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Orientador: Marney Pascoli Cereda / Banca: Luiz Roberto Carroci / Banca: Oliver Vilpoux / Silene Bruder S. Sarmento / Resumo: Não disponível / Abstract: Not available / Doutor

Bibliography: leaves 200-214. / xi, 214 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Three structurally related compounds, 2-acetyltetrahydropyridine (ACTPY), 2-ethyltetrahydropyridine (ETPY) and N-heterocycle, 2-acetyl-1-pyrroline (ACPY), were quantified and found to be unique components of mousy wines. 35 lactic acid bacteria (LAB) were screened for the ability to produce mousy off-flavour. In addition to Lactobacillus brevis and L. cellobiosus, a diversity of LAB species, particularly heterofermentative Lactobacillus spp. and Oenococcus oeni exhibited this ability in a range of ethanolic and wine-based media. The substrates and metabolism of mousy compound formation by LAB were also investigated. A pathway for the formation of ACPY and ACTPY by heterofermentative LAB was proposed. / Thesis (Ph.D.)--University of Adelaide, Dept. of Horticulture, Viticulture & Oenology, 1999

<p>Muscle fatigue has always been of vital importance in most sports. A few possible factors have been reported to be the cause of muscular fatigue during high intensity exercise; depletion of glycogen, oxidative stress, disruption of contractile mechanisms and accumulation of metabolites. One of the theories of the cause of muscular fatigue, both in endurance and intermittent sports, is decreased pH levels due to increased concentration of H+ ions dissociated from lactic acid in muscle. Carnosine, a fairly unnoticed ergogenic aid, taken in the form of β-alanine has shown to potentially delay the onset of fatigue. Supplementation of β-alanine, would increase carnosine levels in muscle and may counteract the decrease in pH since carnosine functions as a H+ buffer. The purpose of the present study was to examine the effects of 8 weeks supplementation of β-alanine in distance runners and Swedish division four soccer players on aerobic capacity, intermittent recovery and muscular fatigue. The runners (n = 15) were tested in lactate profiling tests and the soccer players (n = 22) were tested in the Yo-Yo intermittent endurance test pre and post the 8-week test-period. The yo-yo test did not result in significant difference between the soccer players’ β-group and control-group (p = 0,29). Neither did the lactate test result in significant differences between the distance runners’ β-group and control-group in any of the five variables measured. However, a trend in difference was seen between groups in both velocity at lactate threshold (VLT) (p = 0,11) and recovery blood lactate (RBL) (p = 0,14) where the β-group had increased slightly from 16,8 ± 1,6 km/h to 17,0 ± 1,2 km/h in VLT and decreased from 4,5 ± 1,6 mmol∙L-1 to 3,1 ± 1,0 mmol∙L-1 in RBL. The results suggested that β-alanine may delay the onset of fatigue and improve performance in endurance sports such as running by increasing the removal of lactate acid from muscle.</p>

Muscle fatigue has always been of vital importance in most sports. A few possible factors have been reported to be the cause of muscular fatigue during high intensity exercise; depletion of glycogen, oxidative stress, disruption of contractile mechanisms and accumulation of metabolites. One of the theories of the cause of muscular fatigue, both in endurance and intermittent sports, is decreased pH levels due to increased concentration of H+ ions dissociated from lactic acid in muscle. Carnosine, a fairly unnoticed ergogenic aid, taken in the form of β-alanine has shown to potentially delay the onset of fatigue. Supplementation of β-alanine, would increase carnosine levels in muscle and may counteract the decrease in pH since carnosine functions as a H+ buffer. The purpose of the present study was to examine the effects of 8 weeks supplementation of β-alanine in distance runners and Swedish division four soccer players on aerobic capacity, intermittent recovery and muscular fatigue. The runners (n = 15) were tested in lactate profiling tests and the soccer players (n = 22) were tested in the Yo-Yo intermittent endurance test pre and post the 8-week test-period. The yo-yo test did not result in significant difference between the soccer players’ β-group and control-group (p = 0,29). Neither did the lactate test result in significant differences between the distance runners’ β-group and control-group in any of the five variables measured. However, a trend in difference was seen between groups in both velocity at lactate threshold (VLT) (p = 0,11) and recovery blood lactate (RBL) (p = 0,14) where the β-group had increased slightly from 16,8 ± 1,6 km/h to 17,0 ± 1,2 km/h in VLT and decreased from 4,5 ± 1,6 mmol∙L-1 to 3,1 ± 1,0 mmol∙L-1 in RBL. The results suggested that β-alanine may delay the onset of fatigue and improve performance in endurance sports such as running by increasing the removal of lactate acid from muscle.

Internally-pH-controlled, phosphate containing and non-phosphate containing Italian bulk starter media were compared to reconstituted nonfat dry milk and commercial bulk starter media for their ability to support the growth and activities of commercially frozen thermophilic lactic acid cultures. Cultures grown in internally-pH-controlled media demonstrated superior acid-production capability. The cheese made from cultures grown in internally-pH-controlled media was comparable to that made from the culture grown in commercial medium. However, the internally-pH-controlled media were not bacteriophage inhibitory, nor were the reconstituted nonfat dry milk or two of the three commercial bulk starter media. Hence, cheese whey and nonfat milk based, low solids, bacteriophage inhibitory bulk starter media were formulated for the cultivation of mixed cultures of Streptococcus thermophilus and Lactobacillus bulgaricus. The new media supported the growth of lactobacilli better than the commercial media. Even at low solids levels, the buffering capacities of the new media were comparable to commercial media. Late addition of magnesium hydroxide as a neutralizing agent to commercial as well as experimental bulk starter media resulted in increased growth and improved activities of rod-coccus cultures. The cultures also retained their activities longer under refrigerated storage. Late addition of magnesium hydroxide did not encourage the proliferation of bacteriophages in the growth media. / Graduation date: 1987

Starter cultures of different bacteria strains like lactic acid producing bacteria, Staphylococcus and Kocuria are used when making salami. Starter cultures give the sausage specific flavours and improve the quality and ripening of the final product. Probiotic strains can also be added during the production of salami. Studies have shown that probiotics are good for health and are therefore added to food, such as fermented sausages. In order to work as a probiotic strain, the bacteria have to survive during the production process, storage and through the whole human gastrointestinal tract. The aim of this study was to trace the probiotic strains Lactobacillus casei and Lactobacillus paracasei in salami samples to see if they had survived the production process. Methods used were DNA extraction, PCR, colony PCR and gel electrophoresis. Out of 100 samples in duplicate run in PCR, probiotics were found in only 3 of them. To see if screening of probiotics directly from plates was possible, a colony PCR was done. Colony PCR was made on colonies of two different strains of Lactobacillus casei, Lactobacillus paracasei and Lactobacillus sakei. From each bacteria strain, 5 colonies were analysed. Result showed that colony PCR, to screen for probiotic is a possible method.

Escherichia coli O157:H7 and Salmonella have emerged as the most common foodborne enteric pathogens causing human illness from the consumption of beef. By mandate of the U.S. Department of Agriculture (USDA), Food Safety and Inspection Service (FSIS), the industry has implemented a Hazard Analysis and Critical Control Points (HACCP) system that utilize intervention technologies for controlling, preventing, and/or reducing enteric pathogens. In addition, USDA-FSIS has mandated that each facility must validate, monitor, and verify the effectiveness of each intervention implemented to eliminate E. coli O157:H7 and Salmonella. For this study, microbial decontamination interventions at two beef slaughter facilities were validated to demonstrate effectiveness in eliminating or reducing enteric pathogens. The facilities selected utilized either a lactic acid spray treatment or a combination of hot water followed by a lactic acid treatment. At both facilities, mesophilic plate counts (MPC) were significantly (P < 0.05) reduced, and E. coli and coliforms were eliminated below detectable limits at both facilities. No Salmonella positive samples were detected after either facility's intervention sequence. The framework used in this research to validate interventions can also be utilized in the future for yearly verification of the effectiveness of each intervention.

Thesis (Ph.D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xiv, 182 p.; also includes graphics. Includes abstract and vita. Advisor: Ahmed E. Yousef, Dept.of Food Science and Nutrition. Includes bibliographical references (p. ).

Abstract Lactate utilising bacteria (LUB) assist in reducing the risk of ruminal lactate acidosis when high concentrate diets are fed to feedlot cattle. Ruminal lactate acidosis can lead to lower animal performance and morbidity. Preliminary studies suggested that the strain, Megasphaera elsdenii (M.e.) NCIMB 41125, is a particularly potent LUB. The potential of M.e.NCIMB 41125 to improve the health and performance of feedlot cattle was investigated. Four hundred and forty eight Bonsmara steers (ca. 240 kg) were used in a 100-day feeding trial. Half the steers received at processing 200 mL M.e.NCIMB 41125 per os (LY) and the other half no LUB (LN). The diets in each of these treatments were divided into a low roughage (2%) (RL) and high roughage (8%) (RH) diet. The effects of LY vs. LN, RL vs. RH as main effects and their respective interactions (LYRL, LYRH, LNRL & LNRH) were compared in terms of morbidity, feedlot performance and carcass characteristics. The steers were weighed at two week intervals, feed was offered daily and the orts were removed weekly from each pen. The faecal consistency score and incidence of morbidity were recorded. At slaughter, carcass data were collected and the health status of the liver and rumen epithelium was assessed. Steers dosed with M.e.NCIMB 41125 had a 5.6% better average daily gain (ADG) during weeks 3 - 5 (2.09 kg/day vs. 1.98 kg/day for LY and LN, respectively). Feed conversion ratio (FCR, Weeks 1 - 13) was better for the steers fed the RL than the RH treatment (4.72 kg/kg vs. 4.99 kg/kg for RL and RH, respectively). Steers on the LNRH treatment during weeks 3 - 5 used more feed per kg gain than steers on the other treatments (5.39 kg/kg for LNRH vs. 4.74 kg/kg and 4.72 kg/kg for LYRL and LNRL, respectively). More steers (21) on the LNRL treatment were treated for morbidity than on the other treatments (8, 7 and 5 for LYRL, LYRH and LNRH, respectively). In general, animal performance was not improved by dosing with M.e.NCIMB 41125, but since ADG was improved in the immediate postadaptation phase (weeks 3 - 5) and morbidity levels were lower on the low roughage diet, dosing of steers on low roughage, lactate acidosis-prone, diets with M.e.NCIMB 41125 should prove useful.