Effects of retort conditions on ATP-related compounds in pouched fish muscle

Degradation mechanism and development of detection technologies of ATP-related compounds in aquatic products: recent advances and remaining challenges

The degradation of ATP-related compounds is an important biochemical process that reflects the freshness of aquatic products after death. There has been considerable interest in investigating the factors affecting the degradation of ATP-related compounds in aquatic products and in developing techniques to detect them. This review provides the latest knowledge on the degradation mechanisms of ATP-related compounds during the storage of aquatic products and discusses the latest advances in ATP-related compound detection techniques. The degradation mechanisms discussed include mainly degradation pathways, endogenous enzymes, and microbial mechanisms of action. Microbial activity is the main reason for the degradation of IMP and related products during the mid to late storage of aquatic products, mainly through the related enzymes produced by microorganisms. Further elucidation of the degradation mechanisms of ATP-related compounds provides new ideas for quality control techniques in raw aquatic products during storage. The development of new technologies for the detection of ATP-related compounds has become a significant area of research. And, biosensors further improve the efficiency and accuracy of detection and have potential application prospects. The development of biosensor back-end modalities (test strips, fluorescent probes, and artificial intelligence) has accelerated the practical application of biosensors for the detection of ATP-related compounds.

Assessment of black soldier fly (Hermetia illucens) larvae meal as a potential substitute for soybean meal on growth performance and flesh quality of grass carp Ctenopharyngodon idellus

A 90-day feeding trial was conducted to assess the effects of black soldier fly larvae meal (BSFLM) as a replacement for soybean meal (SM) on growth performance and flesh quality of grass carp. A total of 420 grass carp (299.93 ± 0.85 g) were randomly divided into 7 groups (triplicate) and fed 7 diets with SM substitution of 0% (SM, control), 15% (BSFLM15), 30% (BSFLM30), 45% (BSFLM45), 60% (BSFLM60), 75% (BSFLM75) and 100% (BSFLM100) by BSFLM. The growth performance of grass carp in the BSFLM75 and BSFLM100 groups were significantly lower compared to other groups (P < 0.05). The mid-gut villus height was the lowest in the BSFLM100 group (P < 0.05). Muscle nutritional value was improved due to increased DHA (docosahexaenoic acid), EPA (eicosapentaenoic acid), total HUFA (highly unsaturated fatty acids) and glycine levels, and reached the optimum in the BSFLM100 group (P < 0.05). According to the results of principal component analysis and weight analysis of muscle texture and body color, all the BSFLM diets except BSFLM15 could improve muscle texture and body color and reached the optimum level in the BSFLM100 group. Muscle drip loss and hypoxanthine content were the lowest and muscle antioxidant capacity was the highest in the BSFLM75 group, and water- and salt-soluble protein contents reached the optimum level in the BSFLM60 group (P < 0.05). Dietary BSFLM significantly reduced muscle fiber area and diameter, and increased muscle fiber density and the proportion of small fiber (diameter <20 μm) (P < 0.05). Additionally, sarcomere lengths in the BSFLM75 and BSFLM100 groups were significantly higher than that in the SM group (P < 0.05). The mRNA relative expression levels of MyoD, Myf5, MyHC and FGF6b were remarkably up-regulated at an appropriate dietary BSFLM level (P < 0.05). In conclusion, BSFLM could replace up to 60% SM without an adverse effect on growth performance and improve the flesh quality of grass carp. The optimum levels of dietary BSFLM were 71.0 and 69.1 g/kg diet based on the final body weight and feed conversion ratio. The flesh quality was optimal when dietary SM was completely replaced with BSFLM (227 g/kg diet).

Mechanism of Inosine Monophosphate Degradation by Specific Spoilage Organism from Grass Carp in Fish Juice System

Microbial growth strongly affects the quality and flavor of fish and fish products. This study aimed to explore the role and function of grass carp-borne microorganisms in the degradation of inosine monophosphate (IMP) related compounds in a fish juice system during chill storage (4 °C. Prokaryotic transcriptomic analysis was used to explore the microbial contribution to metabolic pathways and related enzymes. The degree of microbial contribution was verified by the activity of enzymes and metabolite content. Collectively, there were multiple IMP relative product degradation pathways. A. rivipollensis degraded IMP by producing 5'-nucleotidase (5'-NT) while S. putrefaciens degraded IMP mainly by alkaline phosphatase (ALP). Hypoxanthine (Hx) was degraded to uric acid (Ua) induced by P. putida and S. putrefaciens mainly with producing xanthine oxidase (XOD), while A. rivipollensis almost could not produce XOD. This work can used as a guide and provide basic knowledge for the quality and flavor control of aquatic products.

Assessment and Prediction of Fish Freshness Using Mathematical Modelling: A Review

Fish freshness can be considered as the combination of different nutritional and organoleptic attributes that rapidly deteriorate after fish capture, i.e., during processing (cutting, gutting, packaging), storage, transport, distribution, and retail. The rate at which this degradation occurs is affected by several stress variables such as temperature, water activity, or pH, among others. The food industry is aware that fish freshness is a key feature influencing consumers’ willingness to pay for the product. Therefore, tools that allow rapid and reliable assessment and prediction of the attributes related to freshness are gaining relevance. The main objective of this work is to provide a comprehensive review of the mathematical models used to describe and predict the changes in the key quality indicators in fresh fish and shellfish during storage. The work also briefly describes such indicators, discusses the most relevant stress factors affecting the quality of fresh fish, and presents a bibliometric analysis of the results obtained from a systematic literature search on the subject.

Effect of different drying methods on free amino acid and flavor nucleotides of scallop (patinopecten yessoensis) adductor muscle

The effects of hot air drying (HAD), vacuum hot air drying (VHAD), microwave drying (MWD), and vacuum freeze drying (VFD) on free amino acids (FAAs) and flavor nucleotides in scallop adductor muscle (SAM) were studied. The liquid chromatography and multidimensional infrared spectroscopy (MM-IR) were used. Compared with fresh SAM, the main FAAs were glycine, alanine, arginine, and glutamic acid in dried SAM. The total FAAs content in VFD group was 1.40-1.90 times of the other group. The umami taste nucleotides (IMP and AMP) content in the VFD and MWD groups was significantly higher than that in HAD and VHAD groups. Equivalent umami concentrations were found: VFD > MWD > VHAD > HAD. MM-IR analysis was an efficient method for identifying taste components. The results revealed FAAs and flavor nucleotides and the mutual adjustment of compounds were related to drying method, and VFD was preferred for taste substance retention in scallops.

Change Regularity of Taste and the Performance of Endogenous Proteases in Shrimp (Penaens vannamei) Head during Autolysis

This study evaluated the food safety and proximate composition of shrimp head (SH). Potentially toxic elements in SH were below European Union legislation limits. SH had a high content of tasting amino acids (sweet and umami amino acids was 57%) and a high content of functional amino acids (essential amino acids was 37%). Moreover, the changes of flavor and key umami molecules in SH were studied by sensory evaluation, electronic tongue, electronic nose, automated amino acid analyzer, and high performance liquid chromatography (HPLC). The results showed that the significant difference of flavor in SH happened during autolysis. SH with autolysis had the best umami taste at 6 h, which may result from the synergistic work of free amino acids and nucleotide related compounds. Additionally, the performance of endogenous proteases in SH was investigated to efficiently analyze autolysis. The optimum pH and temperature of endogenous proteases in SH were 7.5 and 50 °C, respectively. The autolysis of SH depends on two endogenous proteases (~50 kDa and ~75 kDa). These results suggest that the formation of flavor in SH during autolysis can be controlled, which could provide guidance for SH recycle. SH could consider as one of the food materials for producing condiments.

Innovative Seafood Preservation Technologies: Recent Developments

Fish and fishery products are among the food commodities of high commercial value, high-quality protein content, vitamins, minerals and unsaturated fatty acids, which are beneficial to health. However, seafood products are highly perishable and thus require proper processing to maintain their quality and safety. On the other hand, consumers, nowadays, demand fresh or fresh-like, minimally processed fishery products that do not alter their natural quality attributes. The present article reviews the results of studies published over the last 15 years in the literature on: (i) the main spoilage mechanisms of seafood including contamination with pathogens and (ii) innovative processing technologies applied for the preservation and shelf life extension of seafood products. These primarily include: high hydrostatic pressure, natural preservatives, ozonation, irradiation, pulse light technology and retort pouch processing.

Estimating freshness of ice storage rainbow trout using bioelectrical impedance analysis

This study aimed to evaluate the freshness of ice stored rainbow trout by bioelectrical impedance measurements. Rigor mortis, ATP-related components, K-value, and hardness of rainbow trout muscle during storage were monitored along with impedance. The results showed that the progress of rigor mortis was accompanied by an increase in impedance. Impedance kept decreasing even in rigor state, and during the gradual resolution of rigor mortis with impedance change upon storage of fish was biphasic (r = -0.944, p < .01). Thus, when impedance decreased close to the lowest value, K-value was only about 61.57 ± 0.52%, but still exhibited a high pertinence (r = -0.959, p < .01). A gradual decrease of the hardness of fish muscle upon storage of fish showed a close correlation (r = 0.981, p < .01) with impedance decrease. These results suggested that the impedance measurement has a great potential for predicting the freshness of the rainbow trout during ice storage.

Comparison of quality and nutritional attributes of pond-cultured and container-cultured snakehead (Channa argus argus) fillets after being boiled, fried, and baked

The objective of this study was to compare the quality and nutritional attributes of snakehead (Channa argus argus) fillets (cultured in ponds and containers) after being heated (boiling, frying, and baking). The results revealed that there were few differences in quality (flavor, color, and texture) and nutritional attributes (content of amino acid, dipeptidyl peptidase IV (DPP-IV) and angiotensin I-converting enzyme (ACE) inhibition activity, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity) of snakehead fillets obtained from two cultured modes. Container-cultured samples exhibited more beneficial effects on flavor (more esters) and bioactivity (ACE inhibition and DPPH scavenging activity) than pond-cultured. Frying increased flavor attributes but decreased nutritional value of fish. Boiling was an effective heating method for increasing quality and nutritional attributes of container-cultured snakehead fish. Generally, the container-cultured mode was applicable for culturing snakehead without decreasing quality and nutritional attributes, which deserved more attention. PRACTICAL APPLICATION: The study provided information about the differences of quality properties (flavor and texture) and nutritional attributes (bioactive functions of simulate-digested products) of pond-cultured and container-cultured snakehead fish after being heated. The results will provide some potential values for the application of container-cultured technology.

The mechanism for improving the flesh quality of grass carp (Ctenopharyngodon idella) following the micro-flowing water treatment using a UPLC-QTOF/MS based metabolomics method

The micro-flowing water system can improve the flesh quality of freshwater fish using the traditional pond farming method. However, the mechanism of this phenomenon has not yet been explored. This study intends to examine the changes of metabolites in freshwater fish after treatment with the micro-flowing purification system (MFPS). The UPLC-QTOF/MS based metabolomics method was utilized to screen the metabolites and predict the major possible metabolic pathways after MFPS treatment. There were 377 types of metabolites identified in the fish muscle, of which 54-71 represented significant different metabolites identified during different stages of MFPS treatments. The main mechanism of MFPS treatment in improving the quality of grass carp fish muscle was investigated, and the MFPS treatment was shown to improve the flesh quality and the flavor of grass carp fish muscle. This study could provide the theoretical basis for improving the quality of aquatic products.

Study on the Volatile Organic Compounds and Its Correlation with Water Dynamics of Bigeye Tuna (Thunnus obesus) during Cold Storage

Volatile organic compounds (VOCs) and water play a key role in evaluating the quality of aquatic products. Quality deterioration of aquatic products can produce some off-odour volatiles and can induce water content changes. However, no previous study has investigated a correlation between water dynamics and VOCs of bigeye tuna during cold storage. The changes in VOCs, water dynamics and quality attributes of bigeye tuna (Thunnus obesus) upon storage at 0 °C and 4 °C for 6 days were investigated. The results showed that the values of ATP, adenosine diphosphate (ADP), adenosine monophosphate (AMP), T₂₁ (trapped water) and the relative value of T₁ decreased (p < 0.05), while drip loss and histamine contents increased (p < 0.05), which indicated quality deterioration during cold storage. With haematoxylin and eosin (HE) staining, muscle tissue microstructure was observed. VOCs such as hexanal, heptanal, 4-Heptenal, (Z)-, pentadecanal-, 1-pentanol, 1-hexanol significantly increased, which sharply increased the content of off-odour volatiles. T₂₁ was positively correlated with 1-octen-3-ol, 1-penten-3-ol, while T₂₁ was negatively correlated with hexanal, 1-hexanol. Therefore, good correlations between water dynamics and some VOCs were detected during quality deterioration of bigeye tuna throughout cold storage.

The importance of ATP-related compounds for the freshness and flavor of post-mortem fish and shellfish muscle: A review

ATP degradation is one of the most important biochemical changes in the post-mortem muscle of fish and shellfish. This process has long been recognized as an accurate way to evaluate freshness of fish and shellfish product. This review updates and condenses the overall history and recent advances in understanding the role of ATP-related compounds in post-mortem fish and shellfish muscle including a discussion of key analytical methods, their use as a freshness indicator, their roles in flavor enhancement, the factors affecting their transitions, and the possible mechanisms responsible for their impact on flavor and freshness. Moreover, some challenges and future directions for research regarding ATP-related compounds in fish and shellfish flavor and freshness are presented. With increasing consumer demands for fresh products with extended shelf life, understanding the relationships between ATP-related compounds and their involvement in the freshness and umami taste is a prerequisite for assuring the high quality of fish and shellfish.

Identification of the distribution of adenosine phosphates, nucleosides and nucleobases in royal jelly

Nucleotides, nucleosides and nucleobases play a greater role in the physiological activity of organisms which are highly present in royal jelly (RJ). The objective of the present study is to develop a HPLC method to simultaneous determine nucleotides, nucleosides and nucleobases in RJ and access them in fresh and commercial RJ samples. The LOD and LOQ were 12.2-99.6 μg/L and 40.8-289.4 μg/L, respectively with nearly 100.9% recoveries. Except uric acid, all other compounds were found in RJ samples. Significant difference in the average content of compounds in fresh (2682.93 mg/kg) and commercial samples (3152.78 mg/kg) were observed. AMP, adenosine and adenine were found predominant in all the samples. Significant higher levels of ATP, ADP and AMP was seen in fresh RJ samples, and IMP, uridine, guanosine, and thymidine was seen in commercial RJ samples. The investigated compounds can be used as indexes for assessment RJ freshness and quality.

Online cleanup of accelerated solvent extractions for determination of adenosine 5'-triphosphate (ATP), adenosine 5'-diphosphate (ADP), and adenosine 5'-monophosphate (AMP) in royal jelly using high-performance liquid chromatography

Determination of the levels of adenosine 5'-triphosphate (ATP), adenosine 5'-diphosphate (ADP), and adenosine 5'-monophosphate (AMP) in royal jelly is important for the study of its pharmacological activities, health benefits, and adenosine phosphate degradation. In this study was developed a novel method to determine ATP, ADP, and AMP levels in royal jelly using accelerated solvent extraction (ASE) followed by online cleanup and high-performance liquid chromatography (HPLC) with diode array detection (DAD). The optimum extraction conditions were obtained using an 11 mL ASE cell, ethanol/water (5:5 v/v) as the extraction solvent, 1500 psi, 80 degrees C, a 5 min static time, and a 60% flush volume. Optimum separation of the three compounds was achieved in <25 min using a Waters XBridge Shield RP18 column with 0.05 mol L(-1) NH(4)H(2)PO(4) (pH 5.70) and acetonitrile as the mobile phase. Detection was performed at 257 nm. The method was sensitive (LOD <or= 0.32 mg L(-1)), repeatable (RSD <or= 4.5%), accurate (recovery rates of 87.6-94.2% with RSD <or= 5.4), and precise (intraday RSD <or= 8.5%, interday RSD <or= 3.4%). The ASE extraction procedures developed here were compared with the classical adenosine phosphate extraction procedures (perchloric acid). The results indicate that the two techniques are similar in terms of recovery and reproducibility, but when other factors such as extraction time, environmental protection, and worker's health are considered, ASE is preferable to the classical extraction method. With this ASE-HPLC method, a minisurvey of ATP, ADP, and AMP levels in 15 samples of royal jelly of different origins was performed. Sample results indicated that the AMP concentration was 24.2-2214.4 mg kg(-1), whereas ATP and ADP were not detectable or present only at low levels.