Gelatin based preservation technologies on the quality of food: a comprehensive review.

Gelatin has played a great potential in food preservation because of its low price and superior film forming characteristics. This review provides a comprehensive overview of the latest research progress and application of gelatin preservation technologies (film, coating, antifreeze peptide, etc.), discussing their preservation mechanisms and efficiency through the viewpoints of quality and shelf life of animal and aquatic products as well as fruits and vegetables. It showed that bioactive and intelligent gelatin-based films exhibit antibacterial, antioxidant, water resistance and pH responsive properties, making them excellent for food preservation. In addition, pH responsive properties of films also intuitively reflect the freshness of food by color. Similarly, gelatin and its hydrolysate can be widely used in antifreeze peptides to reduce the mass loss of food during freezing and extend the shelf life of frozen food. However, extensive works are still required to extend their commercial application values.

Effect of Neutral Protease on Freshness Quality of Shucked Pacific Oysters at Different Storage Conditions.

The aim of this study was to investigate the effect of neutral protease treatment on the biochemical properties of various parts of Pacific oysters (Crassostrea gigas) under different storage conditions. The mechanism of quality degradation in the mantle, adductor muscle, gill, and trunk of treated oysters stored at -1.5 °C (superchilling) or 4 °C (refrigeration) for several days using different storage methods was studied. The results showed that the oyster treated with the enzyme exhibited higher glycogen content, flavor nucleotide content, and sensory scores compared to the control group. Superchilling at -1.5 °C was observed to slow the increase in total volatile basic nitrogen (TVB-N), total viable count (TVC), and pH, while maintaining sensory scores better than refrigeration at 4 °C. Both wet superchilling (WS) and dry exposed superchilling (DeS) methods effectively preserved freshness and quality at -1.5 °C. The freshness of the oysters' body trunk changed most significantly. K value, K' value, and AEC value, as the evaluation indexes of oyster freshness, were affected by the storage medium. Therefore, neutral protease enhances the flavor of oysters in a short time, and oysters stored in wet superchilling or dry exposed superchilling conditions have an extended shelf life.

Iron deficiency anemia: a critical review on iron absorption, supplementation and its influence on gut microbiota.

Iron deficiency anemia (IDA) caused by micronutrient iron deficiency has attracted global attention due to its adverse health effects. The regulation of iron uptake and metabolism is finely controlled by various transporters and hormones in the body. Dietary iron intake and regulation are essential in maintaining human health and iron requirements. The review aims to investigate literature concerning dietary iron intake and systemic regulation. Besides, recent IDA treatment and dietary iron supplementation are discussed. Considering the importance of the gut microbiome, the interaction between bacteria and micronutrient iron in the gut is also a focus of this review. The iron absorption efficiency varies considerably according to iron type and dietary factors. Iron fortification remains the cost-effective strategy, although challenges exist in developing suitable iron fortificants and food vehicles regarding bioavailability and acceptability. Iron deficiency may alter the microbiome structure and promote the growth of pathogenic bacteria in the gut, affecting immune balance and human health.

Effect of ultrasound combined with pineapple protease treatment on the tenderness of dried shrimp.

BACKGROUND: In order to improve the tenderness of dried shrimp products as well as to reduce the hardness of the meat during the drying process, shrimp were treated with ultrasound combined with pineapple protease and the tenderization condition was optimized by measuring the texture and shear force of dried shrimp. In addition, the sulfhydryl content, myofibril fragmentation index (MFI) and microstructure were also examined to clarify the mechanisms of shrimp tenderization. RESULTS: The results showed UB1 group with ultrasonic power of 100 W, heating temperature of 50 °C and pineapple protease concentration of 20 U mL-1 were the optimum tenderization conditions, where shrimp showed the lowest hardness (490.76 g) and shear force (2006.35 gf). Microstructure as well as sodium dodecyl sulfate-polyacrylamide gel electrophoresis results suggested that during the tenderization process the muscle segments of shrimps were broken, degradation of myofibrillar proteins occurred, and MFI values and total sulfhydryl content increased significantly (P < 0.05) (MFI value = 193.6 and total sulfhydryl content = 93.93 mmol mg-1 protein for UB 1 group). CONCLUSION: Ultrasound combined with bromelain could be used as a simple and effective tenderization method for the production of tender dried shrimp. The best conditions were 100 W ultrasonic power, 50 °C ultrasonic temperature, and 20 U mL-1 bromelain. © 2024 Society of Chemical Industry.

Explorative study for the rapid detection of adulterated surimi using gas chromatography-ion mobility spectrometry.

Driven by economic interests, surimi adulteration has become a high-frequency issue. This study aims to assess the feasibility of gas chromatography-ion mobility spectrometry (GC-IMS) in detecting surimi adulteration. In this work, three common adulterated surimi models were established by mixing with different fish species and ratios. The fingerprints enabled a clear discrimination among different tuna surimi, and other two surimi models with different mixing ratios also showed VOCs (volatile organic compounds) differences. Results of unsupervised principal component analysis (PCA) and supervised partial least-squares discrimination analysis (PLS-DA) revealed that different types of adulterated surimi models can be well separated from each other. A total of 12, 16, and 9 VOCs were selected as the potential markers in three simulated models by PLS-DA method, respectively. Therefore, GC-IMS coupled with certain chemometrics is expected to serve as an alternative analytical tool to directly and visually detect adulterated surimi.

Comparison of freezing and heating treatment sequence on biochemical properties and flavor of swimming crabs (Portunus Trituberculatus) meat during freeze-thaw cycles.

The objective of this study was to compare the effect of freezing and heating treatment sequences on the biochemical properties and flavor of crab (Portunus trituberculatus) meat during freeze-thaw cycles. The results showed that pH, color, K and microstructure changes in the H-F group were not significant with increasing number of freeze-thaw cycles, but TVB-N values increased and WHC values decreased. However, with the increase in the number of freeze-thaw cycles, pH and WHC significantly decreased and TVB-N, L* and K values significantly increased in the C and F-H groups. Proteins were degraded in all groups, but the lower degree of degradation occurred in the H-F group. Although the total free amino acid content decreased with increasing number of freeze-thaw cycles in each group, the high content of AMP and IMP in the H-F group suggested that it still had a better flavor.

Effects of hemoglobin extracted from Tegillarca granosa on the gut microbiota in iron deficiency anemia mice.

Iron deficiency anemia (IDA) is a serious threat to the health of humans around the world. Tegillarca granosa (T. granosa) is considered as an excellent source of iron due to its abundant iron-binding protein hemoglobin. This study aimed to investigate the effects of hemoglobin from T. granosa on the gut microbiota and iron bioavailability in IDA mice. Compared to normal mice, IDA mice showed reduced microbiota diversity and altered relative abundance (reduced Muribaculaceae and increased Bacteroides). After 4 weeks of administration, hemoglobin restored the dysbiosis of the intestinal microbiota induced by IDA and decreased the Firmicutes/Bacteroidota ratio and the abundance of Proteobacteria. Analysis of the hemoglobin regeneration efficiency of mice treated with hemoglobin confirmed that hemoglobin exhibited high iron bioavailability, particularly at low-dose administration, suggesting that a small amount of hemoglobin from T. granosa markedly elevated the blood hemoglobin level in mice. These findings suggested that IDA could be alleviated by administration of hemoglobin with excellent iron bioavailability, and its therapeutic mechanism may be partially attributed to the regulation of the intestinal microbiota composition and relative abundance. These results indicated that T. granosa hemoglobin may be a promising iron supplement to treat IDA and promote the utilization of aquatic-derived proteins.

Comparative investigation of various modification methods on Trachypenaeus Curvirostris surimi gel: Gelling properties, rheological behaviors and structure characteristics.

The aim of this study was to compare the investigations of various contents of egg white protein (2.0%-8.0%, EWP), microbial transglutaminase (0.1%-0.4%, MTGase), and konjac glucomannan (0.5%-2.0%, KGM) on the gelling properties and rheological behavior of Trachypenaeus Curvirostris shrimp surimi gel (SSG), and assessed the modification mechanisms through the analysis of structure characteristics. The findings suggested that all modified SSG samples (expect SSG-KGM2.0% ) had the higher gelling properties and the denser network structure than those of unmodified SSG. Meanwhile, EWP could give SSG a better appearance than MTGase and KGM. Rheological results showed that SSG-EWP6% and SSG-KGM1.0% had the highest G' and G″, demonstrating that the formation of higher levels of elasticity and hardness. All modifications could increase gelation rates of SSG along with the reduction of G″ during the degeneration of protein. According to the FTIR results, three modification methods changed SSG protein conformation with the increasing α-helix and ß-sheet contents and the decreasing of random coil content. LF-NMR results indicated that more free water could be transformed into immobilized water in the modified SSG gels, which contributed to improve the gelling properties. Furthermore, molecular forces showed that EWP and KGM could further increase the hydrogen bonds and hydrophobic interaction in SSG gels, while MTGase could induce the formation of more disulfide bonds. Thus, compared with another two modifications, EWP modified SSG gels showed the highest gelling properties.

The mechanisms and applications of cryoprotectants in aquatic products: An overview.

Frozen storage technology has been widely used for the preservation of Aquatic products. However, ice crystals formation, lipid oxidation and protein denaturation still easily causes aquatic products deterioration. Cryoprotectants are a series of food additives that could efficiently prolong the shelf life and guarantee the acceptability of frozen aquatic products. This review comprehensively illustrated the mechanism of protein denaturation caused by the ice crystal formation and lipid oxidation. The cryoprotective mechanism of various kinds of antifreeze agents (saccharides, phosphates, antifreeze proteins and peptides) and these cryoprotective structure-activity relationship, application efficiency on the quality of aquatic products were also discussed. Moreover, the advantages and disadvantages of each cryoprotectant are also prospected. Compared with others, antifreeze peptides show higher commercial and application values. While, lots of scientific research works are still required to develop novel antifreeze agent as a versatile ingredient with commercial value, applicable in the aquatic products preservation industry.

Effect of two-stage heating treatment on physicochemical properties of shrimp (Penaeus vannamei) meat.

BACKGROUND: Changes in the physicochemical properties of shrimp meat treated with two-stage heating were investigated. Currently, shrimp products in the processing process are susceptible to uneven dehydration, shrimp meat shrinkage, which results in rough and hard texture, poor chewiness, and seriously affects the edible quality as well as economic benefits. Improving the utilization value of shrimp resources, expanding its market shares, optimizing the tenderness of shrimp is the key to developing new types of fresh and ready-to-eat shrimp products. RESULTS: The results indicated that preheating at 30 °C could not affect the quality of shrimp meat significantly (P > 0.05). As the preheating temperature increased from 40 °C to 50 °C, the hardness and shear force of shrimp meat decreased due to the exposure of protein hydrophobic groups, protein aggregation and degradation, muscle fraction broken, and weight loss increase. Further increase in preheating temperature would lead to further aggregation and gelation of proteins, causing hardness and shear force increase. Besides, the results of microstructure showed that preheating at 40 °C and 50 °C could cause the shrimp muscles to become loose. CONCLUSION: This study showed that the preheating temperature ranging from 40 °C to 50 °C could effectively improve the tenderness of shrimp meat. This study might be useful for developing tenderized shrimp products in the future. © 2022 Society of Chemical Industry.

Effect of hemoglobin extracted from Tegillarca granosa on iron deficiency anemia in mice.

Iron deficiency anemia (IDA) is the most common nutritional deficiency in the world. This study was aimed to evaluate the therapeutic effects of hemoglobin from Tegillarca granosa (T. granosa) on IDA in mice. Mice were randomly divided into five groups: a normal control group, an anemia model group, a positive (FeSO4) control group, a low-dose and high-dose hemoglobin groups. After 4-week iron supplements administration, it was observed that hemoglobin at 2.0 mg iron/kg body weight had better restorative effective on IDA mice than that of FeSO4 with regard to routine blood parameters and serum biochemical indicators. Meanwhile, the IDA-caused alterations of organ coefficients and liver morphology were ameliorated in mice after hemoglobin supplementation in a dose-dependent manner. Further correlation analysis of indicators showed that serum ferritin (iron storage protein) and soluble transferrin receptor (cellular iron uptake membrane glycoprotein) were susceptible to iron deficiency, indicating possibledisorder of iron metabolism caused by IDA. And levels of serum ferritin and soluble transferrin receptor were restored after administration of hemoglobin. These findings confirmed the safety and effectiveness of T. granosa derived hemoglobin in alleviating IDA in mice, suggesting its great potential as an alternative for iron supplementation.

Study on nucleotide, myofibrillar protein biochemical properties and microstructure of freeze-dried scallop striated muscle during storage and rehydration.

The biochemical properties and microstructural changes of freeze-dried Japanese scallop (Patinopecten yessoensis) striated muscle during room temperature storage and rehydration were investigated. The results showed that the content of ATP in freeze-dried scallop muscle remained stable with no significant difference (p > 0.05). However, ATP was rapidly decomposed and AMP accumulated within 1.5 min of rehydration, and HxR and Hx were gradually produced from AMP decomposition with the extension of rehydration time. Besides, the results of chymotryptic digestion patterns demonstrated that the rod of myosin was unstable after dehydration, reflecting lower salt solubility than that of frozen-thawed scallop. In contrast, the myosin subfragment-1 (S-1) was stable, as indicated by the constant of Ca2+-ATPase activity of freeze-dried scallops throughout the storage and rehydration (p > 0.05). Furthermore, the microstructural analysis revealed that the Z line of the freeze-dried scallop was broken after dehydration process. This study might be useful for developing high-quality dehydrated scallops in the future.

Effect of acetylated distarch adipate on the physicochemical characteristics and structure of shrimp (Penaeus vannamei) myofibrillar protein.

To investigate the effect of acetylated distarch adipate (ADA) on the physicochemical properties and structure of shrimp myofibrillar protein (MP), the changes in chemical bonds, secondary structure and protein composition of shrimp MP and MP gel (MPG) were analyzed. Besides, the microstructure, water state, texture properties and water holding capacity (WHC) of MPG with different ADA additions were compared. The results showed that the shrimp MPG with 1% ADA addition had the highest breaking force and gel strength, WHC, and the densest three-dimensional network structure. The ADA had little significant effect on the secondary structure of MP and MPG. In addition, hydrogen and ionic bonds were the main chemical bonds of MP, while MPG is mainly dominated by hydrophobic and disulfide bonds. The correlation analysis of gel properties and water state of MPG showed that bound water and immobilized water had a positive effect on the gel strength.

Differentiation between fresh and frozen-thawed scallop adductor muscle as raw materials for sashimi during cold storage.

The changes of sensory and biochemical characteristics on the fresh and frozen-thawed scallop adductor muscle during storage at 4°C were discussed in this study. The Quality Index Method (QIM) scheme for evaluating scallop adductor muscle as raw materials for sashimi was proposed for the first time. The results of sensory evaluation showed that frozen-thawed scallop adductor muscle within zero to one day of refrigeration can be happily accepted by consumers, indicating the superiority of freezing for long-distance transportation, although the triangle test confirmed that there are still sensorial differences between fresh and frozen-thawed scallop adductor muscle. The microscopic observation of myofibrils extracted from scallop adductor muscle suggested that the myofibrillar protein which constitutes myofibrils has suffered some extent change due to freezing and thawing, even though the head region of myosin remained stable judging by the fact that there was no significant difference in Ca2+ -ATPase activity (p > 0.05). The changes of adenosine triphosphate (ATP) and its related compounds, and pH value during storage can be regarded as indicators to differentiate fresh and frozen-thawed scallop adductor muscle. The changes of Mg2+ -ATPase activity indicated that the interaction between myosin and actin was weakened by the freezing and thawing process. Practical Application: The QIM scheme can be used to evaluate the scallop adductor muscle as raw materials for sashimi. The mechanism of quality changes in the frozen-thawed scallop adductor muscle was discussed in combination with the destruction of myofibrils, ATP degradation and the decrease of pH value. This study has positive significance for improving the quality of frozen-thawed scallop adductor muscle by combining the changes of sensory and biochemical characteristics.

Condition-dependent adenosine monophosphate decomposition pathways in striated adductor muscle from Japanese scallop (Patinopecten yessoensis).

The purpose of this study was to confirm inosine monophosphate (IMP) generation and to clarify the decomposition pathway of adenosine monophosphate (AMP) by investigating the properties of AMP, IMP, and adenosine (AdR) decomposition enzymes in Japanese scallop (Patinopecten yessoensis). The results showed that IMP accumulated due to AMP decomposition via endogenous enzymes in scallops stored at both 4 °C and 20 °C. The AMP decomposition rate was highest in the supernatant of homogenized scallop adductor muscle, followed by the suspended solution and precipitate, while IMP could not be decomposed in scallop. The results indicated that the activity of AdR deaminase was very high, and this enzyme was involved in an intracellular process in scallop. Moreover, 1 min of heating exerted little influence on the AMP and AdR decomposition rates, while 5 min of heating induced enzyme denaturation. The IMP generation rate increased dramatically in scallop crude enzyme solution containing 5 mM ethylenediaminetetraacetic acid (EDTA). This suggests that the major pathway of AMP decomposition might change with variations in metal ion concentrations in Japanese scallop. PRACTICAL APPLICATION: IMP generation in Japanese scallop (Patinopecten yessoensis) caused by endogenous enzymes was confirmed. IMP is very important for the umami taste (a pleasant savory taste) of aquatic products. As IMP accumulation might be achieved by changing the concentration of divalent metal ions and no IMP 5'-nucleotidase activity was detected in scallop, a suitable process to produce good flavor scallops with high IMP contents might be developed.

Effects of thawing methods on the biochemical properties and microstructure of pre-rigor frozen scallop striated adductor muscle.

Postmortem biochemical properties (pH, salt solubility, Ca2+-ATPase activity, ATP-related compounds) and microstructural changes in the striated adductor muscle of pre-rigor frozen Japanese scallops (Patinopecten yessoensis) were studied after thawing and during storage at 4℃. Four thawing methods were used: running water (18℃, R); ice-water (0℃, I); air (4℃, A) and ice-saltwater (-2℃, S). The pH values and salt solubility of R group were lower than the other three thawing groups while I group was highest after thawing. However, no significant difference (P < 0.05) in Ca2+-ATPase activity were detected among 4 groups. The microstructure results indicated that the structure of I group was close to that of fresh scallop. Moreover, ATP decomposition rate was the slowest. Therefore, ice-water thawing is the best method because it induced the least changes in the biochemical properties and microstructures of scallop adductor muscle.