Wheat bran (WB) is a rich source of phenolic compounds (PCs) with antioxidant capacity (AOX). Approximately 90% of these PCs are bound to the cell wall matrix, which limits their bioavailability. Fermentation with Saccharomyces cerevisiae is an effective strategy to release these bound phenolics. This study aimed to evaluate the effect of fermentation on the release of bound PCs in WB and their AOX during an in vitro digestion system. WB was fermented with Saccharomyces cerevisiae for 2, 4, and 6 days and subsequently subjected to simulated digestion. Free PCs were extracted with methanol, while bound PCs were obtained through alkaline hydrolysis. Total PCs were quantified using the Folin–Ciocalteu method, and AOX was assessed through DPPH, TEAC, and FRAP assays. The content of bound PCs significantly increased after fermentation (p < 0.05): 30.24 ± 0.06 mg GAE/g (day 2), 27.18 ± 0.40 mg GAE/g (day 4), and 28.41 ± 0.40 mg GAE/g (day 6), compared with unfermented WB (7.7 ± 0.21 mg GAE/g) (p < 0.05). AOX was notably enhanced; DPPH reached its peak on day 4 (47.38 ± 0.07 µmol TE/g) (p < 0.05). TEAC was highest on day 2 (26.20 ± 0.43 µmol TE/g) compared with the control (20.14 ± 0.22 µmol TE/g) (p < 0.05) and FRAP showed a slight improvement on day 6 (57.38 ± 0.10 µmol TE/g) relative to the control (56.22 ± 0.13 µmol TE/g) (p < 0.05). Fermentation with Saccharomyces cerevisiae promotes the release of bound PCs in WB and enhances its AOX, highlighting its potential as a functional food ingredient.

Fish represent one of the most perishable food groups. Therefore, it is important to find viable alternatives that contribute to the preservation of quality and increase the shelf life of fishery products, and one alternative is to use natural extracts with antimicrobial activity. The objective of this study was to determine the effect of a natural extract prepared with garlic (NGE) on the quality and shelf life of tilapia fillets stored on ice for 18 days. For this purpose, NGE was prepared by homogenizing peeled garlic cloves with distilled water, which were then centrifuged to obtain the extract (NGE); then, the fish fillets were immersed in the extract and were coated in NGE. The fillets with NGE were packed in high-density polyethylene bags and stored in crushed ice for 18 days. The adenosine 5′-triphosphate (ATP) and degradation products, K-value, color, texture, water holding capacity, pH, total mesophilic count, and total volatile bases (TVB-N) were monitored during storage. The ATP content, K-value, pH, total microbial count, and TVB-N changed with respect to ice storage time, and the results between fillets with NGE and control fillets differed. In conclusion, the application of NGE increased the shelf life of fillets stored on ice by 6 days, obtaining a shelf life of 18 days on ice, which shows its potential to improve the utilization of the species.

Fishery products are highly perishable; therefore, effective preservation strategies are essential to maintain their freshness, quality, and shelf life. One promising approach involves the use of edible coatings formulated with natural extracts, such as muicle (Justicia spicigera). This study evaluated the effect of a muicle–chitosan edible coating on the physical, chemical, and microbiological quality of cazon fish (Mustelus lunulatus) fillets stored in ice for 18 days. The muicle extract was obtained by macerating dried leaves for 48 h, and its antibacterial activity was subsequently assessed. A control group (C) and three treatments—muicle extract (ME), chitosan (CH), and a combined muicle–chitosan coating (MECH)—were applied and monitored throughout the storage period. Quality parameters, including pH, colour, water-holding capacity (WHC), texture, total volatile basic nitrogen (TVB-N), and mesophilic microbial counts, were evaluated. The muicle extract exhibited antibacterial activity, with MIC and IC₅₀ values of 3.01 ± 0.73 and 204.56 ± 20.23 µg/mL against Shewanella putrefaciens, and 0.10 ± 0.07 and 118.09 ± 14.51 µg/mL against Listeria monocytogenes, respectively. Treatments of ME, CH, and MECH significantly improved (p < 0.05) the quality of fillets by reducing TVB-N, pH, and microbial load compared to the control. In conclusion, the muicle extract demonstrated antibacterial potential and, either alone or in combination with chitosan, effectively preserved the physical, chemical, and microbiological quality of cazon fillets during ice storage.

In recent years it has been pointed out that the feed of farmed fish has an effect on the quality of the final product. Therefore, this study evaluated the effect of fishmeal (FM) replacement by a mixture of plant protein (MPP) on the development of rigor mortis of tilapia (Oreochromis niloticus). One hundred and twenty fish at an initial average weight of 123 ± 6.3 g were fed with three extruded isonitrogenous and isolipidic 6.2% crude lipids experimental diets, in which FM were replaced by 0% (D0), 50% (D50), and 100% (D100) of MPP (soybean meal, corn meal, wheat meal, and sorghum meal). A reference diet (DC) containing FM as the main protein source was used as a control. The fish were divided into triplicate groups per dietary treatment. The experiment was conducted in a tank system at 26.8°C water temperature for 67 days. The chemical composition of experimental diets and muscle were determined. The glycogen, adenosine 5′-triphosphate (ATP) and related compounds, pH, shear force, and rigor index (RI%) were monitored during storage on ice for 48 h. The results indicated that FM replacement affected (p≤0.05) the muscle composition, where the fish fed with D100 presented the higher content of lipids and ash. Fish fed with D0 and DC presented a more pronounced onset of rigor mortis and also showed a higher IR%, a lower content of glycogen, ATP, adenosine 5′-diphosphate (ADP), adenosine 5′-monophosphate (AMP), pH, and shear force. The changes in chemical composition of muscle and other parameters evaluated indicated that FM replacement increases energy reserves (glycogen, ATP, ADP, and AMP) which delayed the onset of rigor mortis, as well as a lower pH and shear force in the muscle of tilapia. Therefore, the substitution of FM by MPP could contribute to delaying the onset of rigor mortis and with this, the quality and shelf life of tilapia could be increased.

The lion’s paw scallop (Nodipecten subnodosus) is a commercially valuable pectinid whose postharvest quality strongly depends on storage and handling conditions. This study investigated the combined effects of seasonality, postmortem time, and storage temperature on energy metabolism in the adductor muscle, focusing on metabolites associated with rigor mortis and freshness. Adult scallops (~10 cm shell height) were harvested in four seasons (spring, summer, autumn, winter), transported under commercial conditions for approximately 2 h, and stored at 0, 5, and 10 °C for 48 h. Muscle samples were collected every 8 h and analyzed for ATP, ADP, AMP, glycogen, arginine phosphate (Arg-P), and free arginine using HPLC and enzymatic assays. In addition, the adenylate energy charge (AEC) was determined in freshly harvested and post-transport specimens. Initial ATP concentrations ranged from 4.2 to 6.5 µmol/g, with higher levels in winter, while Arg-P varied from 3.1 to 4.8 µmol/g. Seasonality significantly influenced all metabolites except arginine, and transport markedly reduced ATP and AEC, particularly in spring and autumn. Storage at 0 °C resulted in rapid ATP depletion (3.0 µmol/g), indicating accelerated energy collapse. In contrast, scallops stored at 5 and 10 °C maintained ATP levels above 2.5 µmol/g for up to 24 h, delaying rigor mortis, reducing postmortem contraction, and preserving muscle texture and appearance. Overall, these findings demonstrate that moderate refrigeration represents a physiologically suitable and technologically advantageous strategy to optimize scallop postharvest handling, extend shelf life, and enhance product quality for the fresh seafood market.

The present study evaluated the effect of ice storage on the freshness and quality of bullfrog (Lithobates catesbeianus) leg muscle. Biochemical, chemical, physical, and microbiological changes during 24 days of storage were analyzed. A rapid degradation of ATP into its intermediates (AMP, IMP, inosine, and hypoxanthine) was observed, with a significant increase in K-index (6.78% to 79.33%) and hypoxanthine concentration (3.93 ± 0.87 µmol/g), indicating a progressive reduction in freshness. The pH initially decreased due to post-mortem glycolysis but subsequently increased due to microbial activity and protein degradation. Volatile basic nitrogen (TVB-N) content increased significantly, reaching 27.36 mg/100 g, reflecting protein breakdown. A loss of texture was recorded, with a reduction in muscle firmness from 21.93 ± 1.36 Nw to 10.87 ± 1.08 Nw. Microbiological analyses showed an increase in bacterial load, with mesophiles and psychrophiles reaching 6.75 and 6.45 log CFU/g, respectively. These results indicate that the freshness and quality of bullfrog leg under ice storage remain within acceptable limits until day 18, but its quality and freshness decrease significantly toward the end of the study period.