Quality characteristics of Warthog (Phacochoerus africanus) meat

Searching for common patterns in parasite ecology: species and host contributions to beta-diversity in helminths of South African ungulates and fleas of South American rodents

We searched for common patterns in parasite ecology by investigating species and host contributions to the beta-diversity of infracommunities (=assemblages of parasites harboured by a host individual) in helminths of three species of South African ungulates and fleas of 11 species of South American rodents, assuming that a comparison of patterns in distinctly different parasites and hosts would allow us to judge the generality or, at least, commonness of these patterns. We used data on species' composition and numbers of parasites and asked whether (i) parasite species' attributes (life cycle, transmission mode, and host specificity in helminths; possession of sclerotized combs, microhabitat preference, and host specificity in fleas) or their population structure (mean abundance and/or prevalence) and (ii) host characteristics (sex and age) affect parasite and host species' contributions to parasite beta-diversity (SCBD and HCBD, respectively). We found that parasite species' morphological and ecological attributes were mostly not associated with their SCBD. In contrast, parasite SCBD, in both ungulates and rodents, significantly increased with either parasite mean abundance or prevalence or both. The effect of host characteristics on HCBD was detected in a few hosts only. In general, parasite infracommunities' beta-diversity appeared to be driven by variation in parasite species rather than the uniqueness of the assemblages harboured by individual hosts. We conclude that some ecological patterns (such as the relationships between SCBD and parasite abundance/prevalence) appear to be common and do not differ between different host-parasite associations in different geographic regions, whereas other patterns (the relationships between SCBD and parasite species' attributes) are contingent and depend on parasite and host identities.

Characterization of the off-flavor from Pichia pastoris GS115 during the overexpression of an α-l-rhamnosidase

The off-flavor of Pichia pastoris strains is a negative characteristic of proteins overexpressed with this yeast. In the present study, P. pastoris GS115 overexpressing an α-l-rhamnosidase was taken as the example to characterize the off-flavor via sensory evaluation, gas chromatography-mass spectrometer, gas chromatography-olfaction, and omission test. The result showed that the off-flavor was due to the strong sweaty note, and moderate metallic and plastic notes. Four volatile compounds, that is, tetramethylpyrazine, 2,4-di-tert-butylphenol, isovaleric acid, and 2-methylbutyric acid, were identified to be major contributors to the sweaty note. Dodecanol and 2-acetylbutyrolactone were identified to be contributors to the metallic and plastic notes, respectively. It is the first study on the off-flavor of P. pastoris strains, helping understand metabolites with off-flavor of this yeast. Interestingly, it is the first study illustrating 2-acetylbutyrolactone and dodecanol with plastic and metallic notes, providing new information about the aromatic contributors of biological products.

IMPORTANCE

The methylotrophic yeast Pichia pastoris is an important host for the industrial expression of functional proteins. In our previous studies, P. pastoris strains have been sniffed with a strong off-flavor during the overexpression of various functional proteins, limiting the application of these proteins. Although many yeast strains have been reported with off-flavor, no attention has been paid to characterize the off-flavor in P. pastoris so far. Considering that P. pastoris has advantages over other established expression systems of functional proteins, it is of interest to identify the compounds with off-flavor synthesized in the overexpression of functional proteins with P. pastoris strains. In this study, the off-flavor synthesized from P. pastoris GS115 was characterized during the overexpression of an α-l-rhamnosidase, which helps understand the aromatic metabolites with off-flavor of P. pastoris strains. In addition, 2-acetylbutyrolactone and dodecanol were newly revealed with plastic and metallic notes, enriching the aromatic contributors of biological products. Thus, this study is important for understanding the metabolites with off-flavor of P. pastoris strains and other organisms, providing important knowledge to improve the flavor of products yielding with P. pastoris strains and other organisms.

ONE-SENTENCE SUMMARY

Characterize the sensory and chemical profile of the off-flavor produced by one strain of P. pastoris in vitro.

Application of Fat-Tailed Sheep Tail and Backfat to Develop Novel Warthog Cabanossi with Distinct Sensory Attributes

This study compared the use of pork backfat (PF) and fat-tailed sheep tail and backfat (SF) on the physicochemical, fatty acids and sensory attributes of warthog cabanossi. There were no differences between weight loss during drying, moisture content, pH, water activity, salt content and lipid oxidation between the cabanossi types. However, protein and ash contents were higher in PF cabanossi whilst fat content was higher in SF cabanossi. The PF cabanossi had higher polyunsaturated fatty acids (especially n-6), lower monounsaturated fatty acids whilst the saturated fatty acid content was similar between the two cabanossi products. The n-3:n-6 ratio was more beneficial in the SF cabanossi. The descriptive sensory analysis showed two distinct products where PF cabanossi scored higher for most attributes. Although SF cabanossi scored less for these attributes, this cabanossi had unique and acceptable sensory attributes. This study concluded that fat-tailed sheep tail and backfat could be used to produce a unique cabanossi product of acceptable quality.

Profile of Back Bacon Produced From the Common Warthog

The common warthog (Phacochoerus africanus) has historically been hunted and consumed by rural communities throughout its distribution range in Africa. This study aims to develop a processed product from warthog meat in the form of back bacon (Longissimus thoracis et lumborum) as a healthy alternative meat product and to determine its chemical and sensory characteristics derived from adult and juvenile boars and sows. The highest scored attributes included typical bacon and smoky aroma and flavor, and salty flavor, as well as tenderness and juiciness. Neither sex nor age influenced the bacon's chemical composition; the bacon was high in protein (~29%) and low in total fat (<2%). Palmitic (C16:0), stearic (C18:0), linoleic (C18:2ω6), oleic (C18:1ω9c), and arachidonic (C20:4ω6) were the dominant fatty acids. There was an interaction between sex and age for the PUFA:SFA ratio (p = 0.01). The differences between sex and age class are considered negligible regarding the overall profile and healthiness of the bacon.

Genome Wide Assessment of Genetic Variation and Population Distinctiveness of the Pig Family in South Africa

Genetic diversity is of great importance and a prerequisite for genetic improvement and conservation programs in pigs and other livestock populations. The present study provides a genome wide analysis of the genetic variability and population structure of pig populations from different production systems in South Africa relative to global populations. A total of 234 pigs sampled in South Africa and consisting of village (n = 91), commercial (n = 60), indigenous (n = 40), Asian (n = 5) and wild (n = 38) populations were genotyped using Porcine SNP60K BeadChip. In addition, 389 genotypes representing village and commercial pigs from America, Europe, and Asia were accessed from a previous study and used to compare population clustering and relationships of South African pigs with global populations. Moderate heterozygosity levels, ranging from 0.204 for Warthogs to 0.371 for village pigs sampled from Capricorn municipality in Eastern Cape province of South Africa were observed. Principal Component Analysis of the South African pigs resulted in four distinct clusters of (i) Duroc; (ii) Vietnamese; (iii) Bush pig and Warthog and (iv) a cluster with the rest of the commercial (SA Large White and Landrace), village, Wild Boar and indigenous breeds of Koelbroek and Windsnyer. The clustering demonstrated alignment with genetic similarities, geographic location and production systems. The PCA with the global populations also resulted in four clusters that where populated with (i) all the village populations, wild boars, SA indigenous and the large white and landraces; (ii) Durocs (iii) Chinese and Vietnamese pigs and (iv) Warthog and Bush pig. K = 10 (The number of population units) was the most probable ADMIXTURE based clustering, which grouped animals according to their populations with the exception of the village pigs that showed presence of admixture. AMOVA reported 19.92%-98.62% of the genetic variation to be within populations. Sub structuring was observed between South African commercial populations as well as between Indigenous and commercial breeds. Population pairwise F ST analysis showed genetic differentiation (P ≤ 0.05) between the village, commercial and wild populations. A per marker per population pairwise F ST analysis revealed SNPs associated with QTLs for traits such as meat quality, cytoskeletal and muscle development, glucose metabolism processes and growth factors between both domestic populations as well as between wild and domestic breeds. Overall, the study provided a baseline understanding of porcine diversity and an important foundation for porcine genomics of South African populations.

Gastrointestinal helminths from the common warthog, Phacochoerus africanus (Gmelin) (Suidae), in KwaZulu-Natal Province, South Africa, with comments on helminths of Suidae and Tayassuidae worldwide

Thirty warthogs, Phacochoerus africanus, were collected in the Pongola Game Reserve, South Africa and examined for helminths. Gastrointestinal helminth assemblages comprised Gastrodiscus aegyptiacus, the cestode genus Moniezia and seven species of nematodes. A single warthog harboured a metacestode of Taenia hydatigena in the mesenteries. No helminths were found in the heart, lungs or liver of the warthogs. Probstmayria vivipara and Murshidia spp. were the most prevalent as well as abundant helminth species, followed by Physocephalus sexalatus. The incidence of Moniezia did not differ between hosts of different sex or age. Numbers of Murshidia spp. were not affected by host sex, but were higher in adults than in juveniles. Conversely, burdens of Trichostrongylus thomasi were not affected by host age, but were higher in males than in females. While not highly significant, helminth assemblages in male warthogs were more species rich than in females. Helminth communities in the three genera of wild sub-Saharan suids are largely unique, but Ph. africanus and Hylochoerus meinertzhageni share more worm species with each other than with Potamochoerus larvatus, possibly because the former two are more closely related. Overlap between helminth communities of African wild suids and those of other suids and Tayassuidae worldwide is limited.

KINETICS AND ENERGY OF POULTRY MEAT DEHYDRATION IN VACUUM AND MICROWAVE FIELD CONDITIONS

The article presents the results of obtaining dried poultry meat under vacuum conditions using ultrahigh electromagnetic energy sources. A characteristic of the most common principles of drying is presented, which shows that the trends in the technology of drying technology is a reduction of specific energy consumption. From literary sources it is known that this is the best way to preserve meat protein in the native state. This method of drying leads to the release of a large amount of heat, resulting in evaporation can occur at a low temperature. The heat dissipated is spent exclusively on the evaporation of moisture without heating the fabric of the product. The rational modes of microwave-vacuum drying for meat semifinished products are determined. Drying was carried out at a temperature below 40°C and a pressure of 8 kPa with simultaneous processing by an electromagnetic field at a frequency of 2.7 GHz. This contributes to the intensive evaporation of moisture without a significant change in the structure of the surface layer, reducing the length of processing. Microwave-vacuum drying provides high functional and technological properties, namely: moisture-binding ability, water-retaining, fat-retaining ability and mass fraction of residual moisture, and better organoleptic characteristics. According to the sensory evaluation, the samples studied had a more fragile consistency, characterized by dry powders, a pleasant taste and a flavor similar to boiled chicken meat. The article shows the dependence of the mass of condensate on the duration of drying. On the basis of what was determined the duration of drying of the meat additive, which is 3 hours, while the mass fraction of residual moisture is 4.5%. It was established that obtaining dried meat semis from poultry meat under vacuum conditions using ultra high frequency electromagnetic energy sources allows to receive products with less energy and for a shorter period of production.