• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • No language data
  • Tagged with
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Effect of Environmental Enrichments on Fresh and Processed Meat Quality of Turkeys

Melinda Ashley Dennis (14237636) 09 December 2022 (has links)
<p>  </p> <p>Environmental enrichments have been investigated to determine impacts on turkey health and welfare; however, there is limited data to determine the impact of these enrichments on fresh or processed turkey meat quality. One hundred and forty-four turkeys were randomly assigned to six enrichment treatments: control (C), pecking block (PB), platform (P), platform + straw bale (PSB), straw bale (SB), and tunnel (T). Each treatment was replicated within two rooms in the same barn, with 24 pens total (n = 4 pens/treatment). At 19 weeks of age, turkeys were weighed (live weight, kg), and harvested over two days, with three birds from each pen per day (n=144). A subset of 96 turkeys were fabricated into wings, boneless thighs, drumsticks, and boneless breasts at 24 h postmortem in order to determine carcass cutting yields. From the breast and thigh, three, 1.25 cm samples were taken for pH, proximate analysis, and drip loss. From the breast, three, 2.54 cm samples were taken for instrumental color and sensory analysis, with all remaining breast sample used for further processed boneless turkey breast. Breast portions were pumped with a commercial brine (water, salt, brown sugar, sodium phosphate, sodium erythorbate, and sodium nitrite) to 110% by weight. Brined breast was then vacuum sealed and vacuum tumbled (9 rpm for 90 min, stopping every 15 min for 10 min). Tumbled breast was stuffed into a cellulose casing, thermally processed (internal temperature 68.3oC), and smoked to produce boneless turkey logs. From each log, eight, 1.25 cm slices were taken for packaged purge loss, expressed moisture, instrumental color, and texture and sensory analysis. All treatment levels were analyzed using PROC GLM (SAS 9.4, SAS Institute, Cary, NC). Statistical significance level was set at <em>P≤</em>0.05. For fresh turkey, results showed significant differences in live weight by treatment. SB turkeys weighed the least, PB turkeys weighed the most, and T, PSB, C, and P were intermediate in weight (<em>P=</em>0.008). Treatment did not impact the cut-out values for breasts (<em>P=</em>0.387), thighs (<em>P=</em>0.985), wings (<em>P=</em>0.211), and drumsticks (<em>P=</em>0.575). Treatment did not impact breast L* (<em>P=</em>0.777), a* (<em>P=</em>0.247), or b* (<em>P=</em>0.366) or thigh L* (<em>P=</em>0.936) and a* (<em>P=</em>0.067), but PSB thighs displayed the highest b* values and PB thighs displayed the lowest (<em>P=</em>0.037). Finally, for fresh turkey, treatment did not impact breast drip loss (<em>P=</em>0.766), thigh drip loss (<em>P=</em> 0.933), breast pH (<em>P=</em>0.197), or thigh pH (<em>P=</em>0.385). For processed turkey quality, treatment had no effect on a* (<em>P=</em>0.498) or b* (<em>P=</em>0.831) but was significant for L*. SB, T, P, and PSB had lighter color values, C had darker color values, and PB had intermediate values (<em>P=</em>0.024). Finally, for processed turkey quality, treatment did not impact processing yield (<em>P=</em>0.058) or packaged purge loss (<em>P=</em>0.581), but treatment impacted expressed moisture (<em>P=</em>0.041). PB, PSB, C, and T had higher expressed moisture loss, P had the lowest, and SB had intermediate expressed moisture loss (<em>P=</em>0.041).</p>
2

Factors Affecting the Oxidative Stability of Foods-Interesterified Soybean Oil with High Intensity Ultrasound Treatment and Trona Mineral in Packaged Fresh Meats

Lee, Jiwon 01 May 2013 (has links)
Oxidation in oils and muscle foods has been studied for many years to understand its mechanism and furthermore to control and manage it. A series of different processing steps or different packaging techniques can alter oxidative stability. The objective of the current study was to examine oxidative stability of processed oil and to evaluate the effect of carbon dioxide generating mineral on quality of beef and chicken under different storage conditions. In Study 1 (Chapter 3), the effect of ultrasound on oxidative stability of interesterified soybean oil and soybean oil was examined. Sonication did not affect oxidation rate until the oils were highly oxidized. Sonicated interesterified soybean oil exhibited a slightly but significantly lower oxidation rate than non-sonicated oil during long-term storage, while sonication of non-interesterified soybean oil led to a significantly higher oxidation rate than in non-sonicated soybean oil after induction period. In Study 2 (Chapter 4), the feasibility of trona as a CO2 producing product in a model system and in modified atmosphere packaging of beef steaks was investigated. Trona was able to generate more carbon dioxide than sodium bicarbonate with salicylic acid in model systems. Steaks stored with trona/acid mixture had similar color stability and delayed lipid oxidation compared to those stored in high oxygen packaging. In Study 3 (Chapter 5), the effect of packets containing trona and acid placed in a simulated self serve retail case and closed butcher case on the quality of ground beef was studied. Mineral packets did not affect color, lipid oxidation, or microbial growth of ground beef since there was not a sufficient amount of moisture to generate CO2 effectively. In Study 4 (Chapter 6), the quality of chicken breast/thigh portions stored with mineral packets was compared to those without mineral packets during extended storage, and mineral packets had an antimicrobial effect of CO2 only on day 15. In conclusion, high intensity ultrasound did not affect the rate of oxidation of oil until the oil had already become noticeably rancid, and mineral packets containing trona and an acid with low water solubility can be used as CO2 generating sachet if sufficient moisture is given.

Page generated in 0.0618 seconds