MARGRA Lamb Eating Quality and Human Health-Promoting Omega-3 Long-Chain Polyunsaturated Fatty Acid Profiles of Tattykeel Australian White Sheep: Linebreeding and Gender Effects.

John Roger Otto,Robert Tumwesigye Kinobe,Oyelola Abdulwasiu Adegboye,Aduli Enoch Othniel Malau-Aduli,Shedrach Benjamin Pewan

doi:10.3390/antiox9111118

Abstract

Health-conscious consumers increasingly demand healthier, tastier, and more nutritious meat, hence the continuous need to meet market specifications and demand for high-quality lamb. We evaluated the longissimus dorsi muscle of 147 Tattykeel Australian White (TAW) sheep fed on antioxidant-rich ryegrass pastures exclusive to MAGRA lamb brand for meat eating quality parameters of intramuscular fat (IMF) content, fat melting point (FMP) and omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA). The aim was to assess the impact of linebreeding and gender on pasture-fed lamb eating quality and to test the hypothesis that variation in healthy lamb eating quality is a function of lamb gender and not its antioxidant status or inbreeding coefficient (IC). After solid-phase extraction and purification, phenolics and antioxidant enzyme activities were analysed by high-performance liquid chromatography and mass spectrometry. IMF and fatty acid composition were determined using solvent extraction and gas chromatography, respectively. IC was classified into low (0–5%), medium (6–10%) and high (>10%) and ranged from 0–15.6%. FMP and IMF ranged from 28 to 39 °C and 3.4% to 8.2%, with overall means of 34.6 ± 2.3 °C and 4.4 ± 0.2%, respectively, and n-3 LC-PUFA ranged from “source” to “good source” levels of 33–69 mg/100 g. Ewes had significantly (P ˂ 0.0001) higher IMF, C22:5n-3 (DPA), C22:6n-3 (DHA), C18:3n-6, C20:3, C22:4n-6, C22:5n-6, total monounsaturated (MUFA), PUFA and Σn-3 fatty acids and lower total saturated fatty acids (SFA) and FMP, than rams. As IC increased, there were no differences in FMP and IMF. Folin–Ciocalteu total phenolics, ferric reducing antioxidant power and antioxidant activities of glutathione peroxidase, catalase and superoxide dismutase enzymes did not differ by either gender or IC. This study provides evidence that IC is inconsequential in affecting antioxidant status, IMF, FMP and n-3 LC-PUFA in linebred and pasture-fed TAW sheep because the observed variation in individual fatty acids was mainly driven by gender differences between ewes and rams, hence the need to accept the tested hypothesis. This finding reinforces the consistent healthy eating quality of MARGRA lamb brand from TAW sheep regardless of its linebred origin.

Highlights

The Food and Agriculture Organisation (FAO) of the United Nations defines meat quality as the constitutional standard of lean-to-fat ratio and palatability indices that include visual appearance, aroma, drip loss, colour, texture, pH, intramuscular fat content, fatty acid and fat melting point profiles, tenderness, flavour and juiciness [1]
This paper aims to fill some of these knowledge gaps by assessing the impact of linebreeding and gender on pasture-fed lamb eating quality consistency in antioxidant status, intramuscular fat (IMF), Fat melting point (FMP), n-3 LC-PUFA and to test the hypothesis that variation in healthy lamb eating quality will be a function of lamb gender and not its antioxidant status or inbreeding coefficient (IC) as an index of linebreeding
The low dry matter is indicative of fresh pasture with high moisture content, while the high phenolic antioxidants, crude protein, low neutral detergent and high metabolisable energy are all indicative of high palatability, digestibility and total digestible nutrients from the ryegrass pastures that are typical during spring

Summary

Introduction

The Food and Agriculture Organisation (FAO) of the United Nations defines meat quality as the constitutional standard of lean-to-fat ratio and palatability indices that include visual appearance, aroma, drip loss, colour, texture, pH, intramuscular fat content, fatty acid and fat melting point profiles, tenderness, flavour and juiciness [1]. Fat melting point (FMP), intramuscular fat (IMF) content (marbling) and fatty acid (FA) profile all influence eating quality and, consumer preferences for consistent, safe, nutritious and tasty lamb with a healthy FA composition [3]. Lamb has relatively low lipid and saturated fat contents compared to meat from other ruminants [7], and its marbling, tenderness, juiciness, aroma and colour attributes have been known to influence consumer liking [8], carcass [9], meat assignment into quality grades [10], consumer food choices [11] and nutritional value [12]. It is very important that sheepmeat producers guarantee the consistency of their lamb products in order to meet consumer preferences and adapt to the dynamics of purchasing decisions based on meat eating quality

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