This study assessed the effect of boning processing method (hot vs. cold) on pork belly morphological and mechanical traits and the evolution of these traits during refrigerated storage postmortem (PM). A total of 14 crossbred pigs were slaughtered and their carcasses and bellies processed under two conditions: hot boning (n = 14, right sides of carcasses cut immediately after slaughter) and cold boning (n = 14, left sides of carcasses cut 24 h PM). Morphological and mechanical evaluations were made at 1-, 5-, 24- and 48-h PM on the hot-boned bellies, and at 24 and 48 h on the cold-boned ones. Compared to the cold-boned bellies, the hot-boned ones were shorter, wider and thicker (P < 0.01), with greater firmness (flop distance and angle) (P < 0.001) and cohesiveness (skin-fat separation) (P < 0.05 in the dorsal and central sections). At 48 h PM, hot-boned bellies had a thicker skin (P < 0.001) and softer subcutaneous fat in the dorsal-cranial and central sections (finger scores and compression textural test) (P < 0.05). Morphological and mechanical traits for hot-boned bellies confirmed an intense shortening and hardening (increased firmness and cohesiveness), and a slight yield loss from 1 to 24 h PM. From 24 to 48 h PM, there was a certain flattening in hot-boned bellies that was associated with a slight softening (reduced firmness). Although a larger sample may be needed to corroborate these findings, they demonstrate the impact of carcass processing method and refrigerated storage time on belly quality. This may be useful for the pork industry for obtaining the desired type of belly.

The process of meat postmortem aging is a complex one, in which improved tenderness and aroma coincide with negative effects such as water loss and microbial growth. Determining the optimal postmortem storage time for meat is crucial but also challenging. A new visual monitoring technique based on hyperspectral imaging (HSI) has been proposed to monitor pork aging progress. M. longissimus thoracis from 15 pigs were stored at 4 °C for 12 days while quality indexes and HSI spectra were measured daily. Based on changes in physical and chemical indicators, 100 out of the 180 pieces of meat were selected and classified into rigor mortis, aged, and spoilt meat. Discrete wavelet transform (DWT) technology was used to improve the accuracy of classification. DWT separated approximate and detailed signals from the spectrum, resulting in a significant increase in classification speed and precision. The support vector machine (SVM) model with 70 band spectra achieved remarkable classification accuracy of 97.06%. The study findings revealed that the aging and microbial spoilage process started at the edges of the meat, with varying rates from one pig to another. Using HSI and visualization techniques, it was possible to evaluate and portray the postmortem aging progress and edible safety of pork during storage. This technology has the potential to aid the meat industry in making informed decisions on the optimal storage and cooking times that would preserve the quality of the meat and ensure its safety for consumption.

This study presents a novel conservative technique to increase oral opening and overcome rigor mortis during medicolegal autopsy (MLA). The method proposes a myotomy of the temporalis and masseter muscles, taking advantage of the incisions of the cranial opening procedures, to achieve a significant oral opening (≥ 30 mm) in fresh cadavers with established rigor mortis without altering facial aesthetics. The study was performed on 48 individuals aged between 18 and 66 years (20 males and 28 females) who were autopsied at the Instituto Nacional de Patología Forense Dr. Sergio Sarita Valdez (Santo Domingo, Dominican Republic). The proposed technique not only allowed the oral access to all autopsied cadavers but also complied with current ethical standards for preserving facial aesthetics, taking into account the concerns of family members by allowing respectful viewing of the cadaver. This advancement not only contributes to the efficiency of oral autopsies but also influences public perception of forensic procedures and highlights the importance of ethical and aesthetic considerations in the context of MLAs. The proposed technique represents a significant step towards more respectful and ethical forensic practices, and offers practical advantages for a more complete and accurate assessment during MLA.

Estimation of the post-mortem interval (PMI) is mainly based on the state of body cooling, post-mortem lividity (livor mortis) and post-mortem muscle stiffness (rigor mortis). However, the time span of development of these post-mortem phenomena are influenced by a variety of factors concerning the body of the deceased and the environment in which the body is found. Subsequently, this leads to a substantial spread in upper and lower limits of PMI based on determination of the state of these phenomena. Moreover, interpretation of post-mortem phenomena like lividity, rigor and interpretation of the correction factor for Henssge\'s nomogram is subjective. For this reason, PMI estimations are often broad, possibly too broad to be helpful for answering questions which are relevant for the criminal investigation. Therefore, combining the outcome of different methods for estimating the PMI, the so-called compound method, is recommended. Supravital muscle reaction by mechanical stimulation of skeletal muscle is a less known aspect of the compound method. Here we present a series of cases series in which supravital muscle reaction contributed to a more precise estimation of the PMI.

BACKGROUND: Some environmental enrichment methods, such as occupational enrichment (OE), can improve fish growth, but little is known about its effects on fillet quality. In this study, we evaluated the effects of OE using underwater currents on different aspects of fillet quality and muscle metabolism in rainbow trout (Oncorhynchus mykiss), before and after a handling procedure (fasting). The trout were placed in groups of 30 in separate tanks in three treatments for 30 days: no artificial currents (CON), randomly fired underwater currents (RFC), and continuous underwater currents (CUC). Additionally, half of the individuals in each treatment were fasted (5 days, 45.2 °C days).
RESULTS: Slaughter weight, condition factor, and relative growth were lower in CON fish, indicating a positive effect of OE on growth. Rigor mortis, muscle pH, and muscle glycogen levels were similar among treatments, indicating no effect of OE on classical measures of fillet quality. However, significant differences were found regarding fillet colour and muscle enzymes. The fillets of RFC fish were more salmon-pink in colour, which is favoured by consumers. Also, activity levels of pyruvate kinase and glycogen phosphorylase in muscle were significantly higher in CUC fish, probably due to increased energy demands, as pumps were on continually in that treatment.
CONCLUSIONS: Overall, RFC fish seemed to have received enough stimulation to improve growth while not being excessive in terms of exhausting the animals (avoiding negative effects on muscle metabolism), whereas OE may have provided a hormetic effect, allowing fish to better adjust to fasting. © 2023 Society of Chemical Industry.

Shrimp is a popular internationally traded shellfish due to its unique taste, texture, and nutritional value. Shrimp is highly perishable because it has enough free amino acids, high moisture levels, non-nitrogenous compounds used for microbial growth, and melanosis. Shrimp spoilage after death is caused by various reasons, like autolysis (endogenous proteinases actions during shrimp storage), growth of spoilage microorganisms, ATP degradation, melanin formation, and lipid peroxidation. A microbial byproduct, total volatile basic nitrogen, is one of the major reasons for the generation of foul odors from shrimp spoilage. Shrimp freshness monitoring is crucial for market sellers and exporters. Traditional methods for estimating shrimp freshness are expensive and inaccessible to the general public. Sensors are rapid, sensitive, selective, and portable food toxins\' detection tools, devoid of expensive instruments, skilled people, sample pretreatment, and a long detection time. This review addresses shrimp spoilage causes. The mechanisms of different stages of shrimp spoilage after death, like rigor mortis, dissolution of rigor mortis, autolysis, and microbial spoilage mechanisms, are discussed. This review highlights the last five years\' advances in shrimp freshness detection sensors and indicators like colorimetric pH indicators, fluorescence sensors, electronic noses, and biosensors, their working principles, and their sensitivities. Commercially available indicators and sensors for shrimp spoilage monitoring are also discussed. A review highlighting the applications of the different sensors and indicators for monitoring shrimp freshness is unavailable to date. Challenges and future perspectives in this field are explained at the end.

BACKGROUND: Consumer interest in safeguarding animal welfare and increased demand for fresh aquatic products support the need to understand the effects of stunning methods used in aquaculture on the biochemical process affecting fish fillet quality. The present paper aimed at comparing electrical stunning (ES) and cold shock (ICE) in Salmo carpio, an Italian endemic under-investigated species. Rigor mortis evolution, fillet adenosine 5\'-triphosphate (ATP), shape, colour, pH and water holding capacity were assessed by integrating chemical and image analyses.
RESULTS: Seventy-two fish (24 fish per treatment) were stunned by ES, ICE or anaesthesia (AN, used as control), then percussively slaughtered. ES and ICE hastened rigor mortis onset and resolution (21 and 28 h post mortem) compared to AN. This was confirmed by the faster ATP degradation in ES and ICE. Fillet shape features varied during rigor mortis, according to the stunning method, with the perimeter showing irreversible variation in ES and ICE groups. Initial circularity was recovered only in AN, while ICE and ES fillets showed significantly different values, between 0 and 192 h.
CONCLUSIONS: ES is a promising stunning technique for S. carpio, but parameters should be optimized, because of the adverse effect on muscle activity which caused a fast pH drop, and the presence of blood spots in the fillets. Further studies are needed to understand whether fillet shape changes can interfere with filleting or fillet processing and consumer appreciation. © 2022 Society of Chemical Industry.

(1) Many biomechanical studies are performed using fresh frozen cadavers or embalmed specimens, although the biomechanical characteristics do not match the characteristics of in vivo tendons. Therefore, a fresh in vivo-like cadaver model has been introduced recently. As a limitation for studies with fresh cadavers, rigor mortis must be considered. The aim of this study was to evaluate the impact of the biomechanical properties and time of occurrence of rigor mortis in a fresh cadaver model. (2) For this study, 15 fresh porcine cadaver shoulders were used in an established biomechanical in vitro model to evaluate the onset of rigor mortis. Measurements took place at ten points of time (t1-t10) beginning 103 min post mortem (pm). The mobility of the supraspinatus tendon was measured in Newton (N) with a modified sensor-enhanced arthroscopic grasper. (3) The mean load measured at the time point t1 was 28.0 ± 11.2 N. The first significant decrease of mobility occurred 151 min post mortem (t4) at a mean load of 30.2 ± 13.7 N. From 227 min pm to 317 min pm, there was no further significant increase. (4) Tendon mobility decreases significantly within the first three hours after the killing. Therefore, reliable results can be obtained within 150 min post mortem before the onset of rigor mortis alters the biomechanical properties.

Farm animal skeletal muscle, formed through development, growth, and maturation processes, is converted to edible meat during postmortem rigor mortis and aging. Live and postmortem muscle metabolism is the phenotypic determinant of muscle characteristics and meat quality traits such as flavor and color. Meanwhile, animal muscle metabolism, originally programmed by genetic program, is modulated by feeding and environmental conditions through changes in the biosynthetic network. Metabolomics deepens our understanding of metabolisms underlying skeletal muscle growth, maturation, abnormality, and postmortem meat aging. The metabolomics approach is beneficial to explore biomarkers to monitor meat production processes and products, leading to improvements in livestock productivity and meat quality. One of the recent metabolomics findings in animal muscle could be the impact of mitochondrial activity and energy metabolisms on meat quality. The present review overviews the advances in metabolomics studies of farm animal skeletal muscle, to gain an insight into the muscle metabolisms associated with livestock production and meat quality.

Forensic dental autopsy is a fundamental procedure for the study of a death under judicial investigation in the search for postmortem (PM) information that can be compared with the antemortem (AM) data available from the cadaver. One of the major difficulties in taking postmortem evidence is the opening of the mouth, limited in many cases by the phenomenon of cadaveric rigidity or rigor mortis. The aim of this study was to evaluate the effectiveness of a new device designed to facilitate the opening of the dental arches in rigor mortis corpses. For this purpose, a sample of 30 corpses (22 men and 8 women; mean age 42.18 years and 38.75 years) from the Institute of Legal Medicine of the city of Lima (Peru) was analyzed. A forensic odontologist designed and manufactured the apparatus and carried out the sample analysis process. The initial and maximum measurements of oral cavity opening were recorded and a paired Student\'s t-test was applied to observe the difference between these initial and maximum measurements obtained (p < 0.05). The results showed that the average oral opening obtained with the new appliance was 43.83 ± 3.62 mm, with an average initial opening of 6.49 ± 3.04 mm (p < 0.001). The efficacy was similar in men and women (maximum opening M: 51.70 mm - F: 53.00 mm). In 29 of the 30 carcasses studied (96.7%) an opening greater than 40 mm was obtained, the latter being a minimum measurement sufficient to access the oral cavity. The efficacy of this new instrument for oral autopsy purposes is highlighted, since it does not cause destruction of the soft tissues and allows the correct manipulation of the oral structures present.