*3.3. Lipid Oxidation*

Results for lipid oxidation are shown in Table 3. No di fferences were observed in terms of the TBARS detected in the raw batter and cabanossi products. The TBARS of cabanossi reported in this study (0.35 and 0.37 mg MDA equivalent/kg) are lower than those reported previously [59] for ostrich droëwors (7.99 mg MDA equivalent/kg) where pork backfat was used while Mukumbo et al. [47,68] reported values in pork droëwors reaching 0.7–3.8 mg MDA equivalent/kg dry matter (0.6–2.9 mg MDA equivalent/kg) at the end of drying. Deriving from these results, the extent of lipid oxidation during the manufacture of warthog cabanossi using these fat sources can be considered minimal. However, due to the di fferences in MUFA, PUFA and PUFA:SFA, it would have been interesting to observe the shelf stability of these two products, but this could not be done due to limitations of this study, thus further research on this aspect is recommended.

#### *3.4. Descriptive Sensory Analysis*

The sensory profiles of the two cabanossi treatments are presented in Table 5. There were significant di fferences for all aroma attributes (*p* ≤ 0.01) except peppery aroma (*p* > 0.05). The PF treatment was scored higher for most of the aroma attributes. During the sensory panel training, some unique characteristics were detected in the SF cabanossi. Consequently, it was expected that this treatment would score higher for these characteristics viz., charred aroma, sheep-like fatty aroma, mutton aroma and herbaceous aroma (*p* ≤ 0.01). The presence of these sensory attributes could be as a result of mutton specific heterocyclic compounds such as 2-ethyl-3,6-dimethylpyrazine and 2-pentylpyridine, as well as branched chain volatile fatty acids (BCFA) such as 4-methlyphenol acid, 4-methylnonanoic acid and 3-methyl-indole acid, commonly known as skatole [69]. There is a strong link between these BCFA and mutton aromas and flavour [70–72]. In fact, 4-methlyphenol, 4-methylnonanoic and 3-methyl-indole are BCFAs thought to be precursors of undesirable rancid odour and flavour in mutton [70]. Although the origin of these compounds is not clearly understood, they could be products of rumen metabolism of pasture species in the sheep diet [69,70]. Skatole, however, is known to be one of the major compounds that cause boar taint in *Suidae* spp. [69], thus the absence of these sensory attributes in PF cabanossi could be a good indication of the absence of boar taint in both pork backfat and warthog meat. Therefore, the hypothesis that these sensory attributes are SF-related is strengthened.

Pork backfat cabanossi tasted saltier (*p* ≤ 0.05) than SF cabanossi although the salt content (~2.7%) did not di ffer (*p* > 0.05) in the chemical analysis (Table 3). This is attributed to the PF cabanossi being less fatty (chemically) with more protein. The bond between chloride ions and meat proteins is stronger than that of chloride and sodium ions (Hamm [73] cited in [74]), therefore, the extent to which chloride ions bind to protein may be strong enough to suppress the perception of salty flavour [74]. Regarding fatty mouthfeel, it was expected that SF cabanossi would score higher than PF cabanossi since it was higher in chemically analysed fat. Fat particles produce an oily coating around meat particles and this phenomenon causes a higher impression of fat upon chewing the cabanossi.

Concerning appearance, there were no di fferences (*p* > 0.05) in perceived percentage fat and fatty/oily/shininess, but the red-brown colour intensity di ffered between the two treatments. Red brown colour intensity was higher in PF cabanossi compared to SF cabanossi. This may be the influence of more protein recorded for PF cabanossi as opposed to more fat in the SF cabanossi. Fat is usually lighter in colour, thus, if more of it is present in a product, it will mask some of the dark/red colour of meat proteins.

Texture attributes were all significantly di fferent between the two cabanossi products. Pork backfat cabanossi scored higher for first bite, chewiness and residue, whereas this was not the case for sustained juiciness. This is attributed to di fferences in protein and fat content of the products. Fat reduces hardness of meat and meat products by facilitating the di ffusion of moisture during biting and mastication of meat [75]. Less energy and force are therefore required to successfully chew the product resulting in less residue. Furthermore, high fat meat sausages exhibit a better impression of juiciness compared to low fat sausages [75].

Figure 1 is a principal component analysis (PCA) showing the variation and grouping between the two cabanossi products. Factor 1 accounted for the most variation between the cabanossi. The PCA shows a clear distinction between the two products, with each being associated with specific attributes. The SF cabanossi was more associated with sheep-like fatty aroma and flavour, mutton fat aroma and flavour, herbaceous aroma and flavour, charred aroma as well as sustained juiciness. On the other hand, PF cabanossi was more associated with various aroma and flavour attributes typically linked to pork products as shown on the PCA.


**Table 5.** Sensory attributes of cabanossi made with either pork backfat (PF) or sheep tail/backfat (SF).

All data are expressed as mean ± SE (n = 12).
