Potential of fluorescence fingerprints for fish meat authentication: Differences in freshness evaluation in white and dark meat at frozen state.

As dark meat has a faster deterioration rate and its unintentional mixing occurs during processing, it is crucial to know the status and freshness indicators of dark meat to ensure fishery product quality. In this method, fluorescence fingerprints (FFs) was applied as a rapid and noninvasive quality authentication method to determine differences between white and dark meat in the evaluation of freshness indicators at frozen state. Spotted mackerel (Scomber australasicus) fish chunks with different postmortem conditions (0-40 h ice stored) were obtained and frozen.

The influence of processing sequence and frozen storage on the seasoned alaska pollack (Theragra chalcogramma) roe product quality.

The quality of seasoned products of Alaska pollack (Theragra chalcogramma) roe declined dramatically during frozen storage. This research investigated the effects of processing sequence and frozen storage period on seasoned Alaska pollack roe product quality. In addition, the relationship between mechanical properties and protein composition of ovary membrane and eggshell was discussed.

Effects of tyndallization temperature on the sterility and quality of kamaboko.

In this study, kamaboko gels were tyndallized at various temperatures and sterilization efficiency and impact on quality parameters were assessed. The microbiological, physical, and chemical properties of kamaboko gels were determined throughout the tyndallization process. Superior sterilization efficiency was achieved by tyndallization at a higher temperature; and the combination of heat-induced germination and thermal inactivation of spores was proposed as the main reason.

Rapid noninvasive monitoring of freshness variation in frozen shrimp using multidimensional fluorescence imaging coupled with chemometrics.

Shrimp is one of the most delicious and popular food commodities worldwide due to its exceptional taste and characteristics. Freshness is considered as a key factor for shrimp consumers because freshness has a significant relationship with taste and shelf-life of shrimp. However, post-mortem metabolism of shrimp differs from that of fish as they are highly susceptible to post-harvest quality loss, and it is hard to distinguish the freshness variation of shrimp at frozen state instantly.

A novel and simple non-thermal procedure for preparing low-pH-induced surimi gel from Alaska pollock (Theragra chalcogramma) using glucose oxidase.

The aim of this study was to develop a novel and simple non-thermal method for preparing a low-pH-induced surimi gel from Alaska pollock (Theragra chalcogramma). To this end, effect of glucose oxidase (GOD) on gelation properties of the surimi with added 5% glucose was investigated. The surimi containing glucose was blended with 0%-3.

Changes in quality properties and tissue histology of lightly salted tuna meat subjected to multiple freeze-thaw cycles.

The influence of various freeze-thaw cycles on the physicochemical and histological properties of lightly salted tuna meat was studied. Enhanced water-holding capacity and springiness were obtained in the salted samples even after repeated freezing-thawing, which was ascribed to the modifications in tissue microstructure, ice crystal morphology, and protein properties. Intracellular and spherical ice crystals were observed in the salted meat, rather than the extracellular and large ice columns in the unsalted counterparts.

Texture enhancement of salted Alaska pollock (Theragra chalcogramma) roe using microbial transglutaminase.

The aim of our study was to improve the texture quality of salted Alaska pollock (Theragra chalcogramma) roe product using microbial transglutaminase (MTGase). Thus, the effect of 0-1.0% MTGase on the physical properties of the salted roe was assessed.

Relationship among pH, generation of free amino acids, and Maillard browning of dried Japanese common squid Todarodes pacificus meat.

Relationship among pH, generation of free amino acids (FAAs), and Maillard browning was investigated in Japanese common squid during air drying at 40 °C to prevent its discoloration. In the surface color measurement, increase in the b* value which is an indicator for Maillard browning of the dried squid was mitigated at pH 4.0-6.

Expeditious prediction of post-mortem changes in frozen fish meat using three-dimensional fluorescence fingerprints.

The present study was conducted to characterize fluorophores in the fish body using three-dimensional fluorescence fingerprints (3D-FFs) and to utilize these 3D-FFs obtained from frozen horse mackerel (Trachurus japonicus) fillets to predict early post-mortem changes. Alive fish were sacrificed instantly, preserved in ice until 2 days, and then filleted, vacuum packed, and frozen. Subsequently, 3D-FFs of the frozen fillets were acquired using F-7000 aided with a fiber probe.

Effect of pH and heating conditions on the properties of Alaska pollock (Theragra chalcogramma) surimi gel fortified with fish oil.

To improve the quality and functionality of emulsified surimi gels, the effect of pH and heating conditions on the properties of surimi gel fortified with fish oil was investigated. Results showed that pH conditions influenced the solubility and emulsifying properties of surimi proteins and that the gel properties were associated with the protein properties. Under direct heating, the highest gel strength was achieved at pH 8.

Changes in protein properties and tissue histology of tuna meat as affected by salting and subsequent freezing.

The effects of salting and subsequent freezing on the physicochemical and histological properties of frozen-thawed tuna meat were investigated. Salting facilitated the microstructural recovery as indicated by the decrease or disappearance of intracellular holes. The yield of the 0.

The effect of organic salts on the browning of dried squid products processed by air-drying.

To control discoloration of dried Japanese common squid (Todarodes pacificus) product, influence of 0-1% organic salts, including sodium gluconate (Na-gluconate), sodium citrate (Na-citrate), sodium phytate (Na-phytate), sodium benzoate (Na-benzoate) and sodium tartrate (Na-tartrate), on Maillard browning in the squid meat during air-drying was investigated. Changes in surface color of the dried squid were mitigated by the addition of organic salts. Organic salts also showed inhibitory effects on autolysis and generation of free amino acids (FAAs), especially arginine, in both the dried squid meat and the model solution.

Effect of emulsifying stability of myofibrillar protein on the gel properties of emulsified surimi gel.

Several kinds of emulsified surimi gels were prepared from different quality levels of Alaska Pollack surimi, and the relationship between the emulsifying stability (ES) of myofibrillar protein and the properties of the emulsified surimi gels was investigated. Fish oil emulsified into surimi gels enhanced the breaking strength, but this was decreased by denaturation of the surimi protein, and the rate of enhanced gel-forming ability with emulsification decreased with decreasing ES. Expressible drip also decreased with emulsification; however, increasing amounts of lipid in the expressible drip were separated out from the gel upon protein denaturation of the source surimi.

The influence of proteases on the browning of dried squid products processed by air-drying.

To clarify why mantle meat from Japanese common squid (Todarodes pacificus) dried products discolor dramatically when processed by air-drying, the role of endogenous protease(s) on browning during the processing of dried squid products was studied. The involvement of endogenous protease(s) in the generation of Free Amino Acids (FAAs) participating in the Maillard reaction was characterized. The browning and myosin heavy chain degradation during air-drying were obviously mitigated by the addition of metalloprotease inhibitors, especially EGTA and 1,10-phenanthroline, followed by serine proteinase inhibitor, especially PMSF.

High Arachidonic Acid Levels in the Tissues of Herbivorous Fish Species (Siganus fuscescens, Calotomus japonicus and Kyphosus bigibbus).

The lipid and fatty acid compositions in the various organs (muscle, liver, other viscera) and stomach contents of three common herbivorous fish species in Japan, Siganus fuscescens, Calotomus japonicus and Kyphosus bigibbus, were examined to explore the stable 20:4n-6 (arachidonic acid, ARA) sources. Triacylglycerol (TAG), phosphatidylethanolamine (PtdEtn), and phosphatidylcholine (PtdCho) were the dominant lipid classes, while the major FA contents were 16:0, 18:1n-9, 16:1n-7, 14:0, 18:0, 18:1n-7, and some PUFA, including ARA, 20:5n-3 (eicosapentaenoic acid, EPA), 22:5n-3 (docosapentaenoic acid, DPA), and 22:6n-3 (docosahexaenoic acid, DHA). The amounts of these fatty acids were varied among species and their lipid classes.

Textural improvement of salt-reduced Alaska pollack (Theragra chalcogramma) roe product by CaCl2.

Salt-reduced Alaska pollack roe benefits public health by decreasing NaCl intake; however, it has a poor texture with low breaking strength. This study addresses the feasibility of NaCl reduction in salted roe products, with focusing on the improvement of breaking strength using CaCl2. Salted roe products were prepared by immersing Alaska pollack roe in either NaCl solutions (3.

Freshness estimation of intact frozen fish using fluorescence spectroscopy and chemometrics of excitation-emission matrix.

The current study attempted to provide a convenient, non-invasive and time-saving method to estimate the freshness of intact horse mackerel (Trachurus japonicus) fish in a frozen state using autofluorescence spectroscopy in tandem with multivariate analysis of fluorescence excitation-emission matrices (EEM). The extracted fluorescence data from different freshness conditions were pretreated, masked and reorganized to resolve fish fluorescence spectra from overlapping signals and scattering profiles for detecting and characterizing freshness changes. The real freshness values of the examined fish samples were then traditionally determined by the hard chemical analysis using the high performance liquid chromatography (HPLC) method and expressed as K-values.

Properties of gelatin film from horse mackerel (Trachurus japonicus) scale.

Optimal conditions for extracting gelatin and preparing gelatin film from horse mackerel scale, such as extraction temperature and time, as well as the protein concentration of film-forming solutions were investigated. Yields of extracted gelatin at 70 °C, 80 °C, and 90 °C for 15 min to 3 h were 1.08% to 3.

Mechanism study of high browning degree of mantle muscle meat from Japanese common squid Todarodes pacificus during air-drying.

Mantle meat from the Japanese common squid (Todarodes pacificus) browns more than other squid meats during air-drying. The factors contributing to the browning of Japanese common squid, long-finned squid (Photololigo edulis) and bigfin reef squid (Sepioteuthis lessoniana) were studied in boiled and raw meat both before and after air-drying. Dried raw meat from the Japanese common squid browned more than dried boiled meat (b(∗) value, from 4.

Isolation and characterization of acid-soluble collagen from the scales of marine fishes from Japan and Vietnam.

Acid-soluble collagen (ASC) was successfully extracted from the scales of lizard fish (Saurida spp.) and horse mackerel (Trachurus japonicus) from Japan and Vietnam and grey mullet (Mugil cephalis), flying fish (Cypselurus melanurus) and yellowback seabream (Dentex tumifrons) from Japan. ASC yields were about 0.

Stability of the physical properties of plasticized edible films from squid (Todarodes pacificus) mantle muscle during storage.

Unlabelled: Edible films from squid mantle muscle plasticized with different plasticizers were stored at 25 °C, 50% RH before the determination of physical properties. The results showed that tensile strength significantly increased (P < 0.05) upon the storage time, especially for the film plasticized with glucose, while there was no significant change (P ≥ 0.

Effects of koji fermented phenolic compounds on the oxidative stability of fish miso.

Unlabelled: In the present study, Aspergillus oryzae-inoculated koji inhibited lipid oxidation in fermented fish paste rich in polyunsaturated fatty acids following a long fermentation period. The fermentation of koji by A. oryzae liberated several bioactive phenolic compounds, including kojic acid and ferulic acid, which were the most abundant.

Headspace volatiles along with other instrumental and sensory analyses as indices of maturation of horse mackerel miso.

Development of aroma-active compounds during fermentation in the preparation of fermented fish-meat paste product (fish miso) from horse mackerel meat was quantitatively determined and characterized by olfactometric and organoleptic assessments. The critical ripening time was estimated by quantitative and/or qualitative analyses of volatile compounds, peptides, amino acids, product color, and total phenolics of the fish miso matrix throughout fermentation. The results confirmed that the application of koji for the fermentation of horse mackerel meat to produce fish miso significantly reduced the fishy off odor and promoted the development of highly acceptable fish miso with a nutty, cheesy, and fruity aroma.

Effect of meat washing on the development of impact odorants in fish miso prepared from spotted mackerel.

Background: Miso, a fermented soybean paste prepared using koji (rice malt inoculated with Aspergillus oryzae) has been commonly used as a traditional seasoning for several centuries in East Asian countries. A miso-like fermented product was prepared using washed and unwashed meats of spotted mackerel (Scomber australasicus) with improved food functionality and aroma attributes. The evolution of aroma-active volatiles was further evaluated during the early stages of maturation.