Consumer studies on sensory acceptability of boar taint: a review

An overview of drivers and emotions of meat consumption

Emotions are present in almost everything we do, including meat procurement, preparation and consumption. This paper examines the main drivers of this consumption, including sensory and hedonic properties, physiological needs, historical reasons and habits, social influence, ethical motives, practical aspects and other determinants, exploring the meat-related emotions as both an outcome of consumption and as consumption drivers. Emotions are affected by multiple factors relating to the context, the information provided, and the type of product. Positive emotions such as pleasure, satisfaction, proudness and joyfulness have been described in relation to meat, as well as some neutral or negative ones. To enhance positive emotions and increase meat liking, it is essential to improve animal welfare and promote a more sustainable production, focusing on nutritional and sensory quality and providing consumers with reliable information.

Marinade injection of pork as a possible technological strategy to reduce boar taint: Response and attitude of the consumer

Sensory evaluation by consumers allows validation of a solution for the food industry to overcome boar taint and market entire male pork with high levels of boar taint considered "unfit for human consumption". One possible technological strategy for improvement is the injection marination of entire male pork to help minimise the impact of boar taint and improve its marketability. The responses of 120 regular pork consumers, to entire males with high levels of boar taint and castrated pork, both injection-marinated, were evaluated. The results showed a similar response between entire and castrated male pork regardless of sex, and the detection of unpleasant odours and flavours (as farm/animal), thus offering a new alternative to the pork sector to mask the boar taint and revalue this pork. However, it was observed that consumer information on castration and animal welfare of entire male pork is scarce, and it is important to increase their knowledge so that they can place a value on this technological strategy with entire male pork and thus increase their purchase intention.

The Effect of the Boar Taint Masking Strategy (Adding Dried Origanum vulgare or Allium sativum) on Sensory Characteristics

With increasing efforts to ban surgical castration, it is important to find ways to mask the level of boar taint in meat. The aim of this study was to test the possibility of masking boar taint or skatole levels by adding dried Origanum vulgare or Allium sativum and to evaluate consumer sensory preferences towards the skatole concentration in different carcass parts (longissimus lumborum; semimembranosus; neck chop and subcutaneous fat) and the masking strategy (addition of Allium sativum or Origanum vulgare). In the first experiment, the effect of the masking strategy was evaluated at three different skatole concentrations (0.069, 0.269 and 0.463 µg/g). The results showed that the samples with low and medium skatole levels were significantly different between the control group and the groups treated with Origanum vulgare or Allium sativum. In both cases, the addition of Allium sativum and Origanum vulgare had a positive effect on the parameters of abnormal odour and pleasantness of odour (p < 0.05). According to the results of the second experiment, meat samples from leaner parts, such as the neck chop semimembranosus and longissimus lumborum, not treated with Allium sativum and Origanum vulgare for masking, were significantly (p < 0.05) worse in terms of the occurrence of boar taint or abnormal odour than the masked samples. No significant differences were found between the two masking methods.

Heavy Pigs Reared for Italian Dry-Cured Products: Does Immunocastration Influence the Fatty Acid Profile of Loins and Backfat?

The Italian pig sector requires heavy pigs (raised for at least nine months and slaughtered at >160 kg). In order to avoid boar taint and lower the impact on welfare, immunocastration provides an alternative to surgical castration. This study investigated the effects of immunocastration compared to surgical castration on the chemical composition and fatty acid profile of loins (longissimus dorsi muscle) and adipose tissue in Italian heavy pigs raised for dry-cured ham. Twenty-four male pigs were subjected to surgical castration (n = 12) or immunocastration (n = 12). Carcass parameters were monitored at slaughter, and samples of longissimus dorsi muscle and subcutaneous fat were analysed. This study showed no significant differences in carcass characteristics and proximate composition of fresh meat. However, variations were observed in the fatty acid profiles of meat and adipose tissue between groups. Notably, saturated fatty acids, particularly stearic acid (18:0), were higher in the intramuscular fat (IMF) of the immunocastrated pigs compared to the surgically castrated pigs. Conversely, monounsaturated fatty acids, predominantly oleic acid (18:1n-9), were higher in the IMF from the surgically castrated pigs compared to the immunocastrated pigs. While immunocastration may offer benefits in terms of animal growth and carcass composition, it could lead to unfavourable lipid changes in fresh loin meat for Italian heavy pigs.

Outdoor Finishing of Intact Male Portuguese Alentejano Pigs on a Sustainable High-Fiber Diet: Impacts on Blood, Growth, Carcass, Meat Quality and Boar Taint Compounds

This trial evaluated the effect of sex on the blood, growth, carcass, meat quality, and boar taint compounds in male Alentejano (AL) pigs (n = 30). From ~40 to 130 kg LW, castrated (C) and intact pigs (I and IExp groups) were fed commercial diets ad libitum. Between ~130 and 160 kg (slaughter), C and I pigs continued on commercial diets, while IExp were fed an experimental diet containing locally produced pulses and by-products aimed at reducing boar taint. At ~160 kg, blood urea levels were higher in IExp than C pigs, triacylglycerols were lower in both intact groups, and cortisol was lower in IExp. IExp pigs exhibited faster growth, improved feed conversion ratio, carcass higher commercial yield and leaner meat than C pigs. The loin intramuscular fat in intact pigs was lower, less saturated and more polyunsaturated, while total collagen was higher. Fat androstenone content was higher in intact pigs and skatole content was similar across treatments, although they were below threshold values for consumer detection. Finally, although boar taint compounds were low in intact AL pigs raised outdoors, adding pulses and by-products to the experimental diet did not result in a reduction in fat skatole content compared to pigs fed the commercial diet.

Male Reproductive Organ Weight: Criteria for Detection of Androstenone-Positive Carcasses in Immunocastrated and Entire Male Pigs

Immunocastration and rearing of entire males (EMs) are sustainable alternatives to surgical castration. However, these animal carcasses have variable risk of boar taint and should be identified at the slaughter line. We aimed to identify a simple and reliable indicator of androstenone-related boar taint by evaluating pelvic urogenital tract weight as a marker of boar-taint animals at the slaughter line. The pelvic urogenital tract, testes, and accessory sex glands of EMs and immunocastrates (ICs) were collected, dissected, and weighed, before colorimetric measurements of testicular tissue. Additionally, GnRH antibody titers and testosterone, androstenone, and skatole levels were determined. Our results showed that 81.8% of EMs had androstenone levels above the risk threshold (>0.5 µg/g fat; EM/A^high subgroup), whereas in ICs, the C/A^high subgroup with androstenone >0.5 µg/g fat accounted for only 4.3%. Androstenone levels correlated negatively with GnRH antibody titers and positively with testosterone levels and reproductive organ weights. Identification of ICs with androstenone levels above the threshold (IC/A^high subgroup) may be achieved via testes or pelvic urogenital tract weight measurements. However, in EMs, the latter is a more reliable parameter. A principal component analysis based on these variables and hierarchical clustering also distinguished the A^high from the A^low subgroup, irrespective of IC/EM. The findings highlight the possible use of pelvic urogenital tract weight along with testes weight as a simple, reliable, and efficient morphometric indicator for identifying androstenone-positive carcasses of different sex categories.

Spanish Fuet Sausages Fat-Reduced to Diminish Boar Taint: Sensory and Technological Quality

Reduced-fat cured sausages were evaluated as a strategy to reduce boar taint in entire male pork products with high levels of androstenone and skatole, both lipophilic. Three fuet-type sausages (two replicates each) were developed: the control (C) (60% lean, 33.69% fat), and two reduced-fat (60% lean 21.19% fat) products; R1, 6% inulin, 0.5% β-glucan and R2, 3% inulin, 0.5% grape skin and 1% β-glucan. All of them were prepared from entire male pork with an androstenone concentration of 6.887 µg/g and 0.520 µg/g of skatole. Significant differences (p ≤ 0.001) in the moisture content were described between the fuet R1 and the C and R2, which obtained the highest percentage. Regarding the CIELAB, the C samples had the highest L* value, while the R2 sausages were the darkest. Boar taint was reduced in both R1 and R2, with a greater reduction in R2 (p ≤ 0.000). The addition of inulin and β-glucan in fuet R1 provided a similar technological and sensory profile to C. However, both strategies provided a reduction of sexual odour, which was higher when grape skins were included. In addition, R2 gave a characteristic sausage with more odour and flavour, dark colour and overall rating than C and R1.

Diversity of Japanese consumers' requirements, sensory perceptions, and eating preferences for meat

Japanese consumers are generally characterized as preferring high marbling in beef and pork and choosing domestic products. However, the Japanese food market is not homogenous. Understanding the diversity of Japanese consumers will provide benefits for the optimization of meat production and distribution in Japan. This article focuses on three factors affecting purchasing decisions and eating satisfaction, namely, requirements, sensory perception, and eating preferences, in order to understand the diversity of Japanese consumers in a simplified manner. Diversity was observed in Japanese consumers in all three of these factors (requirements, perception, and preference) using a questionnaire survey, sensory and biological procedures, and an eating preference test. These diversities are due to not only sociodemographic characteristics but also biological and physiological factors, background culture, and individual attitudes and criteria. Although consumer variation based on sociodemographic characteristics is of course important, it is equally important to understand diversity by focusing on the individual differences among consumers.

Consumer evaluation of meat quality from barrows, immunocastrates and boars in six countries

The practice of surgical castration of piglets and its alternatives is still under debate. Production of boars may impair meat quality due to boar taint and reduced tenderness compared to meat from surgically castrated male pigs, while immunocastration reduces boar taint and may improve meat quality but seems to be less accepted by the pig chain. In this study, we aimed to evaluate the consumer's sensory appreciation of meat from barrows (BAs), immunocastrates (ICs) and boars (BOs) in six European countries, taking into account the selection of tainted carcass and consumers' appreciation of boar taint. Loin chops of 30 BAs, 30 ICs and 30 BOs were evaluated by 752 consumers in six countries: Belgium, Czech Republic, Poland, Portugal, Romania and Spain. Consumers rated odour, flavour, tenderness, juiciness, overall liking and willingness to buy and sensitivity to and liking of androstenone (AND) and liking of skatole (SKA) was also tested. In each of the six countries, consumers liked the odour of the BO samples less than that of BA, and IC intermediate. For flavour, tenderness, juiciness, overall liking and willingness to buy, liking scores given by the Czech, Polish and Portuguese consumers significantly differed between the BA, BO and IC. Willingness to buy was highest for BA by Czech and Polish consumers and for BA and IC by Portuguese consumers. The frequency of the negative check all terms that apply terms also differed, with a higher frequency of disgusting for BO compared to BA and IC and of off-flavour, irritating, manure, sweat, disappointing compared to BA, and intermediate for IC. 31% of the consumers disliked the odour of AND (NEG_AND), and 36% of them were not sensitive; in contrast, 77% of the consumers disliked SKA (NEG_SKA). The decrease in flavour liking score for BO compared to BA and IC was more outspoken by the NEG_AND consumer, while NEG_SKA consumers gave an overall lower liking score independent of the type of male pig. The results of this study indicate that IC can be a valid alternative for surgical castration.

Sensory Profiling and Liking of Salami and Pancetta from Immunocastrated, Surgically Castrated and Entire Male Pigs

Simple Summary

Alternatives to surgical castration are an important issue in pig production due to societal concerns regarding animal welfare. Castration of piglets is a common practice to avoid boar taint, an unpleasant taste (urine/fecal like) of meat from uncastrated male pigs. In view of abandoning surgical castration and introduction of new alternatives, such as raising entire male pigs and applying immunocastration, several new issues are emerging. These include boar taint occurrence in case of entire male pigs and a deteriorated raw material (meat, fat) quality, which can affect consumer perception. Therefore, more information is needed about the consumer acceptance of products from the different alternatives. In the present study, two types of dry-cured meat products were assessed to give some insights into the sensory characteristic and consumers’ liking of the products coming from immunocastrated, entire male and surgically castrated animals.

Abstract

Consumer studies on acceptability of pork from immunocastrates (IC) and entire males (EM) are of primary importance, if these alternatives are to replace surgical castration (SC) of piglets. Data on the sensory traits and consumers acceptance of IC and EM meat products are still limited. Therefore, the purpose of the study was to (1) describe the sensory profile by quantitative descriptive analysis and (2) test the perception and consumer liking of salami (dry-fermented sausage) and pancetta (dry-cured belly) from EM, IC and SC animals. The consumer tests included the scaling method and check-all-that-apply. Profiling showed that EM products were scored lower in the overall sensory quality compared to IC or SC. EM products differed mainly from IC and SC in the intensity of the manure, sweat odor and flavor, persistent impression and texture (hardness, gumminess and easy to fragment). Salami samples did not differ in liking. In pancetta, the differences were significant for odor liking and visual quality (expected liking). Consumers did not perceive EM products as inferior in terms of liking, while sensory profiling indicated differences for boar taint presence and texture. Using meat originating from IC did not result in any differences in consumers acceptance as compared to products from SC.

Comprehensive SPME-GC-MS Analysis of VOC Profiles Obtained Following High-Temperature Heating of Pork Back Fat with Varying Boar Taint Intensities

Boar taint detection is a major concern for the pork industry. Currently, this taint is mainly detected through a sensory evaluation. However, little is known about the entire volatile organic compounds (VOCs) profile perceived by the assessor. Additionally, many research groups are working on the development of new rapid and reliable detection methods, which include the VOCs sensor-based methods. The latter are susceptible to sensor poisoning by interfering molecules produced during high-temperature heating of fat. Analyzing the VOC profiles obtained by solid phase microextraction gas chromatography–mass spectrometry (SPME-GC-MS) after incubation at 150 and 180 °C helps in the comprehension of the environment in which boar taint is perceived. Many similarities were observed between these temperatures; both profiles were rich in carboxylic acids and aldehydes. Through a principal component analysis (PCA) and analyses of variance (ANOVAs), differences were highlighted. Aldehydes such as (E,E)-nona-2,4-dienal exhibited higher concentrations at 150 °C, while heating at 180 °C resulted in significantly higher concentrations in fatty acids, several amide derivatives, and squalene. These differences stress the need for standardized parameters for sensory evaluation. Lastly, skatole and androstenone, the main compounds involved in boar taint, were perceived in the headspace at these temperatures but remained low (below 1 ppm). Higher temperature should be investigated to increase headspace concentrations provided that rigorous analyses of total VOC profiles are performed.

Non-destructive evaluation of carcass and ham traits and meat quality assessment applied to early and late immunocastrated Iberian pigs

Castration is a common practice in Iberian pigs due to their advanced age and high weight at slaughter. Immunocastration (IC) is an alternative to surgical castration that influences carcass and cut fatness. These traits need to be evaluated in vivo and postmortem. The aims of the present work were (a) to determine the relationship between ham composition measured with computed tomography (CT) and in vivo ultrasound (US) and carcass fat thickness measurements, (b) to apply these technologies to early (EIP) and late (LIP) immunocastrated Iberian pigs in order to evaluate carcass fatness and ham tissue composition and (c) to assess meat quality on these animals and to find the relationships between meat quality traits (namely, intramuscular fat (IMF)) and fat depot thicknesses. For this purpose, 20 purebred Iberian pigs were immunocastrated with three doses of Improvac ®, at either 4.5, 5.5 and 9 or 11, 12 and 14 months of age (EIP or LIP; respectively; n = 10 each) and slaughtered at 17 months of age. Fat depots were evaluated in vivo by US, in carcass with a ruler and in hams by CT. Carcass and cut yields, loin meat quality and loin acceptability by consumers were determined. Also, IMF was determined in the loin and three muscles of the ham. Carcass weight was 14.9 kg heavier in EIP vs LIP, and loin backfat thickness (US- and ruler-measured) was also greater in EIP. Similarly, CT-evaluated ham bone and fat contents were greater and smaller for EIP vs LIP, respectively. Loin and ham IMF were also greater in EIP, but the other meat quality parameters were similar. The acceptability of meat by consumers was high and it did not differ between IC protocols. Correlations between several fat depots measured with the different technologies were high. In conclusion, all these technologies allowed fat depot measurements, which were highly correlated despite being obtained at different anatomical locations.

Recent genetic advances on boar taint reduction as an alternative to castration: a review

Boar taint is an unpleasant odor in male pig meat, mainly caused by androstenone, skatole, and indole, which are deposited in the fat tissue. Piglet castration is the most common practice to prevent boar taint. However, castration is likely to be banished in a few years due to animal welfare concerns. Alternatives to castration, such as genetic selection, have been assessed. Androstenone and skatole have moderate to high heritability, which makes it feasible to select against these compounds. This review presents the latest results obtained on genetic selection against boar taint, on correlation with other traits, on differences in breeds, and on candidate genes related to boar taint. QTLs for androstenone and skatole have been reported mainly on chromosomes 6, 7, and 14. These chromosomes were reported to contain genes responsible for synthesis and degradation of androstenone and skatole. A myriad of work has been done to find markers or genes that can be used to select animals with lower boar taint. The selection against boar taint could decrease performance of some reproduction traits. However, a favorable response on production traits has been observed by selecting against boar taint. Selection results have shown that it is possible to reduce boar taint in few generations. In addition, modifications in diet and environment conditions could be associated with genetic selection to reduce boar taint. Nevertheless, costs to measure and select against boar taint should be rewarded with incentives from the market; otherwise, it would be difficult to implement genetic selection.

Combined Effect of Dietary Protein, Ractopamine, and Immunocastration on Boar Taint Compounds, and Using Testicle Parameters as an Indicator of Success

This study investigates the combined effect of immunocastration, dietary protein level (low, medium or high) and ractopamine hydrochloride supplementation (0 or 10 mg/kg) on the adipose concentrations of androstenone, skatole and indole in pigs, and explores whether body mass, carcass fatness or testicular parameters may be indicators of boar taint in these carcasses. Immunocastration was successful in decreasing testicle functioning, and adipose androstenone and skatole concentrations, in all individuals. Immunocastration decreased testicle weight and length, seminiferous tubule circumference and epithelium thickness. Testicle tissue from immunocastrates was also paler, and less red in color, in comparison to non-castrated controls. Dietary protein level and ractopamine hydrochloride supplementation had no influence on the adipose concentration of androstenone, skatole and indole. Testicle size and color were moderate to strong indicators of androstenone and skatole concentrations in the carcasses, and thus vaccination success. Immunocastration together with the adjustment of dietary protein and ractopamine hydrochloride supplementation, is successful in preventing boar taint while maintaining growth performance.

Feasibility of on/at Line Methods to Determine Boar Taint and Boar Taint Compounds: An Overview

Simple Summary

Due to welfare issues, the physical castration of male pigs is decreasing, and the entire male pig production is increasing. Fattening entire male pigs requires control due to the possibility of accumulating off odour/flavour called boar taint, which is mainly due to two compounds - skatole and androstenone. If carcasses with boar taint reach the market, it can cause a negative consumer reaction which may have economic consequences for the whole meat chain. Thus, it is necessary to sort out carcasses at the slaughter line. Today, a sensory quality control (human nose method) is used in some slaughter plants for this purpose. Detection by physical or chemical methods is also envisaged. A colorimetric method to determine skatole has been used in Danish abattoirs for decades, but it is foreseen that it will soon be replaced by the laser diode thermal desorption ion source coupled with a mass spectrometry equipment that allows a fully automated classification based on skatole and androstenone levels at speed line, with a delay of less than 40 min. Other potential methods such as the electrochemical biosensors, rapid evaporative ionization mass spectroscopy and Raman spectroscopy, still need further development and validation for an application at abattoir level.

Abstract

Classification of carcasses at the slaughter line allows an optimisation of its processing and differentiated payment to producers. Boar taint is a quality characteristic that is evaluated in some slaughter plants. This odour and flavour is mostly present in entire males and perceived generally by sensitive consumers as unpleasant. In the present work, the methodologies currently used in slaughter plants for boar taint classification (colorimetric method and sensory quality control-human nose) and the methodologies that have the potential to be implemented on/at the slaughter line (mass spectrometry, Raman and biosensors) have been summarized. Their main characteristics are presented and an analysis of strengths, weaknesses, opportunities and threats (SWOT) has been carried out. From this, we can conclude that, apart from human nose, the technology that arises as very promising and available on the market, and that will probably become a substitute for the colorimetric method, is the tandem between the laser diode thermal desorption ion source and the mass spectrometry (LDTD-MS/MS) with automation of the sampling and sample pre-treatment, because it is able to work at the slaughter line, is fast and robust, and measures both androstenone and skatole.

The Use of Pork from Entire Male and Immunocastrated Pigs for Meat Products-An Overview with Recommendations

Due to the strong public initiative in Europe and increased regulator focus to mitigate pain, surgical castration of pigs is being gradually abandoned, while the importance of other sex categories like entire males (EM) and immunocastrates (IC) increases. Although beneficial for animal welfare and economics, their use also brings forward several quality problems. Besides the occurrence of boar taint in EM, these include excessive carcass leanness, softer fat, meat color and pH deviations, inferior water holding capacity and increased meat toughness. In this paper, the raw material differences between the male sex categories and their influence on product quality are reviewed, and possible solutions are presented. Using EM for dried or thermally processed products may result in lower processing yields and inferior sensory quality, which may partially be prevented by applying specific processing adaptations. Immunocastration is a viable solution, especially when prolonging the vaccination to slaughter interval. Low to medium levels of boar taint can be effectively managed in most of the meat products, applying procedures like cooking, microbial inoculation or masking (by spices and especially smoking), while highly tainted material can be valorized only by combining various methods and/or with dilution of the tainted meat.

Pork Production with Entire Males: Directions for Control of Boar Taint

Simple Summary

Castration of male piglets has traditionally been carried out to control boar taint, but animal welfare concerns about surgical castration has brought this practice under scrutiny. In addition, castration decreases growth performance and increases the environmental impact of pork production, so alternatives to castration are needed to control boar taint. In this review, we summarize the current knowledge on boar taint metabolism and outline some key areas that require further study. We also describe some opportunities for controlling the boar taint problem and propose that by defining the differences in metabolic processes and the genetic variations that can lead to boar taint in individual pigs, we can design effective custom solutions for boar taint.

Abstract

Boar taint is caused by the accumulation of androstenone and skatole and other indoles in the fat; this is regulated by the balance between synthesis and degradation of these compounds and can be affected by a number of factors, including environment and management practices, sexual maturity, nutrition, and genetics. Boar taint can be controlled by immunocastration, but this practice has not been accepted in some countries. Genetics offers a long-term solution to the boar taint problem via selective breeding or genome editing. A number of short-term strategies to control boar taint have been proposed, but these can have inconsistent effects and there is too much variability between breeds and individuals to implement a blanket solution for boar taint. Therefore, we propose a precision livestock management approach to developing solutions for controlling taint. This involves determining the differences in metabolic processes and the genetic variations that cause boar taint in specific groups of pigs and using this information to design custom treatments based on the cause of boar taint. Genetic, proteomic or metabolomic profiling can then be used to identify and implement effective solutions for boar taint for specific populations of animals.

Health Risk Perception, Consumption Intention, and Willingness to Pay for Pig Products Obtained by Immunocastration

Simple Summary

Public awareness of farm animal welfare has gradually increased. It is well-known that some routine procedures in pig farming are detrimental to animal welfare, including surgical castration, especially without anaesthesia and/or analgesia. Some alternative techniques that offer welfare advantages over surgical castration can be implemented—immunocastration is among them. However, producers fear that consumers may be frightened by this technique and therefore they delay changes in the production system. This work aimed to understand whether Italian consumers perceive a health risk from the immunocastration technique and whether this perception is connected with their willingness to consume and to pay for products derived from immunocastrated animals. The results show that, within the Italian population, there are different levels of perceived health risk and that, as the perception of risk increases, the willingness to consume products obtained from immunocastrated animals decreases (and vice versa). The health risk perception by consumers also changes the willingness to pay for immunocastrated products. Particular attention must be paid to the information transmitted to the consumer if this technology will be widely adopted in pig husbandry.

Abstract

Surgical castration without the use of anaesthesia and/or analgesia is considered to be detrimental for the welfare of pigs and for this reason its abandonment is advocated. Immunocastration is a more welfare-friendly alternative method; however, stakeholders in the pork sector fear consumer rejection due to perceived safety issues of immunocastrated meat. This work aimed to analyse whether Italian consumers perceive a health risk arising from the use of this technique and, if so, how the perceived risk may influence the purchase choices and the willingness to pay for products derived from immunocastrated animals. To achieve this objective, a survey was carried out on a representative sample of the Italian population. The results highlight that consumers perceive different levels of risk related to the use of immunocastration and that this influences purchasing behaviour and willingness to pay. Moreover, it should be noted that the willingness to pay is also influenced by certain demographic factors, since this is positively associated with younger respondents with lower incomes and less knowledge of farming systems, who live in rural areas and have a greater sensitivity to animal welfare. Given the concerns expressed by consumers, particular attention must be paid to the information transmitted if this technology will be widely implemented in pig husbandry.

Valorisation of tainted boar meat in patties, frankfurter sausages and cooked ham by means of targeted dilution, cooking and smoking

Because of the need to abolish the castration of piglets without anaesthesia/analgesia, the pig industry is searching for a mode of action for the valorisation of meat with boar taint, an off-odour in entire male pigs. Carcasses with boar taint were selected by means of sensory and chemical analysis, after which patties with different levels of tainted boar meat were produced, as well as cooked ham and Frankfurter sausages using different smoke condensates and cooking temperatures. For these products orthonasal and retronasal boar taint odour were assessed by a trained expert panel. The results offer guidance regarding dilution of tainted meat (with <400 µg/kg androstenone if skatole is low or <200 µg/kg androstenone in concurrence with ≥37 µg/kg skatole) and the potential application of smoke condensates (e.g., Rudinsmoke C for sausages and Smokez LFBN for ham) as promising boar taint masking strategies.

Use of masking strategies to avoid the boar taint perception in chorizo: consumers' acceptability

The production of entire male pigs is an alternative to surgical castration. However, boar taint may be present in the meat of entire male animals. The aim of the present paper was to investigate the acceptability and sensory properties of chorizo, elaborated under three different levels of androstenone [castrated 0-0.3 mg / kg, medium 0.4-0.9 mg / kg and high 1-2.75 mg / kg] and two masking strategies [rosemary, and rosemary plus smoking] using a Check-All-That-Apply questionnaire. The results showed that, of the strategies employed, the rosemary plus smoked chorizo was the most effective masking strategy to reduce the boar taint in chorizos with high androstenone level (3.7% selection rate for animal flavour), while the closest to the ideal product, according to consumers' description, was high androstenone level plus rosemary chorizo.

Weanling Infants Prefer the Odors of Green Vegetables, Cheese, and Fish When Their Mothers Consumed These Foods During Pregnancy and/or Lactation

Infants' olfactory experience begins before birth and extends after birth through milk and complementary foods. Until now, studies on the effects of chemosensory experience in utero and/or through human milk focused on experimentally controlled exposure to only 1 target food bearing a specific odor quality and administered in sizeable amounts. This study aimed to assess whether early olfactory experience effect was measurable in "everyday conditions" of maternal food intake during pregnancy and lactation, and of infant intake at weaning, leading to expose the infant to corresponding odors as fetus, neonate, and infant up to 8 and 12 months of age. Infants' early food exposures were assessed by asking mothers to fill out diaries about their food consumption during pregnancy and breastfeeding, and about their infant's consumption during complementary feeding. To test odor liking, odorants representing a priori pleasant and unpleasant food odors, as well as odorless stimuli, were presented. The infant's exploratory behavior toward odorized bottles and nonodorized control bottles was measured in terms of mouthing duration, which is thought to reflect attraction and/or appetence. At age 8 months only, positive correlations were found between liking of some unpleasant odors and early exposure to these odors through mother's diet. No correlations were found between infants' liking of the pleasant odors and early exposures to the foods bearing these odors. This study highlights that early exposure to unpleasant food odors may increase subsequent liking (or reduce subsequent dislike) of these food odors at least until the age of 8 months.

Quality of Dry-Cured Ham from Entire, Surgically and Immunocastrated Males: Case Study on Kraški Pršut

Alternative solutions to the surgical castration of piglets need to be assessed because this is a particularly sensitive issue for the processing of traditional pork products. Currently, the available information about the advantages and drawbacks of castration for dry-cured products is limited; thus, the objective of this study was to evaluate the quality of Slovenian dry-cured ham (Kraški pršut) from entire males (EM), immunocastrates (IC) and surgical castrates (SC). Hams (12 per sex group) were processed for one year and physical-chemical, rheological and sensory analysis of the dry-cured hams was performed. With regard to processing aptitude, the main difference was in the subcutaneous fat thickness, which influenced the level of dehydration and salt intake. This was further reflected in the physical-chemical traits and the texture, which were measured instrumentally or assessed by panelists. Regarding the aforementioned traits, EM and IC were generally similar and different from SC. On the contrary, sensory profiling of odor, taste and flavor demonstrated that EM had the lowest overall sensory quality, different from both IC and SC, and presented odors and flavors described as sweat, manure, sharp and persistent. We confirmed that dry-curing did not eliminate the perception of boar taint in the product from EM. The IC were similar in many aspects to EM except for the odor, taste and flavor of dry-cured hams, in which case they were more similar to SC.

Effect of Supplementing Hydrolysable Tannins to a Grower-Finisher Diet Containing Divergent PUFA Levels on Growth Performance, Boar Taint Levels in Back Fat and Intestinal Microbiota of Entire Males

A retrospective data analysis suggested that the levels of boar taint compounds depend on the polyunsaturated fatty acid (PUFA) level of the adipose tissue (AT) being significantly greater in the unsaturated AT. In addition, we recently reported that hydrolysable tannins (HTs) offered to entire males (EMs) reduce skatole and, to a greater extent, indole levels in the AT. Thus, the objective of the study was to determine the impact of HTs and a high dietary level of PUFA on growth performance and board taint compounds in EMs. In addition, the interaction between PUFA and HTs on gut microbiota and its link to intestinal skatole and indole production was investigated. At 25 kg BW, 44 EM originating from 11 litters were randomly assigned within litter to four dietary treatments. Two basal grower (25-60 kg BW) and finisher (60-105 kg BW) diets containing either 2% soy oil (H = high PUFA level) or 2% tallow (L = low PUFA level) were formulated. The H and L diets were either supplemented (H+/L+) or not (H-/L-) with 3% chestnut extract containing 50% HTs. The pigs had ad libitum access to the diets and were slaughtered at 170 days of age. The microbiota composition was investigated through the 16S rRNA gene sequences obtained by next-generation sequencing (Illumia MiSeq platform, San Diego, CA, USA) and analyzed with a specific packages in R, version 3.5.0. Regardless of the PUFA content, the EMs fed the H+ diets were 2% (p < 0.01) less feed efficient overall. This was due to the slower (p = 0.01) growth in the finisher period despite similar feed intake. Carcass characteristics were not affected by the diets. Regardless of HT feeding, the PUFA level in the AT of the H pigs was 10% greater (p = 0.05) than in the L pigs. The indole level tended (p = 0.08) to be 50% lower in the H+ group. Surprisingly, the pigs that were fed diet H- had greater skatole levels than those fed diet L-, with intermediate skatole levels in the H+ and L+. Independent of the PUFA level, the HTs decreased bacteria abundance and qualitatively affected the microbiota composition. In conclusion, these data do not confirm that boar taint compound levels were related to PUFA levels in the AT. However, HTs can be considered to be a promising alternative to conventional antibacterial additives, with no detrimental effects on pig gut health and with appealing properties for reducing the synthesis of the main components of boar taint.

Novel, rapid, low-cost screen-printed (bio)sensors for the direct analysis of boar taint compounds androstenone and skatole in porcine adipose tissue: Comparison with a high-resolution gas chromatographic method

This is the first report on the fabrication, characterisation and application of an electrochemical (bio)sensor system for the simultaneous measurement of skatole and androstenone. A biosensor for androstenone was fabricated using a Meldola's Blue modified SPCE (MB-SPCE) by depositing NADH and the enzyme 3α-hydroxysteroid dehydrogenase onto the MB-SPCE surface; samples of adipose tissue were analysed using the biosensors in conjunction with chronoamperometry. Cyclic voltammetry was used to investigate the electrochemical behaviour of skatole at a screen-printed carbon electrode (SPCE vs. Ag/AgCl). An oxidation peak was observed around +0.55 V (vs. Ag/AgCl) and differential pulse voltammetry was applied for quantification of skatole in adipose tissue (in-situ). Quantitative analysis was achieved using calibration plots obtained from fortified meat samples. The concentrations obtained by the electrochemical and gas chromatographic (GC) methods demonstrated a good positive correlation. The (bio)sensor system completed both measurements within 60 s, as compared to several hours for GC, and at a considerably reduced cost and complexity. Consequently, the novel (bio)sensor system should have applications for analysis of carcasses on the abattoir processing line.

Plant-Derived Extracts Feed-Addition and Packaging Type Influence Consumer Sensory Perception of Pork

This paper investigates whether the combination of the addition of extracts derived from plants (plants derived extracts, PDE) to pork feedstuff and the meat conservation conditions (packaging and time exposure) affect consumers' perception of pork quality, studied by means of visual appraisal, purchase intention and a home test. The three PDE groups were control, garlic extract and blended oil composed by carvacrol, timol, cynamic aldehide and eugenol extracts. Meat was packed in film, vacuum or modified atmosphere (MAP) packaging. A visual test was designed comprising a four-day storage step followed by a four-day exposure step in a refrigerated island display case. All studied effects influenced visual appraisal scores, being time exposure and packaging effects more noticeable than PDE or pig-sex effects. Meat from MAP scored higher than the rest. Scores decreased as exposure time increased, but this evolution was less perceptible in vacuum packaging and was faster for meat from the garlic group. Only gender affected the visual appraisal scores, with women scoring higher than men. Neither PDE addition nor pig sex affected to purchase intention whereas both exposure time and packaging type did. A maximum of 2 days of exposure would be recommended. In the home-test, meat from male pigs obtained higher scores than meat from female pigs, and none of the consumer-related effects influenced the given scores.

Pros and Cons of Alternatives to Piglet Castration: Welfare, Boar Taint, and Other Meat Quality Traits

This paper reviews the pros and cons of various alternatives to the surgical castration of male piglets without pain relief. Castration is mostly motivated by the presence of boar taint in the meat from some entire male pigs. It results in pain during surgery and markedly increases feed costs and the fat content of the carcass. Raising entire male pigs avoids pain at castration, but animals can suffer from increased stress during the finishing period because of aggressive and mounting behavior. Feed efficiency and carcass quality are much better than in surgical castrates. The quality of meat from entire male pigs is lower because of boar taint, a reduced intramuscular fat content, and increased unsaturation of the fat. Immunocastration prevents boar taint, pain associated with surgery, and stress related to aggressive and mounting behavior. Feed efficiency and carcass quality are intermediate between surgical castrates and entire males. Meat quality is similar to surgical castrates. Anesthesia alone prevents pain during surgery, but not after, while analgesia alone mitigates pain after surgery, but not during it. With the currently available methods, the cost of combined anesthesia and analgesia is too high for conventional production systems in most countries.

Attitudes and beliefs of Eastern European consumers towards piglet castration and meat from castrated pigs

Castration of male piglets is a common practice to avoid boar taint but is being questioned. The present work has an exploratory character and aims to investigate the beliefs and attitudes of Eastern European consumers regarding boar taint, surgical castration immunocastration and perception of meat from castrated pigs and to find out possible segments of consumers regarding these attitudes and beliefs. For this purpose, a consumer study was carried out involving 5508 consumers from 13 Eastern European countries (Bosnia and Herzegovina, Bulgaria, Czech Republic, Croatia, North Macedonia, Hungary, Moldova, Poland, Romania, Serbia, Slovakia, Slovenia and Ukraine). The questionnaire included statements related to beliefs about castration and perception of meat from castrated pigs, attitudes towards meat from castrated pigs. Results show that in general beliefs and attitudes of the consumers are not defined, probably because of the lack of knowledge (information was not provided to the consumers) towards these issues. Three different clusters of consumers were obtained with different beliefs towards castration.

Acceptability of Dry-Cured Belly (Pancetta) from Entire Males, Immunocastrates or Surgical Castrates: Study with Slovenian Consumers

Abandoning of male piglets castration in the European Union is a challenge for the pork production sector in particular for high-quality dry-cured traditional products. The information on consumer acceptability of dry-cured products from alternatives is limited, so the objective was to test the consumer acceptability of unsmoked traditional dry-cured belly (Kraška panceta) processed from three sex categories, i.e., surgical castrates (SC), entire males (EM) and immunocastrates (IC). Consumers (n = 331) were asked to taste dry-cured bellies from EM, IC and SC and to score the taste appreciation on a 9 cm unstructured scale. After tasting the pancetta of three sex categories, the consumers attributed the lowest acceptability scores to SC, whereas IC and EM received similar scores. Only about a quarter of consumers attributed the lowest score to EM, mainly when boar taint compounds were present. The results of this study indicate that a certain share of consumers was sensitive to taste deficiencies and that the leanness of this product is very important for consumers.

Reduction of androstenone perception in pan-fried boar meat by different masking strategies

BACKGROUND

Consumers highly sensitive to androstenone María (AND) will probably reject meat from entire male pigs, which tends to have high levels of this hormone. To avoid this, the effect of different masking strategies (sprinkling with mixed spices or fennel, marinating and breading with garlic-parsley or curry) on the sensory parameters of pork loin chops obtained from entire animals with high levels of AND (1.0-2.9 mg kg^-1 AND in fat) and castrated animals (<0.4 mg kg^-1 AND in fat), both with low levels of skatole (<0.1 mg kg^-1 skatole in fat) was investigated.

RESULTS

The garlic-parsley breadcrumbs led to the highest reduction in the perception of AND compared with the other masking strategies used, and preserved the juiciness of the product. There was a negative correlation between AND and fat content.

CONCLUSION

AND odor and flavor can be reduced in meat from entire male pigs by using suitable strategies, the best strategy being the garlic-parsley breadcrumbs. © 2017 Society of Chemical Industry.

Consumer acceptance of minced meat patties from boars in four European countries

A consumer study was performed in four EU countries to further clarify the acceptability of meat with boar taint. In Denmark, France, Italy and Poland, a total of 476 female consumers evaluated 8 meat patties from boars with varying levels of skatole (0.10-0.40μg/g fat tissue) and androstenone (0.47-2.00 μg/g fat tissue), in a pair-wise comparison with patties from castrates. Boar meat patties were always less preferred than the castrate meat patties, regardless of the level of androstenone and skatole. Acceptability of the boar meat patties decreased with increasing skatole level. In samples with low skatole levels, higher levels of androstenone also reduced acceptability among androstenone sensitive consumers. No clear threshold levels for androstenone and skatole could be identified. Maps presenting the reduction in preference due to increasing levels of skatole and androstenone, and corrected for the general acceptance of the meat product were developed, taking into account androstenone sensitivity. Further work is needed, covering the whole range of androstenone and skatole levels found in entire male pigs and for a wider set of meat products.

Eating quality traits of shoulder roast and stir fry cuts outperformed loin and silverside cuts sourced from entire and immunocastrated male pigs

This study investigated the effects of ageing period (2 or 7days), endpoint temperature (70 or 75°C), cut type (loin (M. longissimus thoracis et lumborum), silverside (M. biceps femoris), blade (M. triceps brachii) and chuck tender (M. supraspinatus)), cooking method (roast and stir fry (all cuts) and steak (loin only)) on eating quality attributes of pork from entire and immunocastrated male pigs. Higher intramuscular fat levels were found in all cuts from immunocastrated males compared with entire males. Of the seven cut type×cooking method combinations evaluated, shoulder cuts had the lowest fail rate (P<0.001) and loin steak and silverside cuts scored lowest (P<0.001) for tenderness, juiciness, overall liking, quality grade and re-purchase intention. Although no differences in sensory scores due to gender were observed, boar taint was identified in 10% of entire males. Minimising adverse risks in eating quality due to boar taint in males remains a key industry issue to ensure consistent delivery of high quality pork.

Sensory perception of meat from entire male pigs processed by different heating methods

The aim of this study was to evaluate the perception of androstenone in pork from entire male pigs with different androstenone levels (High≥2mgkg^-1; Medium 0.5-0.7mgkg^-1) applying four different heating methods (vacuum, grill, oven and frying). Androstenone (AND) perception was analysed during and after cooking by a trained panel. During cooking, the highest score for AND odour (greatest perception) was obtained with the grill and vacuum, while frying was the best option for reducing its perception, which was judged to be imperceptible for androstenone medium level (P<0.05). In cooked samples, there were level, heating method and its interaction effects for AND odour and flavour, meat flavour, juiciness and hardness (P<0.05). The samples treated by vacuum and frying had a proper texture profile. However the frying method provided the lowest score in AND perception, making it the best option for reducing both AND odour and flavour. In short, the use of different heating methods strongly affected AND perception.

Sensory evaluation of boar meat products by trained experts

Rearing entire male pigs, one of the alternatives for surgical castration, entails the possible occurrence of boar taint. This study aimed at the investigation of the acceptability of meat from entire male pigs in 8 different meat products (cutlets, bacon, blade loin, tenderloin, dry fermented sausage, cooked ham, dry-cured ham and minced meat) by trained assessors. Generally, the sensory evaluation of meat samples was affected the most in the androstenone (AEON) group, indicating that AEON is the most offensive boar taint compound for sensitive assessors. Differences between the meat products showed the highest potential for processing tainted meat in cold meat products, which was most likely due to the serving temperature on the one hand and production-related influences on the other. However, more insights regarding reducing and masking effects of production-related factors on boar taint are necessary.

Consumers' sensitivity to androstenone and the evaluation of different cooking methods to mask boar taint

Boar taint is an unpleasant odour and flavour present in some entire male pigs that is due to the presence of androstenone and skatole. The aim of the study was to assess the sensitivity of 150 consumers to androstenone and to compare the acceptability and liking of meat from castrated and entire pigs, cooked with different cooking methods. Meat samples consisted of loins from castrated (CM) and entire male pigs (EM) with high levels of androstenone cooked by two cooking methods: sous-vide and fried/breaded with garlic and parsley. Consumers evaluated smell and flavour acceptability, and overall liking of CM and EM for each cooking method. The results of the study showed that dislike of androstenone odour increased significantly with sensitivity. The results of acceptability and overall liking were similar in CM and EM for both cooking methods. Therefore, the two cooking methods used in the study may be useful to mask boar taint.

Yeast inoculation as a strategy to improve the physico-chemical and sensory properties of reduced salt fermented sausages produced with entire male fat

Yeast inoculation of dry fermented sausages manufactured with entire male fat was evaluated as a strategy to improve sausage quality. Four different formulations with entire male/gilt back fat and inoculated/non-inoculated with Debaryomyces hansenii were manufactured. The use of entire male back fat produced the highest weight losses, hardness and chewiness in dry sausages. Consumers clearly distinguished samples according to drying time and D. hansenii inoculation while the use of entire/gilt back fat was not highly perceived. The presence of androstenone and skatole was close to their sensory thresholds. Androstenone was not degraded during the process but skatole was affected by yeast inoculation. D. hansenii growth on the surface regulated water release during ripening, reduced hardness and chewiness in entire male sausages and resulted with similar texture to gilt sausages. Yeast inoculation inhibited lipid oxidation providing fruity odours and less oxidized fatty sausages in the sensory analysis. The effectiveness of yeast to mask boar taint was demonstrated by sensory analysis.

A procedure for sensory detection of androstenone in meat and meat products from entire male pigs: Development of a panel training

This study represents a proposal for training sensory panels in androstenone (AND) perception in meat and meat products. The procedure consists of four main parts: (1) selection and training of a sensory panel (11 panelists) using standards with Vaseline oil media as carriers of AND and skatole (SKA); (2) developing a training method AND detection in meat; (3) dry cured meat product and (4) cooked meat product. All candidates were able to distinguish between AND, SKA and AND+SKA in Vaseline oil, order AND solutions with different concentrations and classify them in the three categories: low, medium and high. The panel was able to differentiate the meat in the three categories, but only the high level in meat products. Due to the individual features in AND perception, specific training for each type of product is required.

Russian and Chinese consumers' acceptability of boar meat patties depending on their sensitivity to androstenone and skatole

The aim of this work was to study the sensitivity of Chinese and Russian female consumers to androstenone and skatole and to identify their preference for pork patties from entire male pigs compared with those from castrated pigs. One-hundred-twenty women in each country were enrolled. The sensitivity of the consumers to both compounds was tested using smell strips and triangular tests. Pairwise tests were performed comparing patties from castrated male pigs with patties from boars with different levels of androstenone and skatole. Approximately 70% of the Russian and 60% of the Chinese consumers were sensitive to skatole and 37% and 32% were sensitive to androstenone, respectively. Nevertheless, a higher percentage of sensitive Russian consumers compared to Chinese consumers disliked the smell of both compounds. In Russia, the consumers' preferences were higher for patties with low levels of both compounds, while no differences were found in China. In both countries, consumers who were sensitive to skatole also preferred patties with low levels of both compounds. Thus, the levels of androstenone and skatole affect boar patty preferences.