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Ultraviolet energy has been used in the past to disinfect drinking water and fruit juice. This paper will discuss the impact of ultraviolet energy on strawberry shelf life. The ultraviolet tunnel used in the study utilizes lamps that are designed to emit specific narrow wavelength spectrum, of 253.7 nanometers. The tunnel was made of polished aluminum and reflects beams of energy within the tunnel. Ultraviolet energy can improve food safety by destroying the microorganisms, such as E coli and salmonella that cause food-borne illnesses. Ultraviolet energy can extend shelf life of produce and make it possible to keep these foods for greater periods of time while keeping the integrity of the berry intact. A review of literature was conducted to identify the pathogens that affected this study, these pathogens were: Grey Mold, Botrytis cinerea ; Dry Crown Rot Botryotinia fuckeliana ; Phomopis Leaf Blight, Phomopsis obscurans and Dendrophoma obscurans ; Rhizopus Rot (leak), Rhizopus stolonifer ; and Tan-brown rot, Discohainesia oenotherae . It was found that ultraviolet viable application range rate were 88.1mj/cm3, 140mj/cm3, 191.9mj/cm3, 243.8mj/cm3, 295.7mj/cm3 and 347.6mj/cm3 lasted longest and these rates were used in the full test run. Results indicated that a significant shelf life extension of strawberries was achieved at each of these treatment levels. The average shelf life of non-treated berries was 14.9 days whereas the average treated strawberries range from 17.25 to 20.9 days. A lowest level of treatment was reached at 15 seconds or 88mj/cm3. A statistical relationship between application rates and shelf life was determined. Using an ANOVA table at 95% confidence interval, it was determined when all samples, as individuals, were considered that the shelf life was extended by exposure to ultraviolet energy. Another ANOVA table was used for each treatment group versus the control group, all treatment groups showed a significant difference opposed to the control group. In conclusion, this study shows that applying ultraviolet energy to strawberries significantly improves shelf life. There was not a significant benefit to exposing the strawberries to added ultraviolet energy.

The effect of acids on the growth, survival and detection of Salmonella enteritidis PT4 is particularly important in view of the number of outbreaks in which mayonnaise has been implicated as a vehicle. Capacitance measurement was compared with colony counting procedures for the enumeration and determination of sub-lethal injury of Salmonella enteritidis during storage under varied conditions of pH, acidulant and temperature. Capacitance monitoring was shown to offer an improved technique for the measurement of sub-lethal injury in cell populations. Higher levels of sub-lethal injury were detected by the extension of capacitance detection time than were indicated by differential colony counts on selective and non-selective media. The extension of detection time noted with sub-lethally injured cell populations was shown to be due to an extended lag phase when cells were placed in the capacitance growth medium and not the result of delayed detection of the growth of a small, uninjured sub-population. Plots of percentage survival and extension of detection time in survivors gave similar curves for acetic and lactic acid. These acids showed both greater lethality and greater ability to inflict sub-lethal injury than the stronger citric or hydrochloric acid. Sub-lethal injury and lethality were not simply related, as little sub-lethal injury was observed with the stronger acids even under conditions that were ultimately highly lethal. The results indicate that weak organic acids cause more reversible damage to cellular sites prior to death: an observation that has implications for choice of resuscitation procedures when examining acidified foods. Injured cells were found to contain lower levels of ATP than healthy unstressed cells. Inhibition with chloramphenicol did not appear to increase injury and total protein patterns for injured and uninjured cells were similar, suggesting that protection afforded by the synthesis of stress proteins is not a significant factor in this case. The recovery of sub-lethally injured cells in various pre-enrichment and selective enrichment media using capacitance detection times and colony counts on selective and non selective media was determined. Buffered peptone water appeared more effective in recovering injured Salmonella compared to Lactose broth. Additionally, selenite cystine was shown to recover cells faster than the other two selective broths tested; the Muller-Kauffmann Tetrathionate broth and the Rappaport Vassiliadis enrichment broth. In this study, different injury conditions were applied; these included acid stress, heating and freezing. According to the lag phases of injured cell populations, short pre-enrichment is not recommended in the present study.

The aim of the study was to determine the fatty acid composition, colour stability and lipid oxidation of fresh mince produced from fallow deer and to evaluate the effect of frozen storage duration on the retail display shelf life of the mince. A total of 31 fallow deer carcasses were used in the study. After cooling for 24hrs, the carcasses were deboned, external fat from the fore and hindquarter muscles removed and individually vacuum packed. For the first trial, seven fallow deer carcasses were used. Meat from the hind and fore-quarters of each carcass was divided into two equal batches per animal. One batch was minced (through a 5 mm die) and packed into oxygen permeable overwraps and refrigerated at 4°C for a period of eight days under retail display conditions. The second batch was vacuum packed and frozen at -20°C for 2 months at the end of which mince was also produced and monitored over an eight-day period under the same conditions that were used for the fresh mince. Colour, pH, lipid and myoglobin stability was determined. Proximate and fatty acid composition was also determined. No differences (P>0.05) were noted between proximate composition of fresh and frozen/thawed minced meat. The lipid content of fallow deer was 2.4 percent (±0.04). Total n3 fatty acids differed (P<0.05) between treatments and decreased with increased storage and display day. There were significant (P<0.05) treatment and time interactions on all measured colour parameters, TBARS and myoglobin forms. Fresh mince was lighter and had higher redness (a*) and yellowness (b*) values than mince from two months frozen stored meat. Hue angle for fresh mince remained stable throughout display whereas it increased for frozen/thawed mince. Fresh mince had lower TBARS values than frozen/thawed mince. Minced meat produced from frozen/thawed deer meat had higher surface met-myoglobin and total met-myoglobin percentages. Surface and total oxy-myoglobin percentage was higher in fresh mince. The first trial clearly showed colour and lipid stability differences between fresh mince and mince from frozen/thawed meat. It also showed that fresh mince has a longer retail display life than mince produced from frozen/thawed meat (six days and four days, respectively). In the second trial, the effects of frozen storage duration on colour and lipid stability were investigated. Twenty-four fallow deer were used. Twelve were harvested in June (6male 6female) and the other twelve in August (6 male 6female) of the same year.Twenty four hours after harvesting, the fore and hindquarter muscles of the carcasses were deboned, vacuum packed and kept at -20°C until October (i.e. 2months and 4months frozen storage period). Upon thawing, the meat was processed into mince following the same procedure used for the first trialand displayed for a fiveday period under retail display conditions. Frozen duration and gender had no effect (P>0.05) on the proximate composition of fallow deer meat. The total amount of saturated fatty acids (SFA) increased and total amount of poly unsaturated fatty acids (PUFA) decreased as frozen duration and display day increased (P<0.05). Frozen duration affected (P<0.01) lipid oxidation and percentage oxy-myoglobin. Mince pH and all colour parameters (L*, a*, b*,hue and chroma) differed (P<0.05) between treatments on day zero and three. Display day was a significant factor (P<0.05) on all measured parameters. By day three all parameters except pH showed signs of extended oxidation and discolouration as evidenced by reduced redness, decreased colour intensity and high TBARS values. This study showed that prolonged frozen storage negatively affects the colour and lipid stability of meat and increases oxidation of PUFAs during frozen storage. However, the study also suggests that although frozen/thawed meat has a shorter retail display shelf life; the proximate composition of the meat remains unchanged.

The broad objective of this study was to determine the effects of natural antioxidants and thermal treatment on quality of meat from Bonsmara and non-descript cattle. A survey was conducted among 222 consumers in Alice (Fort Hare University community), Eastern Cape Province to determine the level of their awareness on application of antioxidants as preservatives in meat and meat products during storage. Representative samples of Muscularis longissimuss thoracis et lumborum and liver were collected from each carcass of Bonsmara (n=40) and non-descript (n=40) cattle reared on natural pasture to determine the effect of natural antioxidants and thermal treatment on their quality. The results from the survey revealed that 51.35 percent of the respondents had not heard about the use of antioxidant as preservatives in meat products. However, among the remaining respondents (48.65 percent) that were aware of antioxidant and its use as preservative, about 19 percent knew of natural antioxidants, 35 percent synthetic antioxidants while 46 percent had knowledge of both. The results further revealed that the majority of the respondents (82 percent) that had knowledge of natural antioxidants were concerned about the use of synthetic antioxidants in meat and meat products due to their health consequences. The in vitro antioxidant and antibacterial analyses of Bidens pilosa and Moringa oleifera leaf extracts revealed that they contain rich bioactive compounds. Furthermore, the addition of leaf extracts from Moringa oleifera (ML, 0.05 and 0.1 percent w/w) and Biden pilosa (BP, 0.05 and 0.1 percent w/w) to ground raw beef as a natural antioxidant were found to improve the physicochemical, oxidative stability and microbiological qualities of meat compared to the control (meat without extract) and BHT treatment (0.02 percent w/w) during 6 days storage at 40 C. Cattle breed did not have much effect on colour parameters. However, the overall pH of ground beef treated with extracts showed lower values than control and BHT treated beef. Also, ground beef samples containing extracts exhibited (P < 0.05) better colour stability, especially higher redness (a* values), than the control. The formation of TBARS in beef samples treated with extracts was significantly (P < 0.05) lower than the control and BHT treatment. The antibacterial assay of the extracts revealed an appreciable broad spectrum activity against the tested bacteria and microbial counts in ground beef samples compared to control and BHT group. Ground beef treated with plant extracts exhibited lower microbial and lactic acid bacterial counts (P < 0.05) at day 0 and 3 than control samples. Moreover, it was observed that application of sous vides thermal method did not significantly affect the fatty acids and mineral loss in beef and liver across the treatments. However, the total concentration of MUFA was lower in raw liver (20.11±2.38 - 21.08±1.23 percent) than in beef (40.22±1.90 - 42.53±1.29 percent), while total PUFA content were higher in liver (30.73±2.60 - 31.11±1.19 percent) than in beef samples (10.13±3.36 - 11.02±2.74 percent) (p < 0.05). The results also revealed that liver samples from Bonsmara and non-descript cattle had a higher percentage of intramuscular fat content of 4.67 ± 0.53 percent and 4.44 ± 0.53 percent respectively, and fat free dry matter of 27.51 ± 1.05 percent and 25.73 ± 1.05 percent, respectively, than the beef samples (p < 0.05). The concentrations of Mg (52.80±0.22 - 53.70±0.02mg/100g) and Zn (8.90±0.15 - 19.60±0.15mg/100g) were higher in beef than liver samples. The level of Ca (17.00±0.17 - 17.50 ± 0.17mg/100g) in liver was higher than that of beef samples. It was concluded that most consumers preferred the use of natural antioxidants in meat products than synthetic antioxidants due to their health risk. The effectiveness of M. oleifera and B. pilosa leaf extracts on meat quality also revealed that these plants are promising candidates as natural preservatives and their application should be considered in the meat industry. Lastly, findings from this study showed that application of the sous vide technique could protect meat products from nutritional loss during thermal treatment.

xiii, 119 p. : ill. (some col.) / Airstream brand travel trailers from the 1950s and 60s have developed a subculture dedicated to their preservation and use. This subculture serves as a case study for how nostalgia, defined in a postmodern context, may promote preservation and creative communion with the past. After examining criticisms of preservation’s focus on material integrity, the discussion focuses on the need to factor user-based relationships into historic preservation. A postmodern reexamination of nostalgia defines it not merely as a longing for the past but also as a form of social critique which seeks to mitigate modernity with the past. Mid-century Airstream preservation reflects a desire to revive specific, positive values of the past in order to ameliorate the future and form temporal continuity. For the mid-century Airstream subculture, nostalgia fosters both restoration and recreation, allowing for an iconic emblem of the past to function in the present rather than fade into obsolescence. / Committee in charge: Dr. Leland Roth, Chairperson; Elizabeth Carter, Member