Improving beef hamburger quality and fatty acid profiles through dietary manipulation and exploitation of fat depot heterogeneity

Background： Hamburger is the most consumed beef product in North America, but lacks in nutritional appeal due to its high fat content and high proportion of saturated fatty acids （SFA）. Objectives of the present study were to improve the FA profiles of hamburgers made with perirenal fat （PRF） and subcutaneous fat （SCF） when feeding steers different diets along with examining differences in sensory attributes and oxidative stability. Diets included a control diet containing 70：30 red clover silage： barley based concentrate, a diet containing sunflower-seed （SS） substituted for barley, and diets containing SS with 15% wheat dried distillers＇ grain with solubles （DDGS-15） or 30% DDGS （DDGS-30）. Hamburgers were made from triceps brachii and either PRF or SCF （80：20 w/w）. Results： Perirenal fat versus SCF hamburgers FA had 14.3% more （P 〈0.05） 18：0, 11.8% less cis （c）9-18：1 （P 〈0.05）, and 1.82% more total trdns （t）-18：1 mainly in the form of tl 1-18：1. During sensory evaluation, PRF versus SCF hamburgers had greater （P 〈0.05） mouth coating, but the difference was less than one panel unit. Examining effects of steer diet within PRF hamburgers, feeding the SS compared to the control diet increased （P 〈0.05） t-18：1 by 2.89% mainly in the form of tl 1-18：1, feeding DGGS-15 diet led to no further changes （P 〉0.05）, but feeding DDGS-30 diet reduced the proportions of （P 〈0.05） of t-18：1 chiefly tl 1-18：1. Feeding SS and DDGS diets had small but significant （P 〈0.05） effects on hamburger sensory attributes and oxidative stability. Conclusions： Feeding high-forage diets including SS and 15% DDGS, and taking advantage of the FA heterogeneity between fat depots offers an opportunity to differentially enhance beef hamburgers with 18：2n-6 biohydrogenation products （Le., t11-18：1） with potential human health benefits without compromising their sensory attributes and oxidative stability during retail display.

Fortification of pork loins with docosahexaenoic acid(DHA) and its effect on flavour

Pork is traditionally low in docosahexanoic acid （DHA, C22：6n-3） and deficient in omega-3 fats for a balanced human diet. DHA as triglycerides was commercially prepared from the microalgae Schizochytfium and injected into fresh pork loins. Treatments of a mixed brine control （CON）, 3.1% sunflower oil in mixed brine （SF） and a 3.1% DHA oil in mixed brine （DHA） were injected into pork loins at 10 mL/100 g and grilled at 205℃. After cooking, the CON and SF pork loins contained 0.03 to 0.05 mg DHA/g of pork and the DHA injected loins contained approximately 1.46 mg DHA/g. This also changed the fatty acid profile of omega-6：omega-3 from, 5 to 1 in the CON pork, to a ratio of 1.7 to 1 in DHA pork. The appearance, odor, oxidation rates and sensory taste, as judged by a trained panel, determined the DHA injected meat to be, ＇slightly desirable＇ and gave lower ＇off flavour＇ scores, relative to the CON and SF injected pork. Pork can be fortified with DHA oil to 146 mg/100 g serving, which would meet half the recommended daily omega 3 fatty acid requirements for adult humans and would be desirable in taste.