## 3 Results and Discussion
### Volatile Analysis
#### 3.3.2 Chilled Samples  
For PEF treated chilled samples, C20:2 (n-6), MUFA, C18:1 cis-9, C20:0, C14:0, C24:0, C16:1, PUFA, and n-6 fatty acids, had VIP scores of >1 indicating that they are the most important variables in relation to sensory perception (Figure 5a; Supplementary Tables S4 and S5). Fatty acid profile of meat can influence meat flavour [24]. Similar to findings in the present study, MUFA, especially C18:1 cis-9, was positively correlated with flavour intensity and overall palatability in beef [3]. This positive correlation was attributed to C18:1 cis-9 that gives a juicier mouthfeel to meat [25]. Interestingly, all the amino acids were important variables contributing to sensory flavour perception. Histidine, proline, threonine, isoleucine, tyrosine, glycine, phenylalanine, and glutamate were the highest contributors to overall flavour perception of chilled lamb samples (Figure 5b). A large number of small peptides and free amino acids generated in dry-cured meats can influence the development of taste, flavour precursors, and aroma attributes [21]. Similar to the present study, [PERSON], [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON] [21] reported that free amino acids like threonine, phenylalanine, isoleucine contributed to brown/roasted flavour of beef, which were desirable to consumers. Moreover, free amino acids like tyrosine, phenylalanine, and threonine contributed to the tenderisation and flavour enhancement in lamb longissimus dorsi muscles treated with chilled ageing conditioning at 4 \({}^{\circ}\)C on the 8 th day of storage [26]. Nearly half of the flavour volatiles determined in this study contributed to the overall flavour perception of chilled samples of lamb. Pyridine, dimethyl disulphide, pyrrole, heptanal, methyl-pyrazine, hexanal, thiophene, 2-methylbutanal, 2-pentylfuran, dimethyl trisulphide, 2-ethylfuran, 2-ethyl-3-methyl pyrazine, and nonanal were the highest contributors of chilled lamb samples flavour (VIP \(>\) 1) (Figure 5c). Similarly, [PERSON] [12] identified dimethyl sulphide, 2-butanone, 2-and 3-methylbutanal, dimethyl trisulphide, nonanal, and ethyl acetate as key flavour components in cooked Irish Angus beef. Among the aldehydes, hexanal, heptanal, and nonanal were also identified as important flavour components in cooked beef by [PERSON] [12]. Heterocyclic and non-heterocyclic compounds containing sulphur and nitrogen are important flavour compounds produced during the Maillard reaction that contribute to meaty, savoury, roasty, and boiled flavour characteristics [14; 16]. Dimethyl and trimethyl sulphide found in this study possessed characteristic meat-like taste as confirmed by GC-O analysis of lamb aroma [27]. Pyrazines that result from the Maillard reaction between free amino acids and reducing sugars are important flavour components that confer characteristic \"grilled meat\" roasted-like flavour [11]. According to [PERSON] et al. [28], a positive correlation was established between pyrazines (2-ethyl-3,5-dimethyl pyrazine, 2,5-dimethyl pyrazine, and 2-ethyl-3,6-dimethyl pyrazine) and sensory attributes like roast meat flavour of grilled lamb. Figure 5: (**a–d**). Variable importance in the projection (VIP) for each variable in the partial-least-squares regression (PLSR) models arising from analysis of PEF treated fresh lamb samples in terms of **(a)** fatty acids, **(b)** amino acids, **(c)** volatile composition; **(d)** fatty acids, amino acids, and volatile composition were examined in relation to sensory attributes. (**e–h**) VIP for each variable in the PLSR models arising from analysis of PEF treated frozen lamb samples in terms of **(a)** fatty acids, **(b)** amino acids, **(c)** volatile composition; **(d)** fatty acids, amino acids, and volatile composition were examined in relation to sensory attributes. VOC codes for Figure 5a–d correspond to Supplementary Table S2 for chilled samples, and codes in Figure 5e–h correspond to Supplementary Table S3 for frozen samples.