Browsing by Subject "shelf life"
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Item Improving the Flavor of Ground Beef by Selecting Trimmings from Specific Locations(2012-08-17) Harbison, Amanda 1989-We hypothesized that carcass subcutaneous fat location would affect sensory and quality traits. Five carcass fat sources were tested: brisket, chuck, plate, flank, and round. Ground beef was formulated using each fat source and extra-lean beef trim (>95% lean) to contain 80% lean trim and 20% fat trim. Patties (100 g) were evaluated for color, lipid oxidation, fatty acid composition and consumer evaluation. Flavor was analyzed using a Gas chromatography with mass spectrometry (GC/MS) on the headspace above a cooked (74 degrees C) patty in a heated (60 degrees C) 473 mL glass jar with a solid phase micro-extraction (SPME) fiber. Color, thiobarbituric acid reactive substance assay (TBARS), consumer sensory, and cook/freezer loss data showed no differences (P > 0.05) among carcass locations. Percentage stearic acid was lower (P = 0.044) in the brisket than in the chuck and flank. The brisket was higher in percentage cis-vaccenic acid (P = 0.016) and in the saturated fatty acid to monounsaturated fatty acid ratio (P = 0.018), and lower (P = 0.004) in the percentage of total saturated fatty acids than all other sources of subcutaneous fat. Butanedione was highest (P = 0.013) in the flank and plate fat. Brisket tended to be higher (P = 0.054) than flank, plate, and round in 1-octen-3-ol. Brisket was higher (P = 0.008) than chuck, flank, and round, but not different (P > 0.05) than plate in octanedione. Brisket was higher (P = 0.003) than all other sources for beefy aroma. Flank was higher (P = 0.047) than chuck and round for chemical aroma. Brisket was higher (P = 0.004) than all other sources except flank for floral aromas. Plate was higher (P = 0.029) than all other sources for heated oil aromas. For secondary aroma descriptor, round was higher (P < 0.001) than flank, plate, and chuck for dairy. While differences in some key fatty acids and aromatics existed among carcass locations, when the fat was diluted with a common lean source, fat source did not have a negative effect on sensory or quality traits. Therefore, formulating ground beef using subcutaneous fat from specific locations on a carcass may improve the beef aromatics without negatively affecting sensory or quality traits.Item Substrate Moisture Content Effects on Growth and Shelf Life of Angelonia angustifolia(2012-07-16) Bingham, AlisonWilting during shelf life is a major cause of postharvest shrink for bedding plants shipped long distances from production greenhouses to retail outlets. The objective of this research was to determine if irrigation at lower, constant substrate moisture content (SMC) during greenhouse production would be a feasible way to acclimate plants for reduced shrinkage during shelf life, while potentially conserving irrigation water. Rooted plugs of Angelonia angustifolia 'Angelface Blue' were grown in greenhouse production until a marketable stage in substrates irrigated at SMC levels of 10, 20, 30, and 40% using a controlled irrigation system. At the end of the greenhouse production stage, plants were irrigated to container capacity and subjected to a simulated shipping environment, in shipping boxes in the dark for two days. After shipping, plants were placed back in the greenhouse and watered minimally to simulate a retail environment. Data was taken at the end of each stage i.e. greenhouse production, simulated shipping, and simulated retail. Parameters measured at the end of the production stage were fresh and senesced flower number, stem number, pre-dawn and mid-day water potential, SPAD meter readings (Experiment 2), and plant height and node number segmented into vegetative, flowering, and bud area. Plant quality was observed and rated. At the end of the simulated retail stage, the same data was taken, along with fresh and dry shoot and root weight. Results indicated that as SMC decreased from 40 to 10%, plants were shorter in height, but had proportional flowering sections (Experiment 1) or more compact flowering sections (Experiment 2). The volume of water received by the 40% SMC plants was three times greater (Experiment 1) and 12 times greater (Experiment 2) than the 20% SMC plants during greenhouse production, and two times greater (Experiment 1) and nine time greater (Experiment 2) during simulated retail. Additionally, the 40% SMC plants used 15 liters (Experiment 1) and 38 liters (Experiment 2) of water during greenhouse production compared to the 20% SMC plants using only three liters in both experiments. During simulated retail the 40% SMC plants used six liters (Experiment 1) and nine liters (Experiment 2) of water while the 20% SMC plants used five liters (Experiment 1) and three liters (Experiment 2) of water. During production, mid-day water potentials decreased as the SMC levels decreased, but at the end of the simulated retail (Experiment 1), the mid-day water potentials were all the same, suggesting plants that were drought stressed during production area were acclimated to lower water levels experienced in retail settings. Overall, the 20% SMC treatment produced the best postharvest quality plant due to reduced plant height without detrimental effects on flowering. The results demonstrate that while conserving water, controlled irrigation at a medium-low SMC can produce high quality plants that have equal shelf life to those that are irrigated at high levels.