Investigation of the Confinement Odour Problem in Exported Lamb using NMR-based Metabolomics : A thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Chemistry at Massey University, Manawatū, New Zealand.

Recent changes to the supply chain practices of meat exporters has increased the potential for consumers to be exposed to the phenomenon of confinement odour, the smell produced by vacuum or modified atmosphere packaged meat which has been chilled and stored for extended periods. This harmless odour, which does not indicate meat spoilage, can lead to the rejection of the product by consumers. This is a problem for NZ lamb meat producers as they form the largest group of exporters of lamb meat in the world, and their largest market is the UK and other EU countries. The processes behind confinement odour development are poorly understood. In this thesis, NMR spectra were acquired of meat, and drip extracts of meat from two different processing plants stored under different temperatures for 11-13 weeks to simulate conditions of exported meat during overseas shipment, transport to warehouse and retail display. The spectra were analysed by multivariate data analysis to find metabolic differences between meat which produces confinement odour and meat which produces either spoilage odour or no odour. Optimisation of extraction of metabolites from meat and drip samples was also carried out. The best sample preparation method for meat and drip included homogenisation by bead beating (meat samples only), protein precipitation using an acetonitrile, methanol and acetone solvent mixture, and removal of solvent by vacuum centrifugation. Multivariate data analysis demonstrated the ability to discriminate drip samples with confinement odour from spoiled samples and the former showed increased lactate concentration with low levels of leucine indicating the presence of Lactic Acid bacteria. The spoiled samples had increased butyrate levels which is indicative of the presence of Clostridium spp. Both bacterial populations were in a late stage of growth. This is consistent with confinement odour as an early indicator of spoilage. This result indicates the potential for drip to be utilised more widely for the analysis of meat metabolites. Additionally, samples could be discriminated by processing plant of origin using multivariate data analysis. Increased levels of pyruvate and decreased levels of glucose in samples from Plant 2 indicated their bacterial populations had progressed to a later stage of growth than the bacterial populations in samples from Plant 1

A Population-Based Surveillance Study of Shared Genotypes of Escherichia coli Isolates from Retail Meat and Suspected Cases of Urinary Tract Infections.

There is increasing evidence that retail food may serve as a source of Escherichia coli that causes community-acquired urinary tract infections, but the impact of this source in a community is not known. We conducted a prospective, population-based study in one community to examine the frequency of recovery of uropathogenic E. coli genotypes from retail meat samples. We analyzed E. coli isolates from consecutively collected urine samples of patients suspected to have urinary tract infections (UTIs) at a university-affiliated health service and retail meat samples from the same geographic region. We genotyped all E. coli isolates by multilocus sequence typing (MLST) and tested them for antimicrobial susceptibility. From 2016 to 2017, we cultured 233 E. coli isolates from 230 (21%) of 1,087 urine samples and 177 E. coli isolates from 120 (28%) of 427 retail meat samples. Urine samples contained 61 sequence types (STs), and meat samples had 95 STs; 12 STs (ST10, ST38, ST69, ST80, ST88, ST101, ST117, ST131, ST569, ST906, ST1844, and ST2562) were common to both. Thirty-five (81%) of 43 meat isolates among the 12 STs were from poultry. Among 94 isolates in the 12 STs, 26 (60%) of 43 retail meat isolates and 15 (29%) of 51 human isolates were pan-susceptible (P < 0.005). We found that 21% of E. coli isolates from suspected cases of UTIs belonged to STs found in poultry. Poultry may serve as a possible reservoir of uropathogenic E. coli (UPEC). Additional studies are needed to demonstrate transmission pathways of these UPEC genotypes and their food sources.IMPORTANCE Community-acquired urinary tract infection caused by Escherichia coli is one of the most common infectious diseases in the United States, affecting approximately seven million women and costing approximately 11.6 billion dollars annually. In addition, antibiotic resistance among E. coli bacteria causing urinary tract infection continues to increase, which greatly complicates treatment. Identifying sources of uropathogenic E. coli and implementing prevention measures are essential. However, the reservoirs of uropathogenic E. coli have not been well defined. This study demonstrated that poultry sold in retail stores may serve as one possible source of uropathogenic E. coli This finding adds to a growing body of evidence that suggests that urinary tract infection may be a food-borne disease. More research in this area can lead to the development of preventive strategies to control this common and costly infectious disease

Guaranteeing Canadian lamb meat quality using near-infrared spectroscopy on intact rack

Lamb racks from commercial carcasses were scanned using near-infrared spectroscopy. The prediction accuracies (R 2) for meat quality traits were assessed. Prediction accuracy ranged between 0.40 and 0.94. When predicted values were used to classify meat based on quality, 88.7%–95.2% of samples were correctly classified as quality guaranteed

Effect of Zataria multiflora Boiss Essential Oil and Grape Seed Extract on the Shelf Life of Raw Buffalo Patty and Fate of Inoculated Listeria monocytogenes

The present study was conducted to investigate the effect of Zataria multiflora Boiss essential oil (ZEO) and grape seed extract (GSE) on microbial and chemical changes in raw buffalo patty at a temperature of 8C. First, chemical composition and minimum inhibitory concentration of oil against Listeria monocytogenes were identified. Then, ZEO and GSE were added in raw buffalo patties and analyzed for spoilage microorganism count, lipid oxidation, pH, sensory attributes and inoculated L.monocytogenes survival at 8C for 9 days. Results revealed that samples containing 0.1 ZEO+0.2 GSE showed significant decrease in the growth of all tested microbial groups as well as the most decrease in the level of lipid oxidation at the end of storage period. Control and samples with 0.1 ZEO were the most preferred samples by sensory panelist, indicating that ZEO and GSE can be practically applied in food systems especially in meat in order to extend the shelf life. Practical Applications: Buffalo meat is highly prone to microbial and chemical spoilage as they are rich in essential nutrients and putrefying in nature. The adverse effects of various chemical preservatives caused to attract the consumer's attention to natural alternatives. Therefore, in order to increase the shelf life and quality characteristics of meat, new processing technologies and new ingredient systems that are associated with natural and organic foods are applied. These results demonstrate the potential combined use of grape seed extract and Zataria multiflora Boiss essential oil to the meat industry in the development of novel healthy meat products with improved shelf life and superior product quality. © 2015 Wiley Periodicals, Inc

Influence of organic diet on the amount of conjugated linoleic acids in breast milk of lactating women in the Netherlands

The aim of the present study was to find out whether the incorporation of organic dairy and meat products in the maternal diet affects the contents of the conjugated linoleic acid isomers (CLA) and trans-vaccenic acid (TVA) in human breast milk. To this purpose, milk samples from 312 breastfeeding mothers participating in the KOALA Birth Cohort Study have been analysed. The participants had documented varying lifestyles in relation to the use of conventional or organic products. Breast milk samples were collected 1 month postpartum and analysed for fatty acid composition. The content of rumenic acid (the main CLA) increased in a statistically significant way while going from a conventional diet (no organic dairy/meat products, 0.25 weight % (wt%), n 186) to a moderately organic diet (50–90 % organic dairy/meat, 0·29 wt%, n 33, P=0.02) and to a strict organic diet (> 90 % organic dairy/meat, 0.34 wt%, n 37, P<=0.001). The levels of TVA were augmented among the participants with a moderately organic diet (0·54 wt%) and those with a strict organic diet (0.59 wt%, P<=0.001), in comparison with the conventional group (0·48 wt%). After adjusting for covariables (recruitment group, maternal age, maternal education, use of supplements and season), statistical significance was retained in the group of the strict organic dairy users (P<0.001 for rumenic acid). Hence, the levels of CLA and TVA in human milk can be modulated if breastfeeding mothers replace conventional dairy and/or meat products by organic ones. A potential contribution of CLA and TVA to health improvement is briefly discussed

Carbon and nitrogen isotopic ratios of urine and faeces as novel nutritional biomarkers of meat and fish intake

Purpose Meat and fish consumption are associated with changes in the risk of chronic diseases. Intake is mainly assessed using self-reporting, as no true quantitative nutritional biomarker is available. The measurement of plasma fatty acids, often used as an alternative, is expensive and time-consuming. As meat and fish differ in their stable isotope ratios, δ13C and δ15N have been proposed as biomarkers. However, they have never been investigated in controlled human dietary intervention studies. Objective In a short-term feeding study, we investigated the suitability of δ13C and δ15N in blood, urine and faeces as biomarkers of meat and fish intake. Methods The dietary intervention study (n = 14) followed a randomised cross-over design with three eight-day dietary periods (meat, fish and half-meat–half-fish). In addition, 4 participants completed a vegetarian control period. At the end of each period, 24-h urine, fasting venous blood and faeces were collected and their δ13C and δ15N analysed. Results There was a significant difference between diets in isotope ratios in faeces and urine samples, but not in blood samples (Kruskal–Wallis test, p < 0.0001). In pairwise comparisons, δ13C and δ15N were significantly higher in urine and faecal samples following a fish diet when compared with all other diets, and significantly lower following a vegetarian diet. There was no significant difference in isotope ratio between meat and half-meat–half-fish diets for blood, urine or faecal samples. Conclusions The results of this study show that urinary and faecal δ13C and δ15N are suitable candidate biomarkers for short-term meat and fish intake

Comparison of fatty acid profile in lamb meat and baby food based on lamb meat

The aim of this study was to compare the fatty acid (FA) profile of fresh lamb meat with those of baby foods based on lamb meat. For this purpose, samples of commercial homogenized (HO) and lyophilized (LIO) baby food based on lamb meat and fresh lamb meat (FM) were analyzed for their FA composition. All fatty acids, except for oleic acid and conjugated linoleic acid (CLA), differed among the three baby products tested. The sum of omega-6 FA and the ratio omega 6/omega 3 FA were lower in FM and LIO meat compared to HO samples. The content of total PUFA n-3 was the highest in FM, because of its highest content of C18:3 n3, EPA, DPA and DHA compared to LIO and HO baby food. The content of arachidonic acid was more than 6-fold higher in FM compared to LIO and HO. This study evidenced the possibility of enhancing the FA profile of commercial baby food based on lamb meat by using meat with healthier FA profile

The in vitro assessment of the bioavailability of iron in New Zealand beef : a thesis presented in partial fulfillment of the requirements for the degree of Master of Science in Physiology at Massey University, Palmerston North, New Zealand /

The bioavailability of iron in New Zealand beef either alone or as part of a 'typical' New Zealand meal was investigated. The solubility of iron and its in vitro absorption by mouse intestinal tissue were used to evaluate iron bioavailability. The solubility of haem and/or non-haem iron in meat (beef longissimus muscle), vegetables and meat-plus-vegetables was investigated. Samples were cooked and then subjected to in vitro gastrointestinal digestion with pepsin followed by a combination of pancreatic enzymes and bile. Cooking at 65°C for 90 minutes reduced the soluble iron concentration in meat by 81% and reduced the haem iron concentration by 27%, which coincided with a 175% increase in non-haem iron concentrations. However, gastrointestinal digestion increased the solubility of iron in cooked meat (333%), vegetables (367%) and meat-plus-vegetables (167%). A proportion (35%) of the haem iron in the meat was broken down by the action of pancreatic enzymes leading to a 46% increase in non-haem iron concentrations, although this was not the case for the meat-plus-vegetables. Validation studies showed that mouse intestinal segments mounted in Ussing chambers maintained integrity and viability, and were responsive to glucose, theophylline and carbachol. Intestinal tissue from iron deficient mice was then used in the Ussing chambers to investigate the absorption of iron from ferrous gluconate and the soluble fractions of meat, vegetables and meat-plus-vegetables after gastrointestinal digestion. Results indicated a trend towards a higher absorption of iron from meat and ferrous gluconate, compared to vegetables and meat-plus-vegetables. However, iron absorption results were difficult to interpret due to the wide variation in the data. This variation was possibly due to errors associated with the sample processing and the analysis of iron, which was by inductively coupled-mass spectroscopy. Overall, the present study showed that before estimations can be made on the bioavailability of food iron, the effects of the cooking and gastrointestinal digestion processes must be considered. Further, the use of in vitro gastrointestinal digestion followed by the use of Ussing chambers to assess intestinal absorption is a potentially valuable system for assessing mineral bioavailability

Determination of benzo[alpha]pyrene in Turkish döner kebab samples cooked with charcoal or gas fire

peer-reviewedIn order to investigate the levels of the potent carcinogen benzo[a]pyrene (B(a)P), 40 samples of döner kebab were analysed. The samples tested included 20 cooked using a charcoal fire and 20 cooked using a gas fire. A liquid chromatographic method was developed using a fluorescence detector. The mean levels of B(a)P were found to be 24.2 (s.e. 0.84) g/kg for charcoal fire cooked meat samples and 5.7 (s.e. 3.48 g/kg) for gas fire cooked meat samples. Sixteen samples were found to be over the maximum level recommended by FAO/WHO (10 g/kg) and all of the samples exceeded the maximum tolerance level of the Turkish Food Codex (1 g/kg)