The effect of storage conditions on the hygiene and sensory status of wild boar meat

A systematic mapping review of links between handling wild meat and zoonotic diseases

1.Hunting, trade, and consumption of wildlife present a serious threat to global public health as it places humans in close contact with zoonotic pathogens.2.We systematically mapped the literature on wild meat handling and zoonotic disease transmission (1996-2022) using the online database Web of Science and Google search engine and identified 6229 articles out of which 253 were finally selected for use in our mapping review; 51 of these provided specific information regarding transmission risks.3.The reviewed studies reported 43 zoonotic pathogens (17 bacteria, 15 viruses, and 11 parasites) that could pose a potential risk to human health.4.Sixteen hygienic and sanitary behaviours were described in the reviewed studies. Disease surveillance was the most frequent. Most of the surveillance studies were carried out in Europe and were less common in the tropics.5.To inform policy and practical actions effectively, it is imperative to broaden our understanding of how various mitigation behaviours can be employed to minimize the risk of transmission.

Wild boar captured in a large corral-style trap or hunted: preliminary comparison of meat quality traits

The management and numerical control of wild boars mainly depend on hunting practices, even if other alternative strategies such as the use of traps and cages can be adopted. There is little information available on the quality of captured wild boar meat. The aim of this study was to evaluate the meat quality of wild boars captured with a large corral-style trap compared to still hunting and collective hunting methods. Longissimus dorsi samples were collected from 60 wild boars, 20 of which were obtained by trapping, 20 by still hunting, and 20 by collective hunting. The animals considered were 32 males and 28 females, weighing between 42 and 68 kg. Muscle pH has been recorded at 1, 24, and 48 hours post-mortem. Furthermore, after 24 hours, color, drip loss, cooking loss, and Warner-Bratzler shear force were also evaluated. Trapping with large enclosures such as corral-style traps, if properly managed, does not seem to adversely affect the quality traits of wild boar meat, which were found to be like those obtained by the still hunting method.

Microbiological Quality of Deer Meat Treated with Essential Oil Litsea cubeba

Simple Summary

Consumers are increasingly turning to healthier and less environmentally harmful diet alternatives. Game is an ideal food from this point of view because it represents meat with a high protein content, low fat content, a favourable composition of fatty acids and minerals. Various types of packaging are often used to extend the shelf life of meats. Packaging can be combined with natural antimicrobials, such as various plant extracts and essential oils, for better effectiveness. Little is known about the microbial quality and preservation of deer meat. In the present study, deer meat was treated with essential oil from Litsea cubeba 0.5 and 1.0% concentration in rapeseed oil combined with aerobic and vacuum packaging. The meat was evaluated for microbiological quality (counts and microbiota identification) for 20 days under refrigerated storage. Our result show that Litsea cubeba essential oil is an effective natural agent against deer meat spoilage bacteria.

Abstract

The present study aimed to evaluate deer meat microbiological quality when treated with essential oil (EO) from Litsea cubeba (dissolved in rapeseed oil at concentrations 0.5 and 1%), in combination with vacuum packaging during 20 days of storage of meat at 4 °C. Total viable counts (TVC), coliforms bacteria (CB), lactic acid bacteria (LAB) and Pseudomonas spp. were analysed at day 0, 1, 5, 10, 15 and 20. MALDI-TOF MS Biotyper technology was applied to identify microorganisms isolated from meat. The highest number of TVC at the end of the experiment was 5.50 log CFU/g in the aerobically packaged control group and the lowest number of TVC was 5.17 log CFU/g in the samples treated with 1.0% Litsea cubeba EO. CB were not detected in the samples treated with 1.0% Litsea cubeba EO during the entire storage period. Bacteria of the genus Pseudomonas were detected only in the aerobically and vacuum packaged control group. The highest number of LAB was 2.06 log CFU/g in the aerobic control group, and the lowest number of LAB was 2.01 log CFU/g in the samples treated with 1.0% Litsea cubeba EO on day 20. The most frequently isolated bacteria from deer meat were Pseudomonas ludensis, Pseudomonas corrugata, Pseudomonas fragi, Bacillus cereus, Staphylococcus epidermidis and Sphingomonas leidyi.

Changes in chilled beef packaged in starch film containing sea buckthorn pomace extract and quality changes in the film during super-chilled storage

This study aimed to evaluate the effects of super-chilled storage (-1.3 °C) combined with starch film packaging containing different contents of sea buckthorn pomace extract (SSF, 0, 1, 2, and 3%, w/w) on the quality of chilled beef. The release kinetics, microstructure, and mechanical properties of the film were also measured to investigate its suitability for super-chilled storage. The results of the meat quality assessment showed that the L*, a*, and sensory evaluation values of the SSF-3% samples were significantly higher (P < 0.05), and the pH, b*, thiobarbituric acid reactive substance (TBARS), total volatile basic nitrogen (TVB-N), and total viable count (TCA) were significantly lower (P < 0.05) than the SSF-0%. The release of SBP from the SSF film was controlled by diffusion. Furthermore, SSF-3% was found to have a compact microstructure and good mechanical properties at the end of the super-chilled storage. The results demonstrated that SSF is an effective packaging material for beef at super-chilling temperatures.

Improving Hunted Wild Boar Carcass Hygiene: Roles of Different Factors Involved in the Harvest Phase

Game meat production strongly differs from that of other meats, as peculiar factors present in the field and in the steps prior to transfer to a game-handling establishment can influence the hygiene of the carcasses and, therefore, of the meat. The effects of such factors were considered in hunted wild boars based on the main hygienic criteria adopted in meat processing. Environmental, animal, and hunting conditions were studied during two selective hunting seasons in Central Italy. A total of 120 hunted wild boar carcasses were sampled after the skinning process and analyzed for aerobic colony count, Enterobacteriaceae count, and Salmonella spp. isolation. The calculated mean values for aerobic colony and Enterobacteriaceae counts were 3.66 and 2.05 CFU/cm2, respectively, in line with the limits set for the meat of other ungulates by EU legislation. Salmonella spp. showed a prevalence of 2.5% (IC 95%: 1.72-3.27%). Statistical analysis of the data performed with the AIC criterion showed that the main parameter to consider for improving the hygienic level of carcasses is to reduce the time in the refrigerator before skinning, followed by hunting on cold days (<10 °C) without rain, hunting animals <60 kg, and reducing the time between shooting and evisceration.

The influence of age and sex on carcass characteristics and chemical composition of the longissimus thoracis et lumborum muscle in wild boars (Sus scrofa)

The aim of this study was to determine the influence of age and sex on carcass characteristics and the chemical composition of the longissimus thoracis et lumborum (LTL) muscle in wild boars (Sus scrofa). Carcass quality parameters varied significantly depending on age and sex, whereas the protein and collagen contents in the muscle were affected by animal age. The carcasses of male yearlings and adults were characterised by the highest processing suitability, which can be attributed to the highest percentage of lean meat in the carcass and a moderate fat and bone content. A higher fat content was found in carcasses of females from all age groups, and a lower bone content was found in yearlings and adult females. The protein content was the highest in the LTL muscle of adult boars, and the collagen content was the highest in piglets; thus, the chemical composition of the muscle was most desirable in adult wild boars and least desirable in piglets.

Microbiological Changes in Meat and Minced Meat from Beavers (Castor fiber L.) during Refrigerated and Frozen Storage

This study aims to evaluate the microbiological status, pH, and water activity of European beaver meat to establish its shelf-life and microbiological safety. In this study, the microbiological profiles of meat and minced meat obtained from the carcasses of beavers were investigated. Microbial evaluation of the chilled meat was performed within 24 h after hunting, on the 7th day and 14th day, and the evaluation of the frozen meat was made during the 11th week of storage. Meat samples were analysed for total viable count (TVC), psychrotrophic bacteria count (PBC), Enterobacteriaceae count (EBC), Escherichiacoli count (EC), total staphylococcal count (TSC), lactic acid bacteria count (LABC) and total yeast and mould counts (TYMC). Tests for the presence of pathogenic bacteria from the genus Salmonella and Listeria were also performed. Additionally, the pH and water activity were determined. The initial amount of TVC was 4.94 log CFU/g in meat samples and 4.80 log CFU/g in minced meat. After 14 days of storage, the TVC increased to 8.33 in meat samples and 8.08 log CFU/g in minced meat. Pathogenic bacteria such as Listeria and Salmonella were not found in the beaver meat tested. The microbiological state of meat stored frozen for 11 weeks was comparable to the state found in meat stored refrigerated for seven days regarding the number of microorganisms.

Wild Boar Meat as a Sustainable Substitute for Pork: A Mixed Methods Approach

Sensory analysis is unusual in sustainability research, although it can offer a neoteric aspect of nature and wild animals’ perception. The study’s objective was to identify consumers’ attitudes towards plant and animal products from wild and conventional foods and put these findings into a broader social context. A blind sensory evaluation with 80 semi-trained assessors was used, segmented by gender, age, education, income, place of origin, family status, number of children, and willingness to pay. Wild boar (Sus scrofa) was chosen as an example of an overpopulated animal species occurring in the wild, which could be considered a partial substitute for pork. Statistical testing in these blind evaluations proved that wild boar meat is not considered less tasty. Therefore, wild boar meat could represent a partial substitute, complementing pork, on which consumers are willing to spend the same amount of money. Despite the mostly indifferent sensory evaluation, focus group responses showed considerable barriers to wild food. This paper concludes that possible educational and popularizing procedures are presented, including forest pedagogy, eliminating consumers’ prejudices. A mixed-methods approach within quantitative and qualitative methodology was chosen.

Effects of Animal, Climatic, Hunting and Handling Conditions on the Hygienic Characteristics of Hunted Roe Doer (Caprelous capreolus L.)

The population of wild animals is increasing, and control strategies based on selective hunting are among the major options adopted. The game meat obtained is therefore available for controlled and certified valuable chains. The understanding of carcass contamination and the factors affecting it is therefore crucial to ensure meat safety and prolonged shelf-life. The carcass hygiene of 64 hunted wild male roe deer (Capreolus capreolus L.) was evaluated in relation to factors potentially affecting it. Aerobic colony and Enterobacteriaceae counts, as well as Salmonella spp. and Listeria monocytogenes detection, were performed. The interaction of the microbial determination with age and weight of the animals, the climate conditions, the shooting procedure, the time between the killing and the evisceration as well as the time of storage of the carcasses in refrigerated conditions before skinning, were evaluated. Neither Salmonella spp. nor Listeria monocytogenes were detected on the carcasses and the average loads detected were 3.39 ± 1.06 UFC/cm2 and 2.27± 1.11 UFC/cm2 for the aerobic colony count and Enterobacteriaceae count, respectively. The loads detected are similar to those reported by UE legislation for slaughtered species. The time of storage before skinning, the environmental temperature during hunting and the time between shooting and evisceration, associated with animal weight, affect the carcass hygiene and must be taken into careful consideration by hunters as food business operators.

Eugenol nanocapsules embedded with gelatin-chitosan for chilled pork preservation

Chilled pork is widely consumed in China. However, various contaminants during storage directly lead to a decline in the quality of chilled pork products. An extract of natural plant sources, eugenol (Eug) exerts good antibacterial and antioxidant effects. Nanometerization was used in this study to improve the insoluble and volatile characteristics of Eug. Eug nanocapsules embedded with gelatin/chitosan (Eug-Gel-CS NPs) were used to preserve chilled pork. Results indicated that Eug-Gel-CS NPs could effectively inhibit increases in the pH, total volatile basic nitrogen (TVB-N), and thiobarbituric acid-reactive substances (TBARS) of chilled pork than that of the Eug group (p < 0.05). The L* and a* values of the Eug-Gel-CS NPs group were significantly higher than those of the Eug and gelatin-chitosan (CS-Gel) groups (p < 0.05). The total number of colonies (TBC) showed that the storage period of the Eug-Gel-CS NPs group could be extended to 15 d, which was significantly different from that of the CK group (8 d) (p < 0.05). The Eug-Gel-CS NPs also effectively delayed the decline in the water- holding capacity (WHC), springiness, and cohesiveness of the chilled pork. Therefore, Eug-Gel-CS NPs exert good antiseptic, antibacterial, and antioxidative effects on preserved chilled pork.

Effect of Age and Sex on the Quality of Offal and Meat of the Wild Boar (Sus scrofa)

The goal of the study was to examine the effect of age and sex on the quality of wild boar offal and meat. A number of 32 hunt-harvested animals was assigned to groups according to age (juveniles and sub-adults) and sex. The quality of offal (liver, kidneys, heart and tongue) and m. semimembranosus was examined. The pH value of m. semimembranosus ranged from 5.45 to 5.88. The highest pH was recorded in the kidney and the liver (6.32-6.54 and 6.12-6.31). The meat in the group of juveniles was brighter (p = 0.042), yellower (p = 0.039), showed a greater drip loss (p = 0.007), cooking loss (p = 0.039), and plasticity (p = 0.028), compared to the sub-adults. The extractable fat content in the m. semimembranosus and offal (p = 0.004), and water to crude protein ratio (p = 0.033), also differed between age groups. The results of the study show different quality attributes of offal and meat of wild boars from two age groups. The obtained quality measures suggest that the culinary and technological usefulness of offal and meat from the wild boars may differ according to the age of hunted animals.

The effect of age and ultimate pH value on selected quality traits of meat from wild boar

The meat from hunted wild boar juveniles (N = 18) and yearlings (N = 17) was analysed to assess the influence of age and the ultimate pH value on selected quality traits. The analysed meat of 55.56% of the juveniles and 64.71% of the yearlings was characterised with normal pH. The pH had been measured 24 and 48 h post mortem. More cases of high ultimate pH (pHu > 5.8) and high maximal pH (about 6.2) have been noted in the meat of younger animals compared with older ones. We found no effect of pHu on the colour coordinates of analysed wild boar meat. A slight effect of age was observed for the lightness (L*) coordinate. The postmortem time was the most important factor influencing meat colour [L*, yellowness (b*), and hue angle]. A high pHu was related to lower drip loss (P = 0.001), lower percentage of free water (P = 0.036), lower cooking loss (P = 0.001), and lower plasticity (P = 0.042). The meat from juveniles showed higher plasticity than meat from yearlings. Summing up, both the pHu level and the age of wild boars may affect some qualitative patterns of meat, changing the technological usability of this raw animal product.

Mapping the dominant microbial species diversity at expiration date of raw meat and processed meats from equine origin, an underexplored meat ecosystem, in the Belgian retail

Although equine meats and their derived smoked or fermented products are popular in some regions of the world, they only form a minor fraction of the global meat consumption. The latter may explain why their associated bacterial communities have not received much attention. In the present study, 69 different samples of equine meats and meat products were investigated. The samples consisted of raw meat from horses (17 samples) and zebra (7), as well as non-fermented but smoked (24) and fermented (21) horse meat products. After purchase, all samples were stored at 4 °C and analysed at expiration date. Besides an estimation of the total microbial counts, specific attention was paid to the identification of lactic acid bacteria (LAB) and catalase-positive cocci, in particular the group of coagulase-negative staphylococci (CNS), involved, due to their technological relevance in view of the elaboration of meat products. Samples that were loosely wrapped in butcher paper instead of vacuum- or modified-atmosphere packages were also screened for pseudomonads and enterobacterial species. In total, 1567 bacterial isolates were collected, subjected to (GTG)₅-PCR fingerprinting of genomic DNA, and identified by multiple gene sequencing (based on the 16S rRNA, pheS, rpoA, rpoB, and/or tuf genes). Overall, the bacterial species diversity consisted mostly of LAB but was contingent on the type of product. Raw meat was dominated by Carnobacterium divergens, Lactobacillus sakei, Lactococcus piscium, and Leuconostoc gelidum, with zebra meat being particularly rich in lactococci. Smoked and fermented horse meat products contained mostly Lb. sakei and, to a lesser degree, Lactobacillus curvatus. In addition, several catalase-positive cocci (mostly Staphylococcus equorum), Anoxybacillus sp., Brevibacterium sp., Brochothrix thermosphacta, and the enterobacterial species Hafnia alvei were found.

Public health risks associated with hepatitis E virus (HEV) as a food-borne pathogen

Hepatitis E virus (HEV) is an important infection in humans in EU/EEA countries, and over the last 10 years more than 21,000 acute clinical cases with 28 fatalities have been notified with an overall 10-fold increase in reported HEV cases; the majority (80%) of cases were reported from France, Germany and the UK. However, as infection in humans is not notifiable in all Member States, and surveillance differs between countries, the number of reported cases is not comparable and the true number of cases would probably be higher. Food-borne transmission of HEV appears to be a major route in Europe; pigs and wild boars are the main source of HEV. Outbreaks and sporadic cases have been identified in immune-competent persons as well as in recognised risk groups such as those with pre-existing liver damage, immunosuppressive illness or receiving immunosuppressive treatments. The opinion reviews current methods for the detection, identification, characterisation and tracing of HEV in food-producing animals and foods, reviews literature on HEV reservoirs and food-borne pathways, examines information on the epidemiology of HEV and its occurrence and persistence in foods, and investigates possible control measures along the food chain. Presently, the only efficient control option for HEV infection from consumption of meat, liver and products derived from animal reservoirs is sufficient heat treatment. The development of validated quantitative and qualitative detection methods, including infectivity assays and consensus molecular typing protocols, is required for the development of quantitative microbial risk assessments and efficient control measures. More research on the epidemiology and control of HEV in pig herds is required in order to minimise the proportion of pigs that remain viraemic or carry high levels of virus in intestinal contents at the time of slaughter. Consumption of raw pig, wild boar and deer meat products should be avoided.