The significant influence of residual feed intake on flavor precursors and biomolecules in slow-growing Korat chicken meat

Abstract

Objective: This study investigated the association between feed efficiency, physicochemical properties, flavor precursors and biomolecules in the thigh meat of Korat (KR) chickens.

Methods: The feed intake and body weight of individual male KR chickens were recorded from 1 to 10 weeks old to calculate the individual residual feed intake (RFI) of 75 birds. At 10 weeks of age, chickens with the 10 highest (HRFI) and lowest RFI (LRFI) were slaughtered to provide thigh meat samples. The physicochemical properties (ultimate pH, water holding capacity [WHC], drip loss) and flavor precursors (guanosine monophosphate, inosine monophosphate (IMP), adenosine monophosphate and inosine) were analyzed conventionally, and Fourier transform infrared spectroscopy was used to identify the composition of biomolecules (lipids, ester lipids, amide I, amide II, amide III, and carbohydrates) and the secondary structure of the proteins. A group t-test was used to determine significant differences between mean values and principal component analysis to classify thigh meat samples into LRFI and HRFI KR chickens.

Results: The physicochemical properties of thigh meat samples from LRFI and HRFI KR chickens were not significantly different but the IMP content, ratios of lipid, lipid ester, protein (amide I, amide II) were significantly different (p<0.05). The correlation loading results showed that the LRFI group was correlated with high ratios of lipids, lipid esters, collagen content (amide III) and beta sheet protein (rg loading >0.5) while the HRFI group was positively correlated with protein (amide I, amide II), alpha helix protein, IMP content, carbohydrate, ultimate pH and WHC (rg loading >0.5).

Conclusion: The thigh meat from chickens with different RFI differed in physiochemical properties affecting meat texture, and in the contents of flavor precursors and biomolecules affecting the nutritional value of meat. This information can help animal breeders to make genetic improvements by taking more account of traits related to RFI.

Keywords: Biomolecules; Flavor Precursor; Physicochemical Properties; Residual Feed Intake; Slow-Growing Chicken.

Figure 1

(A) Comparison of average original spectra from thigh meat samples of HRFI and LRFI Korat chickens. (B) Comparison of 2nd derivative spectra from thigh meat samples of HRFI and LRFI Korat chickens. The infrared spectra were detected in the spectral region from 4,000 to 400 cm⁻¹, resolution 4 cm⁻¹, based on 64 scans. HRFI, high residual feed intake; LRFI, low residual feed intake.

Figure 2

The curve fitting of amide I and secondary structure protein band assignment in thigh meat samples from Korat chickens by residual feed intake.

Figure 3

PCA score plot for PC1 versus PC2 from HFRI and LFRI data (upper) and correlation loading plot for PC1 versus PC2 for physicochemical properties, flavor precursors, biomolecules, secondary structure protein (lower). PCA, principal component analysis; PC, principal components; LRFI, low residual feed intake; HRFI, high residual feed intake; pH24, ultimate pH; WHC, water holding capacity; DL, drip loss; GMP, guanosine monophosphate; IMP, inosine monophosphate; AMP, adenosine monophosphate; Am I, amide I; Am II, amide II; Am III, amide III; Ester, ester lipid; Car, carbohydrate; Alpha, alpha helix; Beta, beta sheet; B turn, beta turn.