrostatic fields, magnetic fields, acoustic fields, liquid nitrogen, and supercooling preservation techniques are expounded upon, which effectively hinder the formation of ice crystals during cryopreservation. The paper outlines the difficulties and potential directions in ice inhibition for effective cryopreservation.

Development and characterization of a new potato starch/watermelon peel pectin composite film loaded with TiO2 nanoparticles and microencapsulated Lycium barbarum leaf flavonoids and its use in the Tan mutton packaging

Reinforced edible film with active nanoparticles has been in increasing demand as a new technology to improve the quality and extend the shelf-life of muscle foods. The study aimed to fabricate and characterize a novel potato starch (Pst)/watermelon peel pectin (Wpp) composite film with the microencapsulated Lycium barbarum leaf flavonoids (MLF) and nano-TiO2 (Pst/Wpp/MLF/TiO2) and further apply the film in Tan mutton preservation. The moisture content, thickness and water vapor permeability (WVP) of the composite film were relatively increased with increasing the percentage of MLF, while nano-TiO2 had slight influence on the thickness, but leaded to a significantly decreased the moisture content and WVP. Also, the SEM images showed that the roughness and porosity were created on the film surface by adding MLF and nano-TiO2. FTIR revealed electrostatic and hydrogen bond interactions between the components in the film system. Meanwhile, MLF and nano-TiO2 effectively enhanced the mechanical strength, UV-barrier, controlled-release, thermal stability, antimicrobial and antioxidation properties of the Pst/Wpp film. Also, the composite film containing MLF and nano-TiO2 significantly inhibited the growth of microorganisms and chemical deterioration of mutton samples, which suggested that such film has potential as a prospective active packaging for preserving Tan mutton.

Effects of frozen of marula fruits (Sclerocarya birrea) on chemical, antioxidant activities, and sensory properties of marula fruit juice

This study determined the effects of frozen storage on physicochemical, phenolic content and antioxidant activities of fruit juice extracted from frozen marula fruits. The marula fruits were frozen for zero to eight weeks after which the frozen marula fruits were thawed between 10 and 12 h and the juice extracted manually. There was 36.35% decrease in vitamin C content of the juice, 36.70% decrease in TPC, 46.50% decrease in FRAP and 53.22% decrease in TFC. The colour of the marula fruit juice decreases with increase in frozen storage time and the marula fruit juice extracted from unfrozen marula fruit was score highest in all the sensory properties evaluated. Although, freezing is one of the best preservative methods of fruits, the type of freezer used for the freezing process determines the nutritional value of the fruits and the juice. A home freezer may not be good to store marula fruits.

Cryoprotective Effect of NADES on Frozen-Thawed Mirror Carp Surimi in Terms of Oxidative Denaturation, Structural Properties, and Thermal Stability of Myofibrillar Proteins

Quality degradation due to the formation and growth of ice crystals caused by temperature fluctuations during storage, transportation, or retailing is a common problem in frozen surimi. While commercial antifreeze is used as an ingredient in frozen surimi, its high sweetness does not meet the contemporary consumer demand for low sugar and low calories. Therefore, the development of new green antifreeze agents to achieve an enhanced frozen-thawed stability of surimi has received more attention. The aim of this study was to develop a cryoprotectant (a mixture of citric acid and trehalose) to enhance the frozen-thawed stability of surimi by inhibiting the oxidative denaturation and structural changes of frozen-thawed mirror carp (Cyprinus carpio L.) surimi myofibrillar protein (MP). The results showed that the amounts of free amine, sulfhydryl, α-helix, intrinsic fluorescence intensity, and thermal stability in the control significantly decreased after five F-T cycles, while the Schiff base fluorescence intensity, amounts of disulfide bonds and surface hydrophobicity significantly increased (p < 0.05). Compared to sucrose + sorbitol (SS), the natural deep eutectic solvents (NADES) effectively inhibited protein oxidation. After five F-T cycles, the α-helix content and Ca2+-ATPase activity of the NADES samples were 4.32% and 80.0%, respectively, higher, and the carbonyl content was 17.4% lower than those of the control. These observations indicate that NADES could inhibit oxidative denaturation and enhance the structural stability of MP.

Relationship between Dietary Polyphenols and Gut Microbiota: New Clues to Improve Cognitive Disorders, Mood Disorders and Circadian Rhythms

Cognitive, mood and sleep disorders are common and intractable disorders of the central nervous system, causing great inconvenience to the lives of those affected. The gut-brain axis plays a vital role in studying neurological disorders such as neurodegenerative diseases by acting as a channel for a bidirectional information exchange between the gut microbiota and the nervous system. Dietary polyphenols have received widespread attention because of their excellent biological activity and their wide range of sources, structural diversity and low toxicity. Dietary intervention through the increased intake of dietary polyphenols is an emerging strategy for improving circadian rhythms and treating metabolic disorders. Dietary polyphenols have been shown to play an essential role in regulating intestinal flora, mainly by maintaining the balance of the intestinal flora and enhancing host immunity, thereby suppressing neurodegenerative pathologies. This paper reviewed the bidirectional interactions between the gut microbiota and the brain and their effects on the central nervous system, focusing on dietary polyphenols that regulate circadian rhythms and maintain the health of the central nervous system through the gut-brain axis.

Edible films/coatings containing bioactive ingredients with micro/nano encapsulation: A comprehensive review of their fabrications, formulas, multifunctionality and applications in food packaging

Due to the consumer's pursuit of safe, nontoxic and nutritious foods, edible and/or biodegradable materials have stood out in food packaging and preservation. In this context, the preparation and application of micro/nano encapsulated active ingredients (M/N-E-BAIs) represent a step toward reinforcing the properties of sustainable and controllable food packaging, particularly for the successful incorporation of new substances and functionalities into traditional edible films/coatings. This review, from the preparation of M/N-E-BAIs, the fabrication of edible film/coating containing M/N-E-BAIs to their characterization of multifunction and the application in food, makes a systematic summary and in-depth discussion. Food-grade polymers can encapsulate bioactive ingredients (BAIs) by chemical, physicochemical and mechanical methods, thereby forming M/N-E-BAIs with suitable sustained-release and unique biological activities. Furthermore, M/N-E-BAIs is incorporated into biopolymer substrates by solvent casting, 3D printing or electrostatic spinning to obtain novel edible films/coatings. This advanced packaging material exhibits superior physicochemical and functional properties over traditional food films/coatings. Besides, their applications in foods as active and intelligent packaging can improve food quality, prolong shelf life and monitor food corruption. Even so, there are still many challenges and limitations in formulation, preparation and application of this new packaging technology that need to be addressed in the future.